Squirrel

In this episode of the, I Can't Sleep Podcast, fall asleep learning about squirrels. When insomnia strikes, we've got you covered. Acorn hoarding, fluffy tails, rampant rodent misbehavior—what's not to love? Happy sleeping!

Transcript

Welcome to the I Can't Sleep Podcast,

Where I read random articles from across the web to bore you to sleep with my soothing voice.

I'm your host,

Benjamin Boster.

Today's episode is from a Wikipedia article titled,

Squirrel.

Squirrels are members of the family Cioridae,

A family that includes small or medium-sized rodents.

The squirrel family includes tree squirrels,

Ground squirrels,

Including chipmunks and prairie dogs,

Among others,

And flying squirrels.

Squirrels are indigenous to the Americas,

Eurasia,

And Africa,

And were introduced by humans to Australia.

The earliest known fossilized squirrels date from the Eocene Epoch,

And among other living rodent families,

The squirrels are most closely related to the mountain beaver and to the dormice.

Etymology The word squirrel,

First attested in 1327,

Comes from the Anglo-Norman esquirrel,

Which is from the Old French esquirrel,

The reflex of a Latin word sciurus,

Which was taken from the Ancient Greek word skiurus,

Shadow-tailed,

Referring to the long bushy tail which many of its members have.

The native Old English word for the squirrel,

A swirna,

Survived into only Middle English as a quirne,

Before being replaced.

The Old English word is of common Germanic origin,

Cognates of which are still used in the other Germanic languages,

Including the German Eichhörn,

Diminutive of eichhorn,

Which is not as frequently used,

The Norwegian ekorn,

The Dutch ekern,

The Swedish ekore,

And the Danish egern.

A group of squirrels is called a drey or a skurry.

Squirrels are generally small animals ranging in size from the African pygmy squirrel and least pygmy squirrel at 10-14 cm in total length,

And just 12-26 g in weight,

To the Bhutan giant flying squirrel at up to 1.

27 m in total length,

And several marmot species which can weigh 8 kg or more.

Squirrels typically have slender bodies with very long,

Very bushy tails and large eyes.

In general,

Their fur is soft and silky,

Though much thicker in some species than others.

The coat color of squirrels is highly variable between and often even within species.

In most squirrel species,

The hind limbs are longer than the forelimbs,

While all species have either four or five toes on each foot.

The feet,

Which include an often poorly developed thumb,

Have soft pads on the undersides and versatile sturdy claws for grasping and climbing.

Tree squirrels,

Unlike most mammals,

Can descend a tree head first.

They do so by rotating their ankles 180 degrees,

Enabling the hind feet to point backward and thus grip the tree bark from the opposite direction.

Squirrels live in almost every habitat,

From tropical rainforests to semi-arid desert,

Avoiding only the high polar regions and the driest of deserts.

They are predominantly herbivores,

Subsisting on seeds and nuts,

But many will eat insects and even small vertebrates.

As their large eyes indicate,

Squirrels have an excellent sense of vision,

Which is especially important for the tree-dwelling species.

Many also have a good sense of touch with vibricy on their limbs as well as their heads.

The teeth of scurids follow the typical rodent pattern,

With large incisors for gnawing that grow throughout life and cheek teeth for grinding that are set back behind a white cap or diastema.

The typical dental formula for scurids is 1.

0.

1.

31.

0.

1.

3.

Many juvenile squirrels die in the first year of life.

Adult squirrels can have a lifespan of 5-10 years in the wild.

Some can survive 10-20 years in captivity.

Premature death may occur when a nest falls from the tree,

In which case,

The mother may abandon her young if their body temperature is not correct.

Many such baby squirrels have been rescued and fostered by a professional wildlife rehabilitator until they could be safely returned to the wild.

Although the density of squirrel populations in many places and the constant care required by premature squirrels means that few rehabilitators are willing to spend their time doing this,

And such animals are routinely euthanized instead.

Stated purposes of squirrel's tails to benefit the squirrel include to keep rain,

Wind,

Or cold off itself,

To cool off when hot by pumping more blood through its tail,

As a counter balance when jumping about in trees,

As a parachute when jumping,

To signal with.

