Selous – Mikumi Census Report

Home , Mikumi National Park, Selous Game Reserve

Systematic Reconnaissance Flight (SRF) Census Report

Aerial Census in the Selous-Mikumi Ecosystem, Dry Season 2018

Conducted by

TANZANIA WILDLIFE RESEARCH INSTITUTE

CONSERVATION INFORMATION AND MONITORING UNIT The Government of the United Republic of Tanzania Ministry of Natural Resources and Tourism Government City, Mtumba P.O. Box 1351-40472 – DODOMA

and

Frankfurt Zoological Society (FZS) P.O. Box 14935 Arusha Tanzania Contact: +255 739 985 768/9

To obtain a copy of this report please contact:

The Director General, Tanzania Wildlife Research Institute P.O. Box 661 Arusha, Tanzania Tel: +255 27 254 9571

Email: [email protected]

Citation: TAWIRI (2019) Aerial Wildlife Survey of Large Animals and Human Activities in the Selous-Mikumi Ecosystem, Dry Season 2018. TAWIRI Aerial Survey Report

Cover photo: Elephants Crossing, ©Robert.J.. Ross The successful implementation of the Selous-Mikumi ecosystem aerial survey was a product of thorough planning, hard work, and good collaboration between government and non-governmental partners. The following partner institutions collaborated with TAWIRI for implementation of the survey:

WILDLIFE DIVISION Wildlife Division works to develop and supervise Government City, Mtumba the implementation of conservation policy, law, P.O. Box 1351, and regulation in the wildlife sector 40472 – DODOMA email: [email protected]

TANZANIA NATIONAL PARKS Tanzania National Parks (TANAPA) was P.O. Box 3134, Arusha established in 1959 to manage and regulate the email: [email protected] use of areas designated as National Parks.

TANZANIA WILDLIFE TAWA established by Ministerial order in 2014 MANAGEMENT AUTHORITY to sustainably conserve and utilize wildlife Dar-es-Salaam Road resources in Game Reserves, Game Controlled Kingolwira Area Areas and open areas. P.O.Box 2658, Morogoro email: [email protected]

NGORONGORO Ngorongoro Conservation Area Authority CONSERVATION AREA (NCAA) established in 1959 cooperates with AUTHORITY indigenous residents in conserving the natural P.O. Box 1 Ngorongoro Crater, and historical resources of this World Heritage Arusha Site. Contact: [email protected]

FRANKFURT ZOOLOGICAL Frankfurt Zoological Society (FZS) is an SOCIETY international NGO working to conserve wildlife P.O. Box 14935 and ecosystems and has been present in Arusha, Tanzania Tanzania since 1959. Contact: [email protected] TAWIRI

EXECUTIVE SUMMARY

This report presents results of an aerial wildlife survey of large animals and human activities covering the Selous-Mikumi ecosystem in Southern Tanzania. The survey was conducted from the 21st October to 24th November 2018 with funding from the Government of Tanzania and German Development Bank (KFW) through the Frankfurt Zoological Society (FZS). The main objective of the census was to establish the population status and geographical distribution of large animals and human activities in the Selous – Mikumi ecosystem. The survey covered a total area of 104,143 km² with a total of 465 transects. Mean height above ground for all aircraft was 351±59 feet, and the average ground speed was 172 ± 14 km/h. Twenty-seven (27) wildlife species were recorded in the survey area. Among these, there were twenty-five (25) mammal species, one reptile and one avian species. The most abundant species was buffalo (66,546 ± 11,470 SE) followed by hippo (31,086 ± 4,934 SE), kongoni (23,250 ± 2,853 SE), wildebeest (22,740 ± 3,330 SE), zebra (22,690 ± 2698), impala (19,296 ± 3,124 SE), warthog (17,475 ± 1,469 SE) and elephant (15,501 ±1,819 SE). On the other hand, the least abundant species were a bushpig (1,208 ± 342 SE), and puku (1,579 ± 586 SE). Furthermore, other species counts were very low to generate statistically meaningful results. These include bushbuck, wild dog and hyena. Notably, one rhino was observed during this survey (Table 3), a fortunate sighting. Key findings:

• The Selous-Mikumi elephant population is stable at about 15,500 animals based on recent censuses (2014 and 2018). No fresh carcasses (less than one-year-old) were recorded and the carcass ratio dropped from 39% in 2014 to 16% in 2018, indicating significant management intervention of curbing poaching. More effort and time is needed to reach 8%, which represent natural mortality. • Conservation of puku needs deliberate efforts before it is too late for recovery of the population in the Kilombero Valley. The population has declined by 97% from over 50,000 in 1998 to less than 3,000 in 2018. • The Nyasa wildebeest need close monitoring following a decade decline. The average population estimate from 1994 to 2006 was around 69,000 wildebeest but from 2009 to 2018 the average population estimate declined to around 19,000 individuals; approximately a 72% decline between the two decades, which needs attention. • Most of the estimated livestock was recorded in the Kilombero valley (cattle 436,360 ± 60,426 SE and shoats 96,477± 21,695 SE), which is more than 60% of the total estimate in the ecosystem (678,303 ± 73,205 SE cattle and 171,893 ± 27,304 SE shoats).

TABLE OF CONTENTS

EXECUTIVE SUMMARY ______i TABLE OF CONTENTS ______ii 1 INTRODUCTION ______1 1.1 Survey Area ______4 2. METHODS ______5 2.1 Transect design and flight plan ______5 2.2 Data collection ______6 2.3 Census parameters and track-log ______7 2.4 Data Analysis ______10 3. RESULTS & DISCUSSION ______11 3.1 Wildlife Estimates for Selous-Mikumi Ecosystem ______11 3.2 Wildlife population trend ______12 3.2.1 Species with a declining trend ______13 3.2.2 Species with increasing trend ______13 3.2.3 Species with stable population trends ______13 3.3 Distribution and Density of Wildlife ______14 3.3.1 Buffalo estimates, distribution and density ______14 3.3.2 Impala distribution and density ______20 3.3.3 Hippo distribution and density ______22 3.3.4 Elephant distribution and density ______23 3.3.5 Elephant carcass distribution and density ______25 3.3.6 Kongoni (hartebeest) distribution and density ______27 3.3.7 Wildebeest distribution and density ______29 3.3.8 Zebra distribution and density ______31 3.3.9 Sable antelope distribution and density ______33 3.3.10 Eland distribution and density ______35 3.3.11 Waterbuck distribution and density ______37 3.3.12 Giraffe distribution and density ______39 3.3.13 Warthog distribution and density ______41 3.3.14 Duiker distribution and density ______43 3.3.15 Puku distribution and density ______44 3.3.16 Kudu distribution and density ______47 3.3.17 Large avian species distribution and density ______49 3.4 Human Activities in the Selous-Mikumi Ecosystem ______50 3.4.1 Human Activity estimates, Distribution and trends ______50 4. ACKNOWLEDGMENTS ______60 5. APPENDICES ______60 5.1 Annex 1. List of flight crew for the 2018 dry season aerial census ______60 5.2 Annex 2. List of ground crew for the 2018 dry season aerial census ______60 5.3 Annex 3. List wildlife species counted in the aerial census dry season, 2018 ______61 5.4 Glossary of Important Census Terminology ______62 6 REFERENCES ______64

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LIST OF TABLES Table 1. SRF surveys of wildlife in the Selous Ecosystem, 1976–2018 ...... 3 Table 2. Basic SRF census parameters, Selous-Mikumi ecosystem SRF 2018 ...... 8 Table 3. Wildlife and elephant carcass estimates in the Selous-Mikumi ecosystem ...... 12 Table 4. Wildlife population trend ...... 14 Table 5. Wildlife estimates per administrative area ...... 16 Table 6. An estimate of elephant carcasses in the census zone ...... 26 Table 7. Human activity estimates in the Selous-Mikumi ecosystem ...... 50 Table 8. Human activity estimates in administrative areas of the Selous-Mikumi ecosystem, dry season 2018...... 58 Table 9. Human activity trends in the Selous-Mikumi ecosystem, dry season 2018 ...... 60

