conservation.arizona.edu - communal nesting

Edelman, A. J. and J. L. Koprowski. 2007. Communal nesting in asocial Abert's squirrels: the role of social thermoregulation and breeding strategy. Ethology 113: 147-154.

thackerk1 — Tue, 30 Jul 2019 22:49:40 +0000

Authors

Andrew J. Edelman

John L. Koprowski

The social thermoregulation hypothesis states that endothermic species will communally nest to reduce energy expenditures on thermoregulation. The hypothesis predicts that the frequency of communal nesting should increase with decreasing ambient temperature. The potential costs of communal nesting (e.g., increased predation risk, resource competition, cuckoldry, parasite/disease transmission, or infanticide) could decrease the frequency of communal nesting especially for asocial breeding females with dependent offspring. We examined the effects of ambient temperature and seasonal reproductive activities on the probability of communal nesting in Abert's squirrels (Sciurus aberti) in the Pinaleño Mountains, Arizona. Most squirrels nested consistently with the same partner in mixed-sex pairs. The proportion of individuals engaging in communal nesting increased with decreasing ambient temperature as predicted by the social thermoregulation hypothesis. The onset of the breeding season greatly reduced the proportion of individuals communally nesting. The negative relationship between ambient temperature and communal nesting supports the use of communal nesting in Abert's squirrels as a mechanism to reduce thermoregulatory costs during cold conditions. The abrupt drop in the frequency of communal nesting during the breeding season is likely due to female abandonment of this behavior. By avoiding communally nesting during the breeding season, females may prevent males from mating with them outside of mating chases, reduce resource competition, and protect offspring from infanticide, diseases, and parasites. Males may gain additional fitness benefits from nesting with females because familiarity with females increases dominance rank in mating activities.

Additional Information

Communal Nesting in Asocial Abert's Squirrels: the Role of Social Thermoregulation and Breeding Strategy

Date of publication:

2007

Topics

Abert’s squirrel

communal nesting

endothermic

Pinaleño Mountains

Ramos-Lara, N., and J.L. Koprowski. 2012. Communal nesting behavior in Mearns’s squirrels (Tamiasciurus mearnsi). Southwestern Naturalist 57: 195-225.

thackerk1 — Tue, 30 Jul 2019 18:18:57 +0000

Authors

Nicolás Ramos-Lara

John L. Koprowski

Communal nesting has been observed frequently in arboreal squirrels of the genus Sciurus and Glaucomys, but only occasionally in Tamiasciurus. During 2006 and 2007, we trapped and radiocollared 38 adult Mearns’s squirrels (Tamiasciurus mearnsi) in Baja California, Mexico, to examine their nesting behavior. We report for the first time instances of communal nesting in Mearns’s squirrels. Same-sex groups were more common than mixed-sex groups. Females engaged more in communal nesting than males. Communal nesting behavior in Mearns’s squirrels seems to be similar to other species of arboreal squirrels; decreasing as mean monthly temperature increases and during the breeding season.

Additional Information

COMMUNAL NESTING BEHAVIOR IN MEARNS’S SQUIRRELS (TAMIASCIURUS MEARNSI)

Date of publication:

2012

Topics

arboreal squirrels

Mearn’s squirrel

communal nesting

nesting behavior

Koprowski, J. L. 1996. Natal philopatry, communal nesting, and kinship in fox squirrels and gray squirrels. Journal of Mammalogy 77(4): 1006-1016.

thackerk1 — Mon, 22 Jul 2019 23:36:31 +0000

Authors

John L. Koprowski

Tree squirrels (Sciuridae: Sciurini) are considered to be asocial; however, communal nesting is reported for most species. I examined the sociality of uniquely marked fox squirrels (Sciurus niger) and gray squirrels (S. carolinensis) to investigate interspecific patterns of natal philopatry, communal nesting, and kinship. Natal philopatry was female-biased in gray squirrels, resulting in the formation of kin clusters, but no fox squirrels remained in their natal areas. Adult male and female squirrels interacted less than expected, suggesting that the social systems of the sexes are separate. Communal nesting occurred in all seasons, but was most frequent in winter. Unrelated adult males commonly nested together in both species. However, adult female fox squirrels rarely nested in groups, although communal nests were common among female gray squirrels. Amicable behaviors were directed only toward closely related females (r = 0.5) within kin groups of gray squirrels; aggression was directed primarily at unrelated females. The female-female bond was important in the formation of groups in gray squirrels.

Additional Information

Natal Philopatry, Communal Nesting, and Kinship in Fox Squirrels and Gray Squirrels

Date of publication:

1996

Topics

fox squirrel

gray squirrel

communal nesting

natal philopatry

sociality

relatedness

Jessen, R. R., G. H. Palmer, and J. L. Koprowski. 2013. Neotropical pygmy squirrels (Sciurillus pusillus) share termite nests. Ecotropica 19:73-76.

thackerk1 — Mon, 22 Jul 2019 18:50:19 +0000

Authors

Rosa R. Jessen

Geoffrey H. Palmer

John L. Koprowski

Nest-site selection is important for reproduction (Benson et al. 2008) and also provides a place for other activities such as resting and shelter or protection from weather and predators (Sealander Jr. 1952, Steele & Koprowski 2001). Nesting habits are also influenced by level of sociality, and can confer fitness advantages (Alexander 1974). Communal nesting is an example of increased sociality found in mammals, including tree squirrels (Wolff & Lidicker Jr. 1981, Layne & Raymond 1994, Koprowski 1996, Ebensperger et al. 2004). Sociality among tree squirrels is poorly understood and communal nesting occurs only rarely in some species of tree squirrels in temperate forests (Halloran & Bekoff 1994, Layne & Raymond 1994, Koprowski 1996).

Tree squirrels in temperate regions nest in cavities of trees, dreys (arboreal bolus structures constructed of twigs and leaves), and occasionally also in burrows (Steele & Koprowski 2001, Thorington Jr. et al. 2012). Diversity of tree squirrels is highest in the tropics, with 19 species occurring in the Neotropics, but few studies have been conducted in these areas (Koprowski & Nandini 2008). Little is known about nesting habits of Neotropical tree squirrels but they appear to use drey and cavity nests (Emmons & Feer 1997). Many Neotropical tree squirrels are believed to be solitary (Emmons & Feer 1997) but some species, such as northern and southern Amazon red squirrels (Sciurus igniventris, S. spadiceus), and Neo-tropical pygmy squirrels (Sciurillus pusillus, Geoffroy 1803), forage in groups of ≤ 4 individuals (Heymann & Knogge 1997, Eason 2010, R. Jessen, pers. obs.). Neotropical pygmy squirrels are diurnal and the smallest tree squirrels in the western hemisphere, but there is a substantial lack of information about their life history and ecology (Emmons & Feer 1997, Koprowski & Nandini 2008). Here we report our observations of Neotropical pygmy squirrels using termite nests to nest communally.

Additional Information

Neotropical pygmy squirrels (Sciurillus Pusillus) share termite nests

Date of publication:

2013

Topics

Neotropical pygmy squirrels

communal nesting

social behavior

Peru

tree squirrel

igapó

Loreto