Albinism in Brazilian common opossums (Didelphis aurita)

Albinism has been sporadically recorded in Virginia opossums (Didelphis virginiana) in the United States and Mexico, but records of pigmentation disorders in other Didelphis spp. are rare. The Brazilian common opossum (Didelphis aurita) is a cat-sized nocturnal omnivorous marsupial that inhabits Atlantic and Araucaria forests in South America. A litter of five young Brazilian common opossums was rescued at Espírito Santo state, southeast Brazil, of which two were albinos (one male, one female) and the remaining had normal pigmentation (three males). The two albinos had a complete lack of integumentary and retinal pigmentation, representing the first recorded cases of albinism in this species (and the first record in a Didelphis sp. other than the Virginia opossum).

Wildlife of Florida Factsheet: Virginia Opossum

Wildlife of Florida Factsheet: Virginia Opossum Learn more about the Florida Opossum! The Wildlife of Florida Factsheet series was created to provide the public with a quick accurate introduction to Florida’s wildlife, including both native and invasive. We hope these factsheets inspire people to investigate wildlife in their own backyard and communities and understand the amazing biodiversity of wildlife in the state of Florida.

Virginia opossum distributions are influenced by human-modified landscapes and water availability in tallgrass prairies

The Flint Hills represent the largest tract of tallgrass prairie in North America and is located near the western edge of the native range of the Virginia opossum (Didelphis virginiana). This region is undergoing rapid landscape changes (e.g., urbanization, agriculture, woody encroachment) that are negatively affecting mammal communities. Although previous research has revealed northward distributional expansions of Virginia opossums facilitated by urban development, no studies have assessed how landscape change affects distribution patterns along the western edge of their geographic range. During 2016–2018, we monitored site (n = 74) occupancy along urban–rural transects in the Flint Hills to assess the influence of landscape change (i.e., urban, grassland, agriculture, woody encroachment) and water availability on the distribution of Virginia opossums. Sites surrounded by urban land cover had greater initial occupancy probabilities and lower extinction rates. Sites closer to permanent water sources experienced greater colonization rates and lower extinction rates. In addition, site extinction rates were lower in areas surrounded by woody encroachment. Our results concur with other studies suggesting that growing urban areas may expand opossum distributions along the edges of their geographic range. Our study also suggests that woody encroachment into tallgrass prairies may provide an alternative pathway for future distributional expansions. Future research must consider the potential for landscape change, along with dynamic water availability, in models predicting the distribution of Virginia opossums.

West Nile Virus Associations in Wild Mammals: An Update

Although West Nile virus (WNV) is generally thought to circulate among mosquitoes and birds, several historic and recent works providing evidence of WNV activity in wild mammals have been published. Indeed, a previous review tabulated evidence of WNV exposure in at least 100 mammalian species. Herein, we provide an update on WNV activity in wild and select other mammals that have been reported since the last major review article on this subject was published in early 2013. Of interest, new species, such as Hoffman’s two-toed sloths (Choloepus hoffmanni), are now included in the growing list of wild mammals that have been naturally exposed to WNV. Furthermore, new instances of WNV viremia as well as severe disease presumably caused by this virus have been reported in wild mammals (e.g., the Virginia opossum [Didelphis virginiana]) from natural and semi-captive (e.g., zoological institution) settings. Regrettably, few recent challenge studies have been conducted on wild mammals, which would provide key information as to their potential role(s) in WNV cycles. Largely based on these recent findings, important future lines of research are recommended to assess which mammalian species are commonly exposed to WNV, which mammal species develop viremias sufficient for infecting mosquitoes, and which mammal species might be negatively affected by WNV infection at the species or population level.