The hairs from squirrel tails are prized in fly fishing when tying fishing flies.

A special quality of squirrel tail hair is that it is all guard hairs,

Not undercoat.

When the squirrel sits upright,

Its tail folded up its back may stop predators looking from behind from seeing the characteristic shape of a small mammal.

Squirrels mate either once or twice a year,

And following a gestation period of 3-6 weeks,

Give birth to a number of offspring that varies by species.

The young are atricial,

Being born naked,

Toothless,

And blind.

In most species of squirrel,

The female alone looks after the young,

Which are weaned at 6-10 weeks,

And become sexually mature by the end of their first year.

In general,

The ground-dwelling squirrel species are social,

Often living in well-developed colonies,

While the tree-dwelling species are more solitary.

Ground-squirrels and tree squirrels are usually either diurnal or crepuscular,

While the flying squirrels tend to be nocturnal,

Except for lactating flying squirrels and their young,

Which have a period of diurnality during the summer.

Because squirrels cannot digest cellulose,

They must rely on foods rich in protein,

Carbohydrates,

And fats.

In temperate regions,

Early spring is the hardest time of year for squirrels because the nuts they buried are beginning to sprout,

And thus are no longer available to eat,

While many of the usual food sources are not yet available.

During these times,

Squirrels rely heavily on tree buds.

Squirrels being primarily herbivores eat a wide variety of plants,

As well as nuts,

Seeds,

Conifer cones,

Fruits,

Fungi,

And green vegetation.

Some squirrels,

However,

Also consume meat,

Especially when faced with hunger.

Squirrels have been known to eat small birds,

Young snakes,

And smaller rodents,

As well as burnt eggs and insects.

Some tropical squirrel species have shifted almost entirely to a diet of insects.

Squirrels like pigeons and other fauna are synanthropes,

In that they benefit and thrive from their interaction in human environments.

This gradual process of successful interaction is called synurbanization,

Wherein squirrels lose their inherent fear of humans in an urban environment.

When squirrels were almost completely eradicated during the Industrial Revolution in New York,

They were later reintroduced to entertain and remind humans of nature.

The squirrel blended into the urban environment so efficiently that when synanthropic behavior stops,

I.

E.

People do not leave trash outside during particularly cold winters,

They can become aggressive in their search for food.

Predation and predatory behavior has been observed in various species of ground squirrels,

In particular the 13-lined ground squirrel.

For example,

Bernard Bailey,

A scientist in the 1920s,

Observed a 13-lined ground squirrel preying upon a young chicken.

Weistrand reported seeing this same species eating a freshly killed snake.

There's also been at least one report of squirrels preying on atypical animals,

Such as an incident in 2005 where a pack of black squirrels killed and ate a large stray dog in Laza,

Russia.

Squirrel attacks on humans are exceedingly rare,

But do occur.

Whitaker examined the stomachs of 139 13-line ground squirrels and found bird flesh in four of the specimens and the remains of a short-tailed shrew in one.

Bradley examined the stomachs of white-tailed antelope squirrels,

Found at least 10% of his 609-specimen stomachs contained some type of vertebrate,

Mostly lizards and rodents.

Morgart observed a white-tailed antelope squirrel capturing and eating a silky pocket mouse.

The living squirrels are divided into five subfamilies,

With about 58 genera and some 285 species.

The oldest squirrel fossil,

Hesperopodus,

Dates back to the Kedronian,

Late Eocene,

About 40-35 million years ago,

And is similar to modern flying squirrels.

A variety of fossil squirrels,

From the latest Eocene to the Miocene,

Have not been assigned with certainty to any living lineage.

At least some of these probably were variants of the oldest basal protosquirrels,

In the sense that they lacked the full range of living squirrels' autopomorphies.

The distribution and diversity of such ancient and ancestral forms suggests the squirrels as a group may have originated in North America.

Apart from these sometimes little-known fossil forms,

The phylogeny of the living squirrels is fairly straightforward.

