Red squirrels cause considerable economic losses. They interfere with conifer reforestation by eating 60 to 100% of cone crops and directly damaging trees through bud consumption and bark stripping. Squirrels also cause damage to human property by nesting in homes and gnawing on household items. They may bite humans if provoked.
Negative Impacts: injures humans (bites or stings); household pest
As of 2008, red squirrels are classified as Least Concern on the ICUN Red List and by the United States government. They are widespread and common, have suitable habitat throughout their range, and face no major threats. One subspecies, Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis), is endangered according to the ICUN Red List. This subspecies is only found in southeast Arizona and its population is about 150 individuals.
US Federal List: endangered
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Red squirrels have well-developed and extremely acute senses of smell, sight, and hearing. They are well known for their ability to communicate by calls. These calls consist of rattles, screeches, growls, buzzes and chirps and are often used in defense of territory or in response to threats from predators. During mating, red squirrels use low aggressive calls or territorial calls to drive off subordinate males. Red squirrels may even be able to recognize each other by individual call. Communication is important because of their territorality. They intensively use vocal communication to advertise these territories and to threaten other squirrels. Both vocal and scent marking aid in the recognition of individuals. Olfactory communication is important because it can leave long-lasting impressions which advertise if the territory is taken and males can discriminate between different olfactory signatures of other males. Another reason chemical communication is advantageous is because it may also reduce predation risk. Scent marking may also enable the squirrels to avoid unnecessary chases and fights by becoming known to their neighbors. Red squirrels may also be able to make predator-specific calls, but evidence of this is still very inconclusive. Red squirrels tend to produce a high-frequency call for aerial predators and a harsher, bark-type call for terrestrial predators. However, it is more commonly observed that these two call types are mixed.
Communication Channels: visual ; tactile ; acoustic ; chemical
Other Communication Modes: pheromones ; scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
Tamiasciurus and Sciurus likely diverged in the late Pliocene. Red squirrels are first reported in the Irvingtonian and are now known from more than 30 late Rancholabrean faunas from the central and eastern United States.
Red squirrels are the third-most commonly harvested furbearer in Canada, bringing in about $1 million annually. Each year in Minnesota, thousands of red squirrels are harvested for consumption by humans. Red squirrels are an important prey item for other economically important species like lynx (Lynx) and martens (Martes).
Positive Impacts: food ; body parts are source of valuable material
Red squirrels impact the forest ecosystem by dispersing seeds and fungi through caching and forgetting about or otherwise failing to return to food caches. The diversity and abundance of beneficial ectomycorrhizal fungi in these caches helps young trees acquire nutrients and grow. They limit the regrowth of trees by eating the seeds and inner tissues of the trees, which can cause significant damage to tree survival and value. Red squirrels provide a feeding opportunity for porcupines (Erethizontidae) during the winter by peeling away the bark of lodgepole pines. Their feeding habits also cause conifers to grow multiple tops, which reduces their timber value but increases suitable nest sites for many arboreal rodents (Rodentia) and passerine birds (Passeriformes). The increased availability of nest sites sustains species richness.
Red squirrels are host to a variety of endoparasites and ectoparasites. Endoparasitic species include 9 species of nematodes, 9 species of tapeworms including the genus (Hymenolepis). Other endoparasites include tularemia bacteria (Francisella tularensis) and Emmonsia crescens), and some kinds of protists like sarocysts (Sarocystis), and (Haplosporanigium). They are also vulnerable to fungal lung disease infection via adiaspiromycosis (Emmonsia parva). Ectoparasites of red squirrels include 31 species of mites, ticks, and chiggers (Glycyphagidae and Acarina), 25 species of fleas including Siphonaptera, Opisodasys robustus, Orchopeas caedens, Orchopeas neotomae, Orchopeas leucopus, Oropsylla idahoensis, Ceratophyllus vison. They may also carry botfly larvae (Cuterebra emasculator). Viruses that infect red squirrels are silverwater virus, California encephalitis virus, and Powassan virus.
