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Susan Lingle - One of the best experts on this subject based on the ideXlab platform.
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the effect of terrain and female density on survival of neonatal white tailed deer and mule deer Fawns
Ecology and Evolution, 2016Co-Authors: Maegwin Bonar, Micheline Manseau, Justin Geisheimer, Travis Bannatyne, Susan LingleAbstract:Juvenile survival is a highly variable life-history trait that is critical to population growth. Antipredator tactics, including an animal's use of its physical and social environment, are critical to juvenile survival. Here, we tested the hypothesis that habitat and social characteristics influence coyote (Canis latrans) predation on white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus) Fawns in similar ways during the neonatal period. This would contrast to winter when the habitat and social characteristics that provide the most safety for each species differ. We monitored seven cohorts of white-tailed deer and mule deer Fawns at a grassland study site in Alberta, Canada. We used logistic regression and a model selection procedure to determine how habitat characteristics, climatic conditions, and female density influenced fawn survival during the first 8 weeks of life. Fawn survival improved after springs with productive vegetation (high integrated Normalized Difference Vegetation Index values). Fawns that used steeper terrain were more likely to survive. Fawns of both species had improved survival in years with higher densities of mule deer females, but not with higher densities of white-tailed deer females, as predicted if they benefit from protection by mule deer. Our results suggest that topographical variation is a critical resource for neonates of many ungulate species, even species like white-tailed deer that use more gentle terrain when older. Further, our results raise the possibility that neonatal white-tailed Fawns may benefit from associating with mule deer females, which may contribute to the expansion of white-tailed deer into areas occupied by mule deer.
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Lingle_Bonar_DryadDataDescription
2016Co-Authors: Susan Lingle, Maegwin BonarAbstract:This Microsoft Word file describes data columns used in two data files: File 1 filename = Fawn_Sightings_Raw_Data which has data for individual sightings of deer Fawns. File 2 = Fawn_Summary_Data.xlsx has a summary row for each fawn
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Altruism and recognition in the antipredator defence of deer: 1. Species and individual variation in fawn distress calls
Animal Behaviour, 2007Co-Authors: Susan Lingle, Drew Rendall, Sergio M. PellisAbstract:Mule deer, Odocoileus hemionus , females actively defend Fawns against predators, including nonoffspring conspecific Fawns and heterospecific white-tailed deer, O. virginianus , Fawns. We hypothesized that the defence of nonoffspring Fawns was due to a recognition error. During a predator attack, females may have to decide whether to defend a fawn with imperfect information on its identity obtained from hearing only a few distress calls. We examined fawn distress calls to determine whether calls made by the two species and by different individuals within each species were acoustically distinctive. The mean and maximum fundamental frequencies of mule deer Fawns were nearly double those of white-tailed deer Fawns, with no overlap, enabling us to classify 100% of calls to the correct species using a single trait. A large proportion of calls was also assigned to the correct individual using a multivariate analysis (66% and 70% of mule deer and white-tailed deer Fawns, respectively, chance = 6% and 10%); however, there was considerable statistical uncertainty in the probability of correct classification. We observed Fawns approach conspecific females in an attempt to nurse; females probed most offspring Fawns with their noses before accepting them, and always probed nonoffspring Fawns before rejecting them, suggesting that close contact and olfactory information were needed to unequivocally distinguish nonoffspring from offspring Fawns. Taken together, these results suggest that acoustic variation alone would probably be sufficient to permit rapid and reliable species discrimination, but it may not be sufficient for mothers to unequivocally distinguish their own fawn from conspecific Fawns.