The three main lineages are the Rataphinae,

Oriental giant squirrels,

Cerelinae and all other subfamilies.

The Rataphinae contain a mere handful of living species in tropical Asia.

The Neotropical pygmy squirrel of tropical South America is the sole living member of the Cerelinae.

The third lineage,

By far the largest,

Has a near cosmopolitan distribution.

This further supports the hypothesis that the common ancestors of all squirrels,

Living in fossil,

Lived in North America,

As these three most ancient lineages seem to have radiated from there.

If squirrels had originated in Eurasia,

For example,

One would expect quite ancient lineages in Africa,

But African squirrels seem to be of more recent origin.

The main group of squirrels can be split into five subfamilies.

The Calocerinae,

60 species mostly found in Southeast Asia.

The Rataphinae,

4 cat-sized species found in South and Southeast Asia.

The Cerinae contains the flying squirrels and the tree squirrels,

83 species found worldwide.

Cerelinae,

A single South American species.

And Zerinae includes three tribes of mostly terrestrial squirrels,

Including the Marmotini,

Marmots,

Chipmunks,

Prairie dogs and other Halarctic ground squirrels.

Zerinae,

African and some Eurasian ground squirrels.

And Protozerinae,

African tree squirrels.

Society Squirrels have been kept as pets in Western society at least until the 19th century.

Because of their small size and tame nature,

They were especially popular with women and the clergy.

Squirrels are a cause for concern because they often cause electrical disruptions.

It has been hypothesized that the threat to the internet,

Infrastructure and services posed by squirrels may exceed that posed by cyber attacks.

Squirrels have been reported to be successfully trained in Chongqing,

China to sniff out illicit drugs and in 2023 a team of six Eurasian red squirrels had become part of a sub-unit within the Chongqing City Police Dog Brigade.

According to the Chongqing Police Department,

Their small size and agility are beneficial as they are able to help the police detect drugs through tiny spaces in warehouses and storage units that dogs are unable to reach.

Ying Jin,

A police dog handler who had been assigned to train these squirrels,

Told the paper that these squirrels have an acute sense of smell,

Are training problems for small rodents was not developed enough to attempt a program like this,

And that her team of squirrels have so far done an excellent job in drug detection exercises but are not yet ready to be deployed.

American Red Squirrel The American Red Squirrel is one of the three species of tree squirrels currently classified in the genus Timmyocerus,

Known as the Pine Squirrels.

The others are the Douglas Squirrel and the Southwestern Red Squirrel.

The American Red Squirrel is variously known as the Pine Squirrel,

North American Red Squirrel,

And Chicory.

It is also referred to as the Hudson's Bay Squirrel,

As in John James Audubon's work The Vivaparous Quadrupeds of North America,

Hence the species name.

The squirrel is a small 200-250 gram 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.

Taxonomy American Red Squirrels should not be confused with Eurasian Red Squirrels,

Since the ranges of these species do not overlap.

They are both commonly referred to as Red Squirrels in these areas.

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.

A recent phylogeny suggests that squirrels as a family can be divided into five major lineages.

Red Squirrels fall within the clade that includes Flying Squirrels and other tree squirrels.

There are 25 recognized subspecies of Red Squirrels.

The Southwestern Red Squirrel was long considered conspecific with T.

Hudsonicus,

But a 2016 phylogenetic study found it to be a distinct species.

Description Red Squirrels can be easily distinguished from other North American tree squirrels by their smaller size,

28-35 cm total length,

Territorial behavior,

And reddish fur with a white venter underbelly.

Red Squirrels are somewhat larger than chipmunks.

The Douglas Squirrel is morphologically similar to the American Red Squirrels,

But has a rust color 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.

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.

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.

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.

American Red Squirrels are primarily granivores,

But incorporate other food items into their diets opportunistically.

In Yukon,

Extensive behavioral observations suggest white spruce seeds comprise more than 50% of a Red Squirrel's diet.

But squirrels have also been observed eating spruce buds and needles,

Mushrooms,

Willow leaves,

Poplar buds and catkins,

Bearberry flowers and berries,

And animal material such as bird eggs or even snowshoe hare leverets young.

