نتایج جستجو برای: spermophilus xanthoprymnus
تعداد نتایج: 364 فیلتر نتایج به سال:
We report the first case of directly observed infanticide in the Alpine marmot (Marmota marmota). Moreover, previous and present observations suggest that 12 young could have been killed by infanticide in the population under study. The bodies of five of them were found with similar neck injuries. In all cases, infanticidal animals were adult males entering a territory in the absence of the res...
1. To examine the hypothesis that stimulation of immune function plays a role in periodic arousal from hibernation, bacterial growth during hibernation was estimated using a simple mathematical model of the general dynamics of bacterial abundance at body temperatures experienced during hibernation. 2. In the model, periodic arousals were important for animals infected with Salmonella at body te...
A new genus of sciurid, Cynomyoides, is named. The new genus includes a new species from the late Clarendonian of Nebraska, C. vatis (type species), and an unnamed species from the early Barstovian of Montana. The dental and mandibular morphology of Cynomyoides is reminiscent of that of the latest Tertiary to Recent prairie dog Cynomys and is believed to be part of the lineage leading to Cynomy...
Fecal samples from arctic ground squirrels (Spermophilus parryii) collected in Alaska (n = 90) and Russia (n = 46) and from red squirrels (Tamiasciurus hudsonicus) in Alaska (n = 35) were examined for the presence of Eimeria spp. (Apicomplexa: Eimeriidae). Four species were recovered from arctic ground squirrels, including Eimeria callospermophili (prevalence = 18%), Eimeria cynomysis (23.5%), ...
Animal communication theory holds that many signals have evolved from nonsignal precursors. This field and laboratory study of California ground squirrels (Spermophilus beecheyi) provides evidence for the coexistence of such a precursor with its derived display. The precursor is an ancient, endogenously sequenced (syntactic) pattern of cephalocaudal grooming movements (CCGs) shared by all roden...
A field study was conducted in Lewis and Clark County, Montana, during the summer of 1986 to determine the fate of Columbian ground squirrel (Spermophilus columbianus) carcasses in the environment. Ground squirrel carcasses were marked with radio transmitters and placed in situations and locations similar to those found in actual rodent control operations. Carcasses were monitored until their f...
In order to survive, small burrowing mammals need to remember the locations of escape burrows. Therefore, it is important to know what types of landmarks are used to aid navigation in the wild. The author tested the ability of free-ranging Columbian ground squirrels (Spermophilus columbianus) to locate escape burrows when local (e.g., vegetation pattern, local relief), global (e.g., forest edge...
The acoustic structure of calls within call types can vary as function of individual identity, sex, and social group membership and is important in kin and social group recognition. Belding’s ground squirrels ~Spermophilus beldingi! produce alarm chirps that function in predator avoidance but little is known about the acoustic variability of these alarm chirps. The purpose of this preliminary s...
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