SciELO - Scientific Electronic Library Online

vol.12 número2Morphometric and allozymic characterization of Necromys benefactus populations in central ArgentinaHolochilus brasiliensis (Rodentia, Cricetidae) en conjuntos arqueofaunísticos del Holoceno tardío de la provincia de Córdoba (Argentina) índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados




  • No hay articulos citadosCitado por SciELO

Links relacionados


Mastozoología neotropical

versión impresa ISSN 0327-9383versión On-line ISSN 1666-0536

Mastozool. neotrop. v.12 n.2 Mendoza jul./dic. 2005


Albinism in the Andean leaf-eared mouse, Phyllotis andium (Rodentia, Cricetidae)

Oswaldo E. Ramirez and Margarita Arana

Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Urbanización Ingeniería, San Martín de Porres, Lima, Perú.

Key words: Albino. Coat color. Peru. Phyllotis. Sigmodontinae.

   An albino specimen of Phyllotis andium Thomas, 1912 was live-trapped in Lomas de Lachay (11° 21' 03" S, 77° 21' 11" W), central coast of Peru, a locality where the authors have been studying population dynamics and the assemblage of trophic cascades within the vertebrate community, from 1998 until 2003. It was a juvenile male weighing 15 g with snow-white fur and pink eyes. Details about the study area, reproduction and population density of this species have been previously reported (Arana et al., 2002).
   Besides, a pair of wild-type P. andium, born in captivity and direct descendants of animals collected two years before in the same locality, had a litter of three pups, where one of them was an albino female, proving that both specimens were heterozygotes for the albino allele.
   The albino specimen collected in Lachay was crossed two consecutive times with the heterozygote female (wild-type that previously was the mother of one female albino). The first litter was constituted both by one albino and one wild-type specimen, while the second litter was constituted by one albino and two wild-type specimens. One F1 albino male was crossed with three different homozygote wild-type females and all F2 offspring had a wild-type phenotype.
   No codominance was observed and albino offspring were distinguished from wild-type mice on the day of birth, as found in albino meadow voles, Microtus pennsylvanicus (Brewer et al., 1993).
   The rareness of conspicuously colored small mammals has been generally considered as the result of a negative selection of coat color by predators (Brown, 1965; Kaufman and Wagner, 1973; Kaufman, 1974a, 1974b), though Peles et al. (1995) showed that albinism in meadow voles proved not to be a disadvantageous trait in grassland habitats of high-nutritional quality and heavy vegetative cover, probably due to the relationship of high-quality habitat and avian predation. Lachay is not a high-quality habitat (those habitats dominated by plant species of high-nutritional food quality, that simultaneously provide heavy vegetative ground cover; Peles et al., 1995). It is a habitat with a strong seasonality in the vegetative ground cover with relatively few retreats for small mammals, and it is the habitat of several resident avian predators (as burrowing owls, grey eagle-buzzards, red-backed buzzard, and American kestrel) and foxes. Under these conditions, albinism is a disadvantageous trait. This is the first discovery of an albino Andean leaf-eared mouse individual in Lachay, in spite of the intense field work carried out collecting rodents in this locality during the last decade.

This research was supported by grants from Red Impacto Biológico El Niño - Organización de Estados Americanos, Consejo Nacional de Ciencia y Tecnología, Fondo Concursable Universidad Peruana Cayetano Heredia, 2000.


ARANA M, O RAMIREZ, S SANTA MARIA, C KUNIMOTO, R VELARDE, C DE LA CRUZ, and ML RUIZ. 2002. Population density and reproduction of two Peruvian leaf-eared mice (Phyllotis spp.). Revista Chilena de Historia Natural 75:751-756.         [ Links ]

BREWER SR, MF LUCAS, JA MUGNANO, JD PELES, and GW BARRETT. 1993. Inheritance of albinism in the meadow vole, Microtus pennsylvanicus. The American Naturalist 130:393-396.         [ Links ]

BROWN LR. 1965. Selection in a population of house mice containing mutant individuals. Journal of Mammalogy 46:461-465.         [ Links ]

KAUFMAN DW. 1974a. Adaptive coloration in Peromyscus polionotus: experimental selection by owls. Journal of Mammalogy 55:271-283.         [ Links ]

KAUFMAN DW. 1974b. Concealing coloration: how is effectiveness of selection related to conspicuosness? The American Naturalist 93:245-247.         [ Links ]

KAUFMAN DW and CK WAGNER. 1973. Differential survival of white and agouti Mus musculus under natural conditions. Journal of Mammalogy 54:281-283.         [ Links ]

PELES JD, MF LUCAS, and GW BARRET. 1995. Population dynamics of agouti and albino meadow voles in high-quality, grassland habitats. Journal of Mammalogy 76:1013-1019.         [ Links ]

Recibido 22 noviembre 2004.
Aceptación final 11 abril 2005.

Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons