Sciurus granatensis (the red-tailed squirrel). was introduced into Lima, Peru and has been observed living freely in the Parque de Las Leyendas Zoo. They have also been spotted in the parks of Lima including Surco, San Isidro, San Miguel, and Chaclacayo as well as the green areas within Pontificia Universidad Católica del Peru. (Allen, 1915; Emmons and Feer, 1990; Jessen, et al., 2010; Leal-Pinedo and Linares-Palomino, 2005; Merrick, et al., 2012; Montes, et al., 2011; Thorington Jr., et al., 2012)is found in South America from southwestern Ecuador to northern Peru, including the Noroeste Biosphere Reserve. These squirrels are considered rare in Peru because they only occupy the most northern parts of the country. They are found along the Gulf of Guayaquil as well as along the Andean slope to Cajamarca. The Andean slope has an elevation ranging from sea-level to 2000 m. These are the only squirrels endemic to the area, except for north of Guayaquil, Ecuador where they share a range with
Guayaquil squirrels are arboreal and live in trees found in both mature and secondary forests, as well as coffee plantations. The forests are evergreen, deciduous and semi-deciduous. The forests in the southern range are humid and montane. These forests are located at an elevation of 1400 to 2000 m along the western Andean slope. The northern range forests are humid and dry, and located at sea level. These forests have vegetation that consists mostly of prickly plants, bushes, and herbaceous plants. (Emmons and Feer, 1990; Jessen, et al., 2010; Merrick, et al., 2012; Thorington Jr., et al., 2012)
Closer to human populations, Guayaquil squirrels have been spotted in the lowlands of Ecuador in communities including Portoviejo County in the Manabí province, and Maconta Abajo. These areas include a mix of forest, corn crops, and papaya crops. The forests in this area are semi-deciduous with a dense, deciduous, groundcover and a thin tree population. The humidity in June and July in Maconta Abajo has been seen to reach up to 97%. The large trees of the urban landscape in Lima, Peru are also known habitat for (Grijalva, et al., 2012; Jessen, et al., 2010; Merrick, et al., 2012; Weigl, 2005), since they can thrive in urban landscapes, as well as in captivity.
In general, Guayaquil squirrels are large squirrels with four pairs of mammae; long, thin, grey tails; long, narrow, black ears; and five digits on their hind feet. There are two distinct color morphs in this species. In the early to mid-1900s these morphs were described as four separate subspecies, however (Allen, 1915; Alston, 1878; Eisenberg and Redford, 1999; Ellerman, 1940; Emmons and Feer, 1990; Jessen, et al., 2010; Merrick, et al., 2012; Thorington Jr., et al., 2012)is now considered to be monotypic. The first morph is found in the lowlands of Ecuador, where the squirrels have shoulders that appear grey due to a coarse mix of white and black fur. Their rumps and tails are a dull orange with patches of black and their underparts are a reddish to dull brown while their heads are black. Their feet can be white or black and their tails are black with white tips. This morph used to be described as the subspecies Sciurus stramineus stramineus and Sciurus stramineus guayanas. Sciurus stramineus stramineus was described as having darker, yellowish grey upperparts while S. stramineus guayanus was described as having paler upperparts and a wash of grey on their underparts. The second color morph is found in Peru and the southern highlands of Ecuador. This morph of has pale grey underparts and tails caused by a heavy frosting of white hairs in their black fur. Their rumps are either a buff, faint, or bright orange and the neck area behind their ears is either pure white or pale yellow. The feet of this morph are black. This morph used to be divided into the subspecies Sciurus stramineus nebouxii and Sciurus stramineus zarumae. The paler version of this morph was considered to be S. stramineus nebouxii, while the darker version was considered to be S. stramineus zarumae. There are often spots of white hair that are longer than the rest of the fur found on both morphs. The Peruvian and south Ecuador highland morph is the morph seen in the Parque de Las Leyendas Zoo.
The mass of Guayaquil squirrels ranges from 460 to 495 g. The length of the head and body range from 180 to 320 mm with the average female head and body length being 250.3 mm and the average male head and body being 251.3 mm in length. The tail length ranges from 250 to 330 mm with the average female tail length being 292.1 mm and the average male tail length being 275.4 mm. The hind foot of (Allen, 1915; Eisenberg and Redford, 1999; Emmons and Feer, 1990; Hayssen, 2008; Merrick, et al., 2012; Thorington Jr., et al., 2012)ranges from 50 to 65 mm in length while the length of the ear ranges from 38 to 39 mm.