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Altruism and recognition in the antipredator defence of deer: 2. Why mule deer help nonoffspring Fawns
Animal Behaviour, 2007Co-Authors: Susan Lingle, W. Finbarr Wilson, Drew Rendall, Randy W. Deyoung, Sergio M. PellisAbstract:Both white-tailed deer, Odocoileus virginianus, and mule deer, O. hemionus, females defend Fawns against coyotes, Canis latrans, but only mule deer defend nonoffspring conspecific and heterospecific Fawns. During a predator attack, females may have to decide whether to defend a fawn while having imperfect information on its identity obtained from hearing a few distress calls. Although imperfect recognition can influence altruistic behaviour, few empirical studies have considered this point when testing functional explanations for altruism. We designed a series of playback experiments with fawn distress calls to test alternative hypotheses (by-product of parental care, kin selection, reciprocal altruism) for the mule deer’s defence of nonoffspring, specifically allowing for the possibility that females mistake these Fawns for their own. White-tailed deer females approached the speaker only when distress calls of white-tailed deer Fawns were played and when their own fawn was hidden, suggesting that fawn defence was strictly a matter of parental care in this species. In contrast, mule deer females responded similarly and strongly, regardless of the caller’s identity, the female’s reproductive state (mother or nonmother) or the presence of their own offspring. The failure of mule deer females to adjust their responses to these conditions suggests that they do not defend nonoffspring because they mistake them for their own Fawns. The lack of behavioural discrimination also suggests that kin selection, reciprocal altruism and defence of the offspring’s area are unlikely to explain the mule deer’s defence of nonoffspring. We identify causal and functional questions that still need to be addressed to understand why mule deer defend Fawns so indiscriminately.
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interspecific variation in antipredator behaviour leads to differential vulnerability of mule deer and white tailed deer Fawns early in life
Journal of Animal Ecology, 2005Co-Authors: Susan Lingle, Sergio M. Pellis, Finbarr W WilsonAbstract:Summary 1 Ungulates are viewed as being highly susceptible to predation during the initial weeks or months of life. Yet aggressive defence by adult females is common in many ungulates and has the potential to reduce the vulnerability of the young significantly. 2 We observed naturally occurring predatory encounters between coyotes Canis latrans Say and deer Fawns to test the hypothesis that a difference in aggressive defence leads to the differential vulnerability of mule deer Odocoileus hemionus Rafinesque and white-tailed deer O. virginianus Zimmermann Fawns in summer, when Fawns are 0–14 weeks in age. Whitetail Fawns suffer higher levels of coyote predation than do mule deer Fawns at that time. The two species of deer are similar in size, but are known to differ in their antipredator behaviour in winter when Fawns are older. 3 Coyotes were less likely to attack mule deer than whitetail Fawns they encountered, and were less likely to kill mule deer than whitetail Fawns they attacked. 4 The presence of a mule deer, but not a whitetail, female with a fawn deterred coyotes from attacking the fawn. Once attacked, Fawns of both species were less likely to be killed when females defended them, but mule deer females were far more likely to defend Fawns. 5 Mule deer females defended Fawns that were not their own offspring, including heterospecific Fawns. Mule deer Fawns were more likely to be defended if they had a larger number of females nearby when encountered. These observations raise the possibility that mule deer, and even whitetail, Fawns may have improved survival in areas with higher densities of mule deer females. 6 These results show that higher levels of defence by mule deer females reduced the vulnerability of mule deer Fawns, contributing to the lower predation rates reported for mule deer than for whitetail Fawns of this age group.
Bret D Wallingford - One of the best experts on this subject based on the ideXlab platform.
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survival rates mortality causes and habitats of pennsylvania white tailed deer Fawns
Wildlife Society Bulletin, 2004Co-Authors: Justin K Vreeland, Duane R Diefenbach, Bret D WallingfordAbstract:Abstract Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) Fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocol-lared neonatal (<3 weeks) Fawns in 2000–2001 and monitored Fawns from capture until death, transmitter failure or collar release, or the end of the study. We estimated survivor-ship functions and assessed influence on fawn survival of road density, habitat edge density, habitat patch diversity, and proportion of herbaceous habitat. We captured 110 Fawns in the agricultural landscape and 108 Fawns in the forested landscape. At 9 weeks after capture, fawn survival was 72.4% (95% CI=63.3–80.0%) in the agricultural landscape and 57.2% (95% CI=47.5–66.3%) in the forested landscape. Thirty-four-week survival was 52.9% (95% CI = 42.7–62.8%) in the agricu...
