Summary1. The habitat requirements of various species have been evaluated by statistical models. However, recent studies have shown that models are often not transferable between regions, limiting their applicability and ability to inform management decisions. One possible cause is that models tend to reflect dominant landscape features, which vary between regions. Transferability, and thus applicability, may be increased by developing models from multiple regions. 2. We addressed this via a case study of two vulture species (white-backed and lappet-faced vultures, Gyps africanus and Aegypius tracheliotos) from six biogeographically different regions across southern Africa. Logistic models, developed using an information-theoretic approach, were used to predict nest occurrence based on explanatory variables derived from a Geographic Information System (GIS), the usual method for species with large ranges. Variables reflected key requirements at different spatial scales: food availability, human disturbance and nesting trees. We developed models using data from single and multiple regions, and tested the cross-regional transferability. We also collected field data to asses the adequacy of the GIS variables. 3. There was a significant negative correlation between specificity and regional generality, multiregion models tending to be more consistently transferable than single-region models but having a weaker fit within the regions where they were developed. Multi-region models of nesting habitat were more structurally similar to each other than single-region models. GIS variables adequately represented the landscape but with differing adequacy between regions. There were no observed fitness benefits to the observed site selection. 4. Synthesis and applications. Models of species distribution are not transferable between regions, and use of models to inform management decisions in regions other than that used for model development should be undertaken with caution. Models are often built using GIS predictors only broadly related to the landscape properties of interest and the adequacy of such proxies can vary between regions, leading to models that emphasize dominant landscape features. Models developed from multiple regions partially overcome this problem by identifying predictors that apply across many regions and are more transferable. However, this increased generality trades off against reduced specificity. Models should be constructed with consideration to their intended use.

Across Africa, the illegal use of poison is triggering a continent-wide scavenger crisis, with vultures suffering the most severe negative consequences. Vultures may die as indirect victims of the conflict between livestock farmers and predators, or they may be directly targeted by poachers with the aim to reduce the role of vultures as sentinels that alert authorities of poaching events. In this study, we provide novel information on vulture mortalities across the commercial farmlands of Namibia. We show that estimated mortalities of vultures due to anthropogenic causes amount to over 800 individuals over the period 2000-2015, which underscores the magnitude of the problem. The highest numbers of vulture deaths were reported from the southern half of the country, with the exception of the areas just south of Etosha national park, and poisoning was the number one cause of reported deaths. Aldicarb or carbofuran were the most commonly used poisons, but strychnine is still used by about one farmer out of ten. Poison is typically used by means of distributing poisoned baits on the landscape. Furthermore, willingness to use poison in the future was highest for farmers who own large properties with high livestock numbers, particularly sheep and goats, farmers who purportedly suffered high livestock losses to predators and who have a negative perception towards predators. We discuss the implications of these results and the possible urgent actions that should be

Climate-driven environmental change and land-use change often interact in their impact on biodiversity, but these interactions have received little scientific attention. Here we study the effects of climate-driven environmental variation (i.e. vegetation greenness) and land-use (protected versus unprotected areas) on body condition of vulture nestlings in savannah landscapes. We combine ringing data on nestling measurements of two vultures (lappet-faced and African white-backed vulture) with land-use and environmental variables. We show that body condition of white-backed vulture nestlings decreased through the study period and was lowest inside protected areas. For the lappet-faced vulture, nestling condition was improved during harsh years with lower than average vegetation greenness assumed to result in increased ungulate mortality, but only within protected areas. Such interaction was not tested for the white-backed vulture due to collinearity. The species-specific effects of land-use and vegetation greenness on nestling condition of the two sympatric vulture species likely stem from their different life-histories, diet preferences and foraging behaviour. While translation of current findings on nestling conditions to their possible influence on population demography and species persistence require further studies, our findings demonstrate how environmental change may trigger selective bottom-up ecosystem responses in arid environments under global change.

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