Comparative Foraging Efficiency of Two Sympatric Jackals, Silver-Backed Jackals ( Canis mesomelas

The foraging efficiency of two sympatric species of jackals, silver-backed jackals (Canis mesomelas) and golden jackals (Canis aureus), was studied in the Ngorongoro crater from July 2014 through May 2015. The focal animal observation method was used and individuals of both species were followed as they foraged from morning to evening. Observations of individuals of both jackal species were made from a vehicle using binoculars and a spotting scope. Three major parameters were used for determination of foraging efficiency: distance travelled while foraging, time spent foraging, and amount of food secured in foraging period. The Mann–Whitney U test showed no significant difference (P>0.05) in distance travelled per unit time of foraging between the two species in the dry and wet seasons, respectively. Golden jackals secured a significantly higher amount of food than the silver-backed jackals in the wet season (Mann–Whitney U test, P<0.05, U=1035.4). Hunting of prey larger than Thomson’s gazelle (Eudorcas thomsonii) fawns was not common. Both species mainly fed on smaller prey such as invertebrates and rodents and scavenged opportunistically. Efficient foraging is crucial for both jackal species especially during their breeding season when they are provisioning dependent pups

Food preferences of golden jackals and sympatric red foxes in European temperate climate agricultural area (Hungary)

Differences in food preferences between two sympatric canids, the golden jackal (Canis aureus), which is currently spreading from south-east Europe and is a little-known species in Europe, and the red fox (Vulpes vulpes) were investigated. Data on diet composition and food availability were collected over a 13-season period, in a temperate climate agricultural area of Hungary. We found that jackals and foxes preferred small mammals (Ivlev’s electivity index, Eis0.38 and 0.39, respectively), and avoided towards wild boar (Eis -0.43 and -0.56, respectively) and cervids (Eis-0.92 and -0.94, respectively). Jackals preferred pheasant less than foxes (Eis0.06 and 0.51, respectively). Within small mammals, both predators preferred the open field living species, with the forest living species being less favoured. The relationship between the available biomass of small mammals, as the primarily important food resource for both canids, and the proportion of consumed biomass of small mammals was not close. This was probably as a result of abundant food resources and high trophic flexibility of the golden jackal and red fox allowing these two closely related carnivores to coexist sympatrically in Central European areas without resource partitioning

On the mating system of the cooperatively breeding saddle-backed tamarin ( Saguinus fuscicollis )

This paper reports on 5 years of observatiors of individually marked saddle-backed tamarins ( Saguinus fuscicollis , Callitrichidae). Although callitrichids have long been presumed to have a monogamous social system, this study shows that the breeding structure of saddle-back tamarin groups is highly variable. Groups most commonly include two or more adult males and a single reproductive female, but occasionally contain only a single pair of adults, or less often, two reproductively active females and one or more males. Data on group compositions, group formations, intergroup movements and copulations show that the social and mating systems of this species are more flexible than those of any other non-human primate yet studied. Infants (usually twins) were cared for by all group members. There were two classes of helpers: young, nonreproductive individuals who helped to care for full or half siblings, and cooperatively polyandrous males who cared for infants whom they may have fathered. The observations suggest that non-reproductive helpers may benefit from their helping behavior through a combination of inclusive fitness gains, reciprocal altruism, and the value of gaining experience at parental care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46874/1/265_2004_Article_BF00295541.pd

The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action

Surveys of small mammals in Tarangire National Park, Tanzania

Small mammals were sampled in Tarangire National Park between 1994 and 1996. Twenty-six species of small mammals, including four species of Soricomorpha, seven species of Chiroptera and 15 species of Rodentia were documented, with some records being the first for the park. Identifications and natural history data (including a list of associated arthropods) are presented for each of the 26 species. Keywords: Tarangire, mammals, Tanzania, rodents, bats, shrews East African Journal of Natural History Vol. 96 (1) 2007: pp. 47-7

Social organization, home ranges, and extraterritorial forays of black‐backed jackals

We radio‐tracked 15 black‐backed jackals(Canis mesomelas)from 8 adjacent family groups onBenfontein Game Farm(i.e., Benfontein)in South Africa to investigate their movement patterns and socialorganization. Jackal family groups consisted of mated pairs(alphas),0–3 nonbreeding adults(betas), andpups, depending on the season. Mean(±SE)home‐range size of alphas(9.4±1.2 km2,n=6)did not differ(P=0.766)from betas(9.8±0.7 km2,n=8). Most beta jackals(8of10)remained philopatric on Ben-fontein, apparently because of the high density of springbok(Antidorcas marsupialis), their preferred prey.Three of 5 alphas and all 8 betas went on extraterritorial forays(i.e., forays). Generally, betas spent more oftheir active time on forays(2–20% of time)than alphas(0–3%;P=0.048), and betas went farther on forays(2–8km)than alphas(2–3 km;P=0.003). The number of forays differed(P<0.001)among seasons; mostforays occurred during summer(64%)when jackals visited neighboring livestock farms, apparently topredate on domestic sheep. Overall, our results indicate forays by jackals are affected by social status,seasonal availability of preferred prey, and the reproductive cycle of jackals. To reduce jackal predation onlivestock farms near reserves, we recommend that preventative measures(e.g., use of herders, jackal controlactivities)be increased during summer when jackals are most likely to travel outside reserves. © 2019 TheWildlife Society