LIST OF FIGURES Figure 1. Selous-Mikumi ecosystem and location in Tanzania (inset) ...... 2 Figure 2. Boundaries of administrative areas in the Selous-Mikumi ecosystem ...... 4 Figure 3. Transect design for the 2018 dry season aerial survey in the Selous-Mikumi ecosystem ...... 6 Figure 4. Track log of flown transects in the Selous-Mikumi ecosystem, 2018...... 9 Figure 5. Buffalo distribution and density in the Selous-Mikumi ecosystem, dry season 2018...... 18 Figure 6. Buffalo population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE) ...... 19 Figure 7. Map of impala distribution and density in Selous-Mikumi ecosystem dry season 2018...... 20 Figure 8. Impala population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 21 Figure 9. Map of hippo distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 22 Figure 10. Hippo population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 23 Figure 11. Elephant distribution and density in the Selous-Mikumi ecosystem, dry season 2018...... 24 Figure 12. Elephant population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 25 Figure 13. Elephant carcass distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 26 Figure 14. Map of kongoni distribution and density in Selous-Mikumi ecosystem, dry season 2018 ...... 27 Figure 15. Kongoni population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 28 Figure 16. Map of wildebeest distribution and density in Selous-Mikumi ecosystem, dry season 2018 ...... 29 Figure 17. Wildebeest population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 30 Figure 18. Map of zebra distribution and density in Selous-Mikumi ecosystem, dry season 2018 ...... 31 Figure 19. Zebra population trend in Selous-Mikumi ecosystem (vertical bars indicate SE)...... 32 Figure 20. Map of sable antelope distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 33 Figure 21. Sable antelope population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 34 Figure 22. Map of eland distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 35 Figure 23. Eland population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 36 Figure 24. Map of waterbuck distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 37 Figure 25. Waterbuck population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 38 Figure 26. Map of giraffe distribution and density in Selous-Mikumi ecosystem, dry season 2018...... 39 Figure 27. Giraffe population trend in the Selous-Mikumi ecosystems (vertical bars indicate SE)...... 40 Figure 28. Distribution and density of warthogs in Selous-Mikumi ecosystem, dry season 2018 ...... 41 Figure 29. Warthog population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 42 Figure 30. Distribution and density of duiker in Selous-Mikumi ecosystem, dry season 2018 ...... 43 Figure 31. Duiker population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)...... 44 Figure 32. Distribution and density of Puku in Selous-Mikumi ecosystem, dry season 2018...... 45 Figure 33. Puku population trend in the Selous-Mikumi ecosystem...... 46 Figure 34. Distribution and density of Greater kudu in the Selous-Mikumi ecosystem, dry season 2018 ...... 47 Figure 35. Greater Kudu population trend in the Selous-Mikumi ecosystem ...... 48 Figure 36. Distribution of large avian species in the Selous-Mikumi ecosystem...... 49 Figure 37. Distribution and density of cattle in Selous-Mikumi ecosystem, dry season 2018 ...... 51 Figure 38. Distribution and density of shoats in Selous-Mikumi ecosystem, dry season 2018 ...... 52 Figure 39. Distribution and density of settlements in Selous-Mikumi ecosystem, dry season 2018 ...... 53 Figure 40. Distribution and density of tree felling in the Selous-Mikumi Ecosystem ...... 54 Figure 41. Map of sawpits distribution and density in the Selous-Mikumi ecosystem ...... 56 Figure 42. Map of cultivation distribution and density in Selous-Mikumi ecosystem, dry season 2018 ...... 56

LIST OF APPENDICES 5.1 Annex 1. List of flight crew for the 2018 dry season aerial census ...... 6 5.2 Annex 2. List of ground crew for the 2018 dry season aerial census ...... 6 5.3 Annex 3. List wildlife species counted in the aerial census dry season, 2018 ...... 6 TAWIRI

LIST OF ABBREVIATIONS AND ACRONYMS

AGL Above Ground Level (measurement of aircraft altitude) CIMU Conservation Information and Monitoring Unit CITES Convention on International Trade in Endangered Species FSO Front Seat Observer FZS Frankfurt Zoological Society GCA Game Controlled Area GPS Global Positioning System GR Game Reserve IUCN International Union for Conservation of Nature KFW German Development Bank (Kreditanstalt für Wiederaufbau) MIKE Monitoring the Illegal Killing of Elephants NCA Ngorongoro Conservation Area NCAA Ngorongoro Conservation Area Authority NP National Park PA Protected Area RSO Rear Seat Observer SGR Selous Game Reserve SNC Selous Niassa Corridor SRF Systematic Reconnaissance Flight TANAPA Tanzania National Parks TAWIRI Tanzania Wildlife Research Institute TWCM Tanzania Wildlife Conservation Monitoring UNESCO United Nations Education, Scientific and Cultural Organization URT United Republic of Tanzania WD Wildlife Division WMA Wildlife Management Area

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1 INTRODUCTION TAWIRI in collaboration with Wildlife Division (WD), Tanzania Wildlife Management Authority (TAWA), Tanzania National Parks (TANAPA), Ngorongoro Conservation Area Authority (NCAA) and Frankfurt Zoological Society (FZS) conducted an aerial wildlife survey in the Selous-Mikumi Ecosystem during the dry season from the 21st October to 24th November 2018. This survey was funded by the German Development Bank (KFW) through the Frankfurt Zoological Society (FZS). The main objective of the census was to establish the population status and geographical distribution of large animals and human activities in the Selous – Mikumi ecosystem. The Selous-Mikumi ecosystem is located in southern Tanzania (Figure 1), and is comprised of various administrative areas: Mikumi National Park, Selous Game Reserve, Kilombero Game Controlled Area, and Selous-Niassa wildlife corridor. Other conservation areas include Wildlife Management Areas of Chingole, Iluma, Jukumu, Kisungule, Kimbanda, Mbarang’andu, Nalika –Tunduru, Ngarambe-Tapika, Liwale, and adjacent open areas (Figure 2).

Census specific objective: To provide the population estimates, trend and distribution of large animals and human activities in the Selous-Mikumi ecosystem by comparing results with previous estimates.

Previous censuses: Several systematic reconnaissance flight (SRF) surveys have been conducted in the Selous-Mikumi Ecosystem since the 1970s (Table 1). However, coverage of the census zones (surveyed areas) has varied considerably over this period from as small as 73,959 km² to as large as 105,730 km2 based on the understanding of the ecosystem.

Main features of the Selous-Mikumi Ecosystem

• Selous Game Reserve is a Natural World Heritage Site since 1982 (UNESCO, 1982; Lovett, 1998)

• Habitats within the ecosystem range from savannah grasslands and woodland to riverine vegetation and swampy area. Miombo woodlands are the dominant vegetation type comprised of Brachystegia, Julbernardia, Pterocarpus and Combretum species.

• High biological diversity with over 2,000 plant species, about 400 bird species and over 20 species of large mammals and reptiles (UNESCO, 1982). Additionally, it hosts the largest populations of buffalo and important range of elephants in Tanzania. However, little is known about the diversity of its smaller flora and fauna.

• The major rivers systems include the Rufiji, Great Ruaha, Luwegu, Kilombero, Luhombero, and Mbarang’andu.

