The wild ancestors of domestic animals as a neglected and threatened component of biodiversity

Domestic animals have immense economic, cultural, and practical value and have played pivotal roles in the development of human civilization. Many domesticates have, among their wild relatives, undomesticated forms representative of their ancestors. Resurgent interest in these ancestral forms has highlighted the unclear genetic status of many, and some are threatened with extinction by hybridization with domestic conspecifics. We considered the contemporary status of these ancestral forms relative to their scientific, practical, and ecological importance; the varied impacts of wild-domestic hybridization; and the challenges and potential resolutions involved in conservation efforts. Identifying and conserving ancestral forms, particularly with respect to disentangling patterns of gene flow from domesticates, is complex because of the lack of available genomic and phenotypic baselines. Comparative behavioral, ecological, and genetic studies of ancestral-type, feral, and domestic animals should be prioritized to establish the contemporary status of the former. Such baseline information will be fundamental in ensuring successful conservation efforts.

How spatial and dietary overlap with domestic livestock affect African wild ass nutrition on the Messir Plateau (Eritrea)

Competition with livestock over forage resources has been identified as a potential threat to the survival of the African wild ass (Equus africanus) in the Danakil ecosystem (Eritrea). The Messir Plateau is an important breeding area for the African wild ass but also hosts cattle, sheep, goats, donkeys, and camels. Locations and fecal samples of African wild ass and livestock were collected in dry and rainfall months. Stable carbon isotopes [δ 13C ‰] in fecal samples were used to assess diet composition and overlaps with domestic herbivores. Fecal samples also were used to assess the nutritional quality of African wild ass and domestic donkey diets. During the dry months, African wild ass were concentrated in the northern section of the Messir Plateau, approximately 9 km from the permanent water source, and overlapped spatially with local livestock. During the rainfall months, African wild ass dispersed throughout the Messir Plateau (124 km2) when a high number of livestock, particularly cattle from the highlands with herders, were concentrated in the northern section. During the rainfall months, the northern section had relatively better vegetation cover and access to seasonal water. The grass contribution to the diet of the African wild ass in both dry and rainfall months overlapped significantly with that of domestic donkeys and cattle. In rainfall months, the percent fecal nitrogen and phosphorus contents of African wild ass were significantly lower than those of domestic donkey samples. The lower nutrient levels in fecal samples of African wild ass during rainfall months may be due to their displacement from the northern sector by the high number of immigrant highland cattle with people. Our work provides evidence as to how the presence of domestic herbivores, particularly cattle, may negatively impact the nutrient level of wild equids and threaten the survival of the critically endangered African wild ass.

EQUINE SARCOIDS IN CAPTIVE WILD EQUIDS: DIAGNOSTIC AND CLINICAL MANAGEMENT OF 16 CASES-A POSSIBLE PREDISPOSITION OF THE EUROPEAN COHORT OF SOMALI WILD ASS (EQUUS AFRICANUS SOMALIENSIS)?

Equine sarcoids (ES) were diagnosed in 12 Somali wild asses (SWA) (Equus africanus somaliensis) from 10 different institutions of the SWA European Endangered Species Programme from 1976 to 2019. Samples of surgically excised masses, biopsies, or necropsy samples were submitted for histologic and virologic analysis. In addition, tissue samples from one onager (Equus hemionus onager), one kulan (Equus hemionus kulan), and two Hartmann's mountain zebras (HMZ) (Equus zebra hartmannae) were examined. Histology confirmed the diagnosis of ES exhibiting the typical microscopic features. Polymerase chain reaction detected bovine papillomavirus type 1 (BPV1) DNA in eight SWA samples and bovine papillomavirus type 2 (BPV2) DNA in one SWA sample. The onager, kulan, and one HMZ sample tested positive for BPV1. The other HMZ tested positive for BPV1 and BPV2. This is the first report of ES in an onager. Surgical excision was the treatment elected by most veterinarians. A follow-up survey of the cases over several years after clinical diagnosis and therapy revealed variable individual outcome with ES recurrence in four cases. Three SWA and the kulan were euthanized due to the severity of the lesions. Nine affected SWA were males with seven having a sarcoid located at the prepuce. Because a genetic disposition is a risk factor for the development of ES in horses, this may also be true for endangered wild equids with few founder animals in their studbook history. Innovative approaches regarding therapy and prevention of ES in wild equids are therefore highly encouraged.