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Many terrestrial mammalian migrations are disappearing before they are documented. The Boma-Jonglei ecosystem in South Sudan, one of the world’s poorest and most conflicted countries, contains some of the largest, longest, and least studied ungulate migrations. A rapidly increasing human population, ongoing armed conflict, and looming oil development, however, threatens the migration of 800,000 white-eared kob (Kobus kob leucotis) and 160,000 tiang (Damaliscus lunatus tiang) in this system. To document these migrations and identify potential conflicts, we examined the movements of ungulates in the Boma-Jonglei ecosystem using data from 14 collared individuals (12 kob, 2 tiang). We identified two separate dry season ranges of kob; from each, kob initiated migration with the onset of the rainy season, and migrated to a shared rainy season range also shared by the tiang. The maximum straight-line distance between telemetry locations of kob (399 km) and tiang (298 km) on their dry and rainy season ranges indicated these migrations were among the longest in Africa. The kob range was 68,805 km2, 29% of which was within national parks and 72% within leased oil concessions (54–83% of parks overlap with potential oil concessions). The range of the tiang (35,992 km2) occurred almost entirely (> 99%) within land leased to oil companies. Because disruption or elimination of these migrations will inevitably lead to significant population reductions, maintenance of the migration routes we identified through additional protection measures are essential to conserve one of the largest ungulate aggregations in the world.

We hand-captured, fitted with motion-sensitive VHF transmitters, and monitored 19 newborn (1–2 days old) Mongolian gazelle Procapra gutturosa Pallas, 1777 calves in Dornod, Mongolia during the 2000 and 2003 calving seasons to identify changes in activity, movements, and sociality with age. Overall, activity was highly variable throughout the day, regardless of age or year. Calf activity increased, however, from day 2 (age = 2 days; 18% total activity) to day 7 (29%), and 3-fold by day 25 (54%). By days 5–8, calves had moved an average of 6.6 km (range: 2–21 km) from capture sites but were still only seen alone or with their mother. By day 24–26, however, they were located an average of 41 km (range: 24–63 km) away from their capture site, and most (7 of 9) were in aggregations of >1000 animals. Mongolian gazelles do not display behaviour associated with “hiders” after about 2–3 weeks. This reflects the wide-ranging, nomadic existence of the species.

Because of its crucial importance for the persistence of the endangered Tehuantepec jackrabbit (Lepus flavigularis), we identified structural characteristics of native vegetation (1) selected by Tehuantepec jackrabbits to establish home ranges, (2) used within home ranges, and (3) in relation to activity and inactivity periods. A neotropical savanna in the Isthmus of Tehuantepec, Oaxaca, Mexico, offered diversity in native flora and heterogeneity in vegetation structure to the studied population of Tehuantepec jackrabbit. Adults and juveniles differed in habitat use patterns. No effect on habitat selection was detected for sex or season. Jackrabbits established home ranges on grassy habitat with discontinuous overstory of nanche (Byrsonima crassifolia) shrubbery and morro (Crescentia) trees. Adults underused dense vegetation where predators may ambush them; juveniles avoided dense vegetation and grassland without overstory. Within adults’ home ranges, habitat selection favoring grassy habitats with nanche and morro was relatively stronger during the activity period (nocturnal and crepuscular hours) and during one of 2 years which had more rainfall. Scattered trees and open shrubbery likely allowed foraging jackrabbits with both visibility and escape routes used to detect and outrun predators. Moreover, during the inactivity period (diurnal hours) adults and juveniles favored nanche shrubbery that provided resting jackrabbits with shelter to hide from predators. Clearly, structure and diversity of native vegetation in the savanna needs to be preserved for conservation of Tehuantepec jackrabbits because deteriorated habitat may pose higher predation rates for a jackrabbit population in risk of extirpation.

In northcentral Namibia, Waterberg Plateau Park (WPP) is a protected area that acts as a refuge for rare and endangered species, while the farmlands surrounding the Park are managed for livestock production, but support populations of wildlife for game farming, trophy hunting, and conservation. During June–October 2006, camera-traps were set within and surrounding WPP to assess leopard (Panthera pardus) density (n = 19 camera stations and 946 camera-trap-nights). Fortuitously, photographic results (2,265 photos of identifiable mammal (n = 37) and bird (n = 25) species) allowed us to assess aspects of species diversity and differences among the Park, the farmland areas along the Waterberg Plateau escarpment, and the flatlands surrounding the escarpment. Species composition among the three areas was markedly different, and made sense with respect to differences in habitat and management features. Camera-trapping efforts, although intended for a narrow purpose, may also provide a rather robust record of differences in mammal and bird diversity in adjacent habitats and can be incorporated into long-term monitoring programs.

If climate limits the geographical distribution of a species, local variation in microclimate may affect the species' local distribution at the edge of its range. We hypothesized that warm urban microclimates may explain the distribution of the Virginia opossum (Didelphis virginiana )i ncentral Massachusetts. We recorded winter temperatures with data-logging sensors in urban, coniferous, deciduous, and open habitats in the human- dominated landscape of the Connecticut River Valley of Massachusetts. Overall, temperatures decreased with elevation. Daily maximum temperatures, a variable used in models of opossum biophysical constraints, were lowest at forested sites, intermediate at urban sites, and highest at open sites; however these were a poor indicator of evening temperatures, which are important to the nocturnal opossum. Open sites had the highest daily temperature fluctuations, and were the coldest at night. Urban and coniferous sites had the least pronounced daily fluctuations in temperature, and urban sites had the warmest nights. Habitat-specific winter temperatures in the Connecticut River Valley indicated that urban sites were most conducive to opossum persistence, but even they were unlikely to sustain populations. Other factors likely help mitigate the influence of harsh climatic conditions on persistence of opossum populations in western Massachusetts.

We examined the relative roles of dominance in agonistic interactions and energetic constraints related to body size in determining local abundances of coyotes (Canis latrans, 8-20 kg), gray foxes (Urocyon cinereoargenteus, 3-5 kg) and bobcats (Felis rufus, 5-15 kg) at three study sites (hereafter referred to as NP, CP, and SP) in the Santa Monica Mountains of California. We hypothesized that the largest and behaviorally dominant species, the coyote, would exploit a wider range of resources (i.e., a higher number of habitat and/or food types) and, consequently, would occur in higher density than the other two carnivores. We evaluated our hypotheses by quantifying their diets, food overlap, habitat-specific abundances, as well as their overall relative abundance at the three study sites. We identified behavioral dominance of coyotes over foxes and bobcats in Santa Monica because 7 of 12 recorded gray fox deaths and 2 of 5 recorded bobcat deaths were due to coyote predation, and no coyotes died as a result of their interactions with bobcats or foxes. Coyotes and bobcats were present in a variety of habitats types (8 out of 9), including both open and brushy habitats, whereas gray foxes were chiefly restricted to brushy habitats. There was a negative relationship between the abundances of coyotes and gray foxes (P=0.020) across habitats, suggesting that foxes avoided habitats of high coyote predation risk. Coyote abundance was low in NP, high in CP, and intermediate in SP. Bobcat abundance changed little across study sites, and gray foxes were very abundant in NP, absent in CP, and scarce in SP; this suggests a negative relationship between coyote and fox abundances across study sites, as well. Bobcats were solely carnivorous, relying on small mammals (lagomorphs and rodents) throughout the year and at all three sites. Coyotes and gray foxes also relied on small mammals year-round at all sites, though they also ate significant amounts of fruit. Though there were strong overall interspecific differences in food habits of carnivores (P