Differential Costs of Reproductive Effort for Male and Female Richardson's Ground Squirrels

Ecology ◽  
1990 ◽  
Vol 71 (3) ◽  
pp. 855-868 ◽  
Author(s):  
Gail R. Michener ◽  
L. Locklear
Keyword(s):  
Reproductive Effort ◽  
Ground Squirrels ◽  
Male And Female ◽  
Differential Costs

Reproductive effort and costs of reproduction in female European ground squirrels

Oecologia ◽  
1999 ◽  
Vol 121 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Susanne Huber ◽  
Eva Millesi ◽  
Manfred Walzl ◽  
John Dittami ◽  
Walter Arnold
Keyword(s):  
Reproductive Effort ◽  
Ground Squirrels ◽  
Costs Of Reproduction

Energy Expenditure in Reproductive Effort of Male and Female Killdeer (Charadrius vociferus)

The Auk ◽  
1988 ◽  
Vol 105 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Dianne H. Brunton
Keyword(s):  
Reproductive Success ◽  
Energy Expenditure ◽  
Parental Care ◽  
Breeding Season ◽  
Reproductive Effort ◽  
Mating Effort ◽  
Parental Effort ◽  
Nest Failure ◽  
Male And Female ◽  
Charadrius Vociferus

Abstract The reproductive investment strategies of the sexes during the breeding season are detailed for Killdeer (Charadrius vociferus), a monogamous plover. I measured the energy investments of the sexes in reproductive, mating, and parental effort. As predicted, males expend more mating effort than females; however, the sexes expend equal amounts of parental effort. Total energy expenditure in reproductive effort (mating and parental effort) during a successful nesting attempt was also equal for the sexes. However, early parental effort expenditures by females, early mating effort expenditures by males, and high rates of nest failure combine to result in female reproductive energy expenditures being significantly higher over the breeding season. This suggests that energy expenditure alone is not adequate for accurate comparisons of the relative investments of the sexes. Studies investigating male and female investments need to consider the degree and pattern of nest failures along with patterns of energy expenditure. The advantages to male and female Killdeer of sharing parental care is demonstrated using adult removal experiments. In general, a deserted parent expends more energy in parental effort than a bi-parental parent and has significantly lower reproductive success. However, males are able to hatch chicks, whereas females lose or abandon their nests within a few days of mate removal. Thus, monogamy in Killdeer appears to result from high nest failure rates, the necessity of two parents for any reproductive success, and the generalizable nature of Killdeer parental care.

Timing is the only thing: reproduction in female yellow ground squirrels (Spermophilus fulvus)

2014 ◽  
Vol 92 (8) ◽  
pp. 737-747 ◽  
Author(s):  
N.A. Vasilieva ◽  
A.V. Tchabovsky
Keyword(s):  
Litter Size ◽  
Body Condition ◽  
Reproductive Effort ◽  
Individual Characteristics ◽  
Ground Squirrels ◽  
Offspring Survival ◽  
Litter Mass ◽  
Individual Offspring ◽  
Female Survival ◽  
Spermophilus Fulvus

Based on 4-year field observations of yellow ground squirrels (Spermophilus fulvus (Lichtenstein, 1823)), we determined whether female reproductive effort, annual reproductive success, and survival were dependent on age, body condition, time of emergence from hibernation, and previous reproduction. The probability of weaning a litter did not vary with female age, body condition, time of emergence, or previous reproduction. Litter size, litter mass, and offspring survival did not vary with age, whereas individual offspring mass was lower in yearlings than in older females. Body condition upon emergence had no effect on litter size, litter mass, offspring mass, and survival. Reproduction did not influence female survival, physical condition upon emergence next spring, or subsequent reproductive efforts. The only factor that affected the extent of reproductive effort and offspring survival was the date of emergence: the later a female emerged, the lower the total and mean offspring mass, and fewer offspring survived. The modulation of reproduction in female S. fulvus by only the timing of vernal emergence and independent of other individual characteristics can be explained by the high costs of missed reproductive opportunity because of short longevity combined with low costs of reproduction when resources are abundant enough to meet both somatic and reproductive needs.

Intraspecific killing of preweaned young in the Columbian ground squirrel, Spermophilus columbianus

1991 ◽  
Vol 69 (3) ◽  
pp. 797-800 ◽  
Author(s):  
James F. Hare
Keyword(s):  
Ground Squirrel ◽  
Ground Squirrels ◽  
Equal Access ◽  
Male And Female ◽  
Spermophilus Columbianus ◽  
Columbian Ground Squirrels

The abandonment of Columbian ground squirrel (Spermophilus columbianus) neonates by their dams when dams and litters were released from field enclosures resulted in the availability of newborn pups aboveground to male and female conspecifics. Four incidents of infanticide were observed and, without exception, perpetrators of infanticide were female, although male conspecifics had equal access to pups. Contrary to an earlier conjecture that male Columbian ground squirrels are the more likely perpetrators of infanticide, this finding is consistent with the majority of incidents documented for this species.

