Ambystoma opacum byTim Halliday ISSN 1026-0269 FROGLOG Newsletter of the IUCN /SSC Amphibian Specialist Group (ASG)

December 2006, Number 78

amphibian species entering ponds individuals. Computer assisted Impacts of from clearcut versus forest habitats pattern-matching software clearcutting on across years. Of the 149,756 developed specifically for A. amphibians amphibians that were captured opacum by Lex Hiby of after 20 years and included in our analysis, 17 of Conservation Research Ltd. of forest re- 18 species at all ponds in all years (Cambridge, UK) drastically establishment migrated to ponds in significantly reduced the number of photo

By: Don R. Church, Henry M. smaller numbers from the clearcut comparisons that needed to be Wilbur and Larissa Bailey habitats than from the forest made by eye. Individuals had habitats associated with each overall high fidelity to their point of The long-term impacts of forestry pond. The one exception was the entry to and exit from a pond within practices on amphibian spring peeper, Hyla crucifer, which and across years. populations remain uncertain. was caught in significantly larger Using recently developed multi- Several studies in eastern North numbers entering from the clearcut state mark-recapture methods America have previously shown habitat at each pond. These (Bailey et al., 2004) and that clearcutting of upland forests results raised the question: Why multimodel inference (Burnham & results in a reduction in the number exactly do fewer amphibians Anderson, 2002) we found that of pond-breeding amphibians that migrate to ponds from clearcut survival probabilities within both migrate to breeding sites. habitats after 20 years of forest breeding and non-breeding However, in general, deciduous reestablishment? The answer to seasons varied among years, forests of eastern North America this question has important populations, and between habitats. are considered relatively resilient implications for how amphibian Annual survival probabilities ranged to logging. A remaining question populations should be managed in from nearly 1 to 0.25 in females and therefore is how amphibian landscapes where forestry is from nearly 1 to 0.48 for males. One populations respond to forest practiced. Competing hypotheses consistency in survival probabilities reestablishment – a process that is among populations was that both include: underway in over 100 million 1) Low counts of animals may female and male salamanders hectares in eastern North America simply reflect historical effects of experienced dramatic mortality alone. initial tree harvesting on during the non-breeding season in a We explored this question in an demographic parameters (i.e., drought year (2001-2002). Interestingly, a previous analysis amphibian assemblage that utilizes populations in clearcuts have not (Church et al., in press) revealed a system of natural sinkhole ponds yet rebounded from mortality, within the George Washington and that the sympatric tiger salamander reduced reproduction, or habitat (Ambystoma tigrinum) did not incur Jefferson National Forest in biased movements that occurred Virginia, USA. Between September high mortality during the non- 20 years ago). breeding season of the drought year 1999 and August 2004, we 2) Survival, annual breeding monitored populations of 18 pond- suggesting that these species differ probability or fecundity remains in their vulnerability to dry conditions breeding amphibian species at 3 reduced in clearcuts. or in what microhabitats they utilize ponds, each approximately 330 3) Animals avoid clearcuts via their in the upland habitats. meters in circumference, using drift movements even after partial Unexpectedly, habitat differences fences, with pitfall traps at 10 forest reestablishment. in survival were overall not meter intervals that completely 4) Combination of above factors. consistent across time or among encircled each pond. Two types We have begun to address populations. Survival probabilities of matrix – a clearcut that was these competing hypotheses with varied such that probabilities were logged in 1989 (hereafter referred a capture-recapture study of sometimes lower and sometimes to as clearcut) and forest that has marbled salamander (Ambystoma higher in clearcut habitats. This not been logged since the early opacum) populations that are finding indicates that survival is 1900’s (hereafter referred to as associated with each pond. We influenced by complex interactions forest), surround each pond in used photos of natural markings among habitat variables, similar proportions. We compared on the dorsal surface of A.opacum populations and climate. the per-pitfall trap counts of each to reconstruct capture histories of