Ecosystem Impact: disperses seeds
Commensal/Parasitic Species:
Red squirrels are primarily granivorous, but they are also opportunistic omnivores in the absence of mast foods. Primary diet items vary with habitat and include the seeds of conifers and other tree types detailed below. They live in a resource pulse system, where foods (conifers like white spruce, Picea glauca) exhibit extreme annual variation. They consume a wide variety of mushrooms, including at least 45 species in the Cascade Mountains alone. Secondary food items include tree buds and flowers, fleshy fruits, tree sap, bark, insects, and other animal materials such as bird eggs or young snowshoe hares (Lepus americanus). During winter, spring, and early summer, bark stripping and tree girdling occurs commonly to access phloem and cambial tissues. Red squirrels are highly selective in their foraging behavior, harvesting cones from the tree species with the highest seed energy per cone first and systematically working their way through species of conifers by energy density per cone.
Red squirrels are primarily larder hoarders. In late summer through autumn, they harvest cones and store them in one or a few central middens. Middens are a central hoard that is easy to defend from competitors and provides a moist, cool environment that prevents cones from opening. Middens vary in size and number depending on habitat, food availability, and individual squirrel. However, they contain enough food to last one to two seasons and are often used by several generations of squirrels In the eastern United States and Canada, red squirrels frequently engage in scatter hoarding, which is a system involving many small hoards instead of a large midden. This accounts for 85% of all hoards and more than 50% of all cones stored in this area The downside to this type of storage is that middens only provides enough food for about 37 days. Red squirrels have a great sense of smell which they use when looking for middens during the winter. Some individuals store their food caches underground and are able to locate these seeds, even under 4 meters of snow. Whenever they do not recover a stockpile of food, the seeds are left to germinate.
Red squirrels pilfer food from other squirrels, but the extent varies greatly by population. Some squirrels the Yukon Territory of Canada almost never pilfer. Mt. Graham Red Squirrels, on the other hand, pilfer 97% of the time and in Vermont pilfering occurred 25% of the time. Age, boldness, and population density may play a role in pilfering.
Animal Foods: birds; mammals; eggs; insects
Plant Foods: wood, bark, or stems; seeds, grains, and nuts; fruit; flowers; sap or other plant fluids
Other Foods: fungus
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Granivore )
Biogeographic Regions: nearctic (Native )
Red squirrels occupy northern boreal coniferous forests abundant with conifer seeds, fungi, and interlocking canopies. This limits them to mountain ranges on the southern and eastern boundaries of their range. In the Rocky Mountains they have been found at elevations up to 2,500 ft (762 m). Populations of red squirrels occur in different habit conditions due to the vastness of their range. They occur in both temperate and polar environments and are considered to be primarily arboreal. They can be found in a mixed variety of forests including coniferous, deciduous, and mixed forests and they are also able to thrive in suburban and urban settings, as long as cool, coniferous forests with dense, interlocking canopies and abundant fungal resources are present.
Range elevation: 0 to 762 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: taiga ; forest ; mountains
Other Habitat Features: urban ; suburban ; riparian
Red squirrels exhibit a type 3 survivorship curve in wild populations. This means that most of the mortality is associated with deaths of the young and only 25% survive longer than 1 year. Despite their small size, red squirrels are considered relatively long lived, with the oldest known squirrel in the wild reaching 10 years of age. The longest recorded lifespan in captivity is 9 years. Mature squirrels are 2 to 4 years old and older squirrels are considered to be over 5 to 6 years old. Their average lifespan in the wild is 5 years.
Range lifespan
Status: wild: 10 (high) years.
Range lifespan
Status: captivity: 9 (high) years.
Average lifespan
Status: wild: 5 years.
Average lifespan
Status: captivity: 9.8 years.
