Grayish mouse opossums generally live in semi-deciduous and tropical forests that exhibit distinct wet and dry seasons (Zarza, Ceballos and Steele, 2003). However, they are also found in other habitats, including scrublands, grasslands, evergreen forests, orchards, fields and secondary-growth forests (Zarza, Ceballos and Steele, 2003). (Nowak, 1991; Zarza, et al., 2003)is most often found at elevations below 1,000 m; but have been observed up to 2,100 m (Zarza, Ceballos and Steele, 2003).
Grayish mouse opossums live in nests near logs, rocks, tree hollows, cacti, and shrubs (Zarza, Ceballos and Steele, 2003). One study found that nearly all specimens of Ceiba pentandra. Additionally, some individuals have been found living in the abandoned nests of birds, including Uropsila leucogastra and Thryothorus pleurostictus (Zarza, Ceballos and Steele, 2003). (Nowak, 1991; Zarza, et al., 2003)in Sinaloa, Mexico lived in hollow areas of dead cacti (Nowak, 1991). Nests are typically made up of dry leaves, small stems and the plant fibers of
In general, this species has brownish to light gray fur on its upper parts and creamy to white fur on its legs (Zarza, Ceballos and Steele, 2003). The venter is yellow-cream in color. Eyes are surrounded by black rings, and the ears are rounded, broad, and lack hair. The fur varies from soft and short to coarse and long (Zarza, Ceballos and Steele, 2003. The tail is prehensile and partly covered in fur (sometimes with a white tip). The tail is about the same length as the body. The hind feet are naked from the toes to the heel and the fourth digit is longer than the others. In mature females, an orange-yellow patch of fur surrounds the inguinal mammae (Zarza, Ceballos and Steele, 2003). Except for this feature, males and females look almost identical. (Zarza, et al., 2003)is very small, the smallest opossum found in Mexico (Zarza, Ceballos and Steele, 2003).
Grayish mouse opossums are solitary mammals and reproduction is promiscuous. Males attract females by emitting clicking sounds (Eisenberg, 1989). During copulation, the male and the female suspend themselves upside down with the use of their prehensile tails (Zarza, Ceballos and Steele, 2003). Throughout copulation, the male grasps the female's neck with his mouth (Zarza, Ceballos and Steele, 2003). Once copulation is over, the male is rejected by the female and both leave the area (Zarza, Ceballos and Steele, 2003). (Eisenberg, 1989; Zarza, et al., 2003)
There is little information regarding gestation for M. robinsoni, a closely related species, gestation is typically 14 days. Females of this species reach sexual maturity when they are approximately 6 months old. (Nowak, 1991). In
There is little information regarding parental investment in. However, similar to other marsupials, young are born very underdeveloped and must stay close to their mother in order to develop fully (Eisenberg, 1989).
In a closely related species, Marmosa robinsoni, weaning does not take place until the young are 60-70 days old (Nowak, 1991). Also, young stay attached to the teat for up to 30 days (Eisenberg, 1989). (Eisenberg, 1989; Nowak, 1991)
There is little information regarding the lifespan of Marmosa, such as Marmosa robinsoni, life expectancy is typically under 1 year of age in the wild and up to 3 years in captivity (Nowak, 1991). (Nowak, 1991). In related species belonging to the genus
Marmosa, they spend much more time on the ground (Zarza, Ceballos and Steele, 2003). When Marmosa species come into contact with one another, they are courageous fighters (Nowak, 1991). (Ceballos, 1990; Nowak, 1991; Zarza, et al., 2003)is a solitary, nocturnal species (Ceballos, 1990). Densities of this animal range between 0.4 to 4.5 individuals per hectare (Zarza, Ceballos and Steele, 2003). Grayish mouse opossums are semi-arboreal and, in comparison to related species in the genus
Home ranges for (Zarza, et al., 2003)have not yet been reported. However, one study indicated that individuals had moved up to 72 meters between successive captures, with an average of 35.2 meters (Zarza, Ceballos and Steele, 2003).
