Anuran Distribution Over an Elevation Gradient

on Bioko Island, Equatorial Guinea

A Thesis

Submitted to the Faculty

of

Drexel University

by

Alexis Layman

in partial fulfillment of the

requirements for the degree

of

Master of Science in Environmental Science

May 2011

ii

Acknowledgements

This study would not have been possible without the logistical and financial support of many. The Bioko Biodiversity Protection Program provided me with use of their field station, equipment, and invaluable support. This would not have been possible without funding from the Exxon Mobil Foundation. Students from the Universidad Nacional de Guinea Ecuatorial (UNGE) and Djibrilla Ousmane were instrumental in data collection. Drexel University students Anika Vittands, Elizabeth Long, and Elliot Chiu provided information for habitat assessment. I would like to thank my committee, Dr. Gail W. Hearn, Dr. Michael P. O’Connor, and Dr. Shaya Honarvar for their guidance, support, and tremendous amount of work they put into this project. I owe a particular debt of gratitude to Dr. Hearn for allowing me the opportunity to study under her and on Bioko Island. It has been the experience by which I define my college career and I am very grateful for it. I am indebted to Dr. O’Connor for his tireless assistance with data analysis. Thank you Dr. Honarvar for the encouragement, guidance, editing, and the countless times you sat through my presentation. The Hearn Lab offered a tremendous amount of support and comic relief. I am particularly grateful to Demetrio Bocuma Meñe and Patrick McLaughlin for all of their help in implementing this project, and without whom I would probably still be trying to set pitfall traps on Bioko. Without Patrick this project would not have been possible. I am extremely grateful for all of his help, mentorship, and countless hours. I owe many thanks to my family and friends within and outside of Drexel University for all of their encouragement and love, particularly Dave for understanding all those cancelled dates and my parents for a life time of support. Without you I don’t know who or where I would be today.

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Table of Contents

LIST OF TABLES………………………………….…………………………………….iv

LIST OF FIGURES…….………………………………………………………………...iv

ABSTRACT…………….…………………………………………………………………v

INTRODUCTION………………………….……………………………………………..1

World Wide Amphibian Decline………………………………………………….1

Amphibians as an Indicator Species………………………………………………4

West African Studies……………………………………………………………...7

Bioko Island……………………………………………………………………….8

OBJECTIVES AND SPECIFIC AIMS………………………………………………….13

MATERIALS AND METHODS...... …………………………………………………….15

PVC Refuges……………………………………………………………………..15

Pitfall Traps………………………………………………………………………15

Anuran Census…………………………………………………………………...17

RESULTS………………………………………………………………………………..19

PVC Refuges……………………………………………………………………..19

Pitfall Traps………………………………………………………………………19

Anuran Census…………………………………………………………………...20

DISCUSSION……………………………………………………………………………22

PVC Refuges……………………………………………………………………..22

Pitfall Traps………………………………………………………………………22

Distribution Over an Elevation Gradient………………………………………...25

Species Presence…………………………………………………………………29

iv

Future Research………………………………………………………………….29

LITERATURE CITED…………………………………………………………….…….33

APPENDIX A: ANURAN SPECIES PRESENT ON BIOKO ISLAND………………..43

APPENDIX B: FIGURES……………………………………………………………….50

APPENDIX C: ANURAN SPECIES EXPECTED ON BIOKO ISLAND……………...56

APPENDIX D: HABITAT ASSESSMENT…………………………………………..…63

v

List of Tables

1. Anuran Species Present on Bioko Island……………………………………..….49

2. Anuran Species Expected on Bioko Island………………………………………56

List of Figures

1. Map of Bioko Island………………………………………….…………………50

2. Map of Biafran Region and the Surrounding Area……………………………....50

3. Altitudinal Range Limits of Amphibians Endemic to the Biafran Region….…...51

4. IUCN Redlist Categories for Amphibians Endemic to the Biafran Region……..51

5. PVC Refuge……………………………………………………………………...52

6. PVC Refuge Array at 1460 m-asl………………………………………………..52

7. Y-shaped Pitfall Trap Array.…………………………………………………….52

8. 3 and 4 Bucket Straight Line Arrays…………………………………………….52

9. Pitfall Trap Bucket Before Modification………………………………………...52

10. Y-shaped Array Before Modification……………………………………………52

11. Capture Rates of Pitfall Traps……………………………………………………53

12. Arthroleptis Census Results...……………………………………………………53

13. Bufo Census Results……………………………………………………………...54

14. Hyperolius Census Results………………………………………………………54

15. Habitat Preference Assessment…………………………………………………..55

vi

Abstract

Amphibians, especially anurans, represent an important opportunity for ecosystem monitoring, specifically in tropical environments. This pilot study explored potential monitoring methods and generated initial potential baseline results for the distribution of common anurans (frogs and toads) over an elevation gradient in a tropical montane ecosystem on Bioko Island, Equatorial Guinea. In order to collect data to determine distribution, PVC refuges and pitfall traps were tested for use in this area. PVC refuges were found to be an ineffective technique for amphibian sampling in this dense tropical ecosystem. Pitfall traps were found to be effective after modifications, such as increasing leaf litter to encourage approach and adding baby oil gel to discourage escape. PVC refuges were ineffective and pitfall trapping rates were not high enough to determine distribution, therefore a novel approach was developed to determine amphibian distribution using amphibian census. This was possible due to the high amphibian density in this area. Data was collected daily via visual detection along trails that served as transects spanning an elevation gradient of over 900 meters. The data from this study shows that different species have varying altitudinal preferences. Frogs in the genus

Arthroleptis were shown to decrease in density with increased elevation. Hyperolius frogs and toads in the genus Bufo did not exhibit a clear density trend based on elevation.

Data obtained from this study is preliminary but useful in laying framework for a long term monitoring project on the island. Long term monitoring can expand the knowledge of Bioko Island species composition and range. Monitoring these populations over time can aid in the understanding of both natural and anthropogenic effects on these populations and the ecosystem.

1

Introduction

Worldwide Amphibian Decline

Global amphibian populations are declining rapidly, and have been for the past several decades (Houlahan 2000; Stuart 2004). There are currently 6,296 known amphibian species, of them, 39 have been reported extinct in the wild since 1500 AD

(IUCN 2010). However, due to insufficient data for many species and population declines being rapid and recent, it is difficult to prove extinction beyond a reasonable doubt

(Stuart 2004). The Global Amphibian Assessment lists 122 species that can no longer be found, and estimates that 113 of these species have gone extinct, or almost extinct since

1980, almost three times the official number of extinct species (IUCN 2010). The

International Union for Conservation of Nature (IUCN) assigns species a threat level based on conservation status, with the most recent evaluation occurring in 2010 (IUCN

2010). The highest threat level is Critically Endangered. Often research funds and conservation efforts are focused on charismatic mega fauna, mammals, and birds, effectively skewing the collective knowledge towards these species. There are 188 species (3.4%) of mammals and 190 species (1.9%) of birds currently listed as Critically

Endangered, compared to 486 species (7.7%) of amphibians. Currently, 836 species

(15.2%) of mammals, and 62 species (0.6%) of birds have insufficient data for the IUCN to assess their conservation status, compared to 1,596 species (25.3%) of amphibians

(IUCN 2010). In amphibian species with sufficient data, at least 2,468 species are experiencing declines in population (Stuart 2004).

Rapid extinctions of amphibians have been noted worldwide, across various climates, altitudes, and habitats, occurring as early as the 1970s (Lips 1998; Pounds

2

2006). Species at high altitudes faced declines in the western United States, with two species going extinct in the wild since the 1980s (Sherman 1993; Drost 1996; IUCN

2010). High elevation declines, particularly over 400 m-asl, were also seen in Puerto

Rico correlated with drought and disease (Burrowes et al. 2004). Similar declines were recorded in Central America and Australia, but the severity was not revealed until recently (Alexander 2001). Disappearance rates of over 75% were seen for many protected upland sites in the neotropics (Whiles 2006). At Monteverde, a montane habitat in Costa Rica, 40% of the anuran fauna went missing in the late 1980s (Pounds 1997).

Although not as dramatic, similar species disappearances were seen simultaneously in

Ecuador, Colombia, and Venezuela, in montane regions (Pounds 2006). While the causes of some of these declines are due to anthropogenic effects, some are particularly concerning because the causes are not evident (Pounds 2006).

Batrachochytrium dendrobatidis, a pathogenic fungus affecting amphibians, commonly known as chytrid, led to mass mortalities and loss of amphibian diversity across eight species of frogs and salamanders in Panama (Lips 2006). This fungus is associated with population decline of 43 amphibian species in Latin America and 93 species worldwide. It can be transmitted from individual to individual or from the environment to an individual, as diseased frogs can shed zoospores. Zoospores can last in soil for 3 months, and diseased frogs can live up to 220 days, giving the fungus ample time and room to spread, even as the population thins and individuals are not making much contact with one another (Lips 2006). Chytrid is causing widespread amphibian die-offs and population declines, and is thought to be a main contributor to the massive

3 global amphibian die-off, including those seen in the Neotropics (Lips 2006; Colón-Gaud

2010).

Amphibian decline is of particular concern due to their role within the ecosystem.

Tadpoles serve as intermediate links in the aquatic food web while adult amphibians were found to be intermediate links in the terrestrial food web (Verburg 2007). Amphibians are also an important link between aquatic and terrestrial habitats, and are responsible for a great deal of nutrient cycling. Due to this role, large-scale amphibian losses can have an effect on the complexity of the ecosystem, nutrient cycling, and the riparian food web

(Verburg 2007). There is also a concern that while scientists are aware of many causes of amphibian die-off, some of these declines are occurring in pristine habitats. Many question why these species are disappearing, and what it means for biodiversity (Stuart

2004).

