Search results for "Animal Science and Zoology"
showing 10 items of 2095 documents
Increasing intensity of deimatic behaviour in response to repeated simulated attacks: a case study on the mountain katydid (Acripeza reticulata)
2022
Abstract How and when deimatic behaviours are performed can change during encounters between predators and prey. Some predators attack repeatedly, investigating and manipulating prey, and in response, an individual’s deimatic behaviour may intensify or may diminish in favour of escaping. The presence of a resource can further force a trade-off between displaying and escaping. Here, we examined the intensity of the katydid’s deimatic behaviour, a visual display, the propensity of their escape response under repeated simulated attacks, and how these responses change in the presence of foraging resources. We found that display intensity increased with repeated simulated attacks and that femal…
Reduction in site fidelity with smaller spatial scale may suggest scale-dependent information use
2014
Animals change the strategy that they use to select breeding sites at the spatial scales of habitat, patch, and microhabitat. In this regard, breeding site fidelity is expected to vary according to environmental predictability, which, in turn, is expected to differ between each spatial scale. However, whether or not animals change their degree of site fidelity at different spatial scales remains unclear. We captured and released males of the terrestrial frog Pseudophryne bibronii into alternative patches within a breeding habitat and determined the extent to which site fidelity influenced individual nest-site choice. We found that males tended to return to their original patch rather than r…
Welcome aboard: are birds migrating across the Mediterranean Sea using ships as stopovers during adverse weather conditions?
2022
Birds use stopovers during migration to interrupt endurance flight in order to minimize immediate and/or future fitness costs. Stopovers on ships is considered an exceptional and anecdotal event in the ornithological literature. This does not match the experience we had in the summer of 2021, during an oceanographic campaign in the Central Mediterranean, when we regularly observed on average 2.8 birds, of at least 13 species, stopping on board during the 25 days of the campaign. The median stopping time was 42 min, ranging from a few minutes to overnight stays on board. The probability of finding a bird stopping aboard increased with wind force and cloud cover. Birds also stopped more often…
Copulation duration, but not paternity share, potentially mediates inbreeding avoidance in Drosophila montana
2014
Studying the incidence of inbreeding avoidance is important for understanding the evolution of mating systems, especially in the context of mate choice for genetic compatibility. We investigated whether inbreeding avoidance mechanisms have evolved in the malt fly, Drosophila montana, by measuring mating latency (a measure of male attractiveness), copulation duration, days to remating, offspring production, and the proportion of offspring sired by the first (P1) and second (P2) male to mate in full-sibling and unrelated pairs. SNP markers were used for paternity analysis and for calculating pairwise relatedness values (genotype sharing) between mating pairs. We found 18 % inbreeding depressi…
Shaping the antipredator strategy: flexibility, consistency, and behavioral correlations under varying predation threat
2014
9 pages; International audience; Recent ecological and evolutionary research emphasizes the importance of adaptive trait integration. For instance, antipredator defenses are built up of several morphological and behavioral components in many species, yet their functional relationships are still poorly documented. Using field-collected freshwater crustaceans Gammarus fossarum in a within-subject design, we investigated the flexibility and consistency of refuge use, photophobia, and exploration behavior as well as their associations, quantified both when predation risk was absent or artificially simulated. In agreement with the "threat-sensitivity" hypothesis, both refuge use and photophobia …
Evaluation of yogurt and various beverages as carriers of lactic acid bacteria producing 2-branched (1,3)-β-D-glucan
2011
8 páginas, 2 figuras, 2 tablas -- PAGS nros. 3271-3278
Invasive catfish in northern Italy and their impacts on waterbirds
2022
Predatory fish have occasionally been observed preying on birds, sometimes repeatedly, but few studies were able to unravel the overall significance of avian prey in fish diet and the predation impacts on bird populations. We used a control/impact study setup, using a Nature Reserve in northern Italy and a nearby control area, to determine: 1) the contribution of waterbirds to wels catfish diet in the Reserve, 2) the population density of wels catfish in the Reserve and control area and 3) the potential impacts of waterbird depredation by wels catfish on waterbird population trends. Our stable isotope Bayesian mixing model indicated that birds contributed 12.2% (5–27.9%, 50% confidence inte…
Productivity of an Atriplex halimus shrubbery and effects of grazing on lambs
2009
The objectives of this study were to 1) evaluate the productivity and forage quality of Atriplex halimus, 2) investigate modifications to shrub structure induced by grazing, and 3) assess live weight changes in lambs grazing on A. halimus with and without a feed supplement (wheat straw ± barley grain). The results showed that A. halimus had low productivity (approximately 1000 kg DM ha–1) but high tolerance to grazing by lambs, although minor modifications in plant structure due to grazing were observed. Lambs grazing A. halimus as a sole diet lost weight (about 60 g lamb−1 d–1; P < 0.01), probably as a consequence of the high salt content of the forage reducing bot…
Do Tengmalm's owls see vole scent marks visible in ultraviolet light?
1997
Scent markings (urine and faeces) of small mammals are visible in ultraviolet (UV) light. Diurnal kestrels, Falco tinnunculususe them as a cue to find areas of food abundance. We studied whether vole-eating, nocturnal Tengmalm's owls, Aegolius funereuscan see vole scent marks using UV-vision. In a laboratory experiment, 14 young (less than 6 months old) and 14 adult (more than 6 months old) owls were individually given a choice between four adjacent arenas: (1) an arena with vole urine and faeces in UV light; (2) an arena with vole urine and faeces in visible light; (3) a clean arena in UV light; and (4) a clean arena in visible light. Owls did not prefer any of the four arenas. Our results…
Plumage colour and male-male interactions in the pied flycatcher
1993
Abstract Abstract. The influence of male colour on male-male interactions in the pied flycatcher, Ficedula hypoleuca , was studied using several types of field experiments. This species exhibits delayed plumage maturation, each male becoming more conspicuously black and white from the first to the second breeding summer. However, individual males vary even more, some old males being as brown as females. When territorial males were presented with a choice between brown and black male intruders (or brown males painted black) they directed more aggression towards the black males. Brown plumage did not help males obtain nestboxes close to other males. If anything browner males were at a disadva…