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Survival rates, mortality causes, and habitats of Pennsylvania white-tailed deer Fawns
Wildlife Society Bulletin, 2004Co-Authors: Justin K Vreeland, Duane R Diefenbach, Bret D WallingfordAbstract:Abstract Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) Fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocol-lared neonatal (
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evaluation of an expandable breakaway radiocollar for white tailed deer Fawns
Wildlife Society Bulletin, 2003Co-Authors: Duane R Diefenbach, Justin K Vreeland, Christopher O Kochanny, Bret D WallingfordAbstract:We evaluated an expandable, breakaway VHF radiocollar design for use on white-tailed deer (Odocoileus virginianus) from birth to about 1 year of age. A similar collar design has been used on caribou (Rangifer tarandus), but we found that the collar did not expand quickly enough to accommodate increase in neck circumference of Fawns during the first 2 months of life. Consequently, we modified the stitching pattern so that the first expansion fold opened faster. We monitored performance of this modification on free-ranging and captive Fawns. Also, we collected data on neck growth in Fawns to document design requirements of expandable collars for white-tailed deer. Mean neck circumference at 270 days and recovered radiocollars expanded as designed. The elastic collar material failed on 3 collars (3%) after 142, 207, and 226 days on Fawns, and 1-5 radiocollars (<4%) were cast by Fawns. Our modification to this radiocollar design reduced fawn discomfort or suffering, allowing researchers to better comply with principles of the Animal Welfare Act.
Guy Van Laere - One of the best experts on this subject based on the ideXlab platform.
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spatial variation in springtime food resources influences the winter body mass of roe deer Fawns
Oecologia, 2003Co-Authors: Nathalie Pettorelli, Jean-michel Gaillard, François Klein, Stéphane Dray, Daniel Chessel, Patrick Duncan, Andrew W. Illius, Nadine Guillon, Guy Van LaereAbstract:It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer Fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chize forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of Fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam (Carpinus betulus), bluebell (Hyacinthoides sp.) and Star of Bethlehem (Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom (Ruscus aculeatus) and beech (Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of Fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.
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Spatial variation in springtime food resources influences the winter body mass of roe deer Fawns
Oecologia, 2003Co-Authors: Nathalie Pettorelli, Jean-michel Gaillard, François Klein, Stéphane Dray, Daniel Chessel, Patrick Duncan, Andrew W. Illius, Nadine Guillon, Guy Van LaereAbstract:It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer Fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chiz forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of Fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam (Carpinus betulus), bluebell (Hyacinthoides sp.) and Star of Bethlehem (Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom (Ruscus aculeatus) and beech (Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of Fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.
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Body mass of roe deer Fawns during winter in 2 contrasting populations
The Journal of Wildlife Management, 1996Co-Authors: Jean-michel Gaillard, Daniel Delorme, Guy Van Laere, Jean-marie Boutin, Bernard BoisaubertAbstract:Because first-year survival and age at sexual maturity of northern ungulates often depend on body mass of Fawns during winter, knowledge of factors affecting body mass of Fawns is necessary to understand population dynamics and management of ungulates in temperate regions. Therefore, we compared body mass of roe deer (Capreolus capreolus) Fawns during winter in two enclosed populations with contrasting climatic and demographic characteristics: Chize (CH) in western France (mild winters, less abundant food and lower birthrates), and Trois Fontaines (TF) in eastern France (cold winters, abundant food and high birthrates). We weighed 2,077 Fawns (1,212 in TF and 865 in CH) of both sexes captured with drive-nets in January and February from 1976 to 1993. Mass of male Fawns was greater than of females in both populations (P < 0.01). Body mass varied among years for both sexes in each population (P < 0.01 in CH; P < 0.01 in TF). Neither climatic conditions between April and December nor population density accounted for yearly variation in body mass of Fawns in TF. Rather, body mass fluctuated randomly about a mean, with no longterm effects on population dynamics. By contrast, body mass of Fawns in CH was correlated with mean daily temperature in June-July (P = 0.01 for males; P = 0.04 for females) and population density (P = 0.02 for males; P = 0.03 for females). Body mass of Fawns was greater in years following cool summers and in years of low population density (r 2 = 0.75, P < 0.01 for males; r 2 = 0.50, P = 0.02 for females). Mass of male Fawns but not female Fawns was greater in January-February when total rainfall in the previous April-May was low (P = 0.01). In CH, yearly variation in fawn body mass supports the range quality hypothesis which states that Fawns entering winter are small owing to poor nutritional conditions the previous summer or high population density. As a consequence, yearly variations in body mass probably have long-lasting effects on population dynamics in CH.
