Spatial partial identity model reveals low densities of leopard and spotted hyaena in a miombo woodland

Abstract

Decline in global carnivore populations has led to increased demand for assessment of carnivore densities in understudied habitats. Spatial capture-recapture (SCR) is used increasingly to estimate species densities, where individuals are often identified from their unique pelage patterns. However, uncertainty in bilateral individual identification can lead to the omission of capture data and reduce the precision of results. The recent development of the two-flank spatial partial identity model (SPIM) offers a cost-effective approach, which can reduce uncertainty in individual identity assignment and provide robust density estimates. We conducted camera trap surveys annually between 2016 and 2018 in Kasungu National Park, Malawi, a primary miombo woodland and a habitat lacking baseline data on carnivore densities. We used SPIM to estimate density for leopard (Panthera pardus) and spotted hyaena (Crocuta crocuta) and compared estimates with conventional SCR methods. Density estimates were low across survey years, when compared to estimates from sub-Saharan Africa, for both leopard (1.9 AE 0.19 SD adults/100 km 2) and spotted hyaena (1.15 AE 0.42 SD adults/100 km 2). Estimates from SPIM improved precision compared with analytical alternatives. Lion (Panthera leo) and wild dog (Lycaon pictus) were absent from the 2016 survey, but lone dispersers were recorded in 2017 and 2018, and both species appear limited to transient individuals from within the wider transfrontier conservation area. Low densities may reflect low carrying capacity in miombo woodlands or be a result of reduced prey availability from intensive poaching. We provide the first leopard density estimates from Malawi and a miombo woodland habitat, whilst demonstrating that SPIM is beneficial for density estimation in surveys where only one camera trap per location is deployed. The low density of large carnivores requires urgent management to reduce the loss of the carnivore guild in Kasungu National Park and across the wider transfrontier landscape.

Prey availability and intraguild competition regulate the spatiotemporal dynamics of a modified large carnivore guild

“…Consequently, KNP has experienced a significant decline in large mammal (Bhima et al., 2003; Munthali & Mkanda, 2002) and carnivore populations (Davis et al., 2021). Lions, once known residents in KNP, are now restricted to dispersing individuals from the wider Malawi–Zambia Transfrontier Conservation Area (Davis et al., 2021; Mésochina et al., 2010), and cheetahs ( Acinonyx jubatus ), also previously known residents, have been extirpated (IUCN/SSC, 2015). While lions are not strictly extirpated from KNP, they are not present at levels that would have an influence on the guild dynamics of resident carnivore populations.…”

“…While lions are not strictly extirpated from KNP, they are not present at levels that would have an influence on the guild dynamics of resident carnivore populations. Leopard and hyena are the only remaining resident large carnivore species in KNP, with densities in 2018 estimated at 1.77 leopard/100 km 2 and 1.62 hyena/100 km 2 (Davis et al., 2021).…”

“…In the early 2000s, poaching was so prolific that populations of several remaining prey species were moved from KNP to Liwonde National Park, Malawi, as their survival could no longer be guaranteed in KNP (Munthali & Mkanda, 2002). Consequently, KNP has experienced a significant decline in large mammal (Bhima et al, 2003;Munthali & Mkanda, 2002) and carnivore populations (Davis et al, 2021). Lions, once known residents in KNP, are now restricted to dispersing individuals from the wider Malawi-Zambia Transfrontier Conservation Area (Davis et al, 2021;Mésochina et al, 2010), and cheetahs (Acinonyx jubatus), also 2015).…”

“…Subsequently, Malawi has the highest deforestation rate in Africa (Mapulanga & Naito, 2019), while protected areas have been subject to widespread subsistence poaching (van Velden et al, 2020). Kasungu National Park (KNP) is a model example of a protected area in Malawi that has experienced these declines in carnivore and prey populations (Davis et al, 2021;Munthali & Mkanda, 2002). As the second-largest protected area in Malawi, comprised of miombo woodland, the primary habitat type across the country (Gondwe et al, 2019), and subject to the same environmental pressures as other reserves, KNP is a novel site to (a) test theories on resource and guild-based competition, and (b) understand how species respond to anthropogenic disturbance.…”

Camera trapping and spatially explicit capture–recapture for the monitoring and conservation management of lions: Insights from a globally important population in Tanzania

“…In our case, we applied this method over areas of between 150 and 550 km 2 , in line with the sizes of areas commonly surveyed when estimating population densities of other large carnivores (e.g. leopard, Davis et al., 2021; tiger, Ngoprasert & Gale, 2019; jaguar, Boron et al., 2016). At the same time, scaling the method to considerably larger areas has been done for other large carnivores (e.g.…”