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Breeding probabilities varied Burnham, K. P., and D. R. The environmental problems in among populations and were Anderson. (2002). Model selection Xochimilco are considered to have found to be Markovian (dependent and multimodel inference: a reduced axolotl populations. In six on whether or not an individual practical information-theoretic years (from 1998 to 2004), axolotl bred in the previous year), ranging approach. 2nd Edition. Springer- density has reduced from 0.006- 2 from 0.22 to 0.52 for animals that Verlag, New York, New York, USA. org/ m to 0.001-org/ m2 had bred the previous year and 488 pp. (Zambrano et al., 2004). This from 0.63 to 0.86 for animals that Church, D.R., L.L. Bailey, H.M. reduction could also be related to had skipped breeding for at least Wilbur, W.L. Kendall &J.E. Hines. its own population dynamics. As one year. Breeding probabilities Iteroparity in the variable egg production is quite high (more also differed between clearcut and environment of the salamander than one thousand eggs are laid forest habitats within each Ambystoma tigrinum. Ecology ( in by healthy females), it suffers from population – they were lower for press). elevated mortality within the first animals entering ponds from For further information please year. These factors have caused clearcuts at two populations by contact Don Church at: some prominent fluctuations in more than 30% but higher at the [email protected] axolotl population dynamics over

third population by 29%. the years. These fluctuations Movement probabilities among The Mexican produce high population declines the 3 populations were low Axolotl in some years, but also large (<0.001-0.08). In contrast, (Ambystoma increments in others, causing low movements between forest and mexicanum) extinction probabilities. However, clearcut habitats within populations By Luis Zambrano extinction probabilities can rise up were often high and heavily biased to 100% in the next 50 years if the The Mexican axolotl (Ambystoma towards leaving clearcuts in favour mortality rate of eggs and larva mexicanum) is endemic to the of forest habitat in two populations increases to less than 5% Mexican high plateau and has a but marginally in favour of (Zambrano et al., submitted). recent evolutionary history (less clearcuts in the same population Reductions in egg and larvae than 10 thousand years). For where clearcut animals had higher survival rates are related to the centuries it inhabited the large breeding probabilities. female’s capacity to lay eggs. wetlands that used to occupy most The reasons for these Studies have shown that axolotls of the Mexican Valley. Today, its differences in clearcut effects have particular preferences for distribution has been reduced to among populations remains laying eggs on plants that help to only two remaining water bodies: unclear but may be due to different create more spatial heterogeneity Xochimilco and Chalco. Both geologies underlying the clearcuts (Martinez, 2007). Plants that systems have been under pressure areas. Differences in alluvial provide shadows and holes where from human activities. Chalco was rubble in the landscape are known eggs and larvae can hide and find dry for many years reducing water to influence local hydrology of food are preferred, suggesting that as a result of a reduced water ponds (nearby ponds fill and dry females search for places where table, leaving only a few small on very different schedules) and their eggs will have better survival ponds for the species to survive in. may also create differences in the rates. However, pollution and bank Fortunately, in recent years this quality of habitats for the erosion have decreased the small water system has been subterranean lifestyle of marbled number of suitable locations and growing due to a lake restoration salamanders. Overall, our results structures for laying eggs. This programme to avoid dust storms so far indicate that forest results in the possibility of reduced and axolotls have been seen. clearcutting can have major reproduction rates. Xochimilco has been under impacts on some demographic Another threat which has been pressure as a source of water parameters even after 20 years but increasing in the last few years is since the Aztecs first settled in the that other landscape features may the biomass of introduced carp area in XIII AC. Today, Xochimilco override these effects under and tilapia - 80 times higher than receives water from a water certain conditions. A complete the biomass of native organisms treatment plant instead of natural answer to the question of whether within Xochimilco: carp eat axolotl springs and suffers from domestic these differences in demography eggs, while tilapia prefer to eat sewage. In addition, increased account for the differences in recently hatched axolotl larvae. tourist activity is poorly regulated abundances in animals between Therefore, the risk of predation of and adds further pollution. habitats awaits population axolotl eggs and larvae by these Introduced species of carp and projections. two exotic species is high and has tilapia (which are now considered been increased by the reduction of References: pests) are a further threat creating the spatial heterogeneity where Bailey, L. L., W .L. Kendall, D. R. erosion problems on banks, by axolotls can hide from their Church & H. M. Wilbur. (2004). their feeding and reproduction predators. These introduced Estimating survival and breeding behaviour changing the trophic species may also affect adult probabilities for pond-breeding web structure, and reducing spatial survival. The large amount of carp amphibians using multi-state heterogeneity. models. Ecology 85:2456-2466. and tilapia has modified the trophic

