Complete albinism in a northern red-backed vole, … albino Northern Red-backed Vole had complete...
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2009 NOTES 167 Hughes, A. L., iUld M. K. Hughes. 1986. Paternal and sexual size dimorphism in North American passerines. Oikos 46: 171-175. Jonsson, P. E., and T. Alerstam. 2008. The adaptive signifi- cance of parental role division and sexual size dimorphism in breeding shorebirds. Biological Journal of the Linnean Society 41: 301-314. Kissner, K. J., P. J. Weatherhead, and C. M. Francis. 2003. Sexual size dimorphism and timing of spring migration in birds. Journal of Evolutionary Biology 16: 154-162. Lovich, J. E., and J. W. Gibbons. 1992. A review of tech- niques for quantifying sexual size dimorphism. Growth, Development & Aging 56: 269-281. Mosher, J. A., and P. F. Matray. 1974. Size dimorphism: a factor in energy savings in broad-winged hawks. The Auk 91: 325-341. Murphy, M. T. 2007. A cautionary tale: cryptic sexual size dimorphism in a socially monogamous passerine. The Auk 124: 515-525. Pyle, P. 1997. Identification guide to North American birds. Slate Creek, Solinas, California. Semenchuk, G. P., Editor. 1992. The atlas of breeding birds of Alberta. Federation of Alberta Naturalists, Edmonton, Alberta, Canada. Szekely, T., J. D. Reynolds, and J. Figuerola. 2000. Sexual size dimorphism in shorebirds, gulls, and alcids: the influence of sexual and natural selection. Evolution 54: 1404-1413. Webster, M. S. 1992. Sexual dimorphism, mating system and body size in New World Blackbirds (lcterinae). Evo- luti0n. 46:1621-1641. Witmer, M. C. 2002. Bohemian Waxwing (Bombycilla gar- rulus). Number 714 in The Birds of North America Online. Edited by A. Poole. Cornell Lab of Ornithology, Ithaca; retrieved from the Birds of North America Online: http:// bna.birds.comell.edu/bna/species/714. Received 9 June 2008 Accepted 5 April 2010 Complete Albinism in a Northern Red-backed Vole, Myodes rutilus, in Alaska JACKSONS. WHITMAN Alaska Department of Fish and Game, Division of Wildlife Conservation, Nongame Program, 1300 College Road, Fair- banks, Alaska 99701 USA; e-mail: [email protected] Whitman, Jackson S. 2009. Complete albinism in a Northern Red-backed Vole, Myodes rutilus, in Alaska. Canadian Field- Naturalist 123(2): 167-168. During a study of small mammal abundance and species composition in interior Alaska, I collected a Northern Red-backed Vole (Myodes rutilus) showing complete albinism. This report documents that extremely rare occurrence, with notes on habitat and morphometrics. Key Words: Myodes ruti/us, Northern Red-backed Vole, albino, Alaska. True albino, or amelanistic individuals are caused by a genetic trait and are completely devoid of melanin. Characteristicly they have unpigmented pink eyes. Mammals with this trait display white pelage. Albi- nism, either partial or complete, is rarely documented in wild populations, thus detailed observations are noteworthy. I captured a single complete albino Northern Red- backed Vole (Myodes rutilus) in a Museum Special snap trap (Woodstream Corporation, Lititz, Pennsyl- vania, USA) baited with a combination of peanut but- ter and rolled oats on 2 August 2007 on Minto Flats State Game Refuge, central Alaska (64.9052°N, 149.0309°W). Dental characteristics and skull mor- phology confirmed the initial species classification. The albino Northern Red-backed Vole had complete white pelage and pink eyes, with standard body mea- surements well within the norm displayed by other conspecifics in interior Alaska. Testes were non-scro- tal, indicating a juvenile male individual. Weight was 17.4 g, with standard measurements (mm) of 119:29: I 9: 14 (total:tail:hind foot:ear). In a sample of I I 1 indi- viduals captured during 2007, weights averaged 20.9 g, with extremes from 7.9 to 36.7 g. Standard meas- urements from this population sample show means of 120.0:29.7:18.9:14.4 (Whitman, unpublished data). This specimen was submitted for curation to the Uni- versity of Alaska Museum of the North (UAM 85050). During 2003-2007, 7926 trapnights using unmodi- fied Museum Special snap traps resulted in captures of 925 Northern Red-backed Voles. An additional 107 individuals were captured in 980 pitfall trapnights (I capture/8906 trapnights; I albino in 1032 M. rutilus captured= 0.097%). No other Northern Red-backed Voles showed any degree of albinism. A check for albi- nism amongst 1653 Northern Red-backed Vole records in the University of Alaska Museum of the North re- vealed six specimens, two of which appeared to be complete albinos. However, I suspect any inference to natural population incidence is negated by the fact that pelage morphs are more likely to be curated than "normal" specimens.