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Figure 1. Selous-Mikumi ecosystem and location in Tanzania (inset)

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Table 1. SRF surveys of wildlife in the Selous Ecosystem, 1976–2018

Year Season Survey Area Area Source (km2) 1976 Wet Selous ecosystem excluding 73,959 Douglas-Hamilton (1976) Kilombero 1976 Dry Selous ecosystem excluding 74,131 Douglas-Hamilton (1976) Kilombero 1981 Wet North & Eastern Selous GR 19,550 TWCM (1981) 1981 Dry North & Eastern Selous GR 10,780 TWCM (1981) 1986 Dry Selous Ecosystem 74,000 Douglas-Hamilton (1986) 1989 Dry Selous Ecosystem 77,866 Tanzania WD (1989) 1991 Wet Selous-Mikumi ecosystem 78,551 TWCM (1991) 1994 Dry Selous-Mikumi ecosystem 91,981 TWCM (1994) 1998 Dry Selous-Mikumi ecosystem 98,725 TWCM (1999) 2002 Dry Selous-Mikumi ecosystem 94,009 TAWIRI (2002) 2006 Dry Selous-Mikumi ecosystem 80,883 TAWIRI (2008) 2009 Dry Selous-Mikumi ecosystem 80,390 TAWIRI (2009) 2013 Dry Selous-Mikumi ecosystem 87,421 TAWIRI (2013) 2014 Dry Selous-Mikumi ecosystem 105,730 TAWIRI (2014) 2018 Dry Selous-Mikumi ecosystem 104,143 This report

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1.1 SURVEY AREA

The Selous–Mikumi ecosystem is located in Southern Tanzania within latitude 6°53’39” to 11°45’36” South and Longitude 35°31’7” – 38°59’21” East. The census zone includes Mikumi National Park in the north and Selous Game Reserve in the center of the ecosystem. It also includes several WMAs in the east and south, the Selous-Niassa Corridor in the south, and the Kilombero Game Controlled Area located in the west of the ecosystem. Also, there are a number of wildlife open areas in the south, west, and east (Figure 2).

Figure 2. Boundaries of administrative areas in the Selous-Mikumi ecosystem

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2. METHODS The aerial census was conducted following the systematic reconnaissance flight (SRF) technique as described by Norton-Griffiths (Norton-Griffiths, 1978). A total count technique was used in the southern part of Mikumi National Park; a mountainous area where flying normal SRF transects was unsafe due to extremely rugged terrain. Three Cessna (206 and 182) aircraft (Table 2 and Appendix I) were used, each flying at a target height of 350 ft (about 100 m) above ground and a target speed of 175 km/h.

2.1 TRANSECT DESIGN AND FLIGHT PLAN

Transects were spaced at 2.5 km, 5 km and 10 km intervals with variable orientation due to the nature of the terrain, ecological gradient and aiming at maximizing the number of samples (Figure 3). Transects were a priori evenly subdivided into subunits of 2.5 km in length, typically 40 seconds of flying time and uploaded onto GPS units. On-transect navigation was maintained using GPS (Garmin 62S, 64S and 695) and a radar or laser altimeter (Lightware SF00).

SRF sample count methods followed the TAWIRI standards protocol including:

• Selecting crews with knowledge of wildlife species

• Testing of the crew on visual acuity and color blindness before departing for fieldwork.

• Selection of observers depended on the experience of individuals. Training flights included a minimum of two (2) sessions for experienced observers and three (3) sessions for new observers.

• Transect flight times ranged from a minimum of 10 to a maximum of 30 minutes.

• Counting sessions (on transect time) did not exceed 3 hours and 30 minutes from start to finish, with most being less than or equal to 3 hours.

Wildlife and human activities were recorded as per TAWIRI census standard protocols. Observers were instructed to take photographs of all groups and carcasses of elephant, and all animal groups with more than 10 individuals. Individual animals in the photographs were counted on the same day of the flight to ensure easy recall of data.

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Figure 3. Transect design for the 2018 dry season aerial survey in the Selous-Mikumi ecosystem

2.2 DATA COLLECTION The survey crew consisted of four individuals in each aircraft (Annex 1). The Pilot navigated the aircraft following a survey plan that was uploaded into the GPS prior to the flight. Front Seat Observers (FSO) were responsible for the inflight recording of transect metadata including the beginning and end points of each transect, the beginning and end time of each transect, flight height above ground using a radar or 6

TAWIRI laser altimeter in each subunit, presence or absence of water and extent of burnt areas. The FSO also announced the subunit identification numbers to the rear seat observers.

Left and right Rear Seat Observers (RSOs) counted and recorded on digital recorders all observations of wild animals and human activities sighted in each sub-unit along the transect. Photos of large groups of more than ten individuals were taken during the survey. The RSOs transcribed recorded data onto data- sheets after each flight session. Counting was confined to a sample area defined by streamers attached on the wing strut on each side of the aircraft with a target width of 150m on the ground. The geographical position of every subunit as called-out by the FSO was recorded together with its observations and subsequently transcribed on data sheets.

Observed elephant carcasses were recorded using categories recommended by the MIKE-CITES program (IUCN, 1998; Craig, 2012), which specifies characteristics to assign carcass classes (1-4) and approximate ages (time period since the death of the animal):

• Carcass I (EC1): Fresh (<1 month). Still has flesh giving the body a rounded appearance. Vultures probably present and ground still moist from body fluids.

• Carcass II (EC2): Recent (<1 year). Rot patch and skin still present. Skeleton not scattered.

• Carcass III (EC3): Old (>1 year). White bones, the skin usually absent, vegetation regrow in rot patch.

• Carcass IV (EC4): Very old (up to 10 years). Bones scattered and turning grey.

2.3 CENSUS PARAMETERS AND TRACK-LOG Transects were designed and maintained for each session flown by each aircraft (Figure 3 and Figure 4). A total area of 104,143 km² was surveyed in 465 transects (Table 2). Mean height above ground for all aircraft was 351±59 feet, and ground speed averaged of 172±14 km/h (Table 2). Transect strip widths were maintained at an average of 150m on each side of the aircraft (Table 2). Majority of transects were flown in East-West direction, although three blocks were flown in North-South and one flown in North- West/South-East directions. A total count (search method) was applied in the south of Mikumi National Park, a mountainous area (Figure 4). Few pockets were not covered due to increased human activities in particular north of Liwale town and Outside South (Mwambesi). The area north of Ilonga (Outside West- Mbarika) was not flown due to low cloud. In Lukwika-Lumesure GR only four transects covered the area.

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Table 2. Basic SRF census parameters, Selous-Mikumi ecosystem SRF 2018

Parameters 5H-CFA 5H-RKE 5H-ZGF COMBINED Survey area (km²) 27,358 32,588 44,197 104,143 Sample Areas (km²) 1,393 1,853 2,146 5,392 Transect distance 4,646 5,867 8,185 18,698 Total number of transects 124 158 183 465 Total number of subunits 1,996 2,404 3,335 7,735 Sample Fraction % 5.1% 5.7% 4.9% 5.2% Flying height: Mean 376 358 332 351 ±59 Standard Deviation 77 54 42 59 Minimum 210 211 209 Maximum 840 520 597 Strip width Left 151 160 134 - Right 150 156 129 - Total 300 316 262 - Average Ground speed (km/h) 194 168 172 172 ±14

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Figure 4. Track log of flown transects in the Selous-Mikumi ecosystem, 2018.

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2.4 DATA ANALYSIS

Collected data were entered into Microsoft Excel and analyzed using Jolly’s unequal sample size method 2 (Jolly, 1969; Norton-Griffith, 1978) to calculate the population estimates. Population trends were plotted and d-test was used to determine whether the change was significant (Cochran, 1954). Species densities and distribution, as well as human activities, were mapped using QGIS 3.6

A carcass ratio is an index that is used to ascertain whether mortality in the elephant population is unnaturally high (Douglas –Hamilton & Burrill 1991). The carcass ratio is calculated from the proportion of dead to live + dead elephants using the following formula:

Carcass ratio: ! *100 (#$!) c is for number of carcasses counted, E number of live elephants counted

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3. RESULTS & DISCUSSION Estimates and distributions of wildlife populations and human activities are presented in this section. Estimates are compared to previous comparable estimates (relative to census area) to show trends over time. Estimates are presented as two figures: the likely population size +/- the statistical variation expressed as standard error (SE). For example, hippopotamus 31,086 ±4,934 SE. The standard error indicates the confidence in the estimate – indicating that if the survey were repeated, the new estimate would be within the range of the estimate plus or minus the SE value. Estimates are presented as totals for the entire survey area and thereafter subdivided by administrative blocks/areas (Figure 2). Distributions are presented in maps, the geographical range of animals and activities observed:

• Density, indicated by shades of colors which are darker where higher concentrations of animals were calculated;

• Point observations (dots) indicating locations where observations were made. Note on accuracy: Aerial survey methods are excellent for surveying large areas, open habitats, and larger animals, but provide poor results for smaller or more cryptic animals and some human activities. Carnivores (largely nocturnal and usually camouflaged), primates and smaller animals such as bush pig and duiker are seen in smaller proportions to their true numbers, and their estimates represent ‘minimum’ likely populations. However, trends over time are still valuable for some species, and distribution maps show important patterns in presence and absence.

