scholarly journals Does risk of predation influence population dynamics? Evidence from cyclic decline of snowshoe hares

1995 ◽  
Vol 22 (1) ◽  
pp. 115 ◽  
Author(s):  
D. S. Hik
Keyword(s):  
Predation Risk ◽  
Body Mass ◽  
Female Body ◽  
Population Decline ◽  
Control Area ◽  
High Rate ◽  
Food Treatment ◽  
Snowshoe Hares ◽  
Risk Of Predation ◽  
Female Body Mass

Like most heavily preyed-upon animals, snowshoe hares (Lepus americanus) have to balance conflicting demands of obtaining food at a high rate and avoiding predators. Adopting foraging behaviours to minimise predation risk may also lead to a decline in condition, and hence fecundity. Predictions of three hypotheses (condition constraint hypothesis, predator-avoidance constraint hypothesis, predation-sensitive foraging (PSF) hypothesis) were tested by comparing changes in the survival and condition of snowshoe hares on four experimental areas in winter during a cyclic peak and decline (1989–1993) near Kluane Lake, Yukon, Canada, where (i) predation risk was reduced by excluding terrestrial predators (FENCE), (ii) food supply was supplemented with rabbit chow ad libitum (FOOD), (iii) these two treatments were combined (FENCE+FOOD), and (iv) an unmanipulated CONTROL was used. Different pattems of survival and changes in body mass were observed in the presence and absence of terrestrial predators. On the CONTROL area, female body mass and fecundity declined, even though sufficient winter forage was apparently available in all years. A similar decrease in body mass was observed on the FOOD treatment, but only during the third year of the population decline. In contrast, female body mass remained high throughout the decline in the absence of terrestrial predators in the FENCE+FOOD and FENCE treatments. Winter survival declined on CONTROL and FENCE areas during the first year of the population decline (1991), but remained higher on FOOD until 1992 and FENCE+FOOD until 1993. These results generally supported the PSF hypothesis where terrestrial predators were present (CONTROL and FOOD grids). Where terrestrial predators were absent (FENCE and FENCE+FOOD), the results supported the alternative condition constraint hypothesis. The evidence suggests that a cascade of sublethal behavioural and physiological effects associated with increased predation risk contribute to the population decline and delayed recovery of cyclic low-phase populations of snowshoe hares.

scholarly journals Movers and stayers: how residential selection contributes to the association between female body mass index and neighborhood characteristics

2016 ◽  
Vol 40 (9) ◽  
pp. 1384-1391 ◽  
Author(s):  
K R Smith ◽  
H A Hanson ◽  
B B Brown ◽  
C D Zick ◽  
L Kowaleski-Jones ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Female Body ◽  
Neighborhood Characteristics ◽  
Female Body Mass

Female Body Mass Index and the election of a Long‐Acting Reversible Contraception for the first time

2021 ◽  
Author(s):  
Giulia Frederico ◽  
Priscilla N. Silva dos Santos ◽  
Jéssica M. Ferreira ◽  
Luis Bahamondes ◽  
Arlete Fernandes
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Female Body ◽  
Female Body Mass ◽  
Long Acting ◽  
First Time

scholarly journals Influence of Female Age and Body Mass on Brood and Duckling Survival, Number of Surviving Ducklings, and Brood Movements in Redheads

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 926-929
Author(s):  
Tina Yerkes
Keyword(s):  
Body Mass ◽  
Female Body ◽  
Survival Rates ◽  
Female Age ◽  
Duckling Survival ◽  
Daily Survival ◽  
Brood Movement ◽  
Female Body Mass ◽  
Brood Success

AbstractI documented brood and duckling survival, the number of surviving ducklings, and brood movements of Redheads, and examined the association between these variables and female age and body mass. Redhead brood success was 55% and duckling daily survival rates averaged 0.868. Female body mass, but not age, was related to brood and duckling survival and the number of surviving ducklings. Successful females were heavier and produced more ducklings. All brood-movement measures differed between successful and unsuccessful females, however, the distance of the first move between wetlands accounted for the most variability in brood success. Increased body mass, but not age, was associated with longer first brood movements.

scholarly journals Nutrient Reserves of Lesser Scaup (Aythya Affinis) During Spring Migration in the Mississippi Flyway: A Test of the Spring Condition Hypothesis

The Auk ◽  
2004 ◽  
Vol 121 (3) ◽  
pp. 917-929 ◽  
Author(s):  
Michael J. Anteau ◽  
Alan D. Afton
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Body Condition ◽  
Female Body ◽  
Population Decline ◽  
Spring Migration ◽  
Aythya Affinis ◽  
Lesser Scaup ◽  
Nutrient Reserves ◽  
Mineral Reserves