While many scientists are trying to discover what is causing these die-offs, others question whether the declines are due to specific perturbations instead of just normal fluctuation in population dynamics (Blaustein 1994; Pounds 1997; Young 2001).

Amphibian populations can exhibit strong variation year to year, and often studies are performed on short-term or small geographic scales which limit their ability to predict long term changes (Meyer et al. 1998; Houlahan 2000). In addition, many species are rare and local. Ultimately these factors contribute to scientists being skeptical about the accuracy of which humans can estimate whether a species is in decline, extinct, or showing natural fluctuations. (Pechmann 1991; Pounds 1997). Some assign chytrid, as the only significant cause of amphibian die-off, saying habitat destruction and pollution are not causative (Pounds & Masters 2009).

4

The concern with calling these patterns declines if they actually represent normal population fluctuations is that future species declines will be ignored as false alarms.

Furthermore, if these claims of decline are false they can draw attention away from known issues, such as deforestation and pollution (Pechmann & Wilbur 1994). However, these declines and extinction rates have not been seen in this magnitude in the past. The current amphibian extinction rates are approximately 211 times the background amphibian extinction rate (McCallum 2007). If these calculations are to include species that are in critical danger, or thought to be extinct than the current extinction rate is

25,039-45,474 times the background amphibian extinction rate (McCallum 2007). Due to these extremely high rates many scientists believe these declines truly represent a pressing issue. However, there is controversy over the root of these declines and what that means for biodiversity (Pounds 1997).

Amphibians as an Indicator Species

An indicator species can be defined as ‘‘a species or group of species that readily reflects the abiotic or biotic state of an environment, represents the impact of environmental change on a habitat, community, or ecosystem, or is indicative of the diversity of a subset of taxa, or of the wholesale diversity, within an area’’ (McGeoch

1998). An appropriate indicator species is one that is able to be monitored over a wide range of stresses and have a broad geographical range (McGeoch 1998; Griffiths 2009).

Amphibians are known to live in a vast range of elevations, latitudes, and habitats, which expose them to a variety of different stressors; therefore they can be used as an indicator for a range of issues (Collins 2005; Seimon 2007). Amphibians inhabit most of the freshwater and terrestrial biomes on Earth, excluding the Antarctic and the deep Arctic

5

(Collins 2005). Survival and reproduction data can therefore be extrapolated over a large geographic range in order to determine trends in population or habitat disturbance (Caro

1999).

Amphibians are also very sensitive to their environment, due to their skin and habitat use (Blaustein & Wake 1990; Wyman 1990; Lips 2006). Their extremely sensitive skin makes amphibians exceptionally vulnerable to toxins and ultra-violet radiation (Cowen 1990; Blaustein 1998). Toxins and contaminants are readily absorbed through the skin of amphibians. Therefore, even contaminations considered small in scale can have an extensive effect on amphibian populations (Cowen 1990). In recent decades there has been an increase in ultraviolet-B (UV-B) radiation, associated with the depletion of the stratospheric ozone (Blaustein 1998). This can not only affect amphibians’ skin, but can also have indirect effects, such as decreases in reproductive success, changes in predator-prey relationships, water chemistry, and food supply

(Ovaska et al. 1997).

Amphibians are unique among vertebrates in that they utilize both aquatic and terrestrial environments, making them a viable indicator for both habitats (Collins 2005).

Pollution in either aquatic or terrestrial habitats can have significant effects on their population (Alford 1999). This is particularly evident with the effects pollution has had on pH. Acid rain can cause low pH in water leading to decreased reproductive success due to mortality in both the embryonic and larval stages (Alford 1999). This can be seen with incomplete absorption of the yolk plug, deformation of the larvae, late or early hatching, varied growth patterns, and disturbed swimming behavior. Increased acidity at breeding sites has led to less diverse populations and the exclusion of certain species

6 from those sites. Acidity is not a problem that is restricted to bodies of water, lower soil pH is also associated with distribution, abundance, and diversity (Alford 1999). Acid rain was once solely associated with the eastern hemisphere, but is being seen more frequently in the western hemisphere, affecting regions in Africa (Cowen 1990). If the pH or pollution in an environment causes the exclusion of a species it can have a fragmentation effect, similar to that seen in deforestation (Becker 2007).

Amphibians rely on interconnected habitats for migration to avoid adverse conditions and access necessary environments, which can leave them vulnerable with even small scale habitat destruction (Cowen 1990). Habitat destruction is a main cause in declining biodiversity worldwide (Pounds 2006). The process of selective harvesting is often proposed as a way to minimize habitat destruction while still utilizing resources.

However, Mitchell et al. 1997 shows that sixteen different amphibian species are dependent on mature hardwoods, which are typically harvested (Mitchell 1997).

Selective harvesting can decrease canopy cover and litter depth and increase levels of photosynthetically active radiation, soil moisture, soil compaction, and suitable habitat for invasive species. It can also lead to fragmentation from forest roads (Marshall 2008).

Habitat destruction is detrimental to amphibians, even on a small scale basis.

Fragmentation has a negative effect on amphibian populations, particularly terrestrial species with aquatic larval stages. Fragmentation can greatly increase the susceptibility of anurans to predation, dehydration, agrochemicals, and other pollutants while migrating to breed (Becker 2007). Anthropogenic fragmentation can lead to species extinctions, while long term isolation due to natural fragmentation can lead to speciation and endemism (Ernst 2006; Laurance & Useche 2009).

7

Amphibians are commonly used as an indicator species due to their wide ranges and sensitivity to their environment, however, this practice is debated (Blaustein & Wake

1990; Griffiths 2009). Some argue that due to the natural flux in amphibian population dynamics, information cannot be accurately extrapolated to other species (Pechmann &

Wilbur 1994). Others argue that the class of amphibians may be used as a broad indicator but not at the species level, because individual species are extremely variable (Pechmann

& Wilbur 1994; Griffiths 2009). Amphibians have a variety of features which make them sensitive to their environment, and allow them to represent the impact of change, including their wide range, highly sensitive skin, habitat use, and life history traits

(Wyman 1990; Lips 1998); (Collins 2003; Beebee 2005).

West African Studies

The majority of research on West African (west of the Saharan desert) amphibians has been basic inventories or species-specific phylogenetic studies

(Eisentraut 1973; Rödel 2002; Stuart 2004; Vences 2004). While over 400 anuran species have been recorded, data has often been collected opportunistically and much is still unknown regarding basic parameters (IUCN 2010). Preliminary information on the distribution, range and density of species in West Africa is essential to further understand life history characteristics of these little studied species, but also to help advise conservation efforts in the future. Density estimates are difficult to obtain in this region.

Rödel and Agyei 2002 were able to obtain preliminary density and distribution data in

Eastern Ghana using mark-recapture techniques (Rödel & Agyei 2002).

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In other regions of earth pitfall trapping has been used as a tool for capturing amphibians, and quantifying effort to estimate density. Literature has shown that pitfall trapping has not been employed in amphibian research for most tropical regions, specifically in Africa. This is likely due to the difficulties in implementing traps in this area as conditions can be very difficult. A couple studies examine amphibian population in relation to altitude. However, these studies do not quantify changes in populations, but are rather inventory studies that include altitudinal ranges (Eisentraut 1973; Bergl 2007).

Bioko Island

Bioko Island, Equatorial Guinea, (West-Central Africa) is located 32 km off the coast of Cameroon and was isolated 12,000 years ago by rising sea levels (Fig. 1). The island has been the focus of conservation efforts due to the high concentrations of endangered primates and sea turtle nesting grounds. Anurans have not been studied in much depth on the island, despite the fact that Bioko Island provides an ideal amphibian habitat. Averaging 25°C and 1,800 mm of rain each year, and boasting huge tracts of undisturbed tropical forest across variable habitat and elevation. Since 1998, 43 species have been recorded on the island, in the families: Arthroleptidae, Bufonidae,

Hyperolidae, Pipidae, and Ranidae. Table 1 includes a full list of the anuran species found on the island, including the two endemic species Arthroleptis Bioko and Leptopelis brevipes. Bioko likely harbors many additional species found on the mainland that are not yet recorded, in addition to potentially new species due to Bioko’s isolation

(Appendix A).

9

Dr. Martin Eisentraut had an expedition to Bioko Island in 1973 in which he summarized the amphibian species he found and the altitudinal zones he found them in.

He classified the zones as pure lowlands, low areas, low mountain zones, mid-mountain zones, and montane habitats. He found four amphibian species in pure lowlands, which are essentially limited to the narrow coastal region. He also found four species in low areas which extend to the foot hills of mountains. There were 13 species in the low mountain zone, five in the mid-mountain zone, and six in montane habitats (Eisentraut

1973). There were four species Dr. Eisentraut recorded on Bioko Island, that have not been recorded on the island since (Table 1). It is possible that one of these species,

Arthroleptis bivittatus, is actually a synonym for Arthroleptis poecilonotus which was recorded by Dr. Eisentraut and as recently as 2010 on Bioko Island (Eisentraut 1973;

IUCN 2010). There is insufficient data for Arthroleptis bivittatus and most of the observations have been from museum specimens. More field observations are needed to determine if these are truly different species (IUCN 2010). Leptopelis palmatus is another species that has not been recorded since Dr. Eisentraut. The only known population of this species exists on Príncipe Island, south and west of Bioko Island in the

Guinea Gulf (IUCN 2010). Dr. Eisentraut records Phrynobatrachus sandersoni on Bioko

Island; however these records actually refer to Phrynobatrachus africanus (IUCN 2010).

Phlyctimantis leonardi has not been recorded on the island since 1973.

It is expected that Bioko should have a similar species make up as Cameroon as it is close to the shore and was isolated relatively recently. Bioko Island and the coastal region of Southeastern Nigeria to South Cameron are considered the Biafran forest and highland region (Fig. 2) (Oates et al. 2004).