Red squirrels differ from other tree squirrels by their deep reddish color, territorial behavior, and their smaller body size. They are less than 30% the size of grey squirrels (Sciurus carolinensis). While size and pelage color can vary geographically, they generally have a reddish back and white underside that is demarcated by dark lateral lines, which are especially visible in summer. A white eye ring is present year-round and tufted ears are during the winter. Variation in the dorsal surface color can range from reddish to ferruginous brown to olivaceous gray, usually with a distinctive reddish or brownish lateral band running down the back. The tail is smaller and flatter than that of other tree squirrels and varies in color from yellowish-gray to rusty red, with a band of black often extending the entire length of tail. Where its range borders that of Douglas squirrels (Tamiasciurus douglasii), red squirrels are distinguished by color of their pelage. The underside of red squirrels is all white or cream, whereas Douglas squirrels are rust colored or with a blackish wash. Tail hairs have yellowish to rusty tips with a black band in red squirrels, whereas those of Douglas squirrels are white-tipped with a black band, making them moderately easy to distinguish from a distance. Male and female red squirrels are very similar in appearance.
Some ecogeographic variation is believed to occur, so length and weight measurements may only hold true for the population(s) in which they were measured. Twenty-five subspecies of red squirrels are recognized. They differ mainly by range distribution. Mass tends to range from 197.3 to 282.2 g, with an average of 212.97. Their total length ranges from 270 to 385 mm, with an average of 327.5. Much of their length is their tail, which is 92 to 158 mm long. Red squirrels have an average hind foot length of 35 to 57 mm and the ear length is 19 to 31 m. Condylobasal length is 42 to 50 mm. Red squirrels have a basal metabolic rate of 166 cm^3 oxygen/hour.
Red squirrels generally experience two annual molts, although the tail molts only once per year. The spring molt occurs from late March through August and starts on the nose and front feet, and ends on the rump. The fall molt is from late August to early December and begins on the tail and then progresses to the rump and the head before ending on the legs and flank. Molt stage can be an important age indicator. Skulls can be aged by looking at dental characteristics such as visible wear and presence of permanent teeth. Their dental formula is I 1/1, C 0/0, P 1/1 or 2/1, M 3/3. The total number of teeth is 20 or 22 depending on the presence of upper P3.
Range mass: 197.3 to 282.2 g.
Average mass: 212.97 g.
Range length: 270 to 385 mm.
Average basal metabolic rate: 166 cm3.O2/g/hr.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Average basal metabolic rate: 1.615 W.
Red squirrels are likely prey for a variety of animals including snakes, birds of prey, and carnivorous mammals. They are preyed upon by Cooper's hawks (Accipiter cooperii), northern goshawks (Accipiter gentilis), bald eagles (Haliaeetus leucocephalus), great gray owls (Strix nebulosa), great horned owls (Bubo virginianus), American kestrels (Falco sparverius), red-shouldered hawks (Buteo lineatus), northern harriers (Circus cyaneus), red-tailed hawks (Buteo jamaicensis), and sharp-shinned hawks (Accipiter striatus). Mammals that prey upon them them are American martens (Martes americana) and fishers (Martes pennanti), weasels (Mustela), mink (Neovison vison), as well as various canids like red foxes (Vulpes vulpes) and felids like lynx (Lynx canadensis). They are also preyed upon by timber rattlesnakes (Crotalus horridus). Humans hunt red squirrels for both their fur and meat.
Alarm calls are the most highly used anti-predator adaptations of red squirrels. Red squirrels tend to produce a high-frequency call for avian predators and a harsher bark-type call for terrestrial predators. However, it is more common that these two call types are mixed when any predator approaches. Red squirrels have a high survival rate even when subjected to heavy predation. It is very hard to catch and kill these animals because they are quite agile and take to the trees or thick vegetation to escape predators. Red squirrels are also fairly aggressive and when cornered, will not hesitate to defend themselves.
Known Predators:
Red squirrels have a defined breeding season lasting 105 days that can occur either once or twice a year. They will mate in early spring from March to May and then again in August to early September. A second breeding period tends to occur in warmer areas of their range. Although mate pairings may occur, red squirrels are generally characterized as promiscuous. Animals in the best condition tend to breed more regularly and successfully than animals in poor condition.
Red squirrels exhibit a scramble competition mating system, in which the main costs to males are locating receptive females. Males typically invade the territory of females in estrus and pursue them in obvious mate chases. During mate chasing, a single dominant male actively pursues a female and drives off other subordinate males using calls or direct chase. Mounting and copulation usually lasts several minutes and occurs several times in the afternoon of the only day the female is receptive. Copulation is frequently initiated by the female and terminated by the male. Mating most often occurs on the ground or in the lower branches of trees. During mating, the male holds the female around the posterior abdomen while resting his head on her back. It is common for both males and females to engage in grooming of the genitals before and after copulation. The adults have no further contact after mating and the male returns to his territory.
