red-tailed squirrels have an orange tail, are smaller, and occur in denser, wetter forests; Deppe's squirrels have a slender tail, gray underside and feet, and are smaller; Yucatan squirrels are gray and smaller; Mexican gray squirrels lack the prominent pale ear patches. (Best, 1995; Emmons, 1990; Reid, 1997)are similar to many other tree squirrel species. There are some distinguishing characteristics however. The
Little is known about the mating system of Sciurus) are similar in their mating and reproduction. Tree squirrels are generally solitary, with individuals coming into contact only to mate. Social ranking of tree squirrels is based on weight and age. The higher ranking males will have more mates. A female tree squirrel goes into estrus once a year for the duration of one day. Through olfactory cues and behavioral changes, males know when to mate with her. More than one male may enter the territory of a female in estrus, and males may fight one another in order to mate. After mating, the male and female separate. There are no lasting pair bonds. (Gurnell, 1987; Walker, 1983), but most tree squirrels (
In Sciurus, gestation lasts between 33-46 days. When tree squirrels are born, they are blind and naked. Their digits are fused together, and they weigh less than one ounce. After 4 days, babies are vocal, emitting squeaks in response to their mother’s stimuli. After 2 weeks, they begin to develop fur. Between 30 to 32 days babies develop teeth and open their eyes. By 4 weeks, the young are learning to groom themselves, and they leave the nest by 6 weeks. Squirrels begin to socialize at 10 weeks just after they are weaned. They are solitary by 15 weeks. Tree squirrels reach sexual maturity between 12 to 15 weeks. (Gurnell, 1987; Walker, 1983)
Little is known about parental investment in the species Sciurus, the father offers no parental care. The mother builds a nest for her young and they reside there until 6 weeks. The mother will cover her nest with brush, in order to protect her young, while she is scavenging for food. Young tree squirrels are weaned at 10 weeks and are independent of their mother after 15 weeks. The mother is responsible for showing the young how to scavenge for food and groom. (Best, 1995; Gurnell, 1987; Walker, 1983). In most members of the genus
Members of the genus Sciurus do not hibernate, but they may remain inactive during periods of cold or inclement weather until they need food. In general, interspecific competition is averted by maintaining strict niches where species overlap. (Gurnell, 1987; Walker, 1983)
In general, males of the genus Sciurus have larger home ranges than females, and they may overlap with those of other males and females. The home ranges of females do not overlap and are generally smaller. (Gurnell, 1987; Walker, 1983)
Scheelea rostrata, Scheelea zonensis, Crescentia alata, Guazuma ulmifolia, Quercus oleoides, Sterculia apetala, Mangiferea indica, Spondias mombin, Bursera simaruba, Ochroma pyramidale, Cochlospermum vitifolium, Enterolobium cyclocarpum, Cecropia, Ficus insipida, Astrcarum standleyanum, Scheelea zonensis, Genipa americana, Apeiba tibourbou, Luehea speciosa, and Trema micrantha. It spends most of its time foraging for soft, juicy fruits. It also eat some vines, flowers, and fungi. (Best, 1995; Emmons, 1990)consumes nuts and fruits of various kinds, including hard-shelled and soft, thin-shelled seeds of fruits such as
The predators of Mustela), martens (Martes), wildcats (Felidae), foxes (Canidae), eagles (Accipitridae), owls (Strigiformes), and snakes (Serpentes). These predators may also feed on young, taking them directly from the nest. (Gurnell, 1987)are generally opportunistic. The following information is in regards to the genus Sciurus: Predators of adult tree squirrels include weasels (
There is no special conservation status for (Best, 1995). This species may be considered "fragile" in some parts of its range in Mexico.
Some commonly used names for (Best, 1995)include ardilla jaspeada, chiza, and ardilla negra. Sciurus comes from the Latin word meaning squirrel and variegatoides signifies the variable coloration of the species.
Matthew Wund (editor), University of Michigan-Ann Arbor.
Kelly Carr (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
living in landscapes dominated by human agriculture.
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
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.
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
an animal that mainly eats fruit
an animal that mainly eats seeds
An animal that eats mainly plants or parts of plants.
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.
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.
specialized for leaping or bounding locomotion; jumps or hops.
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
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.
Best, T. 1995. Mammalian Species: Sciurus variegatoides. The American Society of Mammalogists, 500: 1-6. Accessed March 20, 2004 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/.
Eisenberg, J. 1989. Mammals of the Neotropics. Chicago: University of Chicago Press.
Emmons, L. 1990. Neotropical Rainforest Mammals: A Field Guide. Chicago: University of Chicago Press.
Gurnell, J. 1987. The natural history of squirrels. New York: Facts on File.
Harris, W. 1937. Revision of Sciurus variegatoides, a species of Central American squirrel. Miscellaneous publications, University of Michigan, Musuem of Zoology, 38: 5-39.
Klein, E. 1977. Mamiferos de Honduras. Tegucigalpa, D.C.: Secretaria de Recursos Naturales.
Reid, F. 1997. A field guide to the mammals of Central America and Southeast Mexico. New York: Oxford University Press.
Walker, E. 1983. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press.