Dynamics of direct inter-pack encounters in endangered African wild dogs

Aggressive encounters may have important life history consequences due to the potential for injury and death, disease transmission, dispersal opportunities or exclusion from key areas of the home range. Despite this, little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters in detail. Here, we describe detailed spatial dynamics of inter-pack encounters in African wild dogs (Lycaon pictus), using data from custom-built high-resolution GPS collars in 11 free-ranging packs. On average, each pack encountered another pack approximately every 7 weeks and met each neighbour twice each year. Surprisingly, intruders were more likely to win encounters (winning 78.6% of encounters by remaining closer to the site in the short term). However, intruders did tend to move farther than residents toward their own range core in the short-term (1 h) post-encounter, and if this were used to indicate losing an encounter, then the majority (73.3%) of encounters were won by residents. Surprisingly, relative pack size had little effect on encounter outcome, and injuries were rare (<15% of encounters). These results highlight the difficulty of remotely scoring encounters involving mobile participants away from static defendable food resources. Although inter-pack range overlap was reduced following an encounter, encounter outcome did not seem to drive this, as both packs shifted their ranges post-encounter. Our results indicate that inter-pack encounters may be lower risk than previously suggested and do not appear to influence long-term movement and ranging

Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at root s=7 TeV

A search for the Higgs boson produced in association with a W or Z boson in proton-proton collisions at a center-of-mass energy of 7 TeV is performed with the CMS detector at the LHC using the full 2011 data sample, from an integrated luminosity of 5 fb−1. Higgs boson decay modes to ττ and WW are explored by selecting events with three or four leptons in the final state. No excess above background expectations is observed, resulting in exclusion limits on the product of Higgs associated production cross section and decay branching fraction for Higgs boson masses between 110 and 200 GeV in these channels. Combining these results with other CMS associated production searches using the same dataset in the H→ γγ and H→ b b¯ decay modes, the cross section for associated Higgs boson production 3.3 times the standard model expectation or larger is ruled out at the 95% confidence level for a Higgs boson mass of 125 GeV

Hunting Success of African Wild Dogs in Southwestern Kenya

A pack of 19–29 African wild dogs (Lycaon pictus) in the Masai Mara area of Kenya was monitored during July–August 1989 to document their success in capturing various ungulate species. The pack was most successful killing smaller, abundant ungulate prey, and was not less successful when pack size abruptly was reduced; overall hunting success (all species) was 51%. Abundant prey, low competition with other large carnivores, and large size of pack confound conjecture concerning the evolution of pack size

Prey and estimated food consumption of African wild dogs in Kenya

During 1990, two radio-marked packs of Lycaon pictus were monitored at three different times for 6-25 days each in the Masai Mara area of SW Kenya to estimate prey consumption rates. Male Thomson\u27s gazelles Gazella thomsoni and young wildebeests Connochaetes taurinus were the most common prey. During either a morning (n = 19) or evening (n = 26) monitoring session, some packs did not hunt (11-45% of sessions) or hunted unsuccessfully (60-100% success/session). Packs sometimes lost part or all of a kill (0-27% of kills) to avian or mammalian scavengers. Minimum estimated consumption rates for all three packs (0.08-0.20 kg prey/kg dog/day) seemed to reflect, at a minimum, variation in hunting success, age of pups, and competition with other species (related to pack size)

Serologic Survey of Selected Canine Pathogens Among Free-Ranging Jackals in Kenya

Serum samples from 76 free-ranging adult jackals of three species from four localities in Kenya were examined for circulating antibodies against four canine pathogens: rabies virus, canine parvovirus (CPV-2), canine distemper virus (CDV), and Ehrlichia canis. Samples were collected between April 1987 and January 1988. Among black-backed jackals (Canis mesomelas), the most sampled species, the mean prevalence of antibodies to CPV-2, CDV, rabies virus, and E. canis was 34% (14 positive/55 sampled), 9% (4/55), 3% (1/28), and 2% (1/36), respectively. There were no significantly differences among sampling locations. In one area, antibody prevalence of CPV-2 was significantly higher for golden jackals (C. aureus; 9/16) than for C. mesomelas (5/26). Only three side-striped jackals (C. adustus) were sampled, but antibodies to CPV-2 and CDV were present. As jackals often are the most abundant wild carnivore in African ecosystems, they could serve as an important indicator species to monitor the potential of exposure of rare and endangered canids to specific canine diseases