praying mantises, cerambycid beetles and scarabiid beetles (Zarza, Ceballos and Steele, 2003). This species also preys upon geckos, bird eggs, bird nestlings and fledglings, coconut, banana, small rodents and figs (Nowak, 1991; Zarza, Ceballos and Steele, 2003). (Nowak, 1991; Zarza, et al., 2003)is omnivorous (Zarza, Ceballos and Steele, 2003). Members of this species feed primarily on insects. Specifically, eat
Known predators for pumas, and barn owls (Zarza, Ceballos and Steele, 2003). There is little information on anti-predator adaptations of . Their cryptic coloration and nocturnal habits may be their primary defenses. (Loomis and Stephens, 1962; Zarza, et al., 2003)include
Eutrombicula batatas. No other parasites have been recorded for this species. is a prey item for cougars and barn owls. Geckos are occasionally eaten by , which may affect their populations. (Loomis and Stephens, 1962; Zarza, et al., 2003)individuals are hosts for the chigger species
Baiomys taylori, Hodomys alleni, Neotoma mexicana, Oryzomys palustris and Megasorex gigas. Since regularly eats fruits such as coconut, figs, bananas and oranges, it is likely that they act as seed dispersers. (Zarza, et al., 2003)lives sympatrically with various other small mammals, including
There is little information about the positive economic influencehas on humans.
It is unlikely thathas a negative impact on humans.
According to the IUCN Red List, there is not enough data available for Rattus rattus) has negatively impacted the size of the population (Zarza, Ceballos and Steele).to determine its conservation status. Some researchers have remarked that is quite common and is in no danger of becoming extinct. However, there is an island population off the coast of Mexico where the introduction of a new species (
Recent phylogenetic studies have indicated that Marmosa species and therefore should be placed into a new genus, Tlacuatzin. They were previously recognized as Marmosa canescens. (Voss and Jansa, 2003)is genetically distinct from other
Tanya Dewey (editor), Animal Diversity Web.
Sarah Segerlind (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats all kinds of things, including plants and animals
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
scrub forests develop in areas that experience dry seasons.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
breeding takes place throughout the year
Ceballos, G. 1990. Comparative Natural History of Small Mammals from Tropical Forests in Western Mexico. Journal of Mammalogy, 71 (2): 263-266. Accessed March 11, 2006 at http://www.jstor.org/view/00222372/ap050287/05a00260/0.
Eisenberg, J. 1989. Mammals of the Neotropics. Chicago: University of Chicago Press.
Loomis, R., R. Stephens. 1962. Marmosa canescens in Sonora, Mexico. Journal of Mammalogy, 43: 111. Accessed March 19, 2006 at http://links.jstor.org/sici?sici=0022-2372%28196202%2943%3A1%3C111%3AMCISM%3E2.0.CO%3B2-6.
Nowak, R. 1991. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press.
Sanchez-Cordero, V., P. Illoldi-Rangel, M. Linaje, S. Sarkar, A. Peterson. 2005. Deforestation and extant distributions of Mexican endemic mammals. Biological Conservation, 126: 465-473. Accessed March 11, 2006 at http://uts.cc.utexas.edu/~consbio/Cons/SanchezCordero05.pdf.
Voss, R., S. Jansa. 2003. Phylogenetic Studies on Didelphid Marsupials II. Nonmolecular Data and New IRBP Sequences: Seperate and Combined Analyses of Didelphine Relationships with Denser Taxon Sampling. Bulletin of the American Museum of Natural History, 276: 1-82. Accessed March 11, 2006 at http://www.bioone.org/pdfserv/i0003-0090-276-01-0001.pdf.
Zarza, H., G. Ceballos, M. Steele. 2003. Marmosa canescens. American Society of Mammalogists, 725: 1-4. Accessed February 02, 2006 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/.