Mating System: polygynandrous (promiscuous)
Red squirrels breed once or twice a year, depending on their geographic location. Populations in the south and east generally have two litters a year, one in spring and one in late summer. This pattern occurs all the way up to Quebec and has also occurred in British Colombia. In the northern extent of their range, breeding only occurs once a year, generally in spring. In the eastern United States, two breeding seasons per year is common, one in March and a second in late July. Harsher conditions at the northern latitudes and higher elevations of the squirrels' range most likely limit reproduction to a single breeding season. Interannual variation in female reproduction is also common; there was a halving in the number of breeding females over 2 years in British Columbia. Their reproductive cycle has adapted to the cyclical production of conifer cone output. Female estrus is highest in February to March and June to July. Pregnancy peaks in March to April and August to September in New York. In Colorado, conception generally occurs April to June.
Females are in estrus only 1 day per breeding season. Conception usually occurs within a few hours of mating. Gestation averages 35 days. Newborn young weigh 7.08 g on average. Litter sizes range from 1 to 8 offspring but averages 3.97. Altricial young are born without any hair except vibrissae and fine chin hairs, but develop quickly. The external auditory meatus is obvious at 18 days, eyes open at 26 to 35 days, and pelage is fully developed in only 40 days. Lactation occurs for the first 70 days. After that time, young are cast out to find their own territory. In some cases when the mother is in poor condition she will give part of her territory to her offspring. This increases the probability of survival for the offspring, increasing the overall fitness the mother. Young are active outside the nest in 7 weeks and fully independent shortly after weaning. Dentition is complete and external skeletal measurements reach adult size by 125 days.
Most red squirrel nests are constructed within 30 m of cone caches. Red squirrels prefer natural cavities, but due to lack of such resources in coniferous forests, they construct leaf nests or occasionally underground nests. The most important factors influencing nest-tree selection are tree diameter and branching structure, and the availability of canopy escape routes. Nests are found at heights of 2 to 20 m, and while nest material varies with habitat, they typically include grasses, mosses, inner cambium, shredded bark leaves, feathers, and fur.
Reproduction is dependent on resource abundance. Red squirrels live in a resource-pulse system, where the main food (in most cases the seeds of conifer species like white spruce) fluctuates annually, in some cases spanning three orders of magnitude between failure and mast years. Food available for reproduction in the spring is determined by the abundance of cones produced the previous year. The reliance on and the defense of individual caches allows females to have the potential to assess the level of stored food that is available for current reproduction. However, female squirrels do not have a smaller litter in years of crop failure, so reproduction is expected to be more costly during these years.
Age also affects reproductive cycles in both male and female red squirrels. Females and males are sexually mature at 1 year of age but are still developing. Despite the detriment to their own health by trying to breed and grow simultaneously, 1-year-old females tend to reproduce because they can achieve higher lifetime reproductive success than females delaying their first reproduction. This is also true for young males. Mature females tend to engage in a conservative reproductive strategy in order to allocate reproductive resources only when their own survival costs are maintained. This is not the case for females over 6 years old, who tend to sacrifice their own survival for reproduction because they are unlikely to be able to breed again the following year. Reproduction senescence occurs from 4 years of age onwards.
Breeding interval: Red squirrels breed once or twice a year, depending on their geographic location.
Breeding season: The time of breeding depends on their geographic location.
Range number of offspring: 1 to 8.
Average number of offspring: 3.97.
Average gestation period: 35 days.
Average weaning age: 70 days.
Average time to independence: 7 weeks.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; sperm-storing
Average birth mass: 7 g.
Average gestation period: 37 days.
Average number of offspring: 4.2.
Average age at sexual or reproductive maturity (female)
Sex: female: 342 days.
Females raise the young without any help from males. Gestation averages 35 days and lactation is 70 days. After this the young are no longer dependent on the mother and the offspring relocate to find territories of their own. Mothers sometimes bequeath territories, giving part or all of their territory to one or more of their offspring. This increases the offspring’s’ probability of overwinter survival.
