(Download) "Lactating North American Beavers (Castor Canadensis) Sharing Dens in the Southwestern United States (Notes) (Report)" by Justin W. Fischer, Roger E. Joos & Melissa A. Taylor, Jimmy D. Bergman, David L. Nolte, Dale L. Piaggio, Antoinette J. Neubaum * eBook PDF Kindle ePub Free
eBook details
- Title: Lactating North American Beavers (Castor Canadensis) Sharing Dens in the Southwestern United States (Notes) (Report)
- Author : Justin W. Fischer, Roger E. Joos & Melissa A. Taylor, Jimmy D. Bergman, David L. Nolte, Dale L. Piaggio, Antoinette J. Neubaum
- Release Date : January 01, 2010
- Genre: Life Sciences,Books,Science & Nature,
- Pages : * pages
- Size : 91 KB
Description
The typical colony or family unit of the North American beaver (Castor canadensis) consists of an adult breeding pair, young of the current year, yearlings born the previous year, and occasionally, one or more nonbreeding sub-adults (Bradt, 1938; Aleksiuk, 1968; Svendsen, 1980; Bishir et al., 1983; Hodgdon and Lancia, 1983; Busher, 1987). Reports exist of colonies containing >2 adult females (Hay, 1958; Payne, 1982) and some studies have documented multiple lactating or pregnant females within a colony or territorial area (Bergerud and Miller, 1977; Busher et al., 1983; Wheatley, 1993; Crawford et al., 2008). Wheatley (1993) reported two pregnant North American beavers within a colony in southern Manitoba, but it was not clear whether both animals were residents of the same lodge. Conditions of the ice and distance from neighboring lodges provided anecdotal evidence that both females inhabited the same lodge. Recently, Crawford et al. (2008) examined genetic relationships within and among colonies to determine if they are a socially monogamous species. Interestingly, colonies did contain unrelated individuals and >50% of litters had been sired by multiple males. However, no published literature has documented multiple lactating or pregnant adults residing in the same lodge or den for an extended period of time. Previous studies have used trapping to provide a snapshot in time regarding composition of colonies, but not actual use of lodge or den. Here we report two cases demonstrating multiple reproductively active females using the same den over an extended period of time. We investigated the degree of relatedness among females sharing dens using microsatellite DNA markers. Based on similar work by Crawford et al. (2008), we predicted that communal denning occurs in populations and those females sharing dens are closely related. Therefore, we used DNA genotypes to test the hypothesis that pairwise kinship analysis between co-denning females would infer first-order relationships, with the null hypothesis that they were unrelated.