The Experts below are selected from a list of 5442 Experts worldwide ranked by ideXlab platform
Robert M R Barclay - One of the best experts on this subject based on the ideXlab platform.
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thermoregulation and roost selection by reproductive female big brown bats eptesicus fuscus roosting in rock crevices
Journal of Zoology, 2003Co-Authors: Cori L Lausen, Robert M R BarclayAbstract:A free-ranging maternity colony of big brown bats Eptesicus fuscus roosting in rock crevices along the South Saskatchewan River in south-eastern Alberta, Canada, was studied to understand better the discrepancy that exists in the literature regarding torpor use by reproductive female bats. Using radio-telemetry, thermoregulatory patterns and roost microclimate were recorded for pregnant, Lactating and post-Lactating Females. Relative torpor use is described in several ways: the proportion of days on which torpor was used, depth, minimum body temperature, time spent in torpor, and a comprehensive torpor unit (degree-min). Pregnant and Lactating female E. fuscus used torpor to the same extent overall (degree-min), but pregnant bats used torpor less frequently and with more time in deep torpor. Torpor was used to the greatest extent after weaning (post-lactation). Evidence is presented that the cost : benefit ratio for deep and prolonged periods of torpor may be highest during lactation. Microclimates of rockcrevice roosts mirrored the use of torpor throughout reproduction by bats. Lactation roosts (deeper, larger opening size) were more thermally stable and remained warmer at night compared to the shallow roosts used by pregnant and post-Lactating Females. It is shown that conclusions about relative use of torpor can differ depending on the units of comparison, necessitating measurement of all aspects of torpor (depth, duration and frequency). Comprehensive measurements, individual-based normothermic temperatures, and a definition of torpor that accounts for all energy savings, allow a more accurate depiction of patterns and facilitates inter-study comparisons.
Cori L Lausen - One of the best experts on this subject based on the ideXlab platform.
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thermoregulation and roost selection by reproductive female big brown bats eptesicus fuscus roosting in rock crevices
Journal of Zoology, 2003Co-Authors: Cori L Lausen, Robert M R BarclayAbstract:A free-ranging maternity colony of big brown bats Eptesicus fuscus roosting in rock crevices along the South Saskatchewan River in south-eastern Alberta, Canada, was studied to understand better the discrepancy that exists in the literature regarding torpor use by reproductive female bats. Using radio-telemetry, thermoregulatory patterns and roost microclimate were recorded for pregnant, Lactating and post-Lactating Females. Relative torpor use is described in several ways: the proportion of days on which torpor was used, depth, minimum body temperature, time spent in torpor, and a comprehensive torpor unit (degree-min). Pregnant and Lactating female E. fuscus used torpor to the same extent overall (degree-min), but pregnant bats used torpor less frequently and with more time in deep torpor. Torpor was used to the greatest extent after weaning (post-lactation). Evidence is presented that the cost : benefit ratio for deep and prolonged periods of torpor may be highest during lactation. Microclimates of rockcrevice roosts mirrored the use of torpor throughout reproduction by bats. Lactation roosts (deeper, larger opening size) were more thermally stable and remained warmer at night compared to the shallow roosts used by pregnant and post-Lactating Females. It is shown that conclusions about relative use of torpor can differ depending on the units of comparison, necessitating measurement of all aspects of torpor (depth, duration and frequency). Comprehensive measurements, individual-based normothermic temperatures, and a definition of torpor that accounts for all energy savings, allow a more accurate depiction of patterns and facilitates inter-study comparisons.
Randy J. Nelson - One of the best experts on this subject based on the ideXlab platform.
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maternal aggression persists following lipopolysaccharide induced activation of the immune system
Physiology & Behavior, 2006Co-Authors: Zachary M Weil, Eliot Dow, Stephanie L K Bowers, Randy J. NelsonAbstract:Lactating Females direct aggressive behaviors towards intruders presumably to reduce the likelihood of infanticide of their pups. Infected animals display a constellation of responses that include lethargy, anorexia, and decreased social interactions. This suite of responses is referred to as sickness behavior, and is putatively part of an adaptive strategy to aid the organism in recovery from infection. Previous work has suggested that animals can suppress the behavioral symptoms of sickness in order to engage in adaptive behaviors. To test whether adaptive nest defense is affected by illness, dams received a peripheral injection of either saline or lipopolysaccharide (LPS [50, 400, or 1000 μg/kg]), a non-replicating component of bacterial cell walls that activates the immune system. Simulated infection with LPS reduced body mass and food intake in dams and interfered with litter growth in a dose-dependent manner. Generally, nest defense was unaffected by LPS; the proportion of dams displaying maternal aggression against a male intruder, as well as the latency and duration of aggressive encounters were only suppressed at the highest LPS dose tested. Further, LPS treatment also altered non-agonistic behavior during the aggression test as indicated by reduced social investigation of the intruder and an increased time spent immobile during the session. LPS administration also significantly increased serum corticosterone concentrations in Lactating Females. These findings suggest that maternal aggression is not suppressed by LPS-evoked immune activation at doses that attenuate other aspects of maternal and social behavior.
