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Individual recognition is required in most social interactions, and its presence has been confirmed in many species. In birds, vocal cues appear to be a major component of recognition. Curiously, vocal recognition seems absent or limited in some highly social species such as the black-legged kittiwake, Rissa tridactyla. Using playback experiments, we found that kittiwake chicks recognized their parents vocally, this capacity being detectable as early as 20 days after hatching, the youngest age tested. Mates also recognized each other's long calls. Some birds reacted to their partner's voice when only a part of the long call was played back. Nevertheless, only about a third of the tested birds reacted to their mate's...
Prey-specific anti-predatory behaviour under different degrees of structural complexity determines foraging success of predators. The behaviour of piscivorous fish (largemouth bass, Micropterus salmoides and northern pike, Esox lucius) and their prey (bluegills, Lepomis macrochirus, and fathead minnows, Pimephales promelas) were quantified in 60-min experiments in laboratory pools (2 multiplied by 4 m in diameter, 0 multiplied by 5 m deep) with artificial vegetation at densities of 0, 50, 250, and 1000 stems/m2. Largemouth bass switched predatory tactics from searching to ambushing as plant density increased whereas northern pike always used ambushing. At high plant density, both predators captured minnows, but...
The temporal and spatial distribution of above-ground activith in Merriam's kangaroo rats, Dipodomys merriami, radio-tracked during 10 winters varied in relation to phases of the moon. At the full moon, animals were more likely to be found in their day burrows at scheduled hourly radio fixes, and when they emerged, they stayed closer to home. At partial moon phases, above-ground activity was preferentially allocated to hours when the moon was down. As predicted from an extension of Rosenzweig's (1974, J. Mammal., 55, 193–199) model of optimal above-ground activity, the suppression of nocturnal activity at the full moon was partially offset by relatively great activity at dusk and dawn, and losses to nocturnal...
Fission–fusion dynamics appear common among temperate bats where females form roost groups that change in size and composition, as females switch roosts almost daily. One hypothesis for frequent roost switching is that females move to find suitable thermal conditions as ambient conditions change. Tests of this hypothesis have, however, been conducted mostly at roosts in artificial structures where microclimate is relatively stable. The goal of our study was to determine whether roost switching and roost use by northern long-eared bats, Myotis septentrionalis, that roost in trees are related to ambient conditions. We used generalized linear fixed effects models to explore the influence of roost characteristics and...
The social system of round-tailed ground squirrels, Spermophilus tereticaudus, is quantitatively described in terms of seasonal changes in interaction rates, the effect of age and sex on type and frequency of interaction, the differential response to kin and non-kin, the determinants of dominance, including territoriality, the associations between classes of individuals, and the dispersion of home ranges and core areas. From January to March, the adult squirrels were sociable and nonterritorial. Following copulation in March, they were unsociable and territorial. In May and June, juveniles lived mainly within their mothers' territories. Those juveniles that did not disperse from the study area in late June established...
We examined how short-term impacts of experimentally increased foraging effort by one parent reverberate around the family in a monomorphic seabird (little auk, Alle alle), and whether these effects depend on offspring sex. In many species, more effort is required to rear sons successfully than daughters. However, undernourishment may have stronger adverse consequences for male offspring, which could result in a lower fitness benefit of additional parental effort when rearing a son. We tested two alternative hypotheses concerning the responses of partners to handicapping parents via feather clipping: partners rearing a son are (1) more willing or able to compensate for the reduced contribution of their mate, or...
The amount of food ingested by chicks has often been suggested as being the main proximate factor controlling broodmate aggression in facultatively siblicidal species. Although several experiments have demonstrated that short-term food deprivation causes a temporary increase in aggression, no study has, to our knowledge, experimentally manipulated overall food supplies and considered long-term effects on chick behaviour and life history traits. We provided supplemental food to breeding pairs of black-legged kittiwakes, Rissa tridactyla, over an entire breeding season and compared the aggressive behaviour of their chicks with that of chicks of control pairs. Control A-chicks (first to hatch) showed more frequent...
Five hypotheses of cache recovery behaviour in Clark's nutcracker (Nucifraga columbiana) were examined experimentally. Most caches were made in soil within 5 cm of conspicuous large objects. Both seed-caching and non-seed-caching nutcrackers were able to locate caches. Seed-caching nutcrackers relocated caches using large objects as remembered visual cues. Soil microtopography and small (<2 cm diameter) objects may be used as cues to facilitate cache recovery but are not essential. Non-seed-caching nutcrackers located caches by using soil disturbances at cache sites as visual cues and by searching preferentially near objects where caches were concentrated. Success rates of seed-caching nutcrackers ranged from 52...