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)
The American red squirrel (Tamiasciurus hudsonicus) is one of three species of tree squirrels currently classified in the genus Tamiasciurus, known as the pine squirrels (the others are the Douglas squirrel, T. douglasii, and the southwestern red squirrel, T. fremonti). The American red squirrel is variously known as the pine squirrel, North American red squirrel and chickaree. It is also referred to as Hudson's Bay squirrel, as in John James Audubon's work The Viviparous Quadrupeds of North America (hence the species name). The squirrel is a small, 200–250 g (7.1–8.8 oz), diurnal mammal that defends a year-round exclusive territory. It feeds primarily on the seeds of conifer cones, and is widely distributed across North America wherever conifers are common, except on the Pacific coast of the United States, where its cousin, the Douglas squirrel, is found instead.
The squirrel has been expanding its range into hardwood forests.[3]
American red squirrels should not be confused with Eurasian red squirrels (Sciurus vulgaris); since the ranges of these species do not overlap, they are both commonly referred to as "red squirrels" in the areas where they are native. The specific epithet hudsonicus refers to Hudson Bay, Canada, where the species was first catalogued by Erxleben in 1771.[4] A recent phylogeny suggests the squirrels as a family can be divided into five major lineages. Red squirrels (Tamiasciurus) fall within the clade that includes flying squirrels and other tree squirrels (e.g., Sciurus).[5] There are 25 recognized subspecies of red squirrels.[6]
The southwestern red squirrel (T. fremonti) was long considered conspecific with T. hudsonicus, but a 2016 phylogenetic study found it to be a distinct species.[7]
Red squirrels can be easily distinguished from other North American tree squirrels by their smaller size, 28–35 cm (11–14 in) total length (including tail), territorial behavior, and reddish fur with a white venter (underbelly).[6] Red squirrels are somewhat larger than chipmunks.
The Douglas squirrel is morphologically similar to the American red squirrels, but has a rust-colored venter and is restricted to the southwestern coast of British Columbia and in the Pacific Northwest of the United States. The ranges of the American red squirrel and the Douglas squirrel overlap in southern British Columbia, northwestern Washington and eastern Oregon.[8]
American red squirrels are widely distributed across the North American continent. Their range includes: most of Canada, excluding northern areas with no tree cover, the southern half of Alberta and the southwestern coast of British Columbia; the southern half of Alaska; the Rocky Mountains area of the United States, and northern half of the eastern United States.[6][9] American red squirrels are abundant and not of conservation concern throughout much of their range. American red squirrels were introduced on Newfoundland and have lived there in abundance for decades.[10] However, an isolated population of red squirrels in Arizona has experienced considerable declines in population size. In 1987, this portion of the population was listed as an endangered species.[11]
American red squirrels are primarily granivores, but incorporate other food items into their diets opportunistically.[6] In Yukon, extensive behavioral observations suggest white spruce seeds (Picea glauca) comprise more than 50% of a red squirrel's diet, but squirrels have also been observed eating spruce buds and needles, mushrooms, willow (Salix sp.) leaves, poplar (Populus sp.) buds and catkins, bearberry (Arctostaphylos sp.) flowers and berries, and animal material such as bird eggs or even snowshoe hare leverets (young).[12] White spruce cones mature in late July and are harvested by red squirrels in August and September. These harvested cones are stored in a central cache and provide energy and nutrients for survival over the winter and reproduction the following spring. The fallen scales from consumed seed cones can collect in piles, called middens, up to twelve meters across.[13] White spruce exhibits two- to six-year masting cycles, where a year of superabundant cone production (mast year)[14] is followed by several years in which few cones are produced.[15] American red squirrel territories may contain one or several middens.
