An Analysis of External Features as Predictors of Reproductive Status in Small Mammals

McCravy, Kenneth W.; Rose, Robert K.

doi:10.2307/1381877

Cited by 54 publications

(26 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No trapping was conducted during 2000, complete post-treatment trapping was conducted in 2001-2003. Traps were checked in the morning and afternoon, and the following data were recorded: trap location and size, species, new or recapture, individual identity, age class, sex, mass, and release condition. We classified animals as either adults or subadults based on mass and external evidence of reproductive status (McCravy and Rose, 1992). Animals were individually identified with two unique ear tags.…”

Section: Small Mammal Trappingmentioning

confidence: 99%

Small mammal population and habitat responses to forest thinning and prescribed fire

Converse

Block

White

2006

Forest Ecology and Management

108

View full text Add to dashboard Cite

Section: Small Mammal Trappingmentioning

confidence: 99%

Small mammal population and habitat responses to forest thinning and prescribed fire

Converse

Block

White

2006

Forest Ecology and Management

108

View full text Add to dashboard Cite

“…Peromyscus were aged using pelage characteristics (Conventry 1937;Gottschang 1956;Layne 1968). Microtus were aged using three different criteria, in which possession of any one signified adulthood: (1) duration on the study site (≥3 months), (2) reproductive state (testes descended in males and perforate, lactation condition, or pregnancy in females), or (3) mass (males >28.0 g and females >26.0 g; Nadeau 1985;McCravy and Rose 1992). Although mass may not be an accurate age classification criterion for rodents (Dueser et al 1981(Dueser et al , 1984Tamarin 1984), the goal of the investigation was not to describe natural history patterns over time, but to compare controls and treatments.…”

Section: Field Experimentsmentioning

confidence: 99%

Movement and spatial organization of small mammals following vertebrate predator exclusion

Yunger

2004

Oecologia

View full text Add to dashboard Cite

Predation directly changes the demographics of prey, generally through a numerical decrease. An indirect effect of predators is alteration of movements and spatial patterns of prey. The relationship between these direct and indirect effects can be tested by excluding predators. Home range size of white-footed mice (Peromyscus leucopus) decreased and home range overlaps increased in the absence of predators. Home range size and overlaps of meadow voles (Microtus pennsylvanicus) did not change despite an increase in vole density. P. leucopus had significantly lower interspecific home range overlaps with M. pennsylvanicus than intraspecific overlaps. The changes in P. leucopus spatial behavior may be an indirect effect of predator exclusion resulting from the increase in M. pennsylvanicus densities.

show abstract

“…To accurately assess squirrel populations, external reproductive indicators must be recognizable and accurate. McCravy and Rose (1992) used necropsy to evaluate breeding condition in small rodents. They found nipple size was a better predictor of breeding status than condition of the pubic symphysis or vagina.…”

Section: Developmentreproductive Condition and Litter Sizementioning

confidence: 99%

“…Muul (1969b) and Sollberger (1943) describe the reproductive biology of southern flying squirrels (Glaucomys volans [Linnaeus 1758]). McCravy and Rose (1992) analyze external features that may be used as predictors of reproductive status of small mammals in the field. Morris (1972) reviews aging methods used to assess both relative and absolute age in mammals.…”

Section: Introduction World Status Of Flying Squirrels Ecology In Thementioning

confidence: 99%

Maturation and reproduction of northern flying squirrels in Pacific Northwest forests.

Villa¹,

Carey²,

Wilson³

et al. 1999

View full text Add to dashboard Cite

Northern flying squirrels are the primary prey of northern spotted owls and are important dispersers of fungal spores in Pacific Northwest forests. Despite the importance of these squirrels in forest ecosystems, information is lacking on life history and methods for determining age and reproductive condition. In the laboratory, we measured epiphyseal notch, femur length, rostrum length, least interorbital breadth, rump pelage length and color, and tail width of dead squirrels. We analyzed weight, pelage color, and reproduction for field-collected data from live squirrels. We also described age-class differences in facial features and tail size and shape in the Puget Trough. A birth-year-based age-class system had several advantages over the traditional juvenile-subadult-adult class system. Three age classes can be distinguished in the field, each with varying degrees of accuracy. Reproduction of northern flying squirrels can be reliably determined in live-trapping studies. Enlargement, turgidity, and redness of genitalia are detectable signs of reproductive activity, whereas reduction, flaccidity, and paleness signal inactivity for both males and females. Nipple length is the best indicator for distinguishing sexual maturity of inactive females. The most effective way to avoid mistakes and ambiguity about age and reproductive status in the field is to take descriptive notes. Maturation and reproductive patterns were similar among the Puget Trough, Olympic Peninsula, and northern Cascade studies in Washington. Squirrels in the Coast Range of Oregon, however, displayed different patterns. Regional populations differed in proportion of females reproductively active, the reproductive maturity of yearling females, and survivorship across age classes. Regional variations suggest accurate assessment of age and reproduction is a prerequisite for understanding flying squirrel ecology.Keywords: Northern flying squirrel, maturation, reproductive biology, Oregon, Washington, live-trapping, necropsy. AbstractThere has been substantial research on old-growth Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) forests and wildlife that depend on them (Ruggiero and others 1991). Northern flying squirrels (Glaucomys sabrinus [Shaw 1801]) have been of particular interest because they seem to be keystone species in late-seral forests-a main prey of strigids and mustelids on one trophic level, and a consumer and disseminator of fungal spores on another. Through its mission to develop forest management practices that steward biodiversity, the Ecological Foundations of Biodiversity Research Team has focused research on the relation between northern flying squirrels and forest health.Despite the importance of northern flying squirrels in Pacific Northwest forest ecosystems, information is lacking on life history and methods for determining age and reproductive condition. We began studying flying squirrel populations in 1985 in Douglas-fir forests of the Coast Ranges physiographic province in southwestern Oregon (Franklin and Dyrness 19...

show abstract

An Analysis of External Features as Predictors of Reproductive Status in Small Mammals

Cited by 54 publications

References 16 publications

Small mammal population and habitat responses to forest thinning and prescribed fire

Small mammal population and habitat responses to forest thinning and prescribed fire

Movement and spatial organization of small mammals following vertebrate predator exclusion

Maturation and reproduction of northern flying squirrels in Pacific Northwest forests.

Contact Info

Product

Resources

About