Jean-michel Gaillard - One of the best experts on this subject based on the ideXlab platform.
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Maternal and individual effects in selection of bed sites and their consequences for fawn survival at different spatial scales
Oecologia, 2008Co-Authors: Bram Van Moorter, Jean-michel Gaillard, Philip D. Mcloughlin, Daniel Delorme, François Klein, Mark S. BoyceAbstract:We examined the relationship between survival of roe deer (Capreolus capreolus) Fawns at Trois Fontaines, Champagne-Ardennes, France, and factors related to bed-site selection (predator avoidance and thermoregulation) and maternal food resources (forage availability in the maternal home range). Previous studies have demonstrated that at small scales, the young of large herbivores select bed sites independently from their mothers, although this selection takes place within the limits of their mother’s home range. Fawn survival was influenced largely by the availability of good bed sites within the maternal home range, not by the fawn’s selection of bed sites; however, selection for thermal cover when selecting bed sites positively influenced survival of young Fawns. Typical features of a good home range included close proximity to habitat edges, which is related to forage accessibility for roe deer. The availability of bed sites changed as Fawns aged, probably due to an increased mobility of the fawn or a different use of the home range by the mother; sites offering high concealment and thermal protection became less available in favor of areas with higher forage accessibility. Despite the minor influence of bed-site selection on survival, roe deer Fawns strongly selected their bed sites according to several environmental factors linked to predator avoidance and thermoregulation. Fawns selected for sites providing concealment, light penetration, and avoided signs of wild boar (Sus scrofa) activity. Avoidance of sites with high light penetration by young Fawns positively affected their survival, confirming a negative effect on thermoregulation due to reduced thermal cover. Selection for light penetration by older Fawns was less clear. We discuss these results in the context of cross-generational effects in habitat selection across multiple scales, and the potential influence of the ‘ghost of predation past’.
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Density-dependent responses of fawn cohort body mass in two contrasting roe deer populations
Oecologia, 2006Co-Authors: Petter Kjellander, Jean-michel Gaillard, A. J. Mark HewisonAbstract:We investigated the influence of population density on juvenile body mass in two contrasting roe deer populations, in Sweden (Bogesund) and France (Chizé), in which density was monitored for ≥15 years. We investigated the effect of population density and climatic conditions on cohort performance. We predicted that: (1) body mass of growing Fawns should be sensitive to environmental changes, showing marked between-year variation (i.e., cohort effects), (2) Fawns in the less productive (weakly seasonal, weakly predictable summer weather) habitat of Chizé should show stronger density-dependent responses due to more severe food competition during summer than Fawns in the more productive (markedly seasonal, moderately predictable summer weather) habitat of Bogesund, and (3) Fawns at Bogesund should be heavier both in absolute terms and relative to their size than their conspecifics in Chizé due to a higher degree of fat accumulation in northern environments. In both study sites we found marked cohort variation and clear effects of density, with body mass varying by as much as 29% over years. While neither summer nor winter climate influenced fawn body mass at Bogesund, Fawns tended to be lighter after summers with high temperatures at Chizé. In addition, Fawns were heavier after acorn mast years experienced in utero at Bogesund. As expected, the strength of the density-dependent response of fawn body mass was greater at Chizé than at Bogesund. For a given density, male Fawns were consistently heavier than females in both sites. Lastly, both sexes at Bogesund had higher absolute body mass and were larger for a given body size than in Chizé. Our results clearly demonstrate that absolute density is a poor predictor of roe deer performance and supports the view that habitat quality has an overwhelming importance for determining fawn body mass in roe deer populations.