• Where very few observations were made of a given species (less than 10), no estimate is presented due to the uncertainty in the estimation.

• Human activities are well assessed where there are discrete groups or points of activity (livestock herds or saw pits, for example) but poor where the area covered by an activity (farms) or defining a ‘unit’ (roofs may represent individual homes or outbuildings or commercial structures) is difficult. Trends are often not representative for farming and settlements, and maps of distribution are more valuable.

3.1 WILDLIFE ESTIMATES FOR SELOUS-MIKUMI ECOSYSTEM Twenty-seven (27) wildlife species were recorded in the survey area. Among these, there were twenty-five (25) mammal species, one reptile and one avian species. The most abundant species was buffalo (66,546 ± 11,470 SE) followed by hippo (31,086 ± 4,934 SE), kongoni (23,250 ± 2,853 SE), wildebeest (22,740 ± 3,330 SE), zebra (22,690 ± 2,698), impala (19,296 ± 3,124 SE), warthog (17,475 ± 1,469 SE) and elephant (15,501 ± 1,819 SE). On the other hand, the least abundant species were a bushpig (1,208 ± 342 SE), and puku (1,579 ± 586 SE). Furthermore, other species were very low in number to generate

TAWIRI meaningful results. This includes bushbuck, wild dog and hyena. Notably, one rhino was observed during this survey (Table 3); a fortunate sighting.

Table 3. Wildlife and elephant carcass estimates in the Selous-Mikumi ecosystem

Species Counts Estimate S.E. ± Buffalo 3,604 66,546 11,470 Hippo 1,691 31,086 4,934 Kongoni / hartebeest 1,272 23,250 2,853 Wildebeest 1,270 22,740 3,330 Zebra 1,264 22,690 2,698 Impala 1,032 19,296 3,124 Warthogs 947 17,475 1,469 Elephant 850 15,501 1,819 El. carcass – old 30 550 108 El. carcass - very old 133 2,416 239 Duiker (many spp) 528 11,021 741 Ground hornbill 305 6,025 614 Eland 304 5,541 2,061 Sable antelope 286 5,921 1,201 Reedbuck 231 4,223 1,454 Waterbuck 221 4,049 850 Kudu, greater 125 3,035 1,215 Giraffe 107 1,858 461 Puku 88 1,579 586 Baboon 81 1,584 440 Bushpig 64 1,208 342 Bushbuck 19 370 118 Crocodile 19 348 127 Wild dog 15 274 266 Vervet monkey 14 250 177 Hyaena 3 Dik dik 2 Jackal 2 Rhino 1

3.2 WILDLIFE POPULATION TREND In order to determine wildlife population trends in the Selous-Mikumi ecosystem, a d-test was carried out to compare wildlife population estimates derived from dry season censuses conducted in 2014 and 2018. Results showed that of the 18 wildlife species which were tested, 16 indicated stable population trends. Duiker and warthog were the only species which showed increasing population trends in the Selous ecosystem (d-test >2). 12

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3.2.1 SPECIES WITH A DECLINING TREND None of the tested species showed significant declining trend compared to 2014 estimates (Table 4). However, it is important to note that puku shows a near-significant decline (d =-1.46, p < 0.15) and their range is apparently strongly affected by human activities in the Kilombero area (Figure 32, Figure 37, Figure 38). ). Puku have declined by 97% from 50,000 in 1998.

3.2.2 SPECIES WITH INCREASING TREND Duiker (all species combined) population estimates of 2018 (11,021 ±741 SE) was significantly higher compared to that of 2014 (6,502 ± 559 SE) (d = 4.87, p<0.05, (Table 4). This may represent a significant increase in the population. Note that duiker is difficult to see from the aircraft, and may be confused with other small antelope such as dik-dik, suni or Sharpe’s grysbok. Warthog population estimates increased significantly from 7,977 (± 740 SE) in 2014 to 17,475 (±1,469 SE) in 2018 (d = 5.77, p<0.05) (Table 4).

3.2.3 SPECIES WITH STABLE POPULATION TRENDS Most wildlife species showed stable populations between 2014 and 2018 wildlife surveys (Table 4).

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Table 4. Wildlife population trend Year 2014 2018 Area 105,730 km2 104,143 km2 Species Name Estimate SE Estimate SE d-test Duiker 6,502 559 11,021 741 4.87** Warthog 7,977 740 17,475 1,469 5.77** Baboon 1,507 609 1,584 440 0.10 Buffalo 81,554 14,228 66,546 11,470 -0.82 Eland 5,124 1,288 5,541 2,061 0.17 Elephant 15,217 1,760 15,501 1,819 0.11 Giraffe 3,183 1,874 1,858 461 -0.69 Hippo 23,243 5,483 31,086 4,934 1.06 Impala 23,651 4,206 19,296 3,124 -0.83 Kongoni 20,748 2,335 23,250 2,853 0.68 Kudu 1,299 316 3,053 1,215 1.40 Puku 3,145 901 1,579 586 -1.46 Reedbuck 1,523 397 4,223 1,454 1.79 Sable 6,816 1,157 5,921 1,201 -0.54 Waterbuck 4,347 1,100 4,049 850 -0.21 Wildebeest 17,099 5,131 22,740 3,330 0.92 Zebra 16,500 2,405 22,690 2,698 1.71 ** Significant increase Note that, as per the earlier comment on SRF accuracy, trends and d-tests may not be reliable for smaller or cryptic species. Observations of these species may be susceptible to changes in ground cover (colour or height of vegetation).

Puku has shown a dramatic decline over the past 20 years from over 50,000 in 1998 and based on trends this species could possibly become locally extinct in the Selous ecosystem if action is not taken (refer Puku section).

3.3 DISTRIBUTION AND DENSITY OF WILDLIFE Observations were subdivided by administrative blocks used to aggregate wildlife and activity estimates (Table 5).

TAWIRI Table 5. Wildlife estimates per administrative area

Administrative Area Selous-Niassa Corridor Kilombero GCA Kilombero south (Outside west Outside southeast (Liwale) Lukwika-Lumesule (Outside Mikumi NP Outside Mikumi west (Mahenge)) south (Masasi)) Species Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± 1 Buffalo 12 234 206 12 217 205 318 5,290 4,420 3 55 40 62 1,003 730 2 Hippo 2 33 32 7 290 282 3 Kongoni / hartebeest 14 273 223 17 278 121 273 5,025 1,311 4 Wildebeest 10 195 191 7 129 125 222 3,593 1,461 5 Zebra 17 332 148 79 1,454 546 176 2,848 1,600 6 Impala 3 95 78 54 994 518 39 1,617 1,854 213 3,447 1,454 15 263 251 7 Warthogs 17 495 202 19 350 188 209 3,847 635 7 290 333 10 162 100 8 Elephant 29 602 258 46 847 481 51 825 345 9 Duiker (many spp) 82 2,616 385 174 3,203 478 11 456 133 2 32 22 10 Ground hornbill 25 796 250 3 89 99 40 736 204 3 124 143 11 Eland 12 196 185 115 2,117 1,782 4 65 63 12 Sable antelope 45 1,604 833 26 425 225 16 259 231 13 Reedbuck 3 55 54 14 Waterbuck 1 38 37 7 114 51 3 55 39 El. carcass - very old 3 59 40 1 16 16 20 368 79 8 129 70 1 18 17 15 Kudu, greater 10 377 311 44 810 357 24 995 1,087 16 Giraffe 47 761 349 1 18 17 17 Puku 81 1,464 580 6 98 81 18 Baboon 14 291 212 12 249 168 2 37 36 2 83 79 19 Bushpig 3 113 82 11 202 148 6 97 79 El. carcass - old 1 20 19 7 129 62 20 Bushbuck 6 110 65 1 41 48 21 Crocodile 22 Wild dog 23 Vervet monkey 3 55 39 24 Hyaena 25 Dik dik 26 Jackal 27 Rhino