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 12 meters across.

White spruce exhibits two to six year masting cycles,

Where a year of superabundant cone production,

Mast year,

Is followed by several years in which few cones are produced.

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.

American Red Squirrels are spontaneous ovulators.

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 estrus female.

Estrus females will mate with four to sixteen males.

Gestation has been reported to range from 31 to 35 days.

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 1 to 5,

But most litters contain 3 or 4 offspring.

Offspring are pink and hairless at birth and weigh about 10 grams.

Offspring grow at approximately 1.

8 grams per day while nursing,

And reach adult full 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 and the branches of trees.

Nests are also excavated from witch's 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.

Red squirrels are highly territorial and social with very few non-reproductive physical interactions — 0.

6% of all recorded behaviors in one 19-year study.

The majority of physical interactions are in male-female matings,

And between females and their offspring before the offspring disperse to their own territories.

The non-reproductive physical interactions recorded were all instances of chasing an intruder from a territory.

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.

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.

Offspring that do not receive a midden from their mother typically settle within 100 meters of their natal territory.

Alternative reproductive strategies that result in higher incidences of sexually selected infanticide in years when food is plentiful.

American red squirrels experience severe early mortality.

On average,

Only 22% survive to one year of age.

The survival probability,

However,

Increases to age 3 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.

Increased maternal attention is correlated with increased offspring growth rate and higher lifetime reproductive success.

Chief predators include Canada lynx,

Bobcat,

Coyote,

Great horned owl,

Northern groshawk,

Red-tailed hawk,

American crow,

American marten,

Pacific marten,

Red fox,

Gray fox,

Wolf,

And weasel.

Black squirrels are a melanistic subgroup of squirrels with black coloration on their fur.

The phenomenon occurs with several species of squirrels,

Although it is most frequent with the eastern gray squirrel and the fox squirrel.

Black morphs of the eastern gray and fox squirrels are the result of variant pigment gene.

Several theories have surfaced as to why the black morph occurs,

With some suggesting that the black morph is a selective advantage for squirrels inhabiting the northern ranges of the species,

With the black fur providing a thermal advantage over its non-melanistic counterpart.

Black squirrels share the same natural range as their non-melanistic counterparts.

In addition to their natural range,

Black morphs of eastern gray squirrels were also introduced into other areas of Canada,

The United Kingdom,

And the United States during the 19th and 20th centuries.

Black morphs of eastern gray squirrels occur most frequently in the northern portion of its range around the Great Lakes basin.

Conversely,

Black morphs of fox squirrels typically occur most frequently in the southeastern portions of the species' natural range,

The southeastern United States.

Although they are found more frequently in those regions,

The coloration remains uncommon in most areas that these species inhabit.

However,

Black morphs of eastern gray squirrels form the majority of the species' population in the Canadian province of Ontario and the U.

S.

State of Michigan.

Several municipalities and post-secondary schools in the United States have adopted a black squirrel for branding purposes,

Using it as a symbol and or mascot.

Some municipalities that have adopted the black squirrels as a symbol for their community have also passed ordinances that discourage attempts to threaten them.

The black coloration in both eastern gray squirrels and fox squirrels is believed to stem from a variant pigment gene.

A study published by Febb's Letter in 2014 demonstrated how a pigment gene missing a piece of DNA can be a determinant of any eastern gray squirrel's coat.

The emergence of the black fur in the eastern gray squirrel is believed to be the result of the 24Bp deletion from their melanocortin-1 receptor,

MCR1 gene,

With the specific allele referred to as a MC1R-delta-24.

A study published by BMC Evolutionary Biology pointed to evidence that the variant pigment gene originated from the black fox squirrel,

And was later passed on to eastern gray squirrels as a result of interspecies mating,

Given that the variant gene in both species were identical.

Black coat color is caused by a 24Bp deletion in MC1R in the western population of fox squirrels,

And by a point mutation in the Agouti signaling protein gene in the southeastern population.