10

This region contains the highest mountain in West Africa, the volcano Mount

Cameroon at 4095 meters, on the Coast of Cameroon. The highest point on Bioko Island is the volcano Pico Basilé, at 3017 meters. Elevation restricts population dispersal more effectively in the tropics than in temperate regions (Janzen 1967). Flora and fauna tend to be less adapted to environmental changes, such as the gradient in temperature from the valley to the mountain peak, in regions where temperature is more uniform such as the tropics. When the temperature gradient of the mountain does not fall within the temperature range the species is adapted to the mountain becomes a barrier for dispersal

(Janzen 1967). The Biafran region has a high population of endemic species including 51 endemic amphibian species, 5 of which are recorded on Bioko Island (Bergl 2007). Of these endemic species, 14 (27.5%) are found only below 1600 m-asl, 12 (32.4%) are only found between 800-1600m-asl, 14 (38.9%) are found only above 1200 m-asl, and 14

(64.3%) are only found above 1600m-asl (Fig. 3) (Bergl 2007). Of the endemic species in the Biafran region, amphibians stand out as being highly threatened. The majority these

Biafran endemics, (74.5%) are listed by IUCN as critically endangered (4), endangered

(24) or vulnerable (10) (Fig. 4) (Bergl 2007).

Anuran diversity is the highest in areas with high rainfall and year-round warm temperatures. The Neotropics has the highest anuran diversity, with approximately 40% of the total anuran species of the world occurring in this region. Brazil, which is latitudinally similar to Equatorial Guinea contains 782 native species (14%) (IUCN

2010). The Biafran region has among the most diverse anuran populations, at 215 native species, in 8 families (IUCN 2010). Conditions are ideal as it has the highest mean annual rainfall in Africa, as well as consistently warm temperatures, greater than 20°C (Fraser et

11 al. 1998). Of these 215 species, 47 species in 5 families occur on Bioko Island (Table 1).

It is predicted that many of the species occurring on the main land in this region also occur on Bioko Island, as it was isolated relatively recently. Bioko does not contain the range of habitat seen on the mainland and it is likely that this accounts for the species that have yet to be seen on the island. Dry savannah habitats are not present on Bioko Island.

Three of the families seen on the main land and not on Bioko Island occur mainly in dry savannahs (IUCN 2010). Species with inland ranges are also not predicted to be on

Bioko Island, as they would most likely have not been on the island during isolation.

There are 41 species occurring on the mainland which are predicted to be seen on Bioko

Island based on habitat, range, and abundance, but have not been recorded on Bioko

Island as of yet (Appendix A). One example of a species common on the mainland, but not yet recorded on Bioko Island is Arthroleptis taeniatus. This species is very common in Cameroon, and lives primarily in lowland forests and marshes near the coast; however, it has not yet been recorded on the island (IUCN 2010). Conraua goliath, the largest anuran recorded, was once common on the mainland, and is now endangered due to harvesting for food and the pet trade. It has not yet been recorded on Bioko Island. This may be because its ideal habitat: rapids and cascades of rivers with sandy bottoms, has not been well surveyed on the island, or because C. goliath depends on Dicrea warmingii warmingii, and aquatic herb, as its food source for the first few weeks of tadpole development (Sabater-Pi 1985). It is possible that D. warmingii warmingii is not present on Bioko Island, that C. goliath was not present on the island during isolation, or that C. goliath was previously on the island, but is now locally extinct.

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AmphibiaWeb and IUCN both have extensive amphibian databases, with the geographical ranges for most amphibian species. Species are identified by an expert in the field. The Bioko Biodiversity Protection Program (BBPP) has an ongoing inventory of species found on the island by BBPP employees and researchers since 1998.

Individuals collected or photographed by BBPP staff were identified by the help of amphibian experts Dr. Robert C. Drewes and Dr. David C. Blackburn. Dr. Drewes is the

Curator in the Department of Herpetology for the California Academy of Sciences. He has been studying amphibians and reptiles in Africa since 1969. His research includes evolutionary relationships of African ranoid frogs (Emerson et al. 2000), comparative physiology of arid-adapted anurans (Withers et al. 1984), natural history and biogeography of the African herpetofauana (Drewes 2008), and African environmental ltstudies (Bauer et al. 1992). Dr. Blackburn is a postdoctoral research fellow at the

University of Kansas Biodiversity Institute, but will soon be moving to the position of

Assistant Curator of Herpetology at the California Academy of Sciences. His study areas include systematics and phylogenetics (Blackburn 2009), biogeography (Blackburn

2008), and morphological diversity of anurans (Blackburn 2008a). He has worked in

Malawi, Cameroon, and Nigeria. If an identification has been made solely by a BBPP staff without the help of Dr. Drewes or Dr. Blackburn, its identification is listed as tentative.

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Objectives and Specific Aims Objective

The objective of this study was to obtain information regarding distribution of anurans in regard to altitude and habitat as well as determine feasible methods of trapping. PVC refuges and pitfall trapping are capture techniques that have not been utilized in West

Africa prior to this study. While inventories and phylogeny studies are common on anurans, there have been no studies on Bioko Island where effort was able to be quantified in order to look at a change in anuran population over an elevation gradient.

Specific Aims

1. To determine if PVC refuges are an effective capture technique on Bioko Island.

PVC refuges have been used in deciduous forests in North America in order to survey tree frogs in riparian zones. Prior to this study their use was not examined in tropical rainforests. One aim of this study was to determine if PVC refuges would be appropriate to sample tree frogs in the riparian zone in a tropical rainforest. PVC refuges are simple to set up and monitor. If they were to prove effective for anuran studies this would give future researchers a new and useful tool for monitoring amphibians in a tropical rainforest.

2. To determine if pitfall traps are an effective trapping technique on Bioko Island.

Pitfall trapping is a commonly used means of trapping anurans, and has been shown to be more effective than other methods such as funnel traps. However, prior to this study, pitfall trapping has not been used as a means to capture amphibians in West Africa.

Considering pitfall trapping is such a successful means of capture of anurans, issues with capture rate were not expected. The larger concern was how to implement the pitfall

14 traps and drift fences in the dense habitat which is typical of the primary forests on Bioko

Island.

3. To determine distribution of anuran species around Moka, Equatorial Guinea with attention to altitude and habitat.

Anurans have been studied on Bioko Island, but these studies have been limited to inventories and phylogenetic studies. Prior to this study, amphibians were not monitored in a way which allowed for quantifiable effort, in order to determine relative density and distribution across an elevation or habitat gradient. For some anuran species on the island an altitudinal range has been determined. However, this range has been determined by opportunistic data, and the change in population over a gradient has not been examined. One aim of this study was to examine population changes based on an elevation gradient and habitat gradient. This would provide more information on certain species’ life history traits and range. Having baseline data would allow future research to determine whether or not these variables change over time, possibly with respect to climate change and potential invasion of chytrid.

15

Materials and Methods

PVC Refuges

Three riparian zones, at approximately 1260 m-asl, 1360 m-asl and 1460 m-asl were sampled using PVC refuges. All of the PVC refuges were set along the same stream in three separate zones. The riparian zone at 1260 m-asl was in disturbed habitat with a sandy substrate. The riparian zone at 1360 m-asl was in secondary forest approximately 40 meters from agricultural land. Both of these zones were fairly flat. The riparian zone at 1460 m-asl was in primary forest. In this zone the stream was temporary, and on a steep gradient (Fig. 6). This was the starting location for the stream, originating from a spring. The PVC refuges were 60 cm tall, 5 cm in diameter with 5-2cm diameter holes, inserted vertically into the ground (Fig. 5) Arrays were set using 5 PVC refuges per riparian zone. Refuges were checked in the early mornings, as well as in the afternoons and night. There was a total of 20 trap nights. Two arrays were modified.

The array at 1360 m-asl had 3 PVC refuges replaced, all with 60 cm length PVC with no holes, 1-5 cm diameter, 1 with 3.8 cm diameter, and 1 with 2.5 cm diameter. The array at

1460 meters had 2 PVC refuges replaced also with 60 cm length PVC with no holes drilled, 1 5 cm diameter and 1 with 3.8 cm diameter. Modifications were made based on available material. These modified arrays had 7 trap nights each.

Pitfall Traps

Two sets of pitfall traps were set in Y-shaped arrays (Fig. 7). The angle between each arm of the drift fence was 120°. Drift fences were composed of aluminum screening, 1 meter high, supported by wooden stakes, and were buried approximately 5 cm below ground. Each arm of the fence was 5 meters long. The buckets used were 2

16 gallons with drain holes drilled approximately 5 cm from the bottom of the bucket. The buckets were buried in the ground with their top flush with the surface. The buckets contained a sponge and a piece of aluminum screening hanging within them (Fig. 9).

One of these traps was set at approximately 1410 m-asl in a secondary forest. The other was set at approximately 1510 m-asl, in a secondary forest, approximately 20 meters from a stream (Fig. 10). Pitfall traps in this array had a total of 27 trap nights before modifications. The traps were modified by removing the sponge and the aluminum screening from the bucket, coating the bucket in baby oil gel, and increasing the leaf litter around the fences and buckets. In the trap set at 1410 m-asl all of the buckets were given a 19 cm extension, by cutting out the bottom of the original bucket and placing another bucket beneath it. The Y-shaped arrays had 98 trap nights after modifications.

Four pitfall traps were set in straight arrays with 3 buckets, and one pitfall trap was set in a straight array with 4 buckets (Fig. 8). Drift fences were composed in the same manner, with 5 meters between buckets. One or two buckets in each of these arrays were modified with a 19 cm extension, in the manner discussed above. Baby oil gel was applied to the buckets; the sponge and aluminum screening were not added. Leaf litter was generously scattered around the buckets and the drift fences. A 3-bucket array was set at approximately 1130 m-asl in primary forest, one was set at approximately 1150 m- asl in primary forest. One was set at approximately 1840 m-asl and one at 1950 m-asl, both in bracken fern. The 3-bucket arrays had a total of 83 trap nights. The 4-bucket array was set at approximately 1190 m-asl in a banana plantation and had 23 trap nights.