TAWIRI Outside Mikumi west Administrative Area Outside east (Ngarambe- Outside west (Mbalika) Selous GR Selous Outside north (Kidunga- Selous Outside south TOTAL Tapika) Gonabis) S.E. ± Species Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Obs. Est. S.E. ± Buffalo 265 4,682 3,574 42 1,181 961 2,678 50,030 9,145 212 3,853 3,754 3,604 66,546 11,470 Hippo 17 300 289 1,659 30,353 4,916 6 109 107 1,691 31,086 4,934 Kongoni / hartebeest 37 654 368 7 124 129 851 15,570 2,315 1 18 18 72 1,309 921 1,272 23,250 2,853 Wildebeest 48 848 436 10 177 185 919 16,814 2,878 20 366 351 34 618 517 1,270 22,740 3,330 Zebra 139 2,456 912 7 124 127 800 14,637 1,838 22 403 260 24 436 326 1,264 22,690 2,698 251 Impala 108 1,908 721 543 9,935 1,730 13 238 230 44 800 550 1,032 19,296 3,124 Warthogs 313 5,530 941 320 5,855 701 52 945 424 947 17,475 1,469 Elephant 19 336 189 646 11,819 1,627 59 1,072 457 850 15,501 1,819 Duiker (many spp) 52 919 150 1 18 17 167 3,069 339 39 709 132 528 11,021 741 Ground hornbill 22 389 176 200 3,672 451 4 73 49 8 145 71 305 6,025 614 Eland 154 2,818 999 5 92 90 14 254 171 304 5,541 2,061 Sable antelope 8 141 107 166 3,037 743 25 454 286 286 5,921 1,201 Reedbuck 5 88 55 210 3,842 1,443 11 201 156 2 36 35 231 4,223 1,454 Waterbuck 206 3,769 843 4 73 72 221 4,049 850 17 El. carcass - very old 4 71 33 1 18 17 91 1,665 204 1 18 17 3 55 29 133 2,416 239 Kudu, greater 9 159 154 30 549 192 8 145 92 125 3,035 1,215 17 Giraffe 55 1,006 298 4 73 41 107 1,858 461 Puku 88 1,579 586 Baboon 15 265 181 36 659 283 81 1,584 440 Bushpig 15 265 158 26 476 236 3 55 40 64 1,208 342 El. carcass - old 1 18 17 20 366 82 1 18 18 30 550 108 Bushbuck 3 53 29 9 165 81 19 370 118 Crocodile 19 348 127 19 348 127 Wild dog 15 274 266 15 274 266 Vervet monkey 10 177 172 1 18 18 14 250 177 Hyaena 3 55 53 3 Dik dik 1 18 17 1 18 18 2 Jackal 2 37 35 2 Rhino 1 18 18 1

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3.3.1 BUFFALO ESTIMATES, DISTRIBUTION AND DENSITY Buffalo was the most abundant species in the survey area. More buffalo were estimated in the Selous GR (52,414 ± 9,150 SE) followed by Kilombero South (5,290 ± 4,420 SE), Outside East-Tapika-Ngarambe (4,682 ±3,572 SE) and Mikumi National Park (1,030 ± 730 SE). The stronghold of the buffalo population is in the Selous GR. Buffalo were absent in Kilombero GCA, Outside Mikumi and Outside Selous north. There were few observations in Outside North and South of Selous GR and Outside SE (Mbalika) (Figure 5). Generally, the Buffalo population remained stable from 2013 to 2018 but the long trend from the 1990s indicates a major shift of buffalo population from over 150,000 to less than 70,000 (Figure 6).

Figure 5. Buffalo distribution and density in the Selous-Mikumi ecosystem, dry season 2018. 18

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Figure 6. Buffalo population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)

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3.3.2 IMPALA DISTRIBUTION AND DENSITY Impala was among the most abundant antelope species in the Selous-Mikumi ecosystem. The highest concentration and distribution was found in the northern and central parts of Mikumi NP, North of Selous GR, along the eastern Selous GR border with outside Liwale and Western Selous GR. However, low concentrations were observed in central and southern parts of Selous GR. There were no observations of Impala in Kilombero GCA, Mahenge and in the Selous-Niassa corridor (Figure 7). A long term trend indicates Impala population is fluctuating from the last decades (Figure 8).

Figure 7. Map of impala distribution and density in Selous-Mikumi ecosystem dry season 2018. 20

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Figure 8. Impala population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.3 HIPPO DISTRIBUTION AND DENSITY Hippo was the second most abundant species in the Selous-Mikumi ecosystem. The largest estimate was in the northern and central parts of the Selous GR (30,353 ±4,916 SE) followed by outside South and Outside East. There were no hippo observations in Mikumi NP, Kilombero GCA, Outside North and West of the Selous GR (Figure 9). The pattern of hippo distribution follows the main river system in the Selous GR.

Figure 9. Map of hippo distribution and density in Selous-Mikumi ecosystem, dry season 2018.

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Figure 10. Hippo population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

3.3.4 ELEPHANT DISTRIBUTION AND DENSITY Elephant was among the most abundant species in the Selous-Mikumi ecosystem. The largest estimate was observed in the Selous Game Reserve with an estimate of 11,819 (±1,627 SE), followed by Selous outside south 1,702 (±457 SE), Mikumi NP 825 (±345 SE) and Selous-Niassa corridor 602 (± 258 SE). There were no elephant observations in Outside Mikumi, Selous Outside North, Selous Outside West, Central and Southern parts of Selous–Niassa corridor, Lukwika, Kilombero South and Kilombero GCA (Figure 11).

Elephants were widely distributed over the surveyed area. The highest concentrations were observed in the eastern, central and southern parts of Selous GR and central Mikumi NP. Other densely populated areas were outside Southeast (Liwale WMA). Relatively low-density areas include Outside West (Mahenge) and the northern part of the Selous-Niassa corridor.

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Figure 11. Elephant distribution and density in the Selous-Mikumi ecosystem, dry season 2018.

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Figure 12. Elephant population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

3.3.5 ELEPHANT CARCASS DISTRIBUTION AND DENSITY Fairly old elephant carcasses (EC3 and EC4) were widely distributed over the surveyed area. The highest concentration areas were observed in the northern part of Mikumi NP, northern and southern parts of Selous GR and outside southeast (Liwale). Areas with relatively low concentration were in the central parts of Selous GR, Mahenge and outside-west (Mbarika). Areas, where no carcasses were observed, include Kilombero GCA, the southern part of Mikumi NP, south and center of the Selous-Niassa corridor and outside-south (Masasi). However, these areas had no elephant observations either (Figure 13).

Elephant Carcass: A total of 2,966 (±559 SE) elephant carcasses were estimated in the entire ecosystem, 81% being very old (more than three years) while 19% old (up to three years). There was no record of elephant carcasses that was less than one year old. The carcass ratio (ratio of dead to living + dead elephants, a measure of mortality in the system) has dropped from 39% in 2014 to 16% in 2018 (Table 6).

TAWIRI Table 6. An estimate of elephant carcasses in the census zone Category of Counted % of Estimate SE ± Age of carcasses carcasses Carcasses Total EC1 0 0 <1month EC2 0 0 1-12 months EC3 30 19% 12-36months EC4 133 81% >36Months Total 163 2,966 559

Figure 13. Elephant carcass distribution and density in Selous-Mikumi ecosystem, dry season 2018. 26 TAWIRI

3.3.6 KONGONI (HARTEBEEST) DISTRIBUTION AND DENSITY The largest number of kongoni was recorded in the Selous GR with an estimate of 15,570 (± 2,315 SE), followed by Liwale block 5,025 (±1,311 SE), outside South Selous with an estimate of 1309 (± 921 SE) and outside East Selous 654 (± 368 SE). Kongoni was also observed in Kilombero south and Selous-Niassa corridor. In contrast, there were no observations of Kongoni in Mikumi NP, Kilombero GCA, Lukwika area, Outside Mikumi (Figure 14). The long term trend indicates a recovering population (Figure 15).

