Increasing food security and preventing further loss of biodiversity are two of humanity's most pressing challenges. Yet, efforts to address these challenges often lead to situations of conflict between the interests of agricultural production and those of biodiversity conservation. Here, we focus on conflicts between livestock production and the conservation of wild herbivores, which have received little attention in the scientific literature. We identify four key socio-ecological challenges underlying such conflicts, which we illustrate using a range of case studies. We argue that addressing these challenges will require the implementation of co-management approaches that promote the participation of relevant stakeholders in processes of ecological monitoring, impact assessment, decision-making, and active knowledge sharing.
Using a population of Dall's sheep (Ovis dalli dalli), we examined two of the four main sexual-segregation hypotheses proposed: (1) the reproductive-strategy hypothesis, which proposes that males feed in the best foraging areas to enhance their reproductive fitness and females use areas with lower predation risk to raise offspring; and (2) the sexual dimorphism body size hypothesis, which proposes that females use the areas with best forage to satisfy the nutritional demands of gestation and lactation, and that males, owing to their larger body size, have greater absolute metabolic requirements and therefore have to feed on forages which are more abundant but of lower quality. In our study, males were found farther from cover, in gentle terrain, and at lower altitude than were female groups, which were near cliffs or talus at higher altitudes. Female groups without lambs left cover, but were always active (feeding or moving). Forage density index values were higher in areas used by males than in areas used by female groups. Nutritional components were generally similar, but fibre content was higher in male areas. Signs of wolves (Canis lupus) and predation on Dall's sheep were recorded only at male areas. The results support the reproductive-strategy hypothesis, indicating that predation plays a key role in the development of sexual segregation in Dall's sheep.
The diet of Black-necked swans, Cygnus melancoryphus (Anatidae), was studied in two southern Chilean wetlands in 1993–1995; the Cruces River Sanctuary and the Chihuao-Pichoy River, both near Valdivia. The diet of swans was analyzed by using microhistologic techniques of cell remains in feces collected in the field. The analysis showed that swans were eating predominantly the most abundant submerged aquatic plant, Brazilian waterweed, Egeria densa (Hydrocharitaceae), at both Cruces River (91.9% of diet) and Chihuao-Pichoy River (71.7%). The foraging action of this species was estimated using four forage exclosures in the Chihuao-Pichoy River wetland free from swan grazing, which were compared with foraged controls. Aquatic plant biomass taken in the exclosures was significantly higher (p < 0.05) than biomass sampled outside the exclosures. Cygnus melancoryphus might play an important role as a regulator of aquatic plant biomass, thus contributing to cause a delay in ecological succession. The potential ...