Data was graphed using Microsoft Excel. A one-sample t-test was performed using R

2.12.0.

17

Anuran Census

Anuran census was performed by walking three trails around the village of Moka,

Bioko Island: Balacha North, Balacha South, and Lake Biao. Census was performed with groups of 2-3 individuals at a rate of 1.8-2.3 km/hr. This technique was created within the context of this study and represents a completely new technique for “sampling” anuran populations. This amphibian census was possible due to extremely high densities along the trails during the rainy season, such that encounter rates were high. This technique was based on primate census, which these researchers often conducted along these same trails. A faster census rate than that normally used for primates (1 km/hr) was used for amphibians. Justification for this comes from preliminary observations where anurans would be seen moving off the trail before the researcher was close enough to identify the individual, likely due to amphibians’ high sensitivity to vibrations caused by the approaching researcher. Traveling at a faster rate allowed the researcher to overtake and identify most individuals on the trail before they could escape into the leaf litter.

Anurans were recorded when seen on the trail or its border. Each sighting was recorded by genus and closest meter mark. The trail was marked in 20 meter intervals. Elevation information for each meter mark was recorded using a Garmin GPSmap 60CSX. Census was continuous and anurans were only collected if they could not be identified by sight.

Each 20 meter section of the trail was placed into a 20 meter altitudinal range.

Effort was quantified by multiplying the number of segments assigned to each range by the number of times the trail was transversed. For each census used in the data the entire trail was transversed. On Balacha North 27 censuses were used, on Balacha South 11, and on Lake Biao, 9.

18

Encounter frequency vs. distance along the trail was graphed using Microsoft

Excel. This data set was used to perform a poisson distribution in MatlabR2010b. The data from the poisson distribution was then smoothed in MatlabR2010b. Microsoft Excel was used to generate encounter frequency vs. distance graphs, and perform linear regressions on the data. The linear regression was only used if the R-squared value was greater than 0.50.

19

Results

PVC Refuges

Neither the original nor the redesign PVC refuges yielded captures. There was a total of

29 trap nights, 17 before modifications and 12 after modifications.

Pitfall Traps

The original pitfall traps had zero anuran captures in 27 trap nights. Once redesigned the pitfall traps yielded 29 total captures, in 204 trap nights, a capture rate of

0.142. Anurans caught in the drift fence during the daily check were considered part of the capture, although this was only the case for three captures. The arrays at 1130 m-asl and 1150 m-asl were set in a 3-bucket straight line array in primary forest, their capture rates were 0.148 and 0.100 respectively. The array at 1190 m-asl was set in a 4-bucket straight line array in a banana plantation and had the highest capture rate 0.391. Arrays at

1410 m-asl and 1510 m-asl were set in a Y-shaped array in secondary forest, after modifications their capture rates were 0.167 and 0.061. Arrays at 1840 m-asl and 1950 m-asl were set in bracken fern, the array at 1840 m-asl had no captures in 14 trap nights, the array at 1950 m-asl yielded the second highest capture rate at 0.227. The mean capture rate after modifications was significantly different from zero, with a p-value of

2.2 x 10-16 when a t-test was performed. In this case the t-test is not very powerful

considering the data violates the assumptions of normality and equal variance.

20

Anuran Census

Frogs of the genus Arthroleptis were encountered during census on Balacha North and Balacha South trails. Balacha North and Balacha South had similar habitats throughout the trails, consisting of mainly secondary forest with some agriculture, primary forest, and fern habitat. The trails run parallel to each other, starting in Moka and decreasing in elevation. There were a total of 681 Arthroleptis encounters over 27 censuses on Balacha North, and a total of 72 Arthroleptis encounters over 11 censuses on

Balacha South. A significant trend is seen on Balacha North with an R-squared value of

0.7559 and a p-value of 1.696e-08. There was no significant trend in the data from B

Toads of the genus Bufo were recorded on all three trails during census. Where

Balacha North and Balacha South decreased in elevation from Moka and consisted mainly of secondary forest Lake Biao increased in elevation from Moka. Lake Biao is a plowed over road bed up to 1800 m-asl, above this point the habitat is primarily bracken fern. There were 25 Bufo encounters in 27 censuses on Balacha North, 6 Bufo encounters in 11 censuses on Balacha South, and 66 Bufo encouters in 9 censuses on Lake Biao.

Bufo showed no significant trends on any of the trails, Balacha North (p=0.153), Balacha

South (p=0.582), Lake Biao (0.143) (Fig. 13). It appears that encounter rates are increasing with elevation on Lake Biao at 1800 m-asl, however this is just a general increase with decreased disturbance and it is not significant.

Frogs in the genus Hyperolius were only encountered during census on Lake

Biao, above 1800 m-asl. There were no encounters from 1300-1800 m-asl, where the trail had high anthropogenic disturbance. There were 45 Hyperolius encounters during 9 censuses on Lake Biao. There is no significant trend in the census data (Fig. 14). The

21 encounter rate increases from an average 0.024 encounters/effort from 1800-1940 m-asl to 0.243 encounters/effort from 1940-1960 m-asl, where the trail level off at the top of the mountain.

22

Discussion

PVC Refuge

In the past anurans have been studied in riparian areas using a combination of netting techniques, stream/riverbank pitfall traps, and search and capture (Danielson et al.

2002). These studies have yielded limited results of life history traits for tree frogs in riparian areas as they are capable of evading capture by climbing out of pitfall traps and moving over drift fences (Gibbons 1974; Dodd 1991; Moutlon et al. 1996; Boughton

2000). PVC refuges have been shown to be effective in sampling anurans in riparian habitats in North American deciduous forests (Moutlon et al. 1996; Boughton 2000).

However, they have not been used in tropical rainforests, such as Bioko Island.

Implementing these PVC refuges was an experimental technique for this environment.

After 27 trap nights and minor modifications, such as changing the diameter of the PVC pipe, and replacing PVC with holes with those without, there were no captures. It was determined that PVC refuges are not effective in a tropical rainforest because the anurans have better options for refuges. PVC is better used in a deciduous environment where there are fewer alternative, natural options for cover.

Pitfall Traps

Pitfall trapping is a common and generally accepted means of trapping amphibians (Danielson et al. 2002). It has been shown that pitfall traps are more effective in sampling anurans than other trapping methods, such as funnel traps (Bury

1987; Crosswhite et al. 1999). The Y-shaped array was originally chosen because it has been shown to be the most effective drift fence array in sampling anurans, due to its ability to intercept amphibians moving from different directions (Bury 1987; Crosswhite

23 et al. 1999). This configuration was switched to a straight line array as the straight line arrays were more feasible to set in dense forest. While the straight line arrays actually yielded more captures per trap night; we are unable to make an accurate comparison between the arrays as they were set in different habitats at different elevations.

The 5 meter length was chosen for the arms of each array because it has been shown that 5 meters is an appropriate length for efficient capture rates, but it was still short enough to be feasible in dense forest (Bury 1987). Aluminum screening was chosen as the drift fence material for its sturdiness and in order to minimize the effects on the microenvironment. While plastic is a commonly accepted material for drift fence

(Davies & Hoffmann 2002; Burger et al. 2010), there was the concern that it may not be as sturdy as the aluminum screening, and it may warm the area around it more than the aluminum screening, having a greater effect on the microhabitat.

While it is difficult to accurately compare the effects of the extended bucket to the original bucket, it is evident that the combination of baby oil gel, increased leaf litter, and the removal of the sponge and aluminum screening increased capture rates. Prior to this modification zero anuran captures occurred in 27 trap nights. After this modification 9 captures occurred in 98 trap nights, a rate of 0.092 captures per trap night, using the same arrays. Overall there 43 captures occurred in 211 trap nights, a rate of 0.20 captures per trap night. While experimenting with an Arthroleptis variabilis and a Phrynobatrachus calcaratus, which were caught during opportunistic sampling, we found that the frogs detected the bucket and jumped over it. A possible solution to this is using larger buckets and increased leaf litter. More leaf litter was added around the traps in the hopes that the frogs would travel under the leaf litter and not be aware of the pitfall bucket.

24

Additionally, it is possible that anurans might use the leaf litter and the drift fence as a place to seek shelter. After adding more leaf litter three frogs were found in the drift fence when the traps were checked. Anurans, particularly Arthroleptis and Hyperolius were able to climb the side of the buckets prior to being coated in baby oil gel. After coating the buckets no anurans were observed (in the lab or field) climbing out of the buckets.

Bufo camerunensis were observed jumping from the sponge onto the aluminum screening and escaping from the bucket. The sponges were originally in the buckets in order to provide moisture and prevent desiccation, as well as to give animals potential cover to avoid predation (Enge 2001). As it was the rainy season the buckets consistently had water in the bottom. Leaf litter and mud would wash into the traps, giving the animals cover. The aluminum screening was originally added to give small mammals a way to escape from the trap, and to minimize bycatch. When the aluminum screening was removed bycatch increased. It is believed that rodents preyed on the anurans within the trap. In one case an Arthroleptis variabilis was found dead in the trap with a rodent.

Both of the frog’s legs were missing, and part of its hip. It would beneficial to find an appropriate method of reducing incidental captures without significantly decreasing anuran captures.