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spatial variation in springtime food resources influences the winter body mass of roe deer Fawns
Oecologia, 2003Co-Authors: Nathalie Pettorelli, Jean-michel Gaillard, François Klein, Stéphane Dray, Daniel Chessel, Patrick Duncan, Andrew W. Illius, Nadine Guillon, Guy Van LaereAbstract:It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer Fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chize forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of Fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam (Carpinus betulus), bluebell (Hyacinthoides sp.) and Star of Bethlehem (Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom (Ruscus aculeatus) and beech (Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of Fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.
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Spatial variation in springtime food resources influences the winter body mass of roe deer Fawns
Oecologia, 2003Co-Authors: Nathalie Pettorelli, Jean-michel Gaillard, François Klein, Stéphane Dray, Daniel Chessel, Patrick Duncan, Andrew W. Illius, Nadine Guillon, Guy Van LaereAbstract:It is well established that the dynamics of mammalian populations vary in time, in relation to density and weather, and often in interaction with phenotypic differences (sex, age and social status). Habitat quality has recently been identified as another significant source of individual variability in vital rates of deer, including roe deer where spatial variations in fawn body mass were found to be only about a tenth of temporal variations. The approach used was to classify the habitat into blocks a priori, and to analyse variation in animal performance among the predefined areas. In a fine-grained approach, here we use data collected over 24 years on 1,235 roe deer Fawns captured at known locations and the plant species composition sampled in 2001 at 578 sites in the Chiz forest to determine the spatial structure at a fine scale of both vegetation and winter body mass of Fawns, and then to determine links between the two. Space and time played a nearly equal role in determining fawn body masses of both sexes, each accounting for about 20% of variance and without any interaction between them. The spatial distribution of fawn body mass was perennial over the 24 years considered and predicted values showed a 2 kg range according to location in the reserve, which is much greater than suggested in previous work and is enough to have strong effects on fawn survival. The spatial distribution and the range of predicted body masses were closely similar in males and females. The result of this study is therefore consistent with the view that the life history traits of roe deer are only weakly influenced by sexual selection. The occurrence of three plant species that are known to be important food items in spring/summer roe deer diets, hornbeam (Carpinus betulus), bluebell (Hyacinthoides sp.) and Star of Bethlehem (Ornithogalum sp.) was positively related to winter fawn body mass. The occurrence of species known to be avoided in spring/summer roe deer diets [e.g. butcher's broom (Ruscus aculeatus) and beech (Fagus sylvatica)], was negatively related to fawn body mass. We conclude that the spatial variation in the body mass of Fawns in winter in this forest is as important as the temporal variation, and that the distribution of plant species that are actively selected during spring and summer is an important determinant of spatial variation in winter fawn body mass. The availability of these plants is therefore likely to be a key factor in the dynamics of roe deer populations.
