An Ecological Paradox: The African Wild Dog (Lycaon Pictus) Is Not Attracted to Water Points When Water Is Scarce in Hwange National Park, Zimbabwe.

Henry Ndaimani,Lovelater Sebele,Hillary Madzikanda,Paradzayi Tagwireyi,Benjamin Lee Allen

doi:10.1371/journal.pone.0146263

Henry Ndaimani, Lovelater Sebele + Show 3 more

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https://doi.org/10.1371/journal.pone.0146263

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Abstract

In dry biomes, spatio-temporal variation in surface water resource stocks is pervasive, with unknown effects on the ranging behaviour of large predators. This study assessed the effect of spatial variation in surface water resources on the ranging behaviour of the African wild dog (Lycaon pictus). We analyzed data for 1992 (dry year with 20 water points) and 2000 (wet year with 30 water points) against presence-only data for five packs of L. pictus in a part of Hwange National Park and adjacent smallholder communal farming areas in western Zimbabwe. Modelling the potential habitat for L. pictus using Maxent with distance from water points (Dw) and Normalized Difference Vegetation Index (NDVI) as predictor variables was successful for 2000 (AUC = 0.793) but not successful for 1992 (AUC = 0.423), with L. pictus probability of occurrence near water points being more for year 2000 than for year 1992. The predicted L. pictus range was wider in 1992 (~13888.1 km2) than in 2000 (~958.4 km2) (Test of Proportions, χ2 = 124.52, df = 1, P = 0.00). Using the 2nd order Multitype Nearest Neighbour Distance Function (Gcross), we also observed significant attraction between L. pictus and water points within only ~1km radius for 1992 but up to ~8km radius for 2000. Our study reinforced the notion that surface water resources attract wild dogs in the savannahs but paradoxically less so when water resources are scarce. In particular, our study furthers current understanding of the effects of changing water availability regimes on the endangered L. pictus, providing evidence that the endangered predator’s home range encroaches into potential ecological traps (i.e., smallholder communal farming areas) when water resources are scarce.

Highlights

In dry biomes, the relationship between wildlife and surface water resources is well documented (e.g., [1, 2,3,4,5,6])
Maximum Entropy (MaxEnt) modelling with distance from water points (Dw) and Normalized Difference Vegetation Index (NDVI) as environmental variables successfully explained the distribution of wild dogs for the year 2000 (AUC = 0.793) but failed to do so for the year 1992 (AUC = 0.423) (Fig 3)
Our results indicate that availability of surface water influences the habitat preferences of the African wild dog in two opposing ways

Summary

Introduction

The relationship between wildlife ( large mammals) and surface water resources is well documented (e.g., [1, 2,3,4,5,6]). The availability of surface water is a major driver of selected ungulate distribution in most dry wildlife areas [22,23,24]. This is true for grazing animal species [e.g., impala (Aepyceros melampus)] that need to drink water on a daily basis [25, 26] and carnivorous animal species (e.g., dingoes) that do not need to drink water daily [27]. Arjo et al [6] speculated that additional surface water sources relaxed the arid limitation for coyotes (Canis latrans) in the Great Desert Basin, Utah, USA

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