Nothing is known about reproduction in Sciurus carolinensis and Sciurus niger, which are the two species most closely related to . These two species are polygynandrous and have an estrus that lasts less than one day. There are two main breeding seasons. It is possible for mating to occur outside of these seasons, however the occurrence is greatly reduced. Sciurus carolinensis and S. niger experience a period from August to October where the male testes size is significantly decreased, reducing the chances of successful breeding. Since it is a South American species, may or may not have the same period of reduced testes size. (Brown and Yeager, 1945; Kirkpatrick and Hoffman, 1960; Koprowski, 1993; Koprowski, 1994a; Koprowski, 1994b; Moore, 1957; Oshida and Masuda, 2000; Webley and Johnson, 1983). However, conclusions can be drawn from the mating systems of
The mating system in S. niger and S. carolinensis. Both S. niger and S. carolinensis form a linear dominance hierarchy amongst males. Four to seven males will participate in an estrus, with the dominant male and subordinate satellite males all chasing a female. The dominant male will attempt to copulate with the female but the copulation is often interrupted by either the female escaping or another male interrupting. If the copulation by the dominant male is completed, the male will introduce a copulatory plug and attempt to guard the female. Usually, however, the female will remove the copulatory plug and repeat this process with another male. Most copulation occurs in trees. (Koprowski, 1992; Koprowski, 1993; Koprowski, 1994a; Koprowski, 1994b; McCloskey and Shaw, 1977; Oshida and Masuda, 2000)is not known, but conclusions can be drawn from commonalities in its two closest relatives,
Nothing is known about the reproduction of S. carolinensis and S. niger. S. carolinensis and S. niger have two breeding seasons. Females can breed during both seasons, however most only breed during one season a year. Females usually start reproducing around 15 months of age, while males reach sexual maturity around 10 or 11 months. Gestation in S. carolinensis and S. niger is 44 to 45 days, and most litter sizes range from 2 to 4, however a maximum of 8 and a minimum of 1 is possible. The neonates are born naked, with vibrissae and well-developed claws. Birth mass averages 13 to 18 g. Birth head and body length averages 50 to 60 mm. Juveniles will begin weaning after about 2 months and will become independent after 3 to 4 months. During the weaning time juveniles will leave the nest to forage for food, such as seeds and buds. (Allen, 1942; Barkalow, Jr., et al., 1970; Brown and Yeager, 1945; Harnishfeger, et al., 1978; Kirkpatrick and Hoffman, 1960; Koprowski, 1994a; Koprowski, 1994b; McCloskey and Shaw, 1977; Oshida and Masuda, 2000; Webley and Johnson, 1983). However, conclusions can be drawn from the commonalities in the general reproductive behaviors of
Nothing is known about the reproduction of S. carolinensis and S. niger. These squirrels have altricial young, and female parental care. (Brown and Yeager, 1945; Koprowski, 1994a; Koprowski, 1994b; Oshida and Masuda, 2000). Conclusions can be drawn from the few commonalities in the parental investment of
The Guayaquil squirrel known to live the longest in captivity died at 7.3 years old. The squirrel lived from August 8, 1996 to December 19, 2003 at the Zoologico Nacional de Santiago in Chile. (Weigl, 2005)
These squirrels also willingly interact with people. They have been known to approach people and are quite bold. They have adapted to an urban environment, and are often seen walking on telephone wires to cross streets. (Jessen, et al., 2010; Merrick, et al., 2012)
Home range is not reported in the literature.
Nothing is known about communication and perception in.
Plants are the main source of food for Guayaquil squirrels. They forage on the ground as well as in the tree canopies of the forest. They mainly consume seeds. In Parque de Las Leyendas Zoo they are opportunistic feeders, feeding on the same diet of seeds, fruits, and vegetables as the captive animals, as well as the ornamental flowers found in the zoo. Phytotoma raimondii (the endangered Peruvian plantcutter). (Erdmann, et al., 2008; Jessen, et al., 2010; Merrick, et al., 2012; Nolazco and Roper, 2014; Thorington Jr., et al., 2012)have been observed preying on the eggs of birds, including the eggs of
Guayaquil squirrels and their nests are host to parasitic and commensal species. The flea Polygenis litargus and an Ambylomma species of tick, closely related to Ambylomma maculatum, are two of these species. Assassin bugs, Rhodnius ecuadoriensis, are found in the nests of these squirrels and likely use the squirrels as a food source. The rate of infestation by this insect ranged from 13.6% to 40% of nests studied, with the highest infestation seen in El Guino. The average infestation rate most recently observed in 2012 was 21.1% of nests. Rhodnius ecuadoriensis is a vector of Trypanosoma cruzi. Guayaquil squirrels are also asymptomatic carriers of a Leptospira species of bacteria. Wild-rodent (sylvatic) plague and, in captive squirrels, Plasmodium infections are found as well. (Garnham, 1949; Grijalva and Villacis, 2009; Grijalva, et al., 2012; Jordan, 1950; Montes, et al., 2011; Need, et al., 1991; Pollitzer, 1952)
Rhodnius ecuadoriensis is found in nests and is a known vector of Chagas disease caused by Trypanosoma cruzi. Rhodnius ecuadoriensis has been found in higher rates in squirrel’s nest than in that of mice and birds. The proliferation of Chagas disease in is likely due to passive transportation from infected humans. (Grijalva and Villacis, 2009; Grijalva, et al., 2012; Suarez-Davalos, et al., 2010)
Melissa Hahn (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the southern part of the New World. In other words, Central and South America.
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.
an animal that mainly eats meat
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.
parental care is carried out by females
union of egg and spermatozoan
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 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.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
the business of buying and selling animals for people to keep in their homes as pets.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
living in cities and large towns, landscapes dominated by human structures and activity.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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