For decades, researchers have employed sound to study the biology of wildlife, with the aim to better understand their ecology and behaviour. By utilizing on-animal recorders to capture audio from freely moving animals, scientists can decipher the vocalizations and glean insights into their behaviour and ecosystem dynamics through advanced signal processing. However, the laborious task of sorting through extensive audio recordings has been a major bottleneck.
View Article and Find Full Text PDFCognition helps wildlife exploit novel resources and environments. Raccoons () have successfully adapted to human presence, in part due to their cognitive abilities. However, interactions between humans and wildlife can create conflict.
View Article and Find Full Text PDFAllonursing is the nursing of the offspring of other mothers. Cooperation is an emergent property of evolved decision rules. Cooperation can be explained by at least three evolved decision rules: 1) direct reciprocity, i.
View Article and Find Full Text PDFIn polygynous systems, such as that exhibited by reindeer , mate choice can be difficult to disentangle from male intrasexual competition because male behavior may constrain female choice. Multiple mating may provide an avenue for female mate choice, though it is difficult to identify using behavioral estimators alone. Molecular techniques address this issue by affording ecologists an opportunity to reassess mating systems from a genetic perspective.
View Article and Find Full Text PDFMost studies assessing the impact of noises on zoo animal welfare did not measure sound frequencies outside of the human-hearing range (infrasounds and ultrasounds). Many nonhuman mammals can hear these frequencies, and because loud and variable soundscapes are potentially detrimental for animal welfare, this overlooked aspect of their acoustic environment could have important consequences. This study evaluated the soundscape of an urban zoo in a large frequency range (17.
View Article and Find Full Text PDFBackground: The breeding time of many species has changed over the past 2-3 decades in response to climate change. Yet it is a key reproductive trait that affects individual's parturition time and reproductive success, and thereby population dynamics. In order to predict how climate change will affect species' viability, it is crucial to understand how species base their reproductive efforts on environmental cues.
View Article and Find Full Text PDFA developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species' reproductive success to decrease. The match-mismatch hypothesis (MMH) is an appealing concept that can be used to assess such fitness consequences. However, concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies.
View Article and Find Full Text PDFPhenotypic plasticity has become a key concept to enhance our ability to understand the adaptive potential of species to track the pace of climate change by allowing a relatively rapid adjustment of life-history traits. Recently, population-level trends of an earlier timing of reproduction to climate change have been highlighted in many taxa, but only few studies have explicitly taken into consideration between-individual heterogeneity in phenotypic plasticity. Using a long-term data of a semi-domesticated reindeer (Rangifer tarandus) population, we demonstrated that females differed greatly in their mean calving date but only slightly in the magnitude of their plastic response to the amount of precipitation in April.
View Article and Find Full Text PDFAlthough many studies investigating the impacts of zoo exhibit designs on captive animals exist, none have been performed on how they influence the behavior and welfare of captive Bennett's wallabies (Macropus rufogriseus). Here, we assess the impact of exhibit design on the activity budget and spatial distribution of Bennett's wallabies. We compared animal behavior in two open exhibits (i.
View Article and Find Full Text PDFIn a context of climate change, a mismatch has been shown to occur between some species' reproductive phenology and their environment. So far, few studies have either documented temporal trends in calving phenology or assessed which climatic variables influence the calving phenology in ungulate species, yet the phenology of ungulates' births affects offspring survival and population's recruitment rate. Using a long-term dataset (45 years) of birth dates of a semi-domesticated reindeer population in Kaamanen, North Finland, we show that calving season has advanced by ~ 7 days between 1970 and 2016.
View Article and Find Full Text PDFIn polygynous species, sexual selection is mostly driven by male ability to monopolize access to females in oestrous. In ungulates, the operational sex ratio (OSR), i.e.
View Article and Find Full Text PDFDominance hierarchies play an important role in reducing competition and aggression in social animals. In zoos, changes in group composition are often required due to management protocols, but these changes may have long lasting effects on dominance hierarchies, and, consequently, the wellbeing of the animals. We studied the changes in the female dominance hierarchy that occurred both during and after the formation of a group of 10 adult Japanese macaques at the Zoo de Granby by combining members from two previously established groups.
View Article and Find Full Text PDFMale harassment toward females during the breeding season may have a negative effect on their reproductive success by disturbing their foraging activity, thereby inducing somatic costs. Accordingly, it is predicted that females will choose mates based on their ability to provide protection or will aggregate into large groups to dilute per capita harassment level. Conversely, increasing group size may also lead to a decrease in foraging activity by increasing foraging competition, but this effect has rarely been considered in mating tactic studies.