2 web and with this, the type of food better policies for axolotl ([email protected]) that axolotls normally eat. conservation. Using both scientific Werner, J. K., Heinz, G. & Axolotls are visual predators and local knowledge, this group Lichtenberg, J. (2006) The status and hunt small fish and insects, has created new programmes for of two northern leopard frog but as the tilapia and carp are environmental education. To date, populations in western Montana. competing for the same resources, more people are getting involved in Herpetol. Rev. 37: 325-330. research shows that the axolotl the project and local authorities are ([email protected]) # has switched its feeding habits to generating new concerns for Tim Halliday

include small chironomids and conservation, which we hope will algae (Valiente-Riveros, 2006). result in improved conservation The 12th a Apparently, this has produced action for the Mexican axolotl and meeting of the smaller axolotls with possibly its habitat. African reduced survival capacity. Studies References: Amphibian reflect this in the reduction of Working Group Contreras, R. E. A. V. (2006). axolotl distributions within Distribución potencial del (AAWG)

Xochimilco (Contreras, 2006). Ambystoma mexicanun en los By Mark-Oliver Rödel, Johannes Not all the channels, lakes and canales de la zona chinampera de Penner, S. Gilles Armel Nago wetlands that comprise the Xochimilco. Tesis de Licenciatura and Brice Sinsin Xochimilco water system are en Biología. UNAM-México pp. 49 th The 12 meeting of the African suitable habitat for the axolotl. It Martínez, A. I. 2007. Sitios de Amphibian Working Group seems that they can only survive in reproducción del ajolote (AAWG) was held from the 14-17 channels and lakes with particular (Ambystoma mexicanum). Tesis of August 2006 at Abomey, Benin, characteristics, such as higher de Licenciatura en Biología, West Africa. After the meeting, transparency, higher salinity UNAM-México. In preparation. most participants joined an concentrations and less Valiente-Riveros, E. (2006). Efecto Amphibian Workshop in the abundance of exotic species. de las especies introducidas en Pendjari National Park from 19-22 Currently, from the 180 km of Xochimilco para la rehabilitación August. channels which comprise the del habitat del ajolote (Ambystoma The AAWG is a loosely system, there are only about five mexicanum). Tesis de Maestría en connected (no official association) areas with a longitude smaller than Restauración. UNAM-México. pp. group of people interested in all 10 km that seem suitable for Zambrano, L. V. H. Reynoso and kinds of research concerning permanent axolotl populations. G. Herrera. (2004). Abundancia y African amphibians and is open to The future of the axolotl’s estructura poblacional del ajolote everyone. The meeting is held at survival in the wild is uncertain. (Ambystoma mexicanum) en los irregular intervals, mostly every 2-4 However, this organism has sistemas dulceacuícolas de year, at varying places. The last suffered from human activities for Xochimilco y Chalco. Informe de la meeting took place from 19-21 centuries and has always CONABIO. AS004. México. April 2002 in Watamu, Kenya and managed to survive. This has was, apart from South Africa, the given a little hope for many Zambrano, L, G. Herrera, E. Prado first in a sub-Saharan African researchers that are now involved and V. H. Reynoso. A population country. This year’s meeting was in studying the axolotl in order to matrix model and PVA for the the first in West Africa and was ensure its conservation within its management of Ambystoma mexicanum) (Submitted). organized by us with the financial own environment. The group is support of the former Declining called GIAX (The Axolotl Research For further information please Amphibian Populations Task Force Group-Xochimilco) and has been contact: Luis Zambrano at: (DAPTF), The German formed by researchers from [email protected] or Herpetological Society (DGHT), different academic and visit the GIAX web page: http://ajolote.ibiologia.unam.mx/ Christina Richards and the governmental institutions of Mexico

Biodiversity Monitoring TTransect such as the Institute of Biology- DAPTF Seed Grants Analysis in Africa (BIOTA).

UNAM, Centro de Investigaciones Africa can still be regarded as a Biologicas y Acuicolas de Recipients of Seed Grants from the continent that is very much Cuemanco (CIBAC), UAM- former DAPTF are generally neglected, in terms of Xochimilco, Chapultepec Zoo, expected to publish the results of herpetological research, compared CONABIO and international their projects in refereed journals, to regions such as South America. organizations such as The Durrell or as articles in Froglog. The In addition, most research on Institute for Conservation and following papers report work African amphibians has been Ecology (DICE), The (former) supported by previous DAPTF Seed Grants: conducted by European, American Declining Amphibian Populations and South African researchers. Task Force and The IUCN/SSC Gower, D. J., Oommen, O. V. & Therefore, the specific aim of this Amphibian Specialist Group Wilkinson, M. (2006). Marking meeting was to support and (ASG). With the help of local amphibians with alpha numeric enhance the herpetological people, GIAX continues to fluorescent tags: caecilians lead capacity of students originating generate information to create the way. Herpetol. Re.: 37: 302.

