Abstract: Excessive grazing by livestock is claimed to displace wild ungulates in the Trans-Himalaya. This study compares the seasonal diets and habitat use of sympatric wild naur Pseudois nayaur and domestic goat Capra hircus, sheep Ovis aries and free-ranging yak Bos grunniens in north Nepal and analyses their overlap both within and across seasons. Alpinemeadow and the legumes Oxytropis and Chesneya were critical resources for all animal groups. High overlap occurred cross-seasonally when smallstock (sheep and goats) in summer used the spring and autumn ranges of naur. Relatively high total ungulate biomass (3028 kg km-2) and low recruitment of naur (56 young per 100 adult females in autumn) suggested interspecific competition. The spatio-temporal heterogeneity in composition and phenology of food plants across the steep gradient of altitude, together with rotational grazing, appears to indirectly facilitate coexistence of naur and smallstock. However, owing to high crossseasonal (inter-seasonal) overlaps, competition is likely to occur between these two groups at high stocking densities. Within seasons, naur overlapped more with free-ranging yak than with smallstock. As their habitat use and diets were most similar in winter, when both fed extensively on the same species of shrubs, naur was most likely to compete with yak during that season.



Abstract: Accumulation of carotenoids varies greatly among animal species and is not fully characterized.
Circulating carotenoid concentration data in captive wild animals are limited and may be useful for their management.
Serum carotenoid concentrations and dietary intakes were surveyed and the extent of accumulation
categorized for 76 species of captive wild animals at Brookfield Zoo. Blood samples were obtained opportunistically
from 275 individual animals immobilized for a variety of reasons; serum was analyzed for a- and b-carotene,
lutein 1 zeaxanthin, lycopene, b-cryptoxanthin and canthaxanthin. Total carotenoid content of diets was calculated
from tables and chemical analyses of commonly consumed dietary components. Diets were categorized as
low, moderate or high in carotenoid content as were total serum carotenoid concentrations. Animals were
classified as unknown, high, moderate or low (non-) accumulators of dietary cartenoids. Nonaccumulators had total
serum carotenoid concentrations of 0-101 nmol/L, whereas accumulators had concentrations that ranged widely,
from 225 to 35,351 nmol/L. Primates were uniquely distinguished by the widest range of type and concentration
of carotenoids in their sera. Most were classified as high to moderate accumulators. Felids had high accumulation
of b-carotene regardless of dietary intake, whereas a wide range of exotic birds accumulated only the xanthophylls,
lutein 1 zeaxanthin, canthaxanthin or cryptoxanthin. The exotic ungulates, with the exception of the bovids, had
negligible or nondetectable carotenoid serum concentrations despite moderate intakes. Bovids accumulated only
b-carotene despite moderately high lutein 1 zeaxanthin intakes. Wild captive species demonstrated a wide variety
of carotenoid accumulation patterns, which could be exploited to answer remaining questions concerning carotenoid
metabolism and function.

Abstract: It is necessary to look at the big picture when managing biological resources on the QinghaiXizang (Tibetan) plateau. Plateau pikas (Ochotona curzoniae) are poisoned widely across the plateau. Putative reasons for these control measures are that pika populations may reach high densities and correspondingly reduce forage for domestic livestock (yak, sheep, horses), and because they may be responsible for habitat degradation. In contrast, we highlight the important role the plateau pika plays as a keystone species in the Tibetan plateau ecosystem. The plateau pika is a keystone species because it: (i) makes burrows that are the primary homes to a wide variety of small birds and lizards; (ii) creates microhabitat disturbance that results in an increase in plant species richness; (iii) serves as the principal prey for nearly all of the plateau's predator species; (iv) contributes positively to ecosystem-level dynamics. The plateau pika should be managed in concert with other uses of the land to ensure preservation of China's native biodiversity, as well as long-term sustainable use of the pastureland by domestic livestock.