Figure 14. Map of kongoni distribution and density in Selous-Mikumi ecosystem, dry season 2018

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Figure 15. Kongoni population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.7 WILDEBEEST DISTRIBUTION AND DENSITY The highest estimate of wildebeest was observed in Selous GR estimated at 16,093 (±5,100 SE), followed by Mikumi NP 3,593 (±1461 SE), Outside East Selous 848 (±436 SE) and Selous Outside South 618 (±517 SE). There were no observations in the Kilombero GCA, Kilombero South, Lukwika area and Outside Mikumi (Figure 16). Long term trend indicates that wildebeest are poorly performing within the miombo woodland (Figure 17).

Figure 16. Map of wildebeest distribution and density in Selous-Mikumi ecosystem, dry season 2018

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Figure 17. Wildebeest population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.8 ZEBRA DISTRIBUTION AND DENSITY Zebra were widely distributed over the survey area. The highest estimate of zebra was observed in Selous GR estimated at 14,637 (±1,838 SE), followed by Mikumi NP 2,848 (±912 SE) and Outside West Mikumi 2,848 (±1,600 SE). The relatively low-density area was observed in the central and southern part of the Selous GR, outside Masasi and the Selous-Niassa corridor (Figure 18). Long term trend suggests a recovering population from a declined that was recorded in 1990s through 2013 (Figure 19).

Figure 18. Map of zebra distribution and density in Selous-Mikumi ecosystem, dry season 2018

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Figure 19. Zebra population trend in Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.9 SABLE ANTELOPE DISTRIBUTION AND DENSITY Sable antelope was widely distributed in the Selous GR. The highest estimates of sable antelopes were observed in the Selous GR 3,037 (±743 SE) and Selous-Niassa corridor 1,604 (±833 SE). The highest density was observed in the central part of Selous GR and Mikumi NP., Selous-Niassa and, outside west (Mahenge). There was no observation of Sable in Kilombero GCA, Liwale, Lukwika-Lumesule, outside Mikumi West, outside east (Ngarambe-Tapika) and Selous outside north (Kidunda-Gonabis) (Figure 20). Similar to a few other species, long term trend shows a stable population at about 5000 individuals since the mid 1990’s with exception of low counts that were recorded in 2006 and 2009 (Figure 21).

Figure 20. Map of sable antelope distribution and density in Selous-Mikumi ecosystem, dry season 2018 33

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Figure 21. Sable antelope population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.10 ELAND DISTRIBUTION AND DENSITY Eland showed a restricted distribution over the surveyed area, with relatively larger groups in the southwest, east and outside southwest of the Selous GR (2,818±999 SE) and outside southeast (Liwale) (2,117 ±1782 SE). Furthermore, there was only one observation inside the Mikumi NP and Out West (Mahenge). There were no observations in the Selous-Niassa Corridor and Kilombero GCA (Figure 22). No major changes in the population from long term trends stabilizing around 4000 individuals since the 1990’s (Figure 23).

Figure 22. Map of eland distribution and density in Selous-Mikumi ecosystem, dry season 2018

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Figure 23. Eland population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)

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3.3.11 WATERBUCK DISTRIBUTION AND DENSITY Waterbuck were sparsely distributed in the Selous-Mikumi ecosystem. Relatively high concentrations were recorded in the Selous GR (3,769 ±743 SE) and low concentrations in the outside west (Mahenge) with scattered observations in the Selous-Niassa corridor and outside south-west (Liwale). None were observed in Mikumi NP, Kilombero GCA, outside south-west (Mbarika) and outside north (Kidunda Gonabis) (Figure 24). The waterbuck population declined from about 12,000 animals in the 1990s and stabilized at about 4,000 in recent years (Figure 26).

Figure 24. Map of waterbuck distribution and density in Selous-Mikumi ecosystem, dry season 2018 37

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Figure 25. Waterbuck population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)

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3.3.12 GIRAFFE DISTRIBUTION AND DENSITY Historically, giraffe distribution was restricted in the northern part of the ecosystem with its southern boundary being the Ruaha and Rufiji rivers. The 2018 aerial census indicates that the majority of giraffe were found in group size of 10 to 38 individuals. The highest estimate of giraffe was found in Matambwe sector the Selous GR (1,006 ±298 SE) and Mikumi NP (761 ±349 SE) (Figure 26).

Figure 26. Map of giraffe distribution and density in Selous-Mikumi ecosystem, dry season 2018

TAWIRI Long term trend suggests a population of about 2000 giraffes since the mid 1990’s. Higher estimates were less reliable with relatively wider standard errors (Figure 27).

Figure 27. Giraffe population trend in the Selous-Mikumi ecosystems (vertical bars indicate SE)

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3.3.13 WARTHOG DISTRIBUTION AND DENSITY Warthogs were widely distributed in the Selous-Mikumi ecosystem. Liwale WMA recorded the highest density of warthog in the ecosystem (Figure 28) with an estimate of 5,855 (± 701 SE). The highest concentration was observed outside east (Ngarambe-Tapika) (5,530 ±941 SE) and outside southeast (Liwale) (3,847 ± 635 SE). Other higher concentration areas were the western part and south-central of the Selous GR. Relatively low-density areas were Mahenge north, Selous-Niassa corridor and outside Masasi area (Figure 28). Long term trend suggests a population that is increasing exponentially after a brief decline that was recorded between 1998 and 2006 (Figure 29).

Figure 28. Distribution and density of warthogs in Selous-Mikumi ecosystem, dry season 2018 41

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Figure 29. Warthog population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.14 DUIKER DISTRIBUTION AND DENSITY Duikers were among the most widely distributed species in the Selous-Mikumi ecosystem. The highest concentrations were observed in the outside southeast (Liwale) (3203 ± 478 SE), Outside East (Ngarambe-Tapika) (919 ± 150 SE), Outside south Masasi and Selous-Niassa corridor. The remaining part of the Selous GR showed a sparse distribution pattern. Relatively low-density areas were observed inside Mikumi NP and no observations were made in Kilombero GCA and Outside west Mahenge (Figure 30).

Figure 30. Distribution and density of duiker in Selous-Mikumi ecosystem, dry season 2018

TAWIRI Similar to warthogs, duikers indicates a population that is increasing exponentially since 2006 (Figure 31). A better understanding of these increases (duiker and warthogs) is recommended especially its high concentration occurs in similar areas (Figure 28 and 30).

Figure 31. Duiker population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

3.3.15 PUKU DISTRIBUTION AND DENSITY Puku had a restricted distribution in the Selous-Mikumi ecosystem. Similar to previous census, the species was only observed in Kilombero south (Outside west Mahenge) (98 ± 81 SE) and Kilombero GCA (1,464 ± 580 SE) which is important population in the country (Figure 32) and was stronghold of puku in Africa. Of all medium sized ungulates, puku has suffered a long term decline more than any other species in the Selous-Mikumi Ecosystem. Its population trend shows a gradual and persistent declines over the last decades from about 50,000 individuals in the 1990’s to 3000 in 2018 (Figure 33). Clearly the existence of this population is seriously threatened by the ever increasing degradation of its habitat caused by human activities (refer section 3.4 of this report). Historically, Tanzania was known to have three sub population of puku with Kilombero valley being the stronghold. A relatively small population in the north tip of Lake Nyasa went extinct in the early 1960s (Foley et. al 2014).

TAWIRI The remaining two sub populations in the northern part of lake Rukwa and in the Kilombero valley are declining, with the later at a faster rate. Urgent intervention by the authorities is strongly recommended to save this population before it is too late for its recovery.