3 from tropical African countries. We the future produce autochthonous Frogs and Other Amphibians raised funds to partially cover herpetologists and thus catch up travel and conference costs and with other tropical regions of the Photography: Paul Starosta offered a post-conference world. Text: Teddy Moncuit workshop in the savannah region We are especially grateful to From tiny, exquisitely coloured of the Pendjari National Park, the above listed donors, without frogs to immense toads, the northern Benin. their support this conference would creatures featured in this book The participants comprised not have been possible; to all represent some of nature’s most researchers and graduate students senior herpetologists who remarkable examples of from ten countries: Benin, successfully motivated the decoration, self-defence, and Cameroon, Germany, Ivory Coast, students throughout the adaptability. However, more than Kenya, Netherlands, Nigeria, conference and workshop and just a visual showcase for nature’s South Africa, Switzerland and the were willing to dedicate their genius, the introductory and United States of America. The limited time for teaching; to the accompanying texts also bring to conference was held in Abomey, University Abomey-Calavi for the light the frighteningly delicate the old capital of the formerly support with various technical balance in which the survival of all famous West African kingdom of equipment and local knowledge amphibians hangs. This book Dahomey, and covered topics and the Pendjari Park Project for serves to highlight both the beauty including: the outcome of faunistic allowing housing and field trips in and often-extraordinary abilities of surveys, taxonomic and the Pendjari area. these creatures, and their tragic phylogenetic investigations, human A Mertensiella volume plight. influence on amphibians by habitat (published by the German conversion and degradation, Herpetological Society) will be Job Announcement conservation of amphibian devoted to the conference Executive Officer, Amphibian communities as well as of contributions, but will be also open Specialist Group (ASG) particular species, amphibian for other papers on African and diversity, macro-ecology and Malagasy amphibians. For more The Amphibian Specialist Group distribution, amphibian decline and details please contact M.-O. Rödel (ASG) is seeking a conservation chytrid fungus, amphibian or check the webpage mentioned leader who can take on the global parasites and nutrition (of frogs below. The next AAWG meeting amphibian decline within the broader context of the biodiversity crisis. The and human frog consumption). The will be held in 2008 in Tanzania. ASG, a unit of the IUCN Species participants also gained a valuable Kim Howell, Charles Msuya, and Survival Commission, strives to first impression of the diversity of Wilirk Ngalason will be arranging conserve biological diversity by West African frogs throughout a this meeting that very probably will stimulating, developing, and conference field trip to the semi- take place in Arusha. executing practical programs to deciduous Lama forest and the For further information please study, save, restore, and manage permanently inundated Lokoli contact: [email protected] amphibians and their habitats forest. wuerzburg.de or online at: around the world. The ASG is taking The Pendjari workshop covered http://www.biozentrum.uni- IUCN’s Specialist Group model to topics and activities including: an wuerzburg.de/amphibien_worksho the next level of effectiveness introduction to West African p0.html through the establishment of a savannah amphibians through Secretariat that will serve as a dynamic hub to coordinate a global various field trips; the collecting Froglog Shorts and preserving of frogs to establish web of stakeholders and to leverage voucher and reference collections; the intellectual, institutional, and Helping toads across the road tissue sampling for genetic financial capacity towards shared, investigations; swabbing frogs for European toads (Bufo bufo) die in strategic amphibian conservation chytridiomycosis and checking huge numbers on Europe's roads goals. The Executive Officer will be tadpoles for respective symptoms; and motorways; it is estimated that responsible for coordinating the activities of the ASG to ensure a collecting and processing acoustic a toad has only a 5% chance of unified, strategic and sustainable data, collecting and processing crossing a motorway alive. A approach to global amphibian frog parasites; the collecting of beautifully-produced DVD, Vida de Sapo, examines this problem and conservation, effecting policy change qualitative and quantitative field and communicating the work of data (adults and tadpoles); and describes the measures taken by a group in Spain to reduce toad the ASG to raise the profile of collecting abiotic data (e.g. amphibian issues in the public temperature) for ecological studies. mortality on one stretch of road. The commentary is in Spanish and arena. For further details please see We believe the conference was the full job announcement: English. The DVD is available a great success as more than half http://www.parcplace.org/2006-03- from: Oficina de Medio Ambiente, of the participants were graduate 24CI.htm students, mostly coming from West Universidade de Vigo, Campus Universitario, 36310 Vigo, Spain. FROGLOG is the bi-monthly and East African countries. Its newsletter of the IUCN / SSC success also provides hope that Tim Halliday Amphibian Specialist Group this still neglected continent will in

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