The original bucket design had drain holes drilled 5 cm from the bottom of the bucket. The purpose of this was twofold. It has been shown that anurans may be attracted to the water in the bottom of the bucket and that water in the bottom of a pitfall trap may prevent escape (Bury 1987; Enge 2001). When the extension was added water was able to drain out of the opening between the two buckets. Drain holes were also added in the

25 extension can to ensure that it did not fill up. In future studies it would be beneficial to use larger buckets as the pitfall trap. Having a larger opening would increase capture rates. More experimentation needs to be done, but with increased capture rates using the aluminum screening, or a hardware cloth to allow incidental captures to escape may still be feasible. If the drain holes are drilled higher in the bucket, this may prevent anurans from being able to jump to the hardware cloth or aluminum screening. Having increased leaf litter around the buckets and fence as well as using baby oil gel will also be beneficial in future studies. The one downfall of using baby oil gel to prevent anurans from climbing the bucket is that it needs to be reapplied every 4-5 days, although this may be less frequent in the dry season.

Distribution Over an Elevation Gradient

Population distributions, over the altitudinal gradient varied according to genus.

Arthroleptis encounter rates decreased with altitude. This trend was evident and significant (p=1.696e-08) on Balacha North where there were 681 total Arthroleptis encounters during 27 censuses. The trend was not significant on Balacha South

(p=0.708) with 72 Arthroleptis encounters during 11 censuses. It is possible that the reason a significant trend is not seen on Balacha South is a combination of low census and encounter rates and an unknown change in habitat. There is an Arthroleptis hotspot seen at approximately 1310 m-asl on Balacha South. This elevation corresponds to a 100 meter increment of the trail. It was originally speculated that habitat was influencing the encounter rate is the region, as it is known that Arthroleptis exhibit habitat preference

(Fig. 15) (Vittands Pers comm. 2010).

26

Habitat preference analysis was performed by Anika Vittands in Fall 2010. She found that Arthroleptis had an affinity for tree fern habitat, where as they were less prevalent in banana tree and agricultural habitats (Fig. 15). Elizabeth Long and Elliot

Chiu performed a habitat assessment along Balacha North and Balacha South in Spring of 2011 (Appendix B). The habitat profiles along both the trails are very similar. The habitat changes frequently along each trail. There was a concern that habitat preference would be a confounding variable in the data, however, both trails are mostly secondary forest, primary forest, and bracken fern. Considering that Arthroleptis have fairly even preference for these three habitats, they were considered one category while analyzing the data. There were few segments on either trail with agriculture or banana plantation habitat, and none with elephant grass; these segments did not appear to skew the data.

There were also few segments on either trail with tree fern. Again, these segments did not appear to skew the data.

The 100 meter increment of the trail that has high Arthroleptis encounter rates is secondary forest, which does not explain the spike in encounter rates. It is possible that either a minute habitat difference that was not detected by the visual survey, or a habitat difference further off the trail that is making this area more suitable for amphibians.

Considering that the spike consists of only 7 encounters over the 11 censuses, I believe that the variance is due to low sampling and encounter frequency, and with more data, a clearer trend would be seen, as on Balacha North.

While all Arthroleptis were included in the census, the species Arthroleptis variabilis were the most prevalent. Arthroleptis variabilis have a range within the

Biafran forest and highlands and have been noted at ranges up to 1200 m-asl on

27

Cameroon (Rödel et al. 2004). While the data obtained from this study is preliminary it shows that Arthroleptis, particularly Arthroleptis variabilis may prefer lower elevation.

Bufo were found to be fairly evenly distributed through elevation gradients.

Sampling was low, but no strong trends were seen in. There was a slight increase with elevation on Lake Biao, but this is also correlated with where disturbance was decreased, and the trend was not significant (p=0.1423). There was a total of 66 Bufo encounters on

Lake Biao during the 9 censuses. There was a total of 25 Bufo encounters on Balacha

North during the 27 census and 6 on Balacha South. Bufo were seen from approximately

1120 m-asl to 1950 m-asl during this study. While all Bufo were included in the census, the majority seen were Bufo camerunensis. This species has a range in the Biafran forest and highlands, and most of its records have been below 1000 m-asl (Amiet et al. 2004).

Considering that the lowest point of the census was approximately 1060 m-asl it is possible that Bufo encounters were low because the study area was above their preferred range. However, while Bufo camerunensis is a common species, there are not many records of its elevation (Amiet et al. 2004). While this is preliminary data, it does show that Bufo camerunensis occur at higher elevations, and it may show that Bufo camerunensis does not have much of an altitudinal preference.

Hyperolius encounter rates increased with altitude. During census Hyperolius were only seen on Lake Biao, above 1800 m-asl. The habitat on the Lake Biao trail went from extremely disturbed, a plowed road bed to moderately disturbed bracken fern at approximately 1800 m-asl. However, the encounter rate goes from 0.024 encounters/effort to 0.243 encounters/effort from 1800 m-asl to 1940 m-asl, suggesting that Hyperolius prefer higher elevation. It is possible that the top of Lake Biao is the

28 beginning of their optimal range. More data is needed to make stronger conclusions, as there were only 45 total Hyperolius encounters on the 9 census and the trend was not significant at the 5% level (p=0.08552). It is known that Hyperolius exist at lower elevations, as they were found as low as 1200 m-asl in Moka. Hyperolius tuberculatus was the dominant Hyperolius species. Its range extends from the Biafran forest and highlands east through the northern region of the Democratic Republic of the Congo.

While a more specific range has not been located for Hyperolius tuberculatus they have been surveyed at mid-level altitudes, greater than 1200 m-asl and have been classified as existing in a high altitude range (Pauwels & Rode 2007; Behangana et al. 2009). There is not much existing data regarding their specific altitudinal range. While the data from this study is preliminary it may show that Hyperolius tuberculatus prefer a range higher than

1900 m-asl. It is possible that the highest census point, approximately 1950 m-asl, is in the lower end of their optimal range.

Changes in temperature were evident along the elevation gradient, decreasing with increased elevation. Temperature is one of the most influential factors in species diversity, particularly in ectotherms ((Allen 2002). In general species diversity is positively correlated with temperature as temperature effects metabolic rates (Allen

2002). It has been shown that certain amphibian species have morphological changes with elevation, but these changes vary greatly between species (Werner 1986).

Morphological measurements were taken for animals captured in traps or opportunistically totaling 114 individuals. There were no evident morphological changes along the elevation gradient.

29

Species Presence

Dr. Eisentraut performed the majority of his amphibian survey in 1973 around the village of Moka. In this survey Dr. Eisentraut recorded five species in what he classifies as the mid-mountain zone, and six in montane habitats, the two highest altitude groups he uses. I believe the areas surveyed in this most recent study correlate with these two zones. Of the 11 species Dr. Eisentraut recorded in these zones we recorded five of the same species: Arthroleptis variabilis, Hyperolius ocellatus, Bufo camerunensis,

Phrynobatrachus cornutus and Leptopelis calcaratus. Of the six species not recorded in our survey, five have been recorded recently by BBPP. The one species that Dr.

Eisentraut has recorded in this alititudinal range that has not been recorded since 1973 is

Arthroleptis bivittatus, which may actually a synonym for Arthroleptis poecilonotus, which has been recorded on Bioko Island recently. This similarity in species make-up shows the stability in species diversity over the past four decades.

Future research

More data is needed to be able to confidently determine the distributions of these anurans over an elevation gradient. Census time was short and only conducted during one season. In the future data should be collected year round. This will not only provide more data, but it will provide data for the dry season as well. Collecting census information would be a feasible project for undergraduate students while in Moka. The census techniques are simple, students would only need a short training time before they were able to perform census independently. Pitfall traps could be implemented in order to determine trends in elevation, and in habitat. This study provided information on how

30 to make pitfall traps effective in this particular environment. Effective pitfall traps could therefore be installed at predetermined increments along the elevation gradient. Traps could also be installed in various habitat types in order to provide more detailed information on species’ habitat type preference.

Long-term monitoring is important, as discussed above, amphibians are important indicator species, but for most species little information is known (Wyman 1990;

Blaustein 1994; Lips 2006) . Although Hyperolius tuberculatus appears to have a stable population, the other species focused on in this study do not (Schiøtz et al. 2004). It has been observed that Arthroleptis variabilis is declining in population, and it is believed that this decline is due to forest loss (Rödel et al. 2004). Although Bufo camerunensis is a common species, there is not enough information to determine a population trend

(Amiet et al. 2004). Having a long term monitoring project would provide more information about these species and on Bioko Island. The census was limited to genus for two reasons. Encounters were low, and limiting the census to species provided data that was more feasible to work with. More so, when on census animals are typically identified by sight while the census team continues walking. It is difficult to identify animals to the species level while using this method, and having identification to the genus level gave less room for error. By using pitfall traps to supplement the census information animals can be identified to the species level with less error. Pitfall traps may also lead to a more comprehensive species list for Bioko Island, as species which were not seen during census were captured in the pitfall trap, including a species that has not been seen since 1964

31

It is vital to have more comprehensive information about the species that populate

Bioko Island. Without this information it is impossible to determine if trends are changing. Considering that Bioko is free from many of the issues that are currently plaguing anuran populations, it is an ideal habitat to extrapolate data from (Caro 1999).

Chytrid, which is currently causing widespread amphibian die-offs as discussed above, has not been noted on Bioko Island yet (Lips 2006; Colón-Gaud 2010). The first comprehensive chytrid sampling on the island yet is currently being performed. In this study no frogs were found with the typical signs of chytrid death, such as large-scale die- off, hyperkeratosis, sloughing of the skin, or the chytrid pose (Rosa et al. 2007).

However, chytrid may be present in the environment without causing disease.

Environmental stresses may cause amphibians to become susceptible to chytrid, and other pathogens (Rosa et al. 2007).

Environmental stresses, particularly global climate change have the potential to largely impact these populations. If the top of Lake Biao is the bottom of the ideal range for Hyperolius, as I suspect, global climate change may leave this population without an ideal habitat. Deforestation and habitat destruction is currently the main cause of worldwide anuran decline (Blaustein & Wake 1990; Houlahan 2000; Amiet et al. 2004;

IUCN 2010). Bioko Island is unique in that a great deal of its habitat is relatively undisturbed. Habitat conservation should be made a priority in order to preserve the species that populate the island.