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maternal and mating induced aggression is associated with elevated citrulline immunoreactivity in the paraventricular nucleus in prairie voles
The Journal of Comparative Neurology, 2000Co-Authors: Stephen C Gammie, Randy J. NelsonAbstract:Lactating female rodents are fiercely aggressive against intruders when they are rearing and protecting pups. In monogamous prairie voles, Microtus ochrogaster, males are parental and exhibit a dramatic increase in aggression, termed mating-induced aggression, in association with reproduction. In mice, the gas, nitric oxide (NO), inhibits male aggression, but may have an excitatory role in the production of maternal aggression. In this study, we combined aggressive behavioral testing of female and male prairie voles with immunohistochemistry for citrulline, a marker of NO synthesis, to examine NO synthesis indirectly during maternal and mating-induced aggression. A significant increase in the number of citrulline-positive cells was identified in the paraventricular nucleus (PVN) of the hypothalamus in aggressive Lactating Females compared with unstimulated Lactating Females. A significant increase in the number of citrulline-positive cells was also observed in the PVN of aggressive mated males compared with nonaggressive unmated males and unstimulated mated males. Both nonaggressive unmated males and unstimulated mated males show similar levels of citrulline immunoreactivity in the PVN. In other regions of the brain, no changes in the number of citrulline-positive cells were observed. These results suggest that NO is released specifically in the PVN during both maternal and mating-induced aggression in prairie voles.
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maternal aggression is reduced in neuronal nitric oxide synthase deficient mice
The Journal of Neuroscience, 1999Co-Authors: Stephen C Gammie, Randy J. NelsonAbstract:Lactating Females express rapid extremes in behavior, ranging from gentle nurturance toward offspring to fiercely protective aggression against intruders. Although males often behave aggressively against intruders, female rodents usually express aggression only when rearing and protecting pups. Nitric oxide (NO) inhibits male aggression; however, its role in maternal aggression is unknown. In the present study, female mice with targeted disruption of the neuronal nitric oxide synthase gene (nNOS−/−) displayed significant deficits in maternal aggression relative to wild-type (WT) mice in terms of percentage displaying aggression, the average number of attacks against a male intruder, and the total time spent attacking the male intruder. The nNOS−/− mice displayed normal pup retrieval behavior. Because the specific deficits in maternal aggression in the nNOS−/− mice suggested a possible role for NO in maternal aggression, we combined behavioral testing of WT mice with immunohistochemistry for citrulline, an indirect marker of NO synthesis, to examine indirectly NO synthesis during maternal aggression. A significant increase in the number of citrulline-positive cells was identified in the medial preoptic nucleus, the suprachiasmatic nucleus, and the subparaventricular zone regions of the hypothalamus in aggressive Lactating Females relative to control mice. In other regions of the brain, no changes in the number of citrulline-positive cells were observed across either groups or treatments. These results provide two indirect lines of evidence that NO release is associated with maternal aggression.
Bruno Patris - One of the best experts on this subject based on the ideXlab platform.
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Orientation of newborn mice to Lactating Females: identifying biological substrates of semiochemical interest.
Developmental Psychobiology, 2013Co-Authors: Syrina Al Aïn, Amal Chraïti, Benoist Schaal, Bruno PatrisAbstract:Among mammals, odor-based communication between Females and infants is decisive for neonatal survival. So far, the nature of odor substrates involved in the localization of the mother and their nipples is unknown in mice. The present study aims: (1) to evaluate the specific attractive value of Lactating Females to newborn mice, (2) to localize the abdominal region that is most attractive to pups, and (3) to identify odor substrates that support such attraction. Results showed that 5-6-day-old mice roam preferentially over the abdomen of Lactating Females than the abdomen of non-Lactating Females. In Lactating Females, pups are more attracted to abdominal areas comprising nipples. The blend of odor substrates from nipples, as well as separate sources presumed to compose it, viz. milk, maternal saliva and pup saliva, were detectable and equivalently attractive to pups. The equivalent attraction of these different odor substrates may derive either from overlap in chemical constituents, or from associative learning during nursing.
