Tassel-eared squirrel
Abert's squirrel (Sciurus aberti) is a tree squirrel native to North America. It lives in pine forests and favors the seeds and cones of the Mexican pinyon and the ponderosa pine. It is named in honor of the American naturalist John James Abert.
Di
DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
He
HerbivoreA herbivore is an animal anatomically and physiologically adapted to eating plant material, for example, foliage, for the main component of its die...
Fo
FolivoreIn zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less ...
Gr
GranivoreSeed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of pla...
Li
LignivoreMy
MycophageMycophagy is the process of organisms consuming fungi. Many different organisms gain their energy from consuming fungi; these include birds, mammal...
Ar
ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
Al
AltricialAltricial animals are those species whose newly hatched or born young are relatively immobile. They lack hair or down, are not able to obtain food ...
Sc
ScansorialScansorial animals are those that are adapted to or specialized for climbing. Many animals climb not only in tress but also in other habitats, such...
Te
TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
Vi
ViviparousAmong animals, viviparity is the development of the embryo inside the body of the parent. The term 'viviparity' and its adjective form 'viviparous'...
Po
PolygynandryPolygynandry is a mating system in which both males and females have multiple mating partners during a breeding season.
So
SocialNo
Not a migrantAnimals that do not make seasonal movements and stay in their native home ranges all year round are called not migrants or residents.
A
starts withAbert's squirrels are easily recognized by their long ear tufts, which extend up from each ear. This gives this species a striking similarity to the Eurasian red squirrel, aside from its differing dark coloration. Abert's squirrels vary in color across their range. Most populations have a gray coat with a reddish stripe down the back, a dark stripe along the side, and a white underbelly. Some populations lack the reddish back stripe, instead having fully gray upperparts. A fully black color morph is present in the foothills of the Rocky Mountains in Colorado. Abert's squirrels on Arizona's Kaibab Plateau, commonly known as Kaibab squirrels, have black underparts and a striking white tail.
Abert's squirrels are distributed throughout the southwestern United States and the north central Mexico, where these animals occur in scattered populations. Thus, the United States hold 4 isolated populations of this species, two of which are considerably large, while the other two are small. In Mexico, Abert's squirrels are presented by two large but isolated populations. The ideal habitat of this species is mountainous areas, dominated by ponderosa pine tree. In the past, Abert's squirrels were mistakenly thought to be dependent on this tree. In fact, they just rely heavily on it.
Abert’s squirrels do not appear to be territorial. Usually, multiple individuals may share the same nest. Meanwhile, each individual can use more than a single nest. They are diurnal. Active period of the day starts just before sunrise, lasting until just before sunset. Living among ponderosa trees, these animals occur in large concentrations of 2 - 114 squirrels per square kilometer. They are solitary foragers, spending their daytime hours looking for food. No information is available on whether they have any hibernation or torpor habits. In the beginning of the breeding season, which occurs in spring months, these squirrels display a highly social behavior. During the rest of the year, they are typically less social. Abert's squirrels communicate with conspecifics through vocal, visual, touch, smell and taste. Vocalizations include characteristic high-pitched clucks, barks, screeches and squeals, which are easily distinguished from these of other squirrels.
Abert's squirrels are herbivores, they primarily feed upon certain parts of the ponderosa pine: during the warm season of the year, they consume seeds and buds of this tree, whereas the winter diet typically consists of the inner bark of the ponderosa pine. They are also known to supplement their usual diet with occasional mistletoe and fungi.
Abert’s squirrels are polygynandrous (promiscuous): this is when both males and females have multiple mates. During the mating season, males display aggressive behavior towards each other. A pack of males can follow a female through the forest for about 11 hours by day, led by the dominant male. Abert’s squirrels mate between late February and early June. Gestation period lasts for 43 days, yielding 1 - 5 babies with an average of 3 per litter. Newborn squirrels lack fur and come with closed eyes. Males of this species display no parental care except for guarding their mates after mating. At 7 weeks old, the young begin climbing down to the ground. Weaning occurs after 10 weeks old, whereas sexual maturity is reached by 11 months old.
In spite of being classified as Least Concern, this species is threatened by living in isolated populations, depending on the distribution of ponderosa pine. Another notable concern is habitat destruction by clear-cutting throughout large areas of their natural range.
According to IUCN, the Abert’s squirrel is widely distributed and abundant at some localities but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) and its numbers remain stable.
Due to relying on the ponderosa pines, these animals have hugely affected this tree, which is their main source of food and shelter. On the other hand, they have negatively affected Mount Graham red squirrels, inhabiting the Pinaleño Mountains (Arizona): Abert's squirrels were introduced to the habitat of endangered red squirrels, which consequently led to a harsh resource competition between these two species.
Social animals are those animals that interact highly with other animals, usually of their own species (conspecifics), to the point of having a rec...