This study laid the ground work for a long-term amphibian monitoring system.

This system could be implemented year round with study abroad and local students. This study provided useful baseline data and can be built upon in order to monitor changes in

32 the amphibian population. Changes in population, even slight can be early warning signs for chytrid or show the effects of global climate change, or other environmental stressors.

Having a monitoring system for this understudied area is invaluable.

33

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Appendix A: Anuran Species Recorded on Bioko Island

Table 1: List of Anuran Species Recorded on Bioko Island Since 1973. Arthroleptis Bioko and Leptopelis brevipes are endemic to Bioko Island (dark green). Didynamipus sjostedti, Wolterstorffina parvipalmata, Arlequinus krebsi, Petropedetes cameronensis, and Petropedetes johnstoni are endemic to the Biafran region (light green). Bufo funereus, and Phrynobatrachus plicatus have been recorded as present on Bioko Island, but have yet to be identified as those species by an expert (red). Reported on Bioko by: AW (AmphibiaWeb), IUCN (International Union for Conservation of Nature and Natural Resources), BBPP (Bioko Biodiversity Protection Program) if BBPP has a picture of the species, from the island, it is signified by (photo), ME (Martin Eisentraut). IUCN Status Key: Least Concern (LC), Near Threatened (NT), Vulnerable (VU), Endangered (EN), Critically Endangered (CR), Extinct in Wild (EW), Extinct (EX), Data Defecient (DD), Not Evaluated (NE).

Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Arthroleptis Foulassi (Perret LC AW Cameroon, Gabon adelphus Screeching 1966) IUCN Frog BBPP Arthroleptis bioko Bioko (Blackburn DD AW Squeaker 2010) Frog Arthroleptis (Müller DD ME Sierra Leone (Tumbo Island) bivittatus 1885) Arthroleptis Buea (Peters LC AW Benin, Cameroon, Congo, Congo, the poecilonotus Squeaker 1863; Rödel IUCN Democratic Republic of the, Cote d'Ivoire,

Frog 2000) BBPP Gabon, Ghana, Guinea, Guinea-Bissau, (photo) Liberia, Nigeria, Sudan, Togo, Uganda ME Arthroleptis Forest (Laurent LC BBPP Cameroon, Central African Republic, Congo, sylvaticus Screeching 1954) (photo) Congo, the Democratic Republic of the

Arthrolptidae Frog

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Arthroleptis Variable (Matschie LC AW Cameroon, Central African Republic, Congo, variabilis Squeaker 1893) IUCN Congo, the Democratic Republic of the, Cote Frog BBBP d'Ivoire, Gabon, Ghana, Guinea, Liberia, (photo) Nigeria ME Cardioglossa Ongot (Boulenger LC BBPP Cameroon, Congo, Congo, the Democratic leucomystax Long- 1903) (photo) Republic of the, Cote d'Ivoire, Gabon, Ghana, Fingered Guinea, Liberia, Nigeria Frog Leptopelis Victoria (Werner LC AW South-eastern Nigeria to Cameroun, Gabon, R. boulengeri Forest Tree 1898) IUCN Congo and western R. D. Congo. Frog ME Leptopelis Musole (Boulenger DD AW brevipes Treefrog 1906) IUCN ME Cameroon (Werner LC AW Cameroon, Gabon, Nigeria Leptopelis Forest 1898) IUCN brevirostris Treefrog BBPP (photo) ME Leptopelis Efulen (Boulenger LC AW Cameroon, Central African Republic, Congo, calcaratus Forest Tree 1906) IUCN Congo, the Democratic Republic of the, Frog BBPP Gabon, Nigeria (photo) Leptopelis (Werner LC IUCN Cameroon, the Democratic Republic of the, modestus 1898) BBPP Nigeria (photo) ME

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Leptopelis notatus (Peters LC IUCN Cameroon, Congo, Congo, the Democratic 1875) BBPP Republic of the, Nigeria (photo) ME Leptopelis Palm Forest (Peters VU ME Sao Tome and Principe palmatus Tree Frog 1868) Leptopelis (Peters LC AW Benin, Cameroon, Congo, Congo, the poecilonotus 1863) IUCN Democratic Republic of the, Cote d'Ivoire, BBPP Gabon, Ghana, Guinea, Guinea-Bissau, (photo) Liberia, Nigeria, Sudan, Togo, Uganda Bufo camerunensis Oban (Parker LC AW Cameroon, Central African Republic, Congo, Toad/Camer 1936) IUCN Congo, the Democratic Republic of the, oon Toad BBPP Nigeria (photo) ME Bufo funereus (Bocage LC BBPP Angola, Congo, Democratic Republic of the, 1866) (photo) Gabon, Uganda Bufo gracilipes French (Boulenger LC AW Cameroon, Congo, the Democratic Republic of Congo Toad 1899) IUCN the, Gabon, Nigeria ME Bufo tuberosus Warty Toad/ (Günther LC AW Cameroon, Central African Republic, Congo, Fernando Po 1858) IUCN Congo, the Democratic Republic of the, Gabon Toad BBPP (photo)

ME Didynamipus Four-digit (Andersson EN BBPP Cameroon, Nigeria sjostedti Toad 1903) (photo)

Bufonidae ME

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Nectophryne afra African (Peters LC AW Cameroon, Congo, the Democratic Republic of Tree Toad 1875) IUCN the, Gabon, Nigeria BBPP (photo) ME Nectophryne Bates’ Tree (Boulenger LC BBPP Cameroon, Central African Republic, Congo, batesii Toad 1913) (photo) the Democratic Republic of the, Gabon Wolterstorffina (Werner VU BBPP Cameroon, Nigeria parvipalmata 1898) (photo) Afrixalus dorsalis Striped (Peters LC BBPP Angola, Cameroon, Congo, Congo, the Spiny Reed 1875) ME Democratic Republic of the, Cote d'Ivoire, Frog Gabon, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Togo Afrixalus laevis Liberia (Ahl 1930) LC AW Burundi, Cameroon, Congo, the Democratic Banana IUCN Republic of the, Liberia, Rwanda, Uganda Frog BBPP (photo) Afrixalus (Perret LC AW Cameroon, Gabon, Nigeria paradorsalis 1976) IUCN BBPP (photo) Arlequinus krebsi Mebebque (Mertens EN BBPP Cameroon Frog 1938) (photo) Hyperolius Cinnamon- (Bocage LC BBPP Angola, Cameroon, Congo, Congo, the cinnamomeoventri bellied Reed 1866) (photo) Democratic Republic of the, Gabon, Kenya, s frog Rwanda, Tanzania, United Republic of,

Hyperolidae Uganda, Zambia

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Hyperolius Golden- (Günther LC AW Angola, Cameroon, Central African Republic, ocellatus eyed Reed 1858) IUCN Congo, Congo, the Democratic Republic of Frog BBPP the, Gabon, Nigeria, Uganda (photo) ME Hyperolius (Mocquard LC AW Cameroon, Central African Republic, Congo, tuberculatus 1897) IUCN Congo, the Democratic Republic of the, BBPP Gabon, Guinea, Nigeria (photo) Phlyctimantis Boulenger’s (Perret LC AW Cameroon, Cote d'Ivoire, Ghana, Guinea, boulengeri Striped Frog 1986) IUCN Liberia, Nigeria

Phlyctimantis Olive (Boulenger LC ME Congo, the Democratic Republic, Gabon leonardi Striped Frog 1906)

Amnirana White- (Hallowell LC AW Angola, Benin, Cameroon, Central African albolabris lipped Frog 1856) IUCN Republic, Congo, Congo, the Democratic BBPP Republic of the, Cote d'Ivoire, Gabon, Ghana, (photo) Guinea, Kenya, Liberia, Nigeria, Sierra Leone, ME Tanzania, United Republic of, Togo, Uganda

Conraua crassipes Abo (Peters LC AW Cameroon, Congo, Congo, the Democratic Slippery 1875) IUCN Republic of the, Gabon, Nigeria Frog ME

Ranidae

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Chiromantis African (Günther LC AW Cameroon, Central African Republic, Congo, rufescens Foam-nest 1858) IUCN Congo, the Democratic Republic of the, Cote Tree Frog BBPP d'Ivoire, Ghana, Guinea, Nigeria, Sierra Leone, (photo) Uganda ME Petropedetes Cameroon (Reichenow NT AW Cameroon, Nigeria cameronensis Water Frog 1874) IUCN ME

Petropedetes Johnston’s (Boulenger NT AW Cameroon johnstoni Water Frog 1888) IUCN

Phrynobatrachus African (Janzen LC AW Cameroon, Central African Republic, Congo, africanus Swamp 1967) IUCN Gabon Frog BBPP Phrynobatrachus Eared River (Boulenger LC AW Cameroon, Central African Republic, Congo, auritus Frog/Golde 1900) IUCN Congo, the Democratic Republic of the, n Puddle BBPP Gabon, Nigeria, Rwanda, Uganda Frog (photo) Phrynobatrachus Boutry (Peters LC AW Cameroon, Central African Republic, Congo, calcaratus River Frog 1863) IUCN the Democratic Republic of the, Gabon, BBPP Ghana, Guinea, Liberia, Nigeria, Senegal, (photo) Togo ME

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Family Species Common Primary IUCN Reported Other location(s) Name Description Status on Bioko Phrynobatrachus Horned (Boulenger LC AW Cameroon, Congo cornutus River Frog 1906) IUCN BBPP (photo) ME Phrynobatrachus Coast River (Günther LC BBPP Cote d'Ivoire, Ghana, Guinea, Liberia, Nigeria, plicatus Frog 1858) (photo) Togo ME Phrynobatrachus Sanderson’s (Parker LC ME Cameroon, Equatorial Guinea sandersoni Hook Frog 1935; Parker 1936) Ptychadena Victoria (Werner LC AW Benin, Cameroon, Central African Republic, aequiplicata Grassland 1898) IUCN Congo, Congo, the Democratic Republic of Frog ME the, Cote d'Ivoire, Gabon, Ghana, Guinea, Liberia, Nigeria, Togo Xenopus Cameroon (Fischberg LC AW Angola, Cameroon, Central African Republic, epitropicalis Clawed-frog et al. 1982) Congo, Congo, the Democratic Republic of the, Gabon Xenopus fraseri Fraser’s (Boulenger LC AW Angola, Cameroon, Central African Republic, Clawed-frog 1905) IUCN Congo, Congo, the Democratic Republic of ME the, Gabon

Xenopus Tropical (Gray 1864) LC AW Benin, Burkina Faso, Cameroon, Congo, the tropicalis Clawed IUCN Democratic Republic of the, Cote d'Ivoire, Frog ME Gambia, Ghana, Guinea, Guinea-Bissau,

Pipidae Liberia, Nigeria, Senegal, Sierra Leone, Togo

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Appendix B: Figures

Figure 1. Map of Bioko Island. Figure 2. Map of Biafran Regiion Shows Bioko Island and it’s and Surrounding Area. relationship to Africa. This map shows the Biafran region in gray, spanning the coastal region of Southern Nigeria to the Sanaga River (Oates et al. 2004).