Black morphs may also occur with Colombian ground squirrels,

Eurasian red squirrels,

Richardson's ground squirrels,

And western gray squirrels,

Although it is far more unusual for the latter to display color polymorphism.

No association between melanism and variations in their MC1R was found in Eurasian red squirrels,

With researchers suggesting that the different color variations including black morphs in Eurasian red squirrels and fox squirrels being a polygenic result.

Polymorphism with Richardson's ground squirrels is due to recessive genes.

With regard to black squirrels and melanism,

Two major theories dominate the literature,

That its frequency is a result of crypsis,

And are the result of thermoregulation.

It has been theorized that non-melanistic gray squirrels have a concealment advantage in forests dominated by deciduous trees,

While black squirrels hold a concealment advantage in forested areas in the northern portions of its range,

Where conifer trees are more prevalent.

The theory is based on the idea that forests where coniferous trees are predominant block more sunlight from reaching the forest below,

Providing a dimly lit habitat in which a darker coated squirrel could better conceal itself compared to its lighter counterpart.

It's also suggested that non-melanistic squirrels have a concealment advantage over their melanistic counterparts in deciduous forests,

Because deciduous trees shed their leaves on a seasonal basis,

Illuminating the forested area below it during the winter season.

A study conducted in 1989 on melanistic fox squirrels found the non-melanistic coloration better for concealment while the squirrel was still,

But a melanistic coloration provided better concealment for when it was in motion.

The frequency of black morphed eastern gray squirrels is thought to have been once relatively common throughout the eastern gray squirrel range,

Although their frequency and population have dwindled since the 1700s.

It has been suggested that their population declined due to extensive deforestation and the hunting of squirrels for their meat and pelts,

With the newly changed environment providing non-melanistic gray-colored squirrels an advantage in concealment.

However,

The theory that the black morphed squirrels were more prevalent prior to the 1700s and that deforestation led to their decline has been challenged by some researchers.

One study found a high frequency of black eastern gray squirrels lived in rural southern Ontario,

An area primarily made up of farmland.

Melanism in fox squirrels in the southeastern portion of its natural range has also been associated with crypsis,

As it inhabits forests that go through periodic burnings.

It has been suggested that black squirrels would be harder to detect in forests already burned due to the blackened substrate.

It has also been suggested that black morphed squirrels have a considerably higher cold tolerance than gray squirrels,

Given the color of their coat.

Black coated animals were found to have 18% lower heat loss and temperatures below negative 10 degrees Celsius,

A 20% lower metabolic rate,

And a non-shivering thermogenesis capacity that is higher than a gray morph.

Additionally,

Researchers of the color morph have noted a strong negative correlation with the frequency of black squirrels and areas with high air temperature.

The black coat has been suggested as a selective advantage for squirrels inhabiting the northern ranges of the species,

As it helps them inhabit colder regions.

The apparent thermal advantage has contributed to the expansion of the eastern gray squirrels ranged northward following the end of the last glacial period.

Black morphed eastern gray squirrels have been reported as far north as Sudbury,

Ontario,

Past the traditional range of the eastern gray squirrels.

A study published by the European Journal of Ecology in 2019 on eastern fox squirrels found that the melanistic morphs of the species saw a noticeable increase in their surface temperature,

Fur,

And skin in both sunny and cloudy weather,

Whereas the non-melanistic fox squirrels only saw their surface temperature increase when it was sunny with no cloud cover.

Its ability to gain heat in sunny and cloudy conditions is believed to be the reason why melanistic squirrels are more active during winter mornings.

However,

The same study noted that there was no difference in metabolic heat production between the color morphs.

Among eastern squirrels,

Gray mating pairs cannot produce black offspring.

Gray squirrels have two copies of a gray pigment gene,

And black squirrels have either one or two copies of a black pigment gene.

If a black squirrel has two copies of the black gene,

It will be jet black.

If it has one copy of a black gene and one gray gene,

It will be brown black.

Approximately 9% of melanistic eastern gray squirrels are believed to be jet black.

In areas with high concentrations of black squirrels,

Litters of mixed-color individuals are common.