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Body mass of roe deer Fawns during winter in 2 contrasting populations
The Journal of Wildlife Management, 1996Co-Authors: Jean-michel Gaillard, Daniel Delorme, Guy Van Laere, Jean-marie Boutin, Bernard BoisaubertAbstract:Because first-year survival and age at sexual maturity of northern ungulates often depend on body mass of Fawns during winter, knowledge of factors affecting body mass of Fawns is necessary to understand population dynamics and management of ungulates in temperate regions. Therefore, we compared body mass of roe deer (Capreolus capreolus) Fawns during winter in two enclosed populations with contrasting climatic and demographic characteristics: Chize (CH) in western France (mild winters, less abundant food and lower birthrates), and Trois Fontaines (TF) in eastern France (cold winters, abundant food and high birthrates). We weighed 2,077 Fawns (1,212 in TF and 865 in CH) of both sexes captured with drive-nets in January and February from 1976 to 1993. Mass of male Fawns was greater than of females in both populations (P < 0.01). Body mass varied among years for both sexes in each population (P < 0.01 in CH; P < 0.01 in TF). Neither climatic conditions between April and December nor population density accounted for yearly variation in body mass of Fawns in TF. Rather, body mass fluctuated randomly about a mean, with no longterm effects on population dynamics. By contrast, body mass of Fawns in CH was correlated with mean daily temperature in June-July (P = 0.01 for males; P = 0.04 for females) and population density (P = 0.02 for males; P = 0.03 for females). Body mass of Fawns was greater in years following cool summers and in years of low population density (r 2 = 0.75, P < 0.01 for males; r 2 = 0.50, P = 0.02 for females). Mass of male Fawns but not female Fawns was greater in January-February when total rainfall in the previous April-May was low (P = 0.01). In CH, yearly variation in fawn body mass supports the range quality hypothesis which states that Fawns entering winter are small owing to poor nutritional conditions the previous summer or high population density. As a consequence, yearly variations in body mass probably have long-lasting effects on population dynamics in CH.
Justin K Vreeland - One of the best experts on this subject based on the ideXlab platform.
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survival rates mortality causes and habitats of pennsylvania white tailed deer Fawns
Wildlife Society Bulletin, 2004Co-Authors: Justin K Vreeland, Duane R Diefenbach, Bret D WallingfordAbstract:Abstract Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) Fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocol-lared neonatal (<3 weeks) Fawns in 2000–2001 and monitored Fawns from capture until death, transmitter failure or collar release, or the end of the study. We estimated survivor-ship functions and assessed influence on fawn survival of road density, habitat edge density, habitat patch diversity, and proportion of herbaceous habitat. We captured 110 Fawns in the agricultural landscape and 108 Fawns in the forested landscape. At 9 weeks after capture, fawn survival was 72.4% (95% CI=63.3–80.0%) in the agricultural landscape and 57.2% (95% CI=47.5–66.3%) in the forested landscape. Thirty-four-week survival was 52.9% (95% CI = 42.7–62.8%) in the agricu...
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Survival rates, mortality causes, and habitats of Pennsylvania white-tailed deer Fawns
Wildlife Society Bulletin, 2004Co-Authors: Justin K Vreeland, Duane R Diefenbach, Bret D WallingfordAbstract:Abstract Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) Fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocol-lared neonatal (
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evaluation of an expandable breakaway radiocollar for white tailed deer Fawns
Wildlife Society Bulletin, 2003Co-Authors: Duane R Diefenbach, Justin K Vreeland, Christopher O Kochanny, Bret D WallingfordAbstract:We evaluated an expandable, breakaway VHF radiocollar design for use on white-tailed deer (Odocoileus virginianus) from birth to about 1 year of age. A similar collar design has been used on caribou (Rangifer tarandus), but we found that the collar did not expand quickly enough to accommodate increase in neck circumference of Fawns during the first 2 months of life. Consequently, we modified the stitching pattern so that the first expansion fold opened faster. We monitored performance of this modification on free-ranging and captive Fawns. Also, we collected data on neck growth in Fawns to document design requirements of expandable collars for white-tailed deer. Mean neck circumference at 270 days and recovered radiocollars expanded as designed. The elastic collar material failed on 3 collars (3%) after 142, 207, and 226 days on Fawns, and 1-5 radiocollars (<4%) were cast by Fawns. Our modification to this radiocollar design reduced fawn discomfort or suffering, allowing researchers to better comply with principles of the Animal Welfare Act.
