6 Baka Darwin Initiative project: Camera-trapping survey in Baka Pygmies

1. Enabling Baka attain food security, improved health and sustain biodiversity Lecture 6: Camera-trapping survey in Baka Pygmies hunting territories in southeastern Cameroon Bradly Cain, Guillermo Ros Brull, Eva Ávila Martin, Robert Okale, Rhiannon Rivers, Stephan M. Funk, Julia E. Fa(unpublished)

2. Introduction

3. Effects of wild meat hunting on large animals • Wild meat hunting is the biggest threat to 301 species of mammal (Nasi, 2008) • e.g. 60% of primate species are at risk of extinction from hunting (Tagg et al., 2017). • Large bodied species are particularly vulnerable and are the first to be locally extirpated (Wilkie et al., 2011; Fa et al. 2022)

4. Monitoring animals in dense rainforest • Monitoring animals, even when they are large, by traditional surveys such as line transects is very difficult in dense tropical rainforest • low visibility • difficult access • many areas, e.g. throughout the Congo Basin, are afflicted by civil strife and war and are dangerous to survey • personnel intensive • expensive • inefficient to monitor nocturnal, elusive and rare species • Camera trapping surveys are • highly effective • reliable • non-invasive method • not personnel intensive (can be placed unattended along for extended periods of time) • cost-efficient • suitable to monitor nocturnal, elusive and rare species

5. Camera trapping • Useful to monitor • species richness • density • activity • habitat preference • community structure Duikers

6. Aims • Monitor larger bodied terrestrial mammals weighing about 5kg and more • To quantify species richness • To quantify density • To compare species richness of the Baka hunting territories with published data from the adjacent Dja Faunal Reserve

7. Materials and Methods

8. Location of the survey sites • Three survey areas • South of the Dja Faunal Reserve (DFR) • Within the hunting territories of ten Baka villages (see previous presentation #5 on hunting territories) • Three grids of 12 camera traps each (A, B and C)

9. Location of the published survey in the the Dja Faunal Reserve • Data of our field survey (red and blue squares) were compared with previously published data from the adjacent Dja Faunal Reserve.(grids) • Bruce, T., Amin, R., Wacher, T., Fankem, O., Ndjassi, C., Ngo Bata, M., Fowler, A., Ndinga, H. and Olson, D., 2018. Using camera trap data to characterise terrestrial larger‐bodied mammal communities in different management sectors of the Dja Faunal Reserve, Cameroon. African journal of ecology, 56(4), pp.759-776.

10. Camera trap technicalities • Placed between 40-60cm above ground level (average 45cm) • 90 or 45 degrees relative to the field of view needed to capture full-body images • Placed along game trails or at water points to maximise chance of capturing targeted • Test photos to assure operationality • Cameras are heat activated • When triggered, three consecutive images are captured using infrared flash to cause minimal disturbance to passing animals

11. Analysis • Photographs cleaned, i.e. pictures caused by false triggers removed • The function “camtrapR” within the statistical analysis software R was used • to estimate species richness, species temporal variations and activity radials • The function “vegan” was used • to calculate the rarefaction species accumulation curves • estimating species richness • assessing whether the time was sufficient to calculate species richness • i.e. has the curve reached a plateau? • generally, it initially grows rapidly (as the most common species are found) and then flattens (as the rarest species are sampled). • Diversity index (Shannon-Weiner and Simpson’s ) and the relative abundance index (RAI) were calculated • Focus on grids A and B

12. Results

13. Sampling effort • 24 camera traps in grids A and B • 3 cameras were “lost” • 4 with malfunctions • Camera trap days: 2,291 days operational days • site A: 1,232 (mean 136.8 days/camera) • site B: 1,059 (mean 132.3 days/camera) • 17,722 captured photos • site A: 9,518 • site B: 8,204 • Capture success • 3.94% at site A • 4.25% at site B • no significant difference between sites (p = 0.96).

14. Species accumulation curves • Rarefaction species accumulation curvesestimate the richness of targeted large bodied terrestrial mammals • Curve A has flattened, i.e. when the more rare species are captured, but curves B and C haven´t reached a plateau, i.e. should have been employed for longer • Site A (top) has a higher number of species than sites B (green, bottom) and C (blue, bottom)

15. Confirmed species in sites A and B • Total richness of terrestrial mammals weighing ≥ 5 kg • 12 species • 3 orders, 6 families and 9 genera • Bruce at al. (2018) recorded an additional 10 species • 13 non-targeted mammal species (< 5 kg) were recorded as bycatch across both survey sites • mammals weighing ≥ 5 kg • Ungulates: 821 photos • highest encounter frequency: blue Duiker (Philantomba monticola, Thunberg 1789), RAI = 23.3 • Primates: 201photos • Mandrill (Mandrillus sphinx, Linneaus 1758), RAI = 40.34 • Philodota: 4photos • giant pangolin (Smutsia gigantea, Illiger, 1815) was the only species, RAI = 0.17

16. Confirmed species ≥ 5 kg (left), < 5 kg (right)

17. Species present in the Dja Faunal Reserve but not in sites A and B • African golden cat(Profelisaurata, Temminck, 1827) • Leopard(Panthera pardus, Linnaeus, 1758) • Forest buffalo(Synceruscaffer, Sparrman, 1779) • Bongo(Tragelaphus eurycerus, Ogilby, 1837) • Sitatunga(Tragelaphus spekii, Speke, 1863) • White-bellied duiker(Cephalophus leucogaster, Gray, 1873) • Western lowland gorilla(Gorilla gorilla, Savage, 1847) • Black colobus(Colobus santanas, Waterhouse, 1838) • Forest elephant(Loxodonta cyclotis, Matschie, 1900) • Aardvark(Orycteropus afer, Pallas, 1766)

18. Abundance comparison of sites A and B with the Dja Faunal Reserve • The difference between species RAI in the two sites (for each: first from site A and then site B) compared with the Dja Faunal Reserve • Higher abundance of mandrill (Mandrillus sphinx) and agile mangabey (Cercocebus agilis) in sites A and B • Lower abundance of Peters's duiker (Cephalophus callipygus) and blue duiker (Philantomba monticola)

19. Species richness and abundance in comparison with the Dja Faunal Reserve DFR • Diversity indices comparable • Richness and abundance observed in the present study are significantly lower in comparison to Bruce et al. (2018) in the DFR. • Of 22 larger bodied terrestrial bodied species in the DFR, 10 were not encountered during this survey • Amongst these, African golden cat, leopard, white bellied duiker, sitatunga, buffalo and gorilla are all cited as being sensitive to human disturbance such as logging and hunting

20. Discussion

21. Wildlife in the area is not heavily depleted • Our camera trap data confirm that wildlife in the study area is not heavily depleted. • Species assemblages and population status of species are comparable to those in the protected Dja Faunal Reserve. • However, large-bodied species such as elephant and buffalo were not recorded in our study and may have been overhunted in the area. • The high abundance of mandrills and agile mangabeys contrasts significantly with that in the nearby protected area. This may be related to the fact that agricultural land is more common in the study area and therefore a further source of food for these primates.

22. Next: Bakahealth

23. On behalf of • the Baka • the Project team THANK YOU MERÇI BIEN • Photo: Darwin Initiative Project