View Article and Find Full Text PDFAllosuckling, the suckling of offspring from females other than their own mother, has been reported in a number of mammalian species, including reindeer. The causes and function of this behaviour are still being investigated. We monitored 25 doe-calf pairs of semi-domestic reindeer Rangifer tarandus over 10 weeks to test three allosuckling/allonursing hypotheses: (1) milk theft, calves opportunistically allosuckle; (2) mismothering, misdirected maternal care; and (3) kin-selected allonursing.
View Article and Find Full Text PDFDuring the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group's fission probability, instead of inter-harem movement.
View Article and Find Full Text PDFTwo different processes can lead to a change in individual reproductive output with age in long-lived iteroparous vertebrates. The senescence hypothesis predicts a decline of performance in old age, whereas the terminal allocation hypothesis predicts an increase. Using long-term (>30 years) individually based data of female reindeer, we first assessed age-specific variation in body mass and different components of reproductive output.
View Article and Find Full Text PDF1. Increasing ungulate populations are affecting vegetation negatively in many areas, but few studies have assessed the long-term effects of overbrowsing on individual life-history traits of ungulates. 2.
View Article and Find Full Text PDFReproductive allocation at one age is predicted to reduce the probability of surviving to the next year or to lead to a decrease in future reproduction. This prediction assumes that reproduction involves fitness costs. However, few empirical studies have assessed whether such costs may vary with the age at primiparity or might be overridden by heterogeneities in individual quality.
View Article and Find Full Text PDFIn polygynous species, mate choice is an integrated part of sexual selection. However, whether mate choice occurs independently of the genetic relatedness among mating pairs has received little attention, although inbreeding may have fitness consequences. We studied whether genetic relatedness influenced females' choice of partner in a highly polygynous ungulate--the reindeer (Rangifer tarandus)--in an experimental herd during two consecutive rutting seasons; the herd consisting of 75 females in 1999 and 74 females in 2000 was exposed to three 4.
View Article and Find Full Text PDFThe relative importance of winter harshness and early summer foraging conditions are of prime interest when assessing the effect of global warming on Arctic and mountainous ecosystems. We explored how climate and vegetation onset (satellite-derived normalized difference vegetation index data) determined individual performance in three reindeer populations (data on 27814 calves sampled over 11 years). Snow conditions, spring temperatures and topography were the main determinants of the onset of the vegetation.
View Article and Find Full Text PDFLongevity is the main factor influencing individual fitness of long-lived, iteroparous species. Theories of life history evolution suggest this is because increased longevity allows individuals to (i) have more breeding attempts (time component), (ii) accumulate experience so as to become better able to rear offspring (experience component) or (iii) because individuals reaching old age have above-average quality (quality component). We assess empirically the relative influences of time, experience and quality on the relationship between longevity and individual fitness among female reindeer.
View Article and Find Full Text PDFLarge mammals in seasonal environments have a pattern of high-reproductive synchrony in spring, but how the timing of reproduction affects resource allocation decisions at different stages of the reproductive cycle remains largely unexplored. By manipulating the timing of conception in reindeer (Rangifer tarandus), we tested how the timing of conception affected sex ratio, gestation length and weight development of mother and offspring. Females that conceived at their first ovulation within the rut had a 60.
View Article and Find Full Text PDFWe analysed intercohort variability of live weight and antler length of 5,123 reindeer calves. We further assessed the influence of climate and density on the interannual variation in antler length, and discussed sex-specific resource allocation and response to climate variability. Antler length varied significantly among years and between sexes, with interaction between year and sex.
View Article and Find Full Text PDFAnthropogenic fires in Africa are an ancient form of environmental disturbance, which probably have shaped the savanna vegetation more than any other human induced disturbance. Despite anthropogenic fires having played a significant role in savanna management by herders, previous ecological research did not incorporate the traditional knowledge of anthropogenic fire history. This paper integrates ecological data and anthropogenic fire history, as reconstructed by herders, to assess landscape and regional level vegetation change in northeastern Namibia.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
April 2004
Milk yield and composition of major milk constituents were measured in captive, nursing reindeer. Registration of milk production was performed during two successive lactations (2001 and 2002). The milk yield was significantly affected by week of lactation (P<0.
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