Assessing niche overlap between domestic and threatened wild sheep to identify conservation priority areas

Abstract

Aim:Populations of large ungulates are dwindling worldwide. This is especially so for wild sheep, which compete with livestock for forage, are disturbed by shepherds and their dogs, and are exposed to disease transmissions from livestock. Our aim was to assess spatial patterns in realized niche overlap between wild and domestic sheep to better understand where potential competition might arise, and thus to identify priority areas for wild sheep recovery. Location: Southern Caucasus (220,000 km 2 ). Methods: We studied Gmelin's mouflon (Ovis orientalis gmelinii), an ancestor of domestic sheep, to investigate seasonal habitat use and niche overlap with domestic sheep. To map habitat, we analysed mouflon occurrences collected during 2006-2016, and domestic sheep occurrences from shepherd camp locations digitized on high-resolution satellite imagery. We mapped areas of potential competition between mouflon and domestic sheep and assessed potential habitat displacement. Results: Mouflon and domestic sheep niches overlapped substantially (overlap index I = 0.89, where 1 means perfect overlap) but were not identical. Mouflon habitat was less widespread than domestic sheep habitat (14,000 vs. 40,270 km 2 ) and tended to be located in more rugged areas with less vegetation cover. We identified 51 priority patches as reintroduction candidates if grazing pressure and poaching were reduced. Main conclusions: Our results suggest that competition with domestic sheep might have pushed mouflon into marginal habitat. Thus, conservation efforts focusing on current mouflon habitat might miss suitable reintroduction sites. We demonstrate that a combined habitat model for wild and domestic sheep can identify generalsheep habitat, which might be more useful for conservation planning than understanding current mouflon habitat selection. Our results highlight that considering competition with livestock is important for large ungulate conservation, both in terms of reactive (e.g., lessening livestock pressure in prime habitat) and proactive strategies (e.g., reintroduction in areas with low contemporary overlap).

Landscape connectivity for mammalian megafauna along the Iran-Turkmenistan-Afghanistan borderland

“…As an exception, Persian leopards are widely detected outside the conservation network, perhaps due to their large spatial requirements and shortage of food resources, which drive them to occasionally raid livestock in rural areas Farhadinia, Moll, et al, 2018). In contrast, similar to many Asian countries, ungulates are spatially confined to the conservation network since poaching and interactions with livestock threaten their persistence outside established reserves (Bashari & Hemami, 2013;Bleyhl et al, 2019;Khosravi, Hemami, Malekian, et al, 2018;D. P. Mallon & Zhigang, 2009).…”

Identifying priority areas for restoring mountain ungulates in the Caucasus ecoregion

“…(Damm & Franco, 2014; Shackleton, 1997). Restoring their populations is therefore a conservation priority (Bleyhl et al, 2019; Ripple et al, 2015; Shackleton, 1997). Focusing on bezoar goats in the Caucasus ecoregion, we demonstrate an approach to assess (a) where suitable habitat occurs, (b) why habitat might be unoccupied, and (c) where particular restoration actions would be most beneficial.…”

“…These species are better adapted to wetter and snowier conditions (Gavashelishvili et al, 2018), and we indeed found many moderately suitable bezoar goat habitat patches in the western Greater Caucasus to be highly suitable for turs (Figure 4b). While the complex relationship of competition between multiple mountain ungulates and the resulting niche partitioning and distributions remains weakly understood (Bleyhl et al, 2019; Gavashelishvili et al, 2018), competition is a plausible explanation for the absence of bezoar goats in the western Greater Caucasus. Thus, although we find potentially suitable habitat for bezoar goats in the northwestern Caucasus, we explicitly caution against restoration projects there (e.g., reintroductions) until the biogeographic history and ecology of interactions with other mountain ungulates are better understood.…”

“…Whereas large mammal populations rebounded after 2000 elsewhere in the former Soviet Union, due to better protection and declining human pressure (Bragina et al, 2015; Chapron et al, 2014), such trends have not yet materialized across larger areas in the Caucasus. This underpins the persistently high level of threats to large mammals in this region (Bleyhl et al, 2019; Burton et al, 2018).…”

“…While controlled, scientifically‐grounded hunting of these species can contribute to their conservation (IUCN, 2016; Michel et al, 2015), poaching (i.e., illegal, uncontrolled and often unsustainable offtake) threatens these species, particularly during times of institutional instability, such as armed conflicts, of which there have been many in mountain regions (e.g., Kashmir, Pamir, Dinaric Mountains, Caucasus; Matloff, 2017). Mountain ungulates face additional threats from competition with livestock (Bleyhl et al, 2019), surface mining (Ripple et al, 2015; Shackleton, 1997), and climate change (Grotan, Saether, Filli, & Engen, 2008). As a result, many species today hold out only in small, isolated populations, often solely inside protected areas (Damm & Franco, 2014).…”