Transcript of Complete albinism in a northern red-backed vole, … albino Northern Red-backed Vole had complete...
2009 NOTES 167
Hughes, A. L., iUld M. K. Hughes. 1986. Paternal inve~tmenl and sexual size dimorphism in North American passerines. Oikos 46: 171-175.
Jonsson, P. E., and T. Alerstam. 2008. The adaptive significance of parental role division and sexual size dimorphism in breeding shorebirds. Biological Journal of the Linnean Society 41: 301-314.
Kissner, K. J., P. J. Weatherhead, and C. M. Francis. 2003. Sexual size dimorphism and timing of spring migration in birds. Journal of Evolutionary Biology 16: 154-162.
Lovich, J. E., and J. W. Gibbons. 1992. A review of techniques for quantifying sexual size dimorphism. Growth, Development & Aging 56: 269-281.
Mosher, J. A., and P. F. Matray. 1974. Size dimorphism: a factor in energy savings in broad-winged hawks. The Auk 91: 325-341.
Murphy, M. T. 2007. A cautionary tale: cryptic sexual size dimorphism in a socially monogamous passerine. The Auk 124: 515-525.
Pyle, P. 1997. Identification guide to North American birds. Slate Creek, Solinas, California.
Semenchuk, G. P., Editor. 1992. The atlas of breeding birds of Alberta. Federation of Alberta Naturalists, Edmonton, Alberta, Canada.
Szekely, T., J. D. Reynolds, and J. Figuerola. 2000. Sexual size dimorphism in shorebirds, gulls, and alcids: the influence of sexual and natural selection. Evolution 54: 1404-1413.
Webster, M. S. 1992. Sexual dimorphism, mating system and body size in New World Blackbirds (lcterinae). Evoluti0n. 46:1621-1641.
Witmer, M. C. 2002. Bohemian Waxwing (Bombycilla garrulus). Number 714 in The Birds of North America Online. Edited by A. Poole. Cornell Lab of Ornithology, Ithaca; retrieved from the Birds of North America Online: http:// bna.birds.comell.edu/bna/species/714.
Received 9 June 2008 Accepted 5 April 2010
Complete Albinism in a Northern Red-backed Vole, Myodes rutilus, in Alaska
JACKSONS. WHITMAN
Alaska Department of Fish and Game, Division of Wildlife Conservation, Nongame Program, 1300 College Road, Fairbanks, Alaska 99701 USA; e-mail: [email protected]
Whitman, Jackson S. 2009. Complete albinism in a Northern Red-backed Vole, Myodes rutilus, in Alaska. Canadian Field-Naturalist 123(2): 167-168.
During a study of small mammal abundance and species composition in interior Alaska, I collected a Northern Red-backed Vole (Myodes rutilus) showing complete albinism. This report documents that extremely rare occurrence, with notes on habitat and morphometrics.
Key Words: Myodes ruti/us, Northern Red-backed Vole, albino, Alaska.
True albino, or amelanistic individuals are caused by a genetic trait and are completely devoid of melanin. Characteristicly they have unpigmented pink eyes. Mammals with this trait display white pelage. Albinism, either partial or complete, is rarely documented in wild populations, thus detailed observations are noteworthy.
I captured a single complete albino Northern Redbacked Vole (Myodes rutilus) in a Museum Special snap trap (Woodstream Corporation, Lititz, Pennsylvania, USA) baited with a combination of peanut butter and rolled oats on 2 August 2007 on Minto Flats State Game Refuge, central Alaska (64.9052°N, 149.0309°W). Dental characteristics and skull morphology confirmed the initial species classification. The albino Northern Red-backed Vole had complete white pelage and pink eyes, with standard body measurements well within the norm displayed by other conspecifics in interior Alaska. Testes were non-scrotal, indicating a juvenile male individual. Weight was 17.4 g, with standard measurements (mm) of 119:29:
I9: 14 (total :tail:hind foot:ear). In a sample of I I 1 individuals captured during 2007, weights averaged 20.9 g, with extremes from 7.9 to 36.7 g. Standard measurements from this population sample show means of 120.0:29.7:18.9:14.4 (Whitman, unpublished data). This specimen was submitted for curation to the University of Alaska Museum of the North (UAM 85050).
During 2003-2007, 7926 trapnights using unmodified Museum Special snap traps resulted in captures of 925 Northern Red-backed Voles. An additional 107 individuals were captured in 980 pitfall trapnights (I capture/8906 trapnights; I albino in 1032 M. rutilus captured= 0.097%). No other Northern Red-backed Voles showed any degree of albinism. A check for albinism amongst 1653 Northern Red-backed Vole records in the University of Alaska Museum of the North revealed six specimens, two of which appeared to be complete albinos. However, I suspect any inference to natural population incidence is negated by the fact that pelage morphs are more likely to be curated than "normal" specimens.