Figure 32. Distribution and density of Puku in Selous-Mikumi ecosystem, dry season 2018

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Figure 33. Puku population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE)

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3.3.16 KUDU DISTRIBUTION AND DENSITY Kudu was among the most sparsely distributed species in the Selous-Mikumi ecosystem. It was mostly observed Outside southeast (Liwale) (810 ±357 SE) and Selous GR (549 ±192 SE) Outside south (Masasi). In contrast, low concentrations of kudu were found in northern, eastern and south of Selous GR. However, there were no observations of kudu in Outside west (Mahenge) and Kilombero GCA (Figure 34).

Figure 34. Distribution and density of Greater kudu in the Selous-Mikumi ecosystem, dry season 2018

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The rather sparse distribution of greater kudu in the Selous-Mikumi ecosystem accounts for the wide standard error attached to the population estimates (Figure 35). Consequently, this affects the reliability of the estimates. Nevertheless, long term trend suggests a stable population at about 1,500 to 2,000 individuals since the early 1990’s.

Figure 35. Greater Kudu population trend in the Selous-Mikumi ecosystem (vertical bars indicate SE).

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3.3.17 LARGE AVIAN SPECIES DISTRIBUTION AND DENSITY Large bird species were also widely distributed in the Selous-Mikumi ecosystem. Ground hornbill revealed wide distribution in the Selous GR. There were no avian records in the sampled areas of the Mikumi NP, Kilombero GCA, outside west (Mbarika) and Lukwika-Lumesule GR (Figure 36).

Figure 36. Distribution of large avian species in the Selous-Mikumi ecosystem

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3.4 HUMAN ACTIVITIES IN THE SELOUS-MIKUMI ECOSYSTEM There were fifteen observed human activities in the Selous-Mikumi ecosystem. Livestock was the most abundant activity. A total of 678,303 (± 73,205 SE) cattle were estimated, followed by shoats 171,893 (± 27,304 SE). Thatched huts had an estimate of 86,343 (±6,263 SE). The least observed human activities were Fishing camps 1,114 (±196 SE), charcoal kiln 1,153 (±284 SE), and canoe 2,553 (±563 SE). Other human activities which had too low observations to enable calculation of estimates were cultivation, tree felling and poachers camps (Table 7). Table 7. Human activity estimates in the Selous-Mikumi ecosystem

SN Human activity Counts Estimate SE ± 1 Cattle 37,043 678,303 73,205 2 Shoats 9,567 171,893 27,304 3 Thatched hut 4,304 86,343 6,263 4 Hut with mabati roof 759 13,622 2,290 5 Saw pit 450 9,015 772 6 Boma occupied 270 4,847 663 7 Canoe 139 2,523 563 8 Boma – unoccupied 107 1,981 386 9 Waterhole – Borehole / Pump 64 1,653 334 10 Boma abandoned 83 1,468 368 11 Charcoal kiln 66 1,153 284 12 Fish camp 61 1,114 196 13 Cultivation 21 14 Tree felling 11 15 Poacher’s camp 6

3.4.1 HUMAN ACTIVITY ESTIMATES, DISTRIBUTION AND TRENDS 3.4.1.1 Cattle estimates Cattle were the most abundant human activity, the highest estimates were in the Kilombero GCA (436,360 ± 60,426 SE) followed by survey block Outside-Mikumi (62,888 ± 30,416 SE) and Selous-Niassa corridor (42,297 ± 12,803 SE). The lowest estimates were in Selous GR (5,269 ± 2,841 SE) recorded in two location and Selous outside south (2,072±1460). There were no observations in Lukwika-Lumesule GR and Mikumi NP (Table 8, Figure 37). Generally, cattle are still a challenge in the ecosystem as their number increased significantly (d-test = 4.03, Table 9).

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Figure 37. Distribution and density of cattle in Selous-Mikumi ecosystem, dry season 2018

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3.4.1.2 Shoats estimates The highest numbers of shoats were observed in the Kilombero GCA with an estimate of (96,477 ± 21,695 SE), followed by outside Mikumi (40,850 ± 15,126 SE) and Liwale (8,356 ± 3,556 SE). Other low estimated areas were (1,133 ± 856 SE), Kilombero south (1,324 ± 925 SE), outside south (2,986 ± 1594 SE) and, Selous GR (1,153 ± 923 SE). There were no shoats observations in Lukwika-Lumesule GR (Table 8, Figure 38 ). Similar to cattle, shoats increased significantly (d-test = 2.75, Table 9) in the ecosystem mainly in the Kilombero and Mkata plains north of Mikumi NP (Figure 38).

Figure 38. Distribution and density of shoats in Selous-Mikumi ecosystem, dry season 2018 52

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3.4.1.3 Settlements estimates Settlement in this report referes to thatched house, mabati house and village (many house in one location). Thatched huts were numerous in the Selous-Niassa corridor (19,512 ± 2,545 SE), followed by Kilombero GCA (18,414 ± 3,258 SE), outside east Selous (9,753 ± 2577 SE) and Out-west Selous (8,341 ± 2,219 SE). Other areas with a low concentration of thatched-hut were Outside north Selous GR (2142 ± 530 SE) and Lukwika-Lumesule block (1,534 ± 704 SE) (Table 8). In general, settled areas have not changed their distribution pattern since the 2014 census. The highest density of settlements was observed in Kilombero GCA and outside-west (Mbarika). Relatively low densities but widely spread settlement were recorded in the Selous-Niassa corridor (Figure 39).

Figure 39. Distribution and density of settlement (thatched hut, mabati house and village or many house in one area) in Selous-Mikumi ecosystem, dry season 2018 53

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3.4.1.4 Tree-Felling The distribution pattern of tree-felling showed the highest concentration in the outside-east of the Selous GR (Ngarambe-Tapika WMA), outside south-east (Liwale) and the northern part of the outside-west (Mahenge) and eastern part of the Selous GR. Low concentrations of tree-felling were observed in the Out Mikumi west, southeast Liwale, Kilombero GCA and South-west Mahenge (Figure 40).

Treefelling density per km2

Figure 40. Distribution and density of tree felling in the Selous-Mikumi Ecosystem

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3.4.1.5 Saw-pits Sawpits were widely distributed outside the protected area and corresponding to distribution of tree felling. The highest concentrations were in the outside-east (Ngarambe-Tapika), outside south-east (Liwale), outside-west (Mbarika) and the northern part of outside west (Mahenge). Relatively low-density areas were observed in the Selous-Niassa corridor, outside Mikumi west (Kidunda-Gonabisi) and Lukwika-Lumesule GR. There were no observations of sawpits in the Selous GR and Kilombero GCA. Opening of farms for growing cashew nut in the Liwale area might have triggered the significant increase of sawpit after clearance of the miombo woodland. However, the density of sawpits is high in Liwale and Ngarambe- Tapika WMA.

Figure 41. Map of sawpits distribution and density in the Selous-Mikumi ecosystem 55

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3.4.1.6 Cultivation The 2018 aerial census show that cultivation and fallow land were widely distributed around Mikumi NP and Selous GR. The highest concentration for cultivation was observed in outside north Mikumi, southwest of Mikumi NP, outside-north Selous (Kigunda–Gonabis), outside-east Selous (Liwale) and Selous-Niassa wildlife corridor. Relatively low densities of cultivation were observed in outside-south Selous and outside Lukika-Limesure GR. Areas with no observation of cultivation were Mikumi NP, central-outside Mahenge, Selous GR and Lukwika-Lumesule (Figure 42).