American red squirrels eat a variety of mushroom species, including some that are deadly to humans.[16]
American red squirrels are spontaneous ovulators.[17][18] Females enter estrus for only one day, but venture from their territory prior to ovulation, and these exploratory forays may serve to advertise their upcoming estrus. On the day of estrus, females are chased by several males in an extended mating chase. Males compete with one another for the opportunity to mate with the estrous female. Estrous females will mate with 4 to 16 males. Gestation has been reported to range from 31 to 35 days.[19] Females can breed for the first time at one year of age, but some females delay breeding until two years of age or older. Most females produce one litter per year, but in some years reproduction is skipped, while in other years some females breed twice. Litter sizes typically range from one to five, but most litters contain three or four offspring. Offspring are pink and hairless at birth and weigh about 10 g. Offspring grow at approximately 1.8 g per day while nursing, and reach adult body size at 125 days. They first emerge from their natal nests at around 42 days, but continue to nurse until approximately 70 days.
Nests are most commonly constructed of grass in the branches of trees. Nests are also excavated from witches' broom – abnormally dense vegetative growth resulting from a rust disease – or cavities in the trunks of spruce, poplar, and walnut trees. American red squirrels rarely nest below ground. Each individual squirrel has several nests within its territory, and females with young move them between nests. Some behavior has been reported within human dwellings using insulation as nest material.
A three-year study of a population of red squirrels in southwest Yukon reported female red squirrels showed high levels of multiple-male mating and would even mate with males with similar genetic relatedness. The relatedness of parents had no effect on the neonatal mass and growth rate of their offspring, nor did it affect the survival rate of offspring to one year of age.[20]
Red squirrels are highly territorial and asocial with very few non-reproductive physical interactions (0.6% of all recorded behaviours in one 19-year study).[21] The majority of physical interactions are in male-female matings and between females and their offspring before the offspring disperse to their own territories (see Dispersal and survival). The non-reproductive physical interactions recorded were all instances of chasing an intruder from a territory.[21]
If juvenile American red squirrels are to survive their first winter, they must acquire a territory and midden. They can acquire a territory by competing for a vacant territory, creating a new territory or by receiving all or part of a territory from their mothers. This somewhat rare (15% of litters) female behavior is referred to as breeding dispersal or bequeathal, and is a form of maternal investment in offspring.[22] The prevalence of this behavior is related to the abundance of food resources and the age of the mother. In some cases, females will acquire additional middens prior to reproduction, which they later bequeath to their offspring.[23] Offspring that do not receive a midden from their mother typically settle within 150 m (3 territory diameters) of their natal territory.[22] Observations suggest that male red squirrels have environmentally induced, alternative reproductive strategies that result in higher incidences of sexually selected infanticide in years when food is plentiful.[24]
American red squirrels experience severe early mortality (on average only 22% survive to one year of age). The survival probability, however, increases to age three, when it begins to decrease again. Females that survive to one year of age have a life expectancy of 3.5 years and a maximum lifespan of 8 years.[25] Increased maternal attention is correlated with increased offspring growth rate and higher lifetime reproductive success.[26]
Chief predators include Canada lynx (Lynx canadensis), bobcat (Lynx rufus), coyote (Canis latrans), great horned owl (Bubo virginianus), northern goshawk (Accipiter gentilis), red-tailed hawk (Buteo jamaicensis), American crow (Corvus brachyrynchos), American marten (Martes americana), pacific marten (Martes caurina), red fox (Vulpes vulpes), gray fox (Urocyon cinereoargenteus), wolf (Canis lupus), and weasel (Mustela sp.).[27]
{{cite book}}: CS1 maint: multiple names: authors list (link) The American red squirrel (Tamiasciurus hudsonicus) is one of three species of tree squirrels currently classified in the genus Tamiasciurus, known as the pine squirrels (the others are the Douglas squirrel, T. douglasii, and the southwestern red squirrel, T. fremonti). The American red squirrel is variously known as the pine squirrel, North American red squirrel and chickaree. It is also referred to as Hudson's Bay squirrel, as in John James Audubon's work The Viviparous Quadrupeds of North America (hence the species name). The squirrel is a small, 200–250 g (7.1–8.8 oz), diurnal mammal that defends a year-round exclusive territory. It feeds primarily on the seeds of conifer cones, and is widely distributed across North America wherever conifers are common, except on the Pacific coast of the United States, where its cousin, the Douglas squirrel, is found instead.
The squirrel has been expanding its range into hardwood forests.