Growth and its relationship to the initial annual cycle of the golden-mantled ground squirrel, Spermophilus lateralis

1981 ◽  
Vol 59 (6) ◽  
pp. 865-871 ◽  
Author(s):  
John A. Phillips
Keyword(s):  
Litter Size ◽  
Annual Cycle ◽  
Ground Squirrel ◽  
Growth And Development ◽  
Reproductive Effort ◽  
Ground Squirrels ◽  
Active Season ◽  
Spermophilus Lateralis ◽  
Significant Difference ◽  
Two Populations

Thirty-eight litters of golden-mantled ground squirrels (Spermophilus lateralis), from two populations that experienced different lengths of active season, were born and raised in the laboratory. Growth and development in young were inversely related to litter size. Offspring from smaller litters were both able to attain their prehibernation peak of body mass sooner and hibernate after fewer days of homeothermy than squirrels from larger litters. Young that remained homeothermic throughout the initial overwintering period were always from large litters and among the slowest growing littermates. Fecundity was lower in females from the temporally compressed environment. There was no significant difference between populations in the nutrition provided by mothers to their litters. The results suggest that reproductive effort is more conservative in populations of ground squirrels that experience short seasons of activity, yet this conservatism allows the offspring of those populations to reach independence and attain the prehibernation state of preparedness at an earlier age than their counterparts from populations of more moderate climates.

scholarly journals Allocation of reproductive effort to the male and female strategies in wind-pollinated plants

Oecologia ◽  
1980 ◽  
Vol 45 (2) ◽  
pp. 156-159 ◽  
Author(s):  
Cliff Lemen
Keyword(s):  
Reproductive Effort ◽  
Male And Female

scholarly journals Effects of juvenile and adult diet on ageing and reproductive effort of male and female black field crickets,Teleogryllus commodus

2009 ◽  
Vol 23 (3) ◽  
pp. 602-611 ◽  
Author(s):  
Felix Zajitschek ◽  
John Hunt ◽  
Michael D. Jennions ◽  
Matthew D. Hall ◽  
Robert C. Brooks
Keyword(s):  
Reproductive Effort ◽  
Male And Female ◽  
Field Crickets ◽  
Teleogryllus Commodus ◽  
Black Field ◽  
Adult Diet

scholarly journals Kin recognition and adjustment of reproductive effort in zebra finches

2010 ◽  
Vol 6 (6) ◽  
pp. 762-764 ◽  
Author(s):  
Aneta Arct ◽  
Joanna Rutkowska ◽  
Rafał Martyka ◽  
Szymon M. Drobniak ◽  
Mariusz Cichoń
Keyword(s):  
Genetic Similarity ◽  
Reproductive Effort ◽  
Kin Recognition ◽  
Reproductive Investment ◽  
Taeniopygia Guttata ◽  
Zebra Finches ◽  
Differential Allocation ◽  
Male And Female ◽  
Sexual Traits ◽  
Clutch Mass

The differential allocation theory predicts that females should invest more in offspring produced with attractive partners, and a number of studies support this prediction in birds. Females have been shown to increase reproductive investment when mated to males showing elaborated sexual traits. However, mate attractiveness might also depend on the interaction between male and female genotypes. Accordingly, females should invest more in offspring sired by individuals that are genetically dissimilar or carry superior alleles. Here, we show in zebra finches ( Taeniopygia guttata ) that pairs of unfamiliar genetic brothers and sisters are less likely to reproduce in comparison with randomly mated pairs. Among the brother–sister pairs, those that attempted to breed laid smaller clutches and of lower total clutch mass. Our results provide the first experimental evidence that females adjust their reproductive effort in response to the genetic similarity of their partners. Importantly, these results imply a female ability to assess relatedness of a social mate without prior association.

Social behavior between adult female Richardson's ground squirrels (Spermophilus richardsonii) and their own and alien young

1972 ◽  
Vol 50 (11) ◽  
pp. 1343-1349 ◽  
Author(s):  
G. R. Michener ◽  
D. H. Sheppard
Keyword(s):  
Social Behavior ◽  
Adult Female ◽  
Agonistic Behavior ◽  
Ground Squirrels ◽  
Male And Female ◽  
Spermophilus Richardsonii ◽  
First Contact

Adult female Richardson's ground squirrels were paired at intervals with their own and unrelated young in a neutral cage. Little agonistic behavior occurred between related animals but such behavior was common when the adult and young were unrelated. Conversely, cohesive behavior was common between related animals but not between unrelated animals. A tendency for the adults to treat male and female young differently was noted. With only four exceptions (out of 48 tests) the first contact between adult and young was neutral, nose–nose being most common. The frequency of neutral behavior declined on the second contact and remained at the lower level. Implications of the study with regard to recognition, dispersal, and territory learning are discussed.

Intercolony natal dispersal in the Columbian ground squirrel

1989 ◽  
Vol 67 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Darwin R. Wiggett ◽  
David A. Boag
Keyword(s):  
Ground Squirrel ◽  
Survival Rates ◽  
Ground Squirrels ◽  
Natal Dispersal ◽  
Male And Female ◽  
Spermophilus Columbianus ◽  
Median Distance ◽  
In Transit ◽  
Columbian Ground Squirrels ◽  
Actual Survival

Dispersal of Columbian ground squirrels (Spermophilus columbianus) among 16 colonies located in the Sheep River – Gorge Creek drainage of southwestern Alberta was studied from 1973 to 1986. In total, 73 intercolony movements involving 66 different animals were recorded. Intercolony dispersal movements were strongly biased towards males and were almost exclusively undertaken by 1-year-old squirrels (yearlings). The timing of emigration from the colonies studied was highly synchronous and was correlated with the dates of emergence of new litters. Yearling females that dispersed tended to leave at a later date than did yearling males. Most (91%) animals that dispersed moved to colonies <4 km away but movements of up to 8.5 km were recorded. There was no difference in median distance dispersed for male and female yearlings (2.0 and 1.8 km, respectively). Dispersing squirrels departed from colonies in nonrandom directions apparently following such features as trails and drainage systems. Such movement seemed to enhance the squirrels' chances of successfully locating nearby colonies. Minimum known survival rates while in transit for yearlings were 16% for males and 11% for females. Estimates of actual survival in transit for yearlings were 26% for males and 30% for females.

Sign in / Sign up

Export Citation Format

Share Document