Search results for "mammal"
showing 10 items of 667 documents
Comparative Respiratory Physiology in Cetaceans.
2019
In the current study, we used breath-by-breath respirometry to evaluate respiratory physiology under voluntary control in a male beluga calf [Delphinapterus leucas, body mass range (M b): 151-175 kg], an adult female (estimated M b = 500-550 kg) and a juvenile male (M b = 279 kg) false killer whale (Pseudorca crassidens) housed in managed care. Our results suggest that the measured breathing frequency (f R) is lower, while tidal volume (V T) is significantly greater as compared with allometric predictions from terrestrial mammals. Including previously published data from adult bottlenose dolphin (Tursiops truncatus) beluga, harbor porpoise (Phocoena phocoena), killer whale (Orcinus orca), p…
Identifying potential areas of expansion for the endangered brown bear (Ursus arctos) population in the cantabrian mountains (NW Spain)
2019
Many large carnivore populations are expanding into human-modified landscapes and the subsequent increase in coexistence between humans and large carnivores may intensify various types of conflicts. A proactive management approach is critical to successful mitigation of such conflicts. The Cantabrian Mountains in Northern Spain are home to the last remaining native brown bear (Ursus arctos) population of the Iberian Peninsula, which is also amongst the most severely threatened European populations, with an important core group residing in the province of Asturias. There are indications that this small population is demographically expanding its range. The identification of the potential are…
Defaunation and biomass collapse of mammals in the largest Atlantic forest remnant
2016
Large continuous rainforests are the main hope for sustaining the population of large-bodied vertebrates that cannot cope with fragmentation or unsustainable hunting. The Brazilian Atlantic forest is considered a biodiversity hotspot and although highly fragmented, it still contains large forest patches that may be important for the conservation of mammals that require large areas. Here, we estimated species richness, density and biomass of medium- and large-sized mammals along the largest remnant of the Atlantic rainforest, Brazil (the Serra do Mar bioregion), an estimated area of 8000 km2. We recorded 44 species based on 4090 km of diurnal line transects and camera traps, animal tracks an…
Trophic ecology of a Late Pleistocene early modern human from tropical Southeast Asia inferred from zinc isotopes
2021
Tam Pà Ling, a cave site in northeastern Laos, has yielded the earliest skeletal evidence of Homo sapiens in mainland Southeast Asia. The reliance of Pleistocene humans in rainforest settings on plant or animal resources is still largely unstudied, mainly due to poor collagen preservation in fossils from tropical environments precluding stable nitrogen isotope analysis, the classical trophic level proxy. However, isotopic ratios of zinc (Zn) in bioapatite constitute a promising proxy to infer trophic and dietary information from fossil vertebrates, even under adverse tropical taphonomic conditions. Here, we analyzed the zinc isotope composition (66Zn/64Zn expressed as δ66Zn value) in the en…
Environmental change and disease dynamics: effects of intensive forest management on Puumala hantavirus infection in boreal bank vole populations.
2012
Intensive management of Fennoscandian forests has led to a mosaic of woodlands in different stages of maturity. The main rodent host of the zoonotic Puumala hantavirus (PUUV) is the bank vole (Myodes glareolus), a species that can be found in all woodlands and especially mature forests. We investigated the influence of forest age structure on PUUV infection dynamics in bank voles. Over four years, we trapped small mammals twice a year in a forest network of different succession stages in Northern Finland. Our study sites represented four forest age classes from young (4 to 30 years) to mature (over 100 years) forests. We show that PUUV-infected bank voles occurred commonly in all forest age…
Ecological mechanisms can modify radiation effects in a key forest mammal of Chernobyl
2019
International audience; Nuclear accidents underpin the need to quantify the ecological mechanisms which determine injury to ecosystems from chronic low-dose radiation. Here, we tested the hypothesis that ecological mechanisms interact with ionizing radiation to affect natural populations in unexpected ways. We used large-scale replicated experiments and food manipulations in wild populations of the rodent, Myodes glareolus, inhabiting the region near the site of the Chernobyl disaster of 1986. We show linear decreases in breeding success with increasing ambient radiation levels with no evidence of any threshold below which effects are not seen. Food supplementation of experimental populatio…
Bank vole alarm pheromone chemistry and effects in the field
2021
Chemical communication plays an important role in mammalian life history decisions. Animals send and receive information based on body odour secretions. Odour cues provide important social information on identity, kinship, sex, group membership or genetic quality. Recent findings show, that rodents alarm their conspecifics with danger-dependent body odours after encountering a predator. In this study, we aim to identify the chemistry of alarm pheromones (AP) in the bank vole, a common boreal rodent. Furthermore, the vole foraging efficiency under perceived fear was measured in a set of field experiments in large outdoor enclosures. During the analysis of bank vole odour by gas chromatograph…
Applying the Anna Karenina principle for wild animal gut microbiota: Temporal stability of the bank vole gut microbiota in a disturbed environment.
2020
Gut microbiota play an important role in host health. Yet, the drivers and patterns of microbiota imbalance (dysbiosis) in wild animals remain largely unexplored. One hypothesised outcome of stress on animal microbiomes is a destabilised microbial community that is characterised by an increase in inter-individual differences compared with microbiomes of healthy animals, which are expected to be (a) temporally stable and (b) relatively similar among individuals. This set of predictions for response of microbiomes to stressors is known as the Anna Karenina principle (AKP) for animal microbiomes. We examine the AKP in a wild mammal inhabiting disturbed environments by conducting a capture-mark…
Age structure in a newly established and increasing population: initially high proportion of young birds among nesting Great Grey Owls
2020
AbstractThe mechanisms behind expansions of the distribution of a bird species and the ensuing establishment of new populations are poorly known. The distribution of Great Grey Owl (Strix nebulosa) in the western Palearctic has generally expanded towards southwest during the past fifty years, and particularly so in Fennoscandia. In the past decade, the recorded breeding population in Norway, confined to Hedmark county bordering Sweden, increased from 1 pair in 2009 to > 100 pairs in 2017–2018, extending the southwestern border of the distribution > 100 km. We studied the age structure of this expanding population based on the molting pattern of the wing feathers of birds captured at t…
Mixed company : a framework for understanding the composition and organization of mixed‐species animal groups
2020
Mixed‐species animal groups (MSGs) are widely acknowledged to increase predator avoidance and foraging efficiency, among other benefits, and thereby increase participants' fitness. Diversity in MSG composition ranges from two to 70 species of very similar or completely different phenotypes. Yet consistency in organization is also observable in that one or a few species usually have disproportionate importance for MSG formation and/or maintenance. We propose a two‐dimensional framework for understanding this diversity and consistency, concentrating on the types of interactions possible between two individuals, usually of different species. One axis represents the similarity of benefit types …