Challenges and opportunities in population monitoring of cheetahs

Daniel W Linden,Salim Mandela Mandere,Elena V Chelysheva,Stephanie M Dloniak,David S Green

doi:10.1002/1438-390x.12052

Abstract

AbstractPopulation monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes. Noninvasive survey methods and spatial capture–recapture (SCR) models have revolutionized wildlife monitoring by providing the means to acquire data at large scales and the framework to generate spatially explicit predictions, respectively. Despite opportunities for improved monitoring, challenges can remain in the study design and model fitting phases of an SCR approach. Here, we used a search‐encounter design with multi‐session SCR models to collect spatially indexed photographs and estimate changes in density of cheetahs between 2005 and 2013–2016 in the Masai Mara National Reserve (MMNR) in Kenya. Our SCR models of cheetah encounters suggested little change in cheetah density from 2005 to 2013–2016, with some evidence that density fluctuated annually in the MMNR. The sampling period length (5 vs. 10 months) and timing (early, late, full year) over which spatial encounters were modeled did not alter inferences about density when sample sizes were adequate (>20 spatially distinct encounters). Our average density estimate of ~1.2 cheetahs/100 km2 is consistent with the impression that the MMNR provides important cheetah habitat in Africa. During most years, spatial distribution of vegetation greenness (proxy for ungulate habitat quality) accounted for important variation in encounter rates. The search‐encounter design here could be applied to other regions for cheetah monitoring. While snapshot estimates of population size across time are useful for wildlife monitoring, open population models may better identify the mechanisms behind temporal changes.

Highlights

Population monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes (Ellis et al 2014).Monitoring over space and time requires a feasible scheme and persistence in both dedication and resources to obtain adequate information
Our average density estimate of ~1.2 cheetahs/100 km2 is consistent with the impression that the Masai Mara National Reserve (MMNR) provides important cheetah habitat in Africa
The MMNR is predominantly comprised of open grassland interspersed with riparian areas, supporting a high density and diversity of resident herbivores, which are joined seasonally by migrant populations of wildebeest Connochaetes taurinus, zebra Equus quagga, and Thomson’s gazelle Eudorcas thomsonii from the Serengeti National Park to the southwest and the Loita plains to the northeast (Bell 1971, Stelfox et al 1986, Sinclair and Norton-Griffiths 1995)

Summary

Introduction

Population monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes (Ellis et al 2014).Monitoring over space and time requires a feasible scheme and persistence in both dedication and resources to obtain adequate information. Population monitoring is key to wildlife conservation and management but is challenging at the spatial and temporal extents necessary for understanding changes (Ellis et al 2014). Low replication in either dimension reduces the capacity to explain observed patterns or test hypotheses about perturbation, limiting the value of the monitoring data for informing conservation and management decisions (Yoccoz et al 2001). The monitoring challenge has been acute for wide-ranging, cryptic species that occur at low densities, such as carnivores. These life history features have historically made data collection and analysis difficult and reduced the opportunities for robust inference about population dynamics at relevant spatial and temporal scales (Karanth et al 2006).

Methods

Results

Conclusion