Assessment of the Stress Response in Columbian Ground Squirrels: Laboratory and Field Validation of an Enzyme Immunoassay for Fecal Cortisol Metabolites

2009 ◽  
Vol 82 (3) ◽  
pp. 291-301 ◽  
Author(s):  
Curtis O. Bosson ◽  
Rupert Palme ◽  
Rudy Boonstra
2019 ◽  
Vol 222 (12) ◽  
pp. jeb203588
Author(s):  
Jeffrey D. Roth ◽  
F. Stephen Dobson ◽  
François Criscuolo ◽  
Pierre Uhlrich ◽  
Alexandre Zahariev ◽  
...  

1977 ◽  
Vol 55 (4) ◽  
pp. 693-703 ◽  
Author(s):  
Gail R. Michener

In 1975 and 1976 the times of spring emergence, breeding, and entry into hibernation were compared for Spermophilus richardsonii and S. columbianus in an area of sympatry in the foothills of the southern Alberta Rocky Mountains. Both species emerged earlier in 1976, which had a warmer than normal spring, than in 1975, which had a cooler than normal spring. In both years S. richardsonii emerged earlier than S. columbianus and remained active longer. Juvenile S. richardsonii entered hibernation when 17–20 weeks old whereas juvenile S. columbianus were 10–11 weeks old. Yearling S. richardsonii bred, whereas yearling S. columbianus did not. Breeding success affected the time of entry into hibernation but not the time of emergence from hibernation in the next spring. A possible relationship between the periodic arousals during hibernation and the emergence pattern of squirrels in spring is discussed. The significance of flexibility of spring emergence, length of the active season, and age at breeding to survival and species ecology is considered.


2005 ◽  
Vol 83 (4) ◽  
pp. 546-552 ◽  
Author(s):  
David R Broussard ◽  
F Stephen Dobson ◽  
J O Murie

To maximize fitness, organisms must optimally allocate resources to reproduction, daily metabolic maintenance, and survival. We examined multiple years of live-trapping and observational data from a known-aged population of female Columbian ground squirrels, Spermophilus columbianus (Ord, 1815), to determine the influences of stored resources and daily resource income on the reproductive investments of females. We predicted that because yearling females were not fully grown structurally while producing their first litter, they would rely exclusively on income for reproduction, while reproductive investment in older females (≥2 years of age) would be influenced by both stored resources (capital) and daily income. Results from path analysis indicated that both yearlings and older females were income breeders. However, initial capital indirectly influenced investment in reproduction of yearling and older females. Females with the greatest initial capital maintained high body masses while investing relatively more income in reproduction. By considering influences of both capital and income, important relationships can be revealed between these resources and their influence on life histories.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Maura Turriani ◽  
Nicola Bernabò ◽  
Barbara Barboni ◽  
Gianluca Todisco ◽  
Luigi Montini ◽  
...  

Serinus canariais a widespread domestic ornamental songbird, whose limited knowledge of biology make compelling studies aimed to monitor stress. Here, a commercial enzyme immunoassay was adopted to measure immunoreactive corticosterone (CORT) in singleSerinus canariadropping sample, to monitor the daily fecal excretion of CORT in birds bred singly or in-group and to detect the effect promoted by aviary or small transport cage restraint. A robust daily rhythm of CORT was recorded in animals held on short-day light cycle, independent of bred conditions (single or group), which persisted when space availability was modified in single bred animal (transfer in aviary and transport cages). By contrast, a significant change in CORT excretion was recorded when group bred animals are restrained in a smaller cage. The daily rhythm in CORT excretion in response to manipulation showed the greatest response at the beginning of the light period, followed by the absence of the peak usually recorded at the end of the dark phase. These data indicated that EIA could be used as a reliable noninvasive approach to monitor the stress induced by restraint conditions inSerinus canaria.


2012 ◽  
Vol 90 (6) ◽  
pp. 736-743 ◽  
Author(s):  
Philip H. Jones ◽  
Jeffrey L. Van Zant ◽  
F. Stephen Dobson

The imbalanced reproductive success of polygynous mammals results in sexual selection on male traits like body size. Males and females might have more balanced reproductive success under polygynandry, where both sexes mate multiply. Using 4 years of microsatellite DNA analyses of paternity and known maternity, we investigated variation in reproductive success of Columbian ground squirrels, Urocitellus columbianus (Ord, 1815); a species with multiple mating by both sexes and multiple paternity of litters. We asked whether male reproductive success was more variable than that of females under this mating system. The overall percentage of confirmed paternity was 61.4% of 339 offspring. The mean rate of multiple paternity in litters with known fathers was 72.4% (n = 29 litters). Estimated mean reproductive success of males (10.27 offspring) was about thrice that of females (3.11 offspring). Even after this difference was taken into account statistically, males were about three times as variable in reproductive success as females (coefficients of variation = 77.84% and 26.74%, respectively). The Bateman gradient (regression slope of offspring production on number of successful mates) was significantly greater for males (βM = 1.44) than females (βF = 0.28). Thus, under a polygynandrous mating system, males exhibited greater variation in reproductive success than females.


1981 ◽  
Vol 59 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
D. A. Boag ◽  
J. O. Murie

Annual weight gain in Columbian ground squirrels (Spermophilus columbianus) was studied over a period of 7 years in a large colony in southwestern Alberta. Juveniles approximately tripled their weight during the period from emergence to immergence, achieving about 60% of adult weight at onset of their first hibernation. Males were heavier than females and the weight gain in both sexes varied significantly among years. The weight characteristics of the age-classes up to 3 years were different from one another. Full potential weight was not achieved until squirrels were in their fourth summer. Males were always significantly heavier than females in nonjuvenile squirrels and the amount of weight gained by these classes varied significantly among years.


Ethology ◽  
2014 ◽  
Vol 120 (11) ◽  
pp. 1101-1109 ◽  
Author(s):  
Dawson Clary ◽  
Lindsay J. Skyner ◽  
Calen P. Ryan ◽  
Laura E. Gardiner ◽  
W. Gary Anderson ◽  
...  

2007 ◽  
Vol 71 (1) ◽  
pp. 190-194 ◽  
Author(s):  
ANTONI DALMAU ◽  
ALFRED FERRET ◽  
GEMA CHACON ◽  
XAVIER MANTECA

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