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Figure 3. Altitudinal rangn e limits of amphibians endemic to the Biafran Region. Adapted from Bergl, 2007: represents the number of species in each anuran family which are restricted to each altitudinal range in the Biafran forest and highlands.

Figure 4. IUCN Redlist categories for amphibians endemic to the Biafran Region. Adapted from Bergl, 2007: represents the number of species in each anuran family which have been assigned to each threat level, endemic to the Biafran forest and highlands. Critically Endangered (CR), Endangered (EN), Vulnerable (VU), Near Threatened (NT) Least Concern (LC), Data Deficient (DD)

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Figure 5. PVC Refuge. Figuure 6. PVC Refuge Arraay at 1460 m-asl

5 m 120° 5 m

Figure 7. Y-shaped Pitfall Trap Array Figure 8. Three and Four Bucket Straight Line Arrays

Figure 9. Pitfall Trap Bucket Figure 10. Y-Shaped Array Before Modification Before Modifications

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Figure 11. Capture Rates of Pitfall Traps. This chart represents the capture rates for individual pitfall traps. If a trap was modified, the capture rates after moodifications are represented here. Traps are labeled with the type of habitat they are in: PF (Primary Forest), BP (Banana Plantation), SF (Secondary Forest), and BF (Bracken Fern).

Figure 12. Arthroleptis Census. This figure represents the encounter rates of frogs in the genus Arthroleptis on the Balacha North and Balacha South trails.

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Figure 13. Bufo Census. This figure represents the encounter rates of Buufo on the Balacha North, Balacha South, and Lake Biao trails.

Figure 14. HyH perolius Census. This figure represents the encounter rates of Hyperolius on the Lake Biao trail.

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Figure 15. Habitat Preference Assessment. Moka, Bioko Island, (Fall 2010).

Appendix C: Species Expected on Bioko Island

List of Species Expected on Bioko Island Based on Presence on the Mainland, Suitable Habitat, and Range. IUCN Status Key: Least Concern (LC), Near Threatened (NT), Vulnerable (VU), Endangered (EN), Critically Endangered (CR), Extinct in Wild (EW), Extinct (EX), Data Defecient (DD), Not Evaluated (NE)

Family Species Common Primary IUCN Habitat Range Name Description Status Arthroleptis (Blackburn DD Montane forest, Cameroon: Mount Manengouba, perreti et al. 2009) leaft litter 1400-2200 m-asl Striped (Boulenger LC Shallow marshes Cameroon, Central African Republic, The Screeching 1906) in forests Democratic Republic of the Congo, Arthroleptis Frog Equatorial Guinea, Gabon taeniatus Uncertain: Angola, Congo Rainforest (Andersson DD Montane, perhaps Cameroon, Congo, The Democratic Screeching 1905) lowland forests, Republic of the Congo Arthroleptis Frog forest floor Uncertain: Central African Republic, tuberosus Equatorial Guinea, Gabon Elegant (Boulenger LC Moist lowland Southwest Cameroon to mainland Long- 1906) forest and Equatorial Guinea, below 1000 m-asl Cardioglossa fingered degraded forest elegans Frog Equatorial (Boulenger LC Lowland tropical Cameroon, Central African Republic, The Guinea 1903) moist forest Democratic Republic of the Congo, Long- Equatorial Guinea Cardioglossa fingered Uncertain: Congo, Gabon

Arthroleptidae escalerae Frog

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Family Species Common Primary IUCN Habitat Range Name Description Status Rio Benito (Boulenger LC Moist lowland Cameroon, Central African Republic, The Long- 1900) and lower Democratic Republic of the Congo, fingered montane forest Equatorial Guinea, Gabon, Nigeria Cardioglossa Frog Uncertain: Congo, below 1200 m-asl gracilis Cardioglossa (Blackburn DD Montane forest Cameroon: Mount Manengouba, manengouba 2008b) 2100 m-asl Blackspotte (Nieden NT Lowland moist Southwestern Cameroon and extreme d Long- 1908) forest and southern Nigeria, low altitudes Cardioglossa fingered degraded habitat nigromaculata Frog near mature forest (Amiet VU Around springs Cameroon: Eastern slopes of Mount 1980b) and streams in Cameroon and Bimbia Hill, 200-1000 Leptodactylodon forests m-asl bueanus Leptodactylodon Speckled (Boulenger VU Strictly a forest Cameroon: south of the Sanga River, ventrimarmoratus Egg Frog 1904) species south-western, 50-1150m-asl Gaboon (Hallowell LC Arboreal Angola, Cameroon, Central African Forest 1855) secondary forest, Republic, Congo, The Democratic Treefrog swamp forest, and Republic of the Congo, Equatorial Guinea, degraded habitats Gabon, Nigeria Leptopelis aubryi outside forests

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Family Species Common Primary IUCN Habitat Range Name Description Status Niger Forest (Boulenger LC Primary and Cameroon, Central African Republic, Treefrog 1895) secondary Congo, The Democratic Republic of the lowland Congo, Equatorial Guinea, Gabon, Nigeria rainforest, secondary Leptopelis growth, and palm millsoni plantations Kala Forest (Amiet LC Dense primary Cameroon, Congo, Gabon, Nigeria Treefrog 1992) and open Uncertain: Angola, Central African secondary Republic, The Democratic Republic of the Leptopelis lowland forest Congo, Equatorial Guinea, below 1000 omissus m-asl Red (Reichenow LC Humid lowland Cameroon, Congo, The Democratic Treefrog 1874) rainforest Republic of the Congo, Equatorial Guinea, Gabon, Nigeria Uncertain: Angola, Central African Leptopelis rufus Republic Southern (Boulenger LC Lowland forest Extreme southeastern Nigeria, southern Night Frog 1904) and southwestern Cameroon, and Nyctibates mainland Equatorial Guinea, corrugatus up to 900 m-asl Gaboon (Boulenger LC Lowland Cameroon, Congo, The Democratic Forest Frog 1900) rainforest Republic of the Congo, Equatorial Guinea, Gabon, Nigeria Scotobleps Uncertain: Angola, low altitudes gabonicus

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Family Species Common Primary IUCN Habitat Range Name Description Status Hairy Frog (Boulenger LC Fast-flowing Eastern Nigeria: Osamba Hills to extreme 1900) rivers in lowland western Democratic Republic of the forests, and in Congo: Mayombe Hills, Cameroon, secondary and Equatorial Guinea, Gabon, Nigeria Trichobatrachus agricultural Uncertain: Angola, Congo robustus habitats African (Boulenger LC Primary Forest, Cameroon, Central African Republic;

Giant Toad 1888) along the banks Congo, The Democratic Republic of the or larger rivers Congo, Côte d'Ivoire, Equatorial Guinea, Amietophrynus Gabon, Ghana, Liberia, Nigeria

Bufonidae superciliaris Uncertain: Sierra Leone African (Peters LC Lowland Cameroon, Congo, The Democratic Acanthixalus Wart Frog 1875) rainforest Republic of the Congo, Gabon, Nigeria spinosus Koehler’s (Mertens LC Montane and Extreme southeastern Nigeria through Green Frog 1940) lowland moist southwestern Cameroon, Gabon forest, grassy Uncertain: Congo, Equatorial Guinea Chlorolius meadows and koehleri coffee plantations Sharpsnout (Peters NT Lowland mature Southwestern Cameroon Hyperolius Reed Frog 1875) forests with large up to 1300 m-asl acutirostris trees Bolifamba (Mertens LC Bushland, Cameroon, Central African Republic, Reed Frog 1938) lowland Nigeria Uncertain: Congo, The Democratic Hyperolius Republic of the Congo, Equatorial Guinea,

Hyperolidae bolifambae Gabon

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Family Species Common Primary IUCN Habitat Range Name Description Status Dizangue (Amiet NT Degraded former Southwestern Cameroon: coastal areas, Hyperolius Reed Frog 1980a) forest (farm bush) within 30 km of the coast bopeleti on sandy soil Lime Reed (Peters LC Clearings in Benin, Cameroon, Côte d'Ivoire, Ghana, Frog 1876) forest, secondary Guinea, Liberia, Nigeria, Sierra Leone, Hyperolius forest, degraded Togo fusciventris forest, farmbush Dotted Reed (Günther LC Large swamps in Cameroon, Côte d'Ivoire, Gabon, Ghana, Frog 1858) secondary Guinea, Liberia, Nigeria, Sierra Leone, Hyperolius habitats Togo guttulatus Uncertain: Equatorial Guinea Bobiri Reed (Schiøtz LC Lowland moist Cameroon, Côte d'Ivoire, Ghana, Nigeria Hyperolius Frog 1967) forest, degraded Uncertain: Benin, Liberia, Togo sylvaticus forest, bush land Gray-eyed (Boulenger LC Closed-canopy, Cameroon, The Democratic Republic of Frog 1903) undisturbed the Congo, Equatorial Guinea, Gabon, rainforest Nigeria Uncertain: Angola, Central African Opisthothylax Republic, Congo immaculatus