Figure 42. Map of cultivation distribution and density in Selous-Mikumi ecosystem, dry season 2018 56

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Table 9. Human activity trends in the Selous-Mikumi ecosystem, dry season 2018

Year of Survey 2014 2018 d-test Surveyed Area 105,730km² 104,143 km² Human activity Estimates SE Estimates SE Cattle 383,321 224 678,303 73,205 4.03** Shoats 96,894 122 171,893 27,304 2.75** Poacher's camps 107 6 112 52 0.09 Sawpits 9,268 39 9,015 772 -0.33 Hut with mabati roof 5,799 26 13,622 5,566 1.41 Boma occupied 6,976 24 4,847 1,558 -1.37 Canoe 1,145 14 2,523 753 1.83 Boma - unoccupied 329 9 1,981 951 1.74 ** Strongly increased

Overall, human activities in the Selous-Mikumi Ecosystem pose threats to the conservation of wildlife animals by hindering linkages, loss of habitat and creating hard edges in protected areas. The recent experience in increasing sawpits signifies major habitat conversion within the ecosystem especially the area toward the Masasi Open (important hunting areas) where is rich in wildlife species. Increased number of livestock in some areas signals a major threat to wildlife conservation especially in the Kilombero valley where large herd of buffalo have disappeared from the core range within the Game controlled area. The Kilombero GCA calls for deliberate efforts to conserve wildlife habitat so as to avoid local extinction of important species. Equally, human activities were also recorded inside other protected areas, with very poorly performing in WMAs. The linkage of wildlife animals between Tanzania and Mozambique via the Selous-Niassa corridor might be the past if the current rate of widely spreading settlement and agriculture activities continues unchecked. Even though within the corridor there are around four WMAs, the rate of spread of human activities within the WMAs are uncontrolled therefore there is a need for a review the modality of how the WMA within the corridor are managed. The impact of hard edges is increasingly recognised as major threat to wildlife conservation. Unlike Serengeti-Mara ecosystem where hard edges are now preventing movement of migratory species, the Selous-Mikumi ecosystem still has room to better plan and manage the hard edge effect for the better of ecological functioning within the ecosystem.

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5.3 ANNEX 3. LIST WILDLIFE SPECIES COUNTED IN THE AERIAL CENSUS DRY SEASON, 2018 Common name Scientific name Mammals Buffalo Syncerus caffer Bushbuck Tragelaphus scriptus Kongoni/Hartebeest Alcelaphus buselaphas Duiker, common Sylvicapra grimmia Wildebeest Connochaetes taurinus Sable antelope Hippotragus niger Kudu Greater Tragelaphus strepsiceros Baboon Papiocynocephalus Bush pig Potamochoerus larvatus Crocodile Crocodylus niloticus Wild dog Lycaon pictus Eland Taurotragus oryx Vervet monkey Chlorocebus pygerythrus Hyaena Crocuta crocuta Jackal Canis aureus Dik-dik Madoqua spp Rhino Diceros bicornis Elephant Loxodonta africana Giraffe Giraffa camelopardalis Hippopotamus Hippopotamus amphibius Impala Aepyceros melampus Puku Korbus vardoni Reedbuck Redunca spp Warthog Phacochoerus aethiopicus Waterbuck Kobus ellipsiprymnus Zebra Equus burchelli Birds Ground hornbill Bucorvus leadbeateri

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5.4 GLOSSARY OF IMPORTANT CENSUS TERMINOLOGY Survey Area (Z) Survey area (also referred to as census zone) is defined as the whole area in which the number of animals is to be estimated. In some censuses, the survey area is divided into sub-zones (strata) for various reasons. For example, divisions could be based on political and/or management boundaries, or ecological zones.

Sample The sample zone is that portion of the survey area that is actually searched and counted. To count every single animal in a protected area would be prohibitively expensive and time-consuming (sizes ranging from about 200 to 150,000 km2). For this reason, only parts of the survey area are searched and assume that what is seen in those parts (samples) are representative to what we would see if we searched over the other parts. In SRF the sample zone is made up of transects and each transect is a sample unit.

Population Estimate (Y) All animals and human activities within the counting strips are recorded during an SRF. The assumption is made that animals are evenly distributed over the survey area so that, if 10% of the area is searched, it will contain about 10% of the animals. This allows us to estimate the number of animals in the survey area. The standard error is used to describe how exact (reliable) our population estimate is.

Standard Error (S) Because animals are less likely to be even distributed over the census zone, each transect (sample) will vary in the density of animals that it contains. Any single population estimate may, therefore, be higher or lower than the true population total. The potential magnitude of this sampling error can be determined by examining the variation between the numbers of animals counted in each of the sample units. The standard error is a measure of this variation.

If the standard error is small, then we can estimate the population to within a narrow range of numbers (we say the estimate is precise). If the standard error is high, the true population estimate lies within a wide range of possible numbers. Caution must be taken when interpreting estimates with wide standard errors (above 20% of the estimate) as the wider the SE the less reliability should be put on the estimate.

Critical management decisions should not be based on a single SRF estimate and, more specifically, with wide standard errors.

Confidence Limits (Cl) The population sizes presented in our reports are estimates (see "Population estimate", above), and therefore, it is helpful to know the lowest and highest probable population size. Confidence limits are a way

6 TAWIRI of describing these upper and lower bounds on our estimate. By default the confidence limits presented in our reports are “95% confidence limits", that is, there is a 95% probability that the true population size falls within these limits. The formula for calculating the 95% confidence limits is (95% CL):

95% CL = Y ± (SE x t value).

Where: Y = Population estimate SE = the standard error of the estimate Y. "t critical value" depends on sample size (number of transects), and it can be looked up in statistics books (e.g., Rohlf and Sokal 1981: Page 81)

Significant Difference (d test between population estimates) It is often required to compare two or more population estimates for a given species, to conclude whether the species is increasing or decreasing in numbers. If estimates from two different surveys are different, it might be due to: 1. Chance. Estimates always vary from one survey to another because of how the animals are distributed, and due to which transects (of all the possible transects) we flew.

2. The number of animals in the protected area has increased or decreased. d-value is used to test the difference between two independent estimates. The statistical test takes into account the standard error of a population estimate and determines whether the variation between estimates is more likely to be due to sample variation or a true change in population size. A significant difference between population estimates strongly suggests that the population has increased or decreased between surveys. If the difference is not significant, then we do not have any statistical evidence for population change; in effect, we must assume the population has stayed the same. Two estimates are significantly different from each other at the 5% level if the d value is greater than 1.96.

6 TAWIRI 6 REFERENCES

Cochran, William G. 1954. ‘The Combination of Estimates from Different Experiments’. Biometrics 10 (1): 101–29. doi:10.2307/3001666. Norton-Griffiths, M. (1978). Counting Animals. Nairobi: African Wildlife Foundation.

UNESCO. (1982). Convention concerning the protection of the world cultural and natural heritage: World

Heritage Committee Sixth Session Paris. Paris: UNITED NATIONS EDUCATIONAL,

SCIENTIFIC AND CULTURAL ORGANIZATION CONVENTION.

Craig, G. Colin. 2012. Aerial Survey Standards for the MIKE Programme — Version 2.0. Approved by MIKE Technical Advisory Committee. Nairobi: CITES MIKE.

Douglas-Hamilton, Iain, and Anne Burrill. ‘Using Carcass Ratios to Determine Population Trends’. In African Wildlife: Research and Management. Proceedings of an International Symposium, 8-11 December 1986, Kampala, Uganda, edited by Fredrick I. B. Kayanja and Eric L. Edroma, 98–105. Paris: ICSU, 1991.

ESRI. 2014. ArcGIS (version 10.1). Windows 7. Redlands, CA, USA: Environmental Systems Research Institute.

Frederick, Howard, and Mike Norton-Griffiths. 2013. ‘Discussion Paper for the Aerial Survey Standards for the Proposed Aerial Census of Elephants in the Selous Game Reserve, Tanzania, September 2013’. Tanzania Wildlife Research Institute.

Jolly, GM. 1969. ‘The Treatment of Errors in Aerial Counts of Wildlife Populations’. E. Afri. Agric. For. J 34: 50–55. Norton-Griffiths, M. (1978). Counting Animals. Nairobi: African Wildlife Foundation.

Quantum GIS Development Team. 2014. Quantum GIS Geographic Information System (version 2.6). Quantum GIS Geographic Information System.

TAWIRI. 2013. Aerial Census of Large Animals in the Selous-Mikumi Ecosystem, Dry Season, 2013: Population Status of African Elephant. Aerial Survey Report. Tanzania Wildlife Research Institute.

6 Tanzania Wildlife Research Institute P.O. Box 661, Arusha, Tanzania Tel: +255 27 254 9571 Email: [email protected] | Website: tawiri.or.tz