A description of the social network of a population aids us in understanding dispersal, the spread of disease, and genetic structure in that population. Many animal populations can be classified as fission–fusion societies, whereby groups form and separate over time. Examples discussed in the literature include ungulates, primates and cetaceans (Lott and Minta, 1983, Whitehead et al., 1991, Henzi et al., 1997, Christal et al., 1998 and Chilvers and Corkeron, 2002). In this study, we use a heuristic simulation model to illustrate potential problems in applying traditional techniques of association analysis to fission–fusion societies and propose a new index of association: the fission decision index (FDI). We compare...
In field-based choice experiments, we examined sex recognition and mate choice in male western toads,Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male?male amplexus never lasted more than 3 s, but male?female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females...
At a colony of Gunnison's prairie dogs, Sciuridae:Cynomys gunnisoni, containing marked individuals of known genetic relationships, anti-predator calling was investigated in response to moving, stuffed specimens of a natural predator, the American badger,Taxidea taxus. Females with kin in the home territory called more often than females without nearby kin, and females with nearby offspring were especially likely to call. Male gunnisons commonly gave anti-predator calls as well, but male calling was unrelated to kinship of nearby listeners. 1996 The Association for the Study of Animal Behaviour Published in Animal Behaviour, volume 51, issue 4, on pages 871 - 880, in 1996.
This work quantifies the geographic variation (dialects) in the vocalizations of southern Rocky Mountain pikas and presents data on the vocal responses of pikas to playback of recorded vocalizations of two dialects. Pika vocalizations were tape-recorded in twenty-six locations in Wyoming, Colorado, Utahnext term and New Mexico. Two dialects (based on duration of note and frequency of fundamental) were found in short calls. One dialect was north of the Colorado River (dialect A), and the other was south of the Colorado River (dialect B). There was seasonal variation in the incidence of vocalizations with a peak of songs in late spring and a peak of short calls in late summer. Results of this study indicate that acoustic...
Six female desert tortoises, Gopherus agassizii, were observed to consume the soil of a ‘limelayer’ on an exposed site, or to excavate through the overburden where the layer was not exposed. The calcium content of soil from the layer mined was significantly higher than that of adjacent surface soil. All geophagous episodes involved reproductively mature females during the nesting season, a period in which the females were in potential calcium stress. To our knowledge this is the first report of mining and long-term exploitation of natural mineral deposits by a lower vertebrate and may represent behaviour at least as complicated as that seen in many ungulates. Published in Animal Behaviour, volume 30, issue 2,...
Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail...
Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest...
Wild and game-farm mallards (Anas platyrhynchos) raised in pure strain and mixed groups were tested for initial mate preference in a choice test. Female mallards showed no significant preference but males of either strain raised with females of their own strain significantly preferred female models of their own strain during the test. Males raised with females of the other strain merely showed attenuation of their preference for female models of their own strain and did not show preference for female models of the other strain. Game-farm mallards approached models significantly sooner than wild mallards and there was a significant sex X mate interaction.
An evaluation of Maynard Smith's models of sexual strategies, credited to Oberdieck, Fernando, published in 1978. Published in Animal Behaviour, volume 26, issue 2, on pages 1 - 1, in 1978.
The detection of stress arising from parasitic infection bySarcoptes scabieisand from pregnancy is explored, using a fractal analysis of head lifting behaviour and feeding–non-feeding activity sequences in female Spanish ibex,Capra pyrenaica, under natural conditions. Because organisms under stress increase their metabolic rate and, in consequence, energy consumption, it follows that stress will, generally, lead to a reduction in complexity (fractal dimension) of exploratory behaviour. In the present study the fractal dimension of the three measures of complexity used declined with stress, both from pregnancy and from parasitic infection. This observation provides a new and effective way to assess the general state...
Two hypothesized benefits of delayed dispersal are access to resources and prolonged brood care (or??parental nepotism). Resource abundance (mistletoe wealth) is a key factor influencing whether sons stay home in western bluebirds, Sialia mexicana, but nepotism is also observed. Western bluebird sons commonly remain in their family groups throughout the winter, whereas daughters usually disperse before winter. Because pairing often takes place in winter groups, with newly formed pairs settling on exclusive all-purpose territories in spring, selection for sexual competition and nepotism co-occur and may simultaneously influence patterns of aggression within groups. We measured aggression at mealworm feeder stations,...
One foraging strategy that scavengers can employ to discover unpredictable food sources is to associate directly with predators who inadvertently provide food. The common raven, a well known feeding generalist, is also a prominent scavenger of wolves' kills and is found to be in close association with this predator. We tested the hypothesis that ravens preferentially associate with wolves in winter as a kleptoparasitic foraging strategy. The presence, absence and behaviour of ravens was documented during winter observations of wolves, coyotes, Canis latrans, and elk, Cervus elaphus, as well as the landscape in the absence of these three species. Ravens were found to be in close association with wolves when they...
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