168 THE CANADIAN FIELD-NATURALIST Vol. 123
Habitat from which the albino Northern Red-backed Vole came was interior boreal forest at 110 m elevation. No notable logging or other anthropogenic changes have occurred within l 0 km of the site. Overstory vegetation was composed of an open mixed forest of Alaska Paper Birch (Betula neoa/askana) and White Spru~e (Picea glauca) with approximately 50% canopy closure. The understory (stems per 1-m-radius plot frame) was comprised of Labrador Tea, Ledum groenlandicum (90 stems, 59% of total stems), Mountain Cranberry, Vacciniwn vitis-idaea (30, 20%), Bog Blueberry, Vaccinium uliginosum (22, 14%), and minor amounts of grass, Calamagrostis sp. (5, 3%), Horsetail, Equisetum sp. (4, 3%), and Red-fruited Bastard Toadtlax, Geocaulon lividum (2, 1 %). Plant systematics and nomenclature follows Hulten ( 1968) with updates provided by Viereck and Little (2007). Habitat suitable for Northern Red-backed Voles occurs in a continuum on the north side of the Alaska Range through Alaska and eastward into Yukon Territory, Canada, thus, this individual was not likely from a geographically isolated population.
Although there are numerous references to albinism in various microtine populations (Microtus montanus: Warren 1929; Pinter and Negus 1971; Jannett 1981; M. ochrogaster: Pinter and Negus 1971; M. pennsylvanicus: Owen and Shakelford 1942; Barrett 1975, Brewer et al. 1993, Parsons and Bondrup-Nielsen 1995; M. pinetorum: Schantz 1960; Paul 1964; Clethrionomys (Myodes) gapperi: Bowman and Curran 2000), the incidence (captures/100 trapnights or percentage of total catch) of albinism is rarely reported. As well, most references are of partial albinism or leucism, with few completely albino references. I can provide no plausible argument to suggest that albinistic individuals are not captured in proportion to their occurrence in the population.
Acknowledgments M. Rabe assured adequate funding for the project
through the State Wildlife Grants program, administered by the Alaska Department of Fish and Game, Wildlife Conservation Division, Nongame Program.
L. Olson and B. Jacobsen at the University of Alaska Museum of the North kindly accepted and expertly curated this and other specimens. A. Greenblat of Shadow Aviation in Fairbanks provided timely and safe transportation. L. Whitman, T. Jung, and one anonymous reviewer provided helpful editorial comments.
Literature Cited Barrett, G. 1975. Occurrence of an albino Microtus penn·
sy/vanicus in Ohio. Journal of Mammalogy 75: 102. Bowman, J., and R. M. Curran. 2000. Pa1tial albinism in
the red-backed vole, Clethrionomys gapperi, from New Brunswick. Northeastern Naturalist 7: 181-182.
Brewer, S. R., M. F. Lucas, J. A. Mugnano, J. D. Peles, and G. W. Barrett. 1993. Inheritance of albinism in the meadow vole (Microtus pennsy/vanicus). American Midland Naturalist 130: 393-396.
Hutten, E. 1968. Flora of Alaska and neighboring territories: A manual of the vascular plants. Stanford University Press, California. I 008 pages.
Jannett, F. J ., Jr. 1981. Albinism and its inheritance in populations of the montane vole. Journal of Heredity 72: 144146.
Owen, R. D., and R. M. Shakelford. 1942. Color aberrations in Microtus and Pitymys. Journal of Mammalogy 23: 306314.
Parsons, G. J., and S. Bondrup-Nielsen. 1995. Partial albinism in an island population of meadow voles, Microtus pennsylvanicus, from Nova Scotia. Canadian Field-Naturalist I 09: 263-264.
Paul, J. R. 1964. Second record of an albino pine vole. Journal of Mammalogy 45: 485.
Pinter, A. J., and N. C. Negus. 1971. Coat color mutations in two species of voles (Microtus mmztanus and Microtus ochrogaster) in the laboratory. Journal of Mammalogy 52: 196-199.
Schantz, V. S. 1960. Record of an albino pine vole. Journal of Mammalogy 41: 129.
Viereck, L.A., and E. L. Little, Jr. 2007. Alaska trees and shrubs. Second edition. University of Alaska Press, Fairbanks, Alaska. 359 pages.
Warren, E. R. 1929. An albino field mouse. Journal of Mammalogy 10: 82.
Received 26 October 2007 Accepted 8 March 20 l 0
