Rafinesque's big-eared bat
|Rafinesque's big-eared bat|
|Species distribution (in the southeastern United States) based on data from the IUCN.|
As its name implies, this species has large ears that are over an inch long. The genus name Corynorhinus means "club-nosed." Similar to the Townsend's big-eared bat, this species has two lumps on either side of its nose. Rafinesque's big eared bat is a medium sized bat with a length of about 7.5-10cm (3-4 inches) and a wingspan of 25-30cm (10-12 inches). These bats range in mass from 6-13g (0.2-0.45 ounce). The bat is gray on on the dorsal side and white on the underside. The ears and face are a pinkish-brown color while the forearm and wing membrane is dark brown.
Some sources report maximum lifespan as 10 years, although robust data are lacking. More research has been done on the closely-related Townsend's big-eared bat and estimates for this species' lifespan range from 16 up to 30 years in the wild.
While uncommon throughout its range, this species is found in a variety of habitats from coastal plains, riparian areas, to mountainous areas like the Great Smoky Mountains National Park. In all cases, these bats are associated with large swathes of relatively mature forest.
Rafinesque's big-eared bats, like all bats in the southeastern United States, are insectivorous, nocturnal, and locate food primarily by echolocation. They consume a wide range of insects, including mosquitoes, beetles, and flies, although moths make up 90% of the diet. Insects can be caught by gleaning (e.g., from foliage or cave walls) or on the wing (i.e., aerial hawking).
Due to seasonality, geographical location, and frequent roost-switching, C. rafinesquii can be found in a variety of locations. Tree roosts may be in living or dead trees but are usually quite large (one study reported average diameter at breast height of tree roosts to be 79cm with a height of 18.5m). Rafinesque's big-eared bats can also be found in abandoned buildings, under bridges, in wells, and in caves.
While listed as least concern by the International Union for the Conservation of Nature (previously listed as vulnerable), Rafinesque's big-eared bats are listed as a Candidate II Species of Concern by the U.S. Fish and Wildlife Service. Additionally, it is listed as threatened by state agencies throughout most of its range.
White nose syndrome is a serious disease caused by a fungal pathogen that has devastated several species of bats in the eastern United States. Unlike some other species of bats with which it shares its range, the Rafinesque's big-eared bat does not appear to be affected by the disease. Hypothesized reasons include use of hibernacula that may not provide optimal growing conditions for the causal agent (the fungus Pseudogymnoascus destructans), relatively frequent arousals from torpor, and/or the usage of shallow bouts of torpor by this species.
- Arroyo-Cabrales, J. & Ticul Alvarez Castaneda, S (2008). "Corynorhinus rafinesquii". IUCN Red List of Threatened Species. Version 2009.2. International Union for Conservation of Nature. Retrieved 1 February 2010.
- Schwartz, Charles Walsh; Schwartz, Elizabeth Reeder (2001). The Wild Mammals of Missouri (2nd ed.). p. 97.
- Animal Diversity Web, Reyes, E. (2002) Corynorhinus rafinesquii
- Mammalian Species, Jones, C. (1977). No. 69, pp. 1-4 Plecotus rafinesquii
- Channel Islands National Park - Townsend's Big-eared Bats, U.S. National Park Service.
- , Lacki, M.J. and K.M. Ladeur. (2001). Seasonal use of lepidopteran prey by Rafinesque's big-eraed bats (Corynorhinus rafinesquii). The American Midland Naturalist 145(1):213-217.
- , Trousdale, A.W. and D.C. Beckett. (2005). Characteristics of tree roosts of Rafinesque's big-eared bat (Corynorhinus rafinesquii) in southeastern Mississippi. The American Midland Naturalist 154(2):442-449.
- , Lance, R.F. et al. (2001). Day-roost selection by Rafinesque's big-eared bat (Corynorhinus rafinesquii) in Louisiana forests. Journal of Mammalogy 82(1):166-172.
- , Bat Conservation International and Southeastern Bat Diversity Network. (2013). A conservation strategy for Rafinesque's big-eared bat (Corynorhinus rafinesquii) and southeastern myotis (Myotis austroriparus). Bat Conservation International, Austin, TX. (specific citations from page 41-43 and page 93)
- A video demonstrating one type of roost habitat for this species in Florida can be seen here.
- A poster from the Mammoth Cave International Center for Science and Learning about Rafinesque's big-eared bats within the park.
- A short video about Rafinesque's big-eared bats produced by Texas Parks and Wildlife.
- Southeastern Bat Diversity Network website