AbstractThe continental scaup population (Lesser [Aythya affinis] and Greater [A. marila] combined) has declined markedly since 1978. One hypothesis for the population decline states that reproductive success has decreased because female scaup are arriving on breeding areas in poorer body condition than they did historically (i.e. spring condition hypothesis). We tested one aspect of that hypothesis by comparing body mass and nutrient reserves (lipid, protein, and mineral) of Lesser Scaup at four locations (Louisiana, Illinois, Minnesota, and Manitoba) between the 1980s and 2000s. We found that mean body mass and lipid and mineral reserves of females were 80.0, 52.5, and 3.0 g higher, respectively, in the 2000s than in the 1980s in Louisiana; similarly, body mass and lipid and mineral reserves of males were 108.8, 72.5, and 2.5 g higher, respectively. In Illinois, mean body mass and lipid reserves of females were 88.6 and 56.5 g higher, respectively, in the 2000s than in the 1980s; similarly, body mass and lipid and mineral reserves of males were 80.6, 76.0, and 2.7 g higher, respectively. Mean body mass of females were 58.5 and 58.9 g lower in the 2000s than in the 1980s in Minnesota and Manitoba, respectively; mean body mass of males, similarly, were 40.7 g lower in Minnesota. Mean lipid reserves of females in the 2000s were 28.8 and 27.8 g lower than those in the 1980s in Minnesota and Manitoba, respectively. Mean mineral reserves of females in the 2000s were 3.2 g lower than those in the 1980s in Manitoba. Consequently, females arriving to breed in Manitoba in the 2000s had accumulated lipid reserves for 4.1 fewer eggs and mineral reserves for 0.8 fewer eggs than those arriving to breed there in the 1980s. Accordingly, our results are consistent with the spring condition hypothesis and suggest that female body condition has declined, as reflected by decreases in body mass, lipids, and mineral reserves that could cause reductions in reproductive success and ultimately a population decline.

scholarly journals Effects of population density and female body mass on litter size in European roe deer at a continental scale

2017 ◽  
Vol 63 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Katarina Flajšman ◽  
Tomasz Borowik ◽  
Boštjan Pokorny ◽  
Bogumiła Jędrzejewska
Keyword(s):  
Population Density ◽  
Body Mass ◽  
Litter Size ◽  
Female Body ◽  
Roe Deer ◽  
Continental Scale ◽  
Female Body Mass

scholarly journals Female body mass index (BMI) influences art outcomes: an evaluation of 3740 IVF/ICSI cycles

2018 ◽  
Vol 110 (4) ◽  
pp. e120-e121
Author(s):  
J.B. Oliveira ◽  
F. Dieamant ◽  
R. Baruffi ◽  
C.G. Petersen ◽  
A.L. Mauri ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Female Body ◽  
Female Body Mass

The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears

1999 ◽  
Vol 77 (1) ◽  
pp. 132-138 ◽  
Author(s):  
G V Hilderbrand ◽  
C C Schwartz ◽  
C T Robbins ◽  
M E Jacoby ◽  
T A Hanley ◽  
...  
Keyword(s):  
Body Size ◽  
Population Density ◽  
Body Mass ◽  
Litter Size ◽  
Adult Female ◽  
North American ◽  
Female Body ◽  
Brown Bears ◽  
Hair Samples ◽  
Female Body Mass

We hypothesized that the relative availability of meat, indicated by contribution to the diet, would be positively related to body size and population productivity of North American brown, or grizzly, bears (Ursus arctos). Dietary contributions of plant matter and meat derived from both terrestrial and marine sources were quantified by stable-isotope analysis (δ13C and δ15N) of hair samples from 13 brown bear populations. Estimates of adult female body mass, mean litter size, and population density were obtained from two field studies of ours and from other published reports. The populations ranged from largely vegetarian to largely carnivorous, and food resources ranged from mostly terrestrial to mostly marine (salmon, Oncorhynchus spp.). The proportion of meat in the diet was significantly correlated with mean adult female body mass (r = 0.87, P < 0.01), mean litter size (r = 0.72, P < 0.01), and mean population density (r = 0.91, P < 0.01). Salmon was the most important source of meat for the largest, most carnivorous bears and most productive populations. We conclude that availability of meat, particularly salmon, greatly influences habitat quality for brown bears at both the individual level and the population level.

Sign in / Sign up

Export Citation Format

Share Document