conservation.arizona.edu - nesting behavior

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

Palmer, G. H., J. L. Koprowski, and A. J. Pernas. 2013. Nest tree and site selection of an introduced population of red-bellied squirrels (Sciurus aureogaster). Journal of Mammalogy 94:1274-1281.

thackerk1 — Wed, 24 Jul 2019 21:30:22 +0000

Authors

Geoffrey H. Palmer

John L. Koprowski

Anthony J. Pernas

Nests play a crucial role in the life history of tree squirrels, and can be a critical component of their biology that enables them to be a successful invasive species. Red-bellied squirrels (Sciurus aureogaster) were introduced to Elliott Key, Florida, in the late 1930s, and spread to nearby islands. Red-bellied squirrels were believed extirpated by Hurricane Andrew in 1992, but were rediscovered on Elliott Key in 2005. In 2006 and 2007, we surveyed for squirrel nests and measured vegetation to evaluate forest characteristics associated with nest-site selection by squirrels, and compared these data to measurements collected at random locations. Squirrels placed nests in large trees with more canopy linkages in mixed-hardwood forest, and the nest trees were in areas with large trees, high tree density and canopy cover, and lower recent hurricane damage. Red-bellied squirrels selected characteristics of nest trees and forest structure in similar ways to individuals in their native range, and to other species of tree squirrels in general. Results from our research allowed land managers to assess possible management actions and provided important information for them to develop an effective management strategy. Park officials are currently working toward complete eradication of the introduced population of red-bellied squirrels from the Florida Keys. We suggest that behaviors of individuals in native ranges may elucidate patterns for individuals introduced to novel environments; however, we also caution that care must be taken in further extrapolation. Our findings emphasize the importance of understanding ecology of introduced species for effective management.

Additional Information

Nest tree and site selection of an introduced population of red-bellied squirrels (Sciurus aureogaster)

Date of publication:

2013

Topics

habitat selection

invasive species

Mexican gray squirrel

nesting behavior

species eradication

tree squirrel

red-bellied squirrels

Biscayne National Park

Leonard, K. M. and J. L. Koprowski. 2009. A comparison of habitat use and demography of red squirrels at the southern edge of their range. American Midland Naturalist 162: 132-145.

thackerk1 — Tue, 23 Jul 2019 22:17:11 +0000

Authors

Kathrine M. Leonard

John L. Koprowski

Populations at the edge of their geographic range may demonstrate different population dynamics from central populations. Endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis), endemic to southeastern Arizona, represent the southernmost red squirrel population and are found at lower densities than conspecifics in the center of the range. To determine if differences are due to conditions at the southern periphery of the range, we compared habitat characteristics, demography, body mass, space use and nesting behavior with another subspecies located at the southern edge of the range, the Mogollon red squirrel (T. h. mogollonensis). We found that mean and minimum daily temperatures were higher at Mt. Graham whereas maximum temperatures were higher in the White Mountains, male Mogollon red squirrels were heavier than male Mt. Graham red squirrels in all seasons and female Mogollon red squirrels were slightly heavier than female Mt. Graham red squirrels in spring, proportion of squirrels in reproductive condition was lower in female Mogollon red squirrels, Mogollon red squirrels had smaller home ranges, used different types of nests and traveled less distance to nest than Mt. Graham red squirrels. There were no differences in annual rainfall, seedfall, habitat characteristics or survival between mountain ranges. Localized conditions appear to account for the disparity between populations. These differences demonstrate the importance of evaluating attributes of peripheral populations for maximizing persistence and intraspecific diversity.

Additional Information

A Comparison of Habitat Use and Demography of Red Squirrels at the Southern Edge of Their Range

Date of publication:

2009

Topics

Mount Graham Red Squirrel

Mongollon red squirrel

habitat use

body mass

nesting behavior