Congo (Tornier LC Lowland forest, Cameroon, Central African Republic, The Dwarf 1896) still, shaded water Democratic Republic of the Congo, Hymenochirus Clawed Equatorial Guinea, Gabon, Nigeria

Pipidae boettgeri Frog Uncertain: Angola, Congo, Uganda

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Family Species Common Primary IUCN Habitat Range Name Description Status Cameroon (Fischberg LC Lowland Angola, Cameroon, Central African Clawed et al. 1982) rainforest Republic, Congo, The Democratic Frog Republic of the Congo, Equatorial Guinea, Silurana Gabon epitropicalis Uncertain: Sudan Volcano (Kobel et al. NT Montane Cameroon: Mount Manenguba and the Clawed 1980) grassland and Bamileke and Bamenda Plateaus, Xenopus amieti Frog pastureland up to 1900 m-asl Andre’s (Loumont LC Lowland forest, Cameroon, Central African Republic, Clawed 1983) small water holes Gabon Frog and shady Uncertain: Congo, The Democratic swamps Republic of the Congo, Equatorial Guinea Xenopus Andrei Andersson’s (Andersson LC Lowland forest Cameroon, Central African Republic, Cameroon 1903) species Congo, The Democratic Republic of the Frog Congo, Equatorial Guinea, Gabon Uncertain: Angola Amnirana lepus West (Duméril LC Primary forest in Cameroon, Côte d'Ivoire, Ghana, Guinea, African 1856) swamps or along Liberia, Nigeria Aubria Brown Frog streams Uncertain: Togo

occidentalis Goliath (Boulenger EN Fast flowing Southwestern Cameroon: Nkongsamba Frog 1906) streams or rivers and Equatorial Guinea: South to Mount

Ranidae Conraua goliath in forests Alen, below 1000 m-asl

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Family Species Common Primary IUCN Habitat Range Name Description Status Llanga Frog (Perret LC Primary and Southwestern and southern Cameroon to 1977) slightly disturbed mainland Equatorial Guinea, south to Hylarana rainforest Central Gabon amnicola Uncertain: Congo, 1000 m-asl Petropedetes (Barej et al. NE Cameroon: Mount Kupe and Mount euskircheni 2010) Nlonako Petropedetes (Barej et al. NE Cameroon: Mount Kupe, 920 m-asl juliawurstnerae 2010) Petropedetes Fuch’s (Barej et al. NE Eastern Nigeria to southern Gabon, vulpiae Water Frog 2010) 450 m-asl Bate’s River (Boulenger LC Lowland Cameroon, Gabon, Ghana, Nigeria Frog 1906) rainforest, Uncertain: Equatorial Guinea, Togo degraded secondary Phrynobatrachus vegetation near batesii forest Phrynobatrachus Spiny (Zimkus NE Montane Forest Cameroon: Mount Oku, near summit, chukuchuku Puddle Frog 2009) 2800m-asl (Plath et al. NE Lowland and Cameroon: southwestern foothills of 2006) submontane Mount Nlonako Phrynobatrachus secondary 450 m-asl nlonakoensis rainforest

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Appendix D: Habitat Assessment

Habitat Assessment on Balacha North, performed by Elliot Chiu and Elizabeth Long (Spring 2011). Agriculture (A), Banana Trees (B), Colonizing Species (C), Dried Stream (DS), Primary Forest (PS), Secondary Forest (S), Secondary Forest High Growth (SH) and Tree Fern (TF).

Meter Primary Secondary Tertiary mark vegetation vegetation vegetation Comments 0 Road 20 BF 40 S BF 60 BF S 80 BF 100 BF 120 SH BF 140 SH 160 SH 180 BF SH 200 SH 220 SH 240 SH BF 260 SH BF 280 SH 300 SH 320 SH TF 340 SH 360 SH TF 380 SH TF 400 S SH 420 S SH 440 S SH 460 SH TF 480 SH 500 SH 520 SH BF 540 SH 560 SH 580 SH BF 600 SH 620 SH 640 SH 660 SH 680 SH BF 700 BF SH 720 BF

740 SH 760 SH 780 SH 800 SH P 820 SH C 840 SH 860 SH 880 SH 900 SH 920 SH 940 SH 960 SH SH 980 SH 1000 SH SH 1020 SH SH 1040 SH 1060 SH 1080 SH 1100 SH 1120 SH 1140 SH 1160 SH 1180 SH 1200 SH 1220 SH 1240 SH 1260 SH 1280 SH 1300 SH 1320 SH 1340 SH 1360 SH 1380 SH SH 1400 SH 1420 SH 1440 SH 1460 SH 1480 SH TF 1500 SH TF 1520 SH 1540 SH 1560 SH BF 1580 SH BF 1600 SH 1620 SH BF 1640 SH SH 1660 SH 1680 SH

1700 SH 1720 SH 1740 SH 1760 SH 1780 SH 1800 SH TF 1820 SH TF 1840 SH 1860 SH 1880 SH 1900 SH TF 1920 SH 1940 SH 1960 SH 1980 SH P 2000 SH P 2020 SH P 2040 TF SH 2060 TF 2080 TF 2100 TF 2120 TF 2140 SH 2160 SH 2180 SH P TF 2200 TF 2220 SH 2240 SH TF 2260 SH P 2280 SH P 2300 TF P B 2320 SH P B 2340 P TF 2360 P TF 2380 P TF 2400 P TF 2420 P 2440 P 2460 P 2480 P 2500 P 2520 P BF 2540 P 2560 A 2580 BF B 2600 BF 2620 BF 2640 BF SH

2660 SH 2680 SH P 2700 SH B 2720 SH 2740 SH 2760 BF 2780 SH 2800 SH B BF 2820 SH B 2840 SH 2860 SH BF 2880 SH 2900 SH 2920 SH 2940 SH 2960 SH 2980 SH 3000 SH 3020 SH 3040 SH 3060 SH 3080 SH 3100 SH 3120 SH 3140 SH B P 3160 SH B P 3180 SH B 3200 SH B 3220 SH 3240 SH 3260 SH 3280 SH 3300 SH 3320 SH F 3340 SH 3360 SH 3380 SH 3400 SH 3420 SH 3440 SH 3460 SH 3480 SH 3500 SH 3520 SH 3540 SH 3560 SH 3580 SH 3600 SH

3620 SH 3640 SH 3660 SH 3680 SH 3700 SH 3720 SH 3740 SH 3760 SH

Habitat Data: Balacha South

Habitat Assessment of Balacha South, performed by Elliot Chiu and Elizabeth Long (Spring 2011).Agriculture (A), Banana Trees (B), Colonizing Species (C), Dried Stream (DS), Primary Forest (PS), Secondary Forest (S), Secondary Forest High Growth (SH) and Tree Fern (TF)

Meter Primary Secondary Tertiary mark vegetation vegetation vegetation Comments 0 Road 20 SH 40 SH 60 SH TF 80 SH 100 SH TF 120 TF 140 SH 160 SH 180 C 200 B C TF DS 220 C DS 240 SH 260 TF SH DS 280 A 300 A 320 A 340 SH 360 SH 380 SH 400 SH 420 SH 440 SH 460 SH 480 SH 500 SH 520 SH 540 SH 560 SH

580 SH TF 600 SH 620 SH TF 640 SH C 660 SH 680 TF SH 700 TF 720 TF 740 TF 760 SH 780 TF SH 800 TF SH 820 SH 840 SH 860 SH 880 SH 900 TF C 920 TF C 940 TF 960 SH 980 TF SH 1000 TF SH 1020 TF 1040 TF 1060 SH 1080 SH TF 1100 TF SH 1120 SH TF 1140 TF 1160 TF 1180 TF 1200 SH P 1220 SH 1240 SH 1260 SH TF 1280 SH 1300 SH 1320 SH 1340 TF SH 1360 TF SH 1380 TF SH 1400 TF SH 1420 SH 1440 SH TF 1460 SH 1480 SH C 1500 SH TF 1520 TF SH

1540 SH 1560 SH C 1580 SH 1600 SH 1620 SH 1640 SH 1660 SH 1680 B SH 1700 SH 1720 TF B 1740 TF B 1760 SH B 1780 SH 1800 TF SH 1820 SH 1840 SH TF 1860 SH 1880 SH 1900 SH TF 1920 SH TF 1940 SH 1960 SH 1980 SH 2000 SH 2020 SH 2040 SH 2060 TF SH 2080 SH TF 2100 SH 2120 SH 2140 SH 2160 SH 2180 P SH TF 2200 SH TF P 2220 TF 2240 TF SH 2260 TF SH DS 2280 TF SH 2300 SH P 2320 SH P 2340 TF SH 2360 SH TF 2380 SH TF P 2400 TF 2420 TF 2440 SH TF P 2460 TF 2480 TF

2500 SH TF 2520 TF 2540 SH TF 2560 SH TF 2580 SH TF 2600 TF C 2620 TF SH P 2640 SH P 2660 SH P 2680 SH P 2700 SH P 2720 SH P TF 2740 SH P TF 2760 SH SH P 2780 SH P 2800 SH 2820 SH 2840 SH 2860 SH 2880 SH P 2900 SH 2920 SH 2940 SH 2960 SH 2980 SH 3000 SH