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orientation of newborn mice to Lactating Females identifying biological substrates of semiochemical interest
Developmental Psychobiology, 2013Co-Authors: Syrina Al Ain, Amal Chraïti, Benoist Schaal, Bruno PatrisAbstract:Among mammals, odor-based communication between Females and infants is decisive for neonatal survival. So far, the nature of odor substrates involved in the localization of the mother and their nipples is unknown in mice. The present study aims: (1) to evaluate the specific attractive value of Lactating Females to newborn mice, (2) to localize the abdominal region that is most attractive to pups, and (3) to identify odor substrates that support such attraction. Results showed that 5–6-day-old mice roam preferentially over the abdomen of Lactating Females than the abdomen of non-Lactating Females. In Lactating Females, pups are more attracted to abdominal areas comprising nipples. The blend of odor substrates from nipples, as well as separate sources presumed to compose it, viz. milk, maternal saliva and pup saliva, were detectable and equivalently attractive to pups. The equivalent attraction of these different odor substrates may derive either from overlap in chemical constituents, or from associative learning during nursing. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 55: 113–124, 2013
Steeve D Cote - One of the best experts on this subject based on the ideXlab platform.
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foraging behaviour at multiple temporal scales in a wild alpine equid
Oecologia, 2012Co-Authors: Antoine Stlouis, Steeve D CoteAbstract:Forage abundance, forage quality, and social factors are key elements of the foraging ecology of wild herbivores. For non-ruminant equids, forage-limited environments are likely to impose severe constraints on their foraging behaviour. We used a multi-scale approach to study foraging behaviour in kiang (Equus kiang), a wild equid inhabiting the high-altitude rangelands of the Tibetan Plateau. Using behavioural observations and vegetation sampling, we first assessed how patterns of plant abundance and quality affected (i) the instantaneous forage intake rate (fine scale) and (ii) the proportion of time spent foraging (coarse scale) across seasons. We also tested whether foraging behaviour differed among group types, between sex in adults, and between Females of different reproductive status. At a fine scale, intake rate increased linearly with bite size and increased following a type II curvilinear function with biomass on feeding sites. Forage intake rate also increased linearly with plant quality. Male and female kiangs had similar intake rates. Likewise, gravid and Lactating Females had similar intake rates as barren and non-Lactating Females. At a coarse scale, kiangs spent longer time feeding in mesic than in xeric habitats, and spent more time feeding in early summer and fall than in late summer. Groups of adults with foals spent less time feeding than male groups and groups of adults without foals. Our findings suggest that kiangs use flexible foraging behaviours in relation to seasonal variations of vegetation quality and abundance, a likely outcome of the extreme seasonal conditions encountered on the Tibetan Plateau.
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trade offs in activity budget in an alpine ungulate contrasting Lactating and nonLactating Females
Animal Behaviour, 2008Co-Authors: Sandra Hamel, Steeve D CoteAbstract:Optimal time allocation to foraging behaviour may be constrained by intrinsic and extrinsic factors forcing animals to adopt compromises to meet their daily energetic needs. Our goal was to assess the influence of individual characteristics and extrinsic factors on the activity budget of marked adult female mountain goats, Oreamnos americanus. As lactation entails important energetic costs, we specifically aimed at contrasting activity budgets of Lactating and nonLactating Females. We determined female activity budgets using 10-min interval scan sampling between 2002 and 2005. Lactating Females, Females raising sons and Females that were subordinate for their age spent more time foraging than nonLactating Females, Females raising daughters and dominant Females, respectively. Although foraging is typically incompatible with scanning, increased time spent foraging was mainly performed at the expense of time spent lying rather than time spent in vigilance. Lactating Females also increased time spent ruminating while lying compared with nonLactating Females. All Females traded lying time for increased foraging and ruminating times in early and late summer. Females spent less time foraging on warm days, and foraged more at dusk than during the rest of the day. Age and body mass did not influence female activity budgets. Our results indicate that Lactating Females partly compensated for the costs of lactation by trading lying for foraging time, and reorganized lying time to increase the proportion of time spent ruminating. This study emphasizes the fundamental behavioural trade-offs that female mammals must face to meet their daily energetic requirements and allows a better understanding of how these compromises vary through the lactation period.