Though melanistic gray squirrels are sometimes referred to as super squirrels in the media,

A study conducted in 1990 of black and gray morphs of the eastern gray squirrel concluded that there was no major difference in behavior between the morphs.

The same study also found no difference between the morphs when reacting to either a humid or canid predator.

However,

Another study in 2010 also found that gray morphs of the eastern gray squirrel were more prone to initiate flight than black morphs after hearing a red-tailed hawk.

Although the fact that black morphs were less likely to initiate flight after hearing a red-tailed hawk may not be an effect of pigmentation,

Rather the environment they inhabit.

Given the higher frequency of black morphs in an urban setting,

It has been suggested that black morphs have a higher tolerance for human urban stimuli.

It has also been suggested that behavioral differences with regard to mating may exist between the urban and rural populations of eastern gray squirrels.

A 2019 study on fox squirrels found that there was no noticeable difference in metabolism between the different color morphs of that species.

However,

The same study on fox squirrels found that melanistic fox squirrels were more active than their non-melanistic counterparts during the winter and spring months.

These melanistic fox squirrels found to be 30% more active during the mornings than their non-melanistic counterparts.

Conversely,

The non-melanistic fox squirrels were more active during the autumn season.

It has been suggested that the black squirrel's higher heat gain for its surface temperature is the reason why they are able to be active earlier in the day and remain active longer.

Natural populations of black morph eastern gray and fox squirrels can be found in the natural ranges of both species in North America,

Although their frequency varies depending on the area.

Black fur for both species of squirrels is rare and occurs at rates of less than 1%.

It has been suggested that 1 in 10,

000 eastern gray squirrels are a black morph.

It has been suggested that the frequency of the black morph in the eastern gray squirrel populations has declined since the late 1700s,

Especially south of the Great Lakes.

There is a higher frequency of the black morph in the northern portions of the eastern gray squirrel's range,

Which includes the southern portions of central Canada and northern United States.

In particular,

Large populations of black squirrels are found within the Great Lakes Basin,

With a notable increase in their frequency between the 41st parallel north and the 45th parallel north.

Black squirrels occur with the highest frequency in Ontario and Michigan and are the predominant color morph found in those areas,

With the black morph accounting for 66% of squirrels documented in iNaturalist in Ontario and 56% in Michigan.

Different populations of black morphs are also present in the other provinces states that surround the Great Lakes,

With approximately 15% of the eastern gray squirrels in those regions reported to be melanistic.

Black squirrel populations south of the Great Lakes remain largely localized,

With the frequency of black squirrels varying from one region to another.

Black squirrels were found to be more common in urban areas as opposed to rural areas and forests.

Among ex-urban populations of eastern gray squirrels,

The black morph only occurs in high frequencies in Ontario and northern Michigan.

Conversely,

Black morphs of fox squirrels occur with the highest frequency in the southeastern portion of its natural range,

The southeastern United States.

Like the eastern gray squirrels,

The frequency of black fox squirrels is dependent on the area reaching a maximum frequency of 13%.

Although they occur more frequently in the southeastern United States,

Large populations of black morph fox squirrels may be found in other areas of the species' natural range,

Including council bluffs Iowa and around the Missouri River.

Approximately half of the fox squirrels found in council bluffs are melanistic.

Melanistic fox squirrels in council bluffs have since expanded across the Missouri River to other areas in the Omaha Council Bluffs metropolitan area,

With melanistic fox squirrels now accounting for 4.

6 to 7.

6% of fox squirrels in Omaha.

Several populations of black morph squirrels were the result of reintroduction repopulation programs intended to reintroduce the species and or the black morph to areas they once inhabited but had been wiped out by human hunting and predators in previous centuries.

Black squirrels in Washington,

D.

C.

Originated from 18 black morphs captured at Rondo Provincial Park in Ontario and released in the parks around the National Mall in 1902 and in 1906 by Teddy Roosevelt.

There remains a level of uncertainty as to why the black morphs were introduced into the National Mall,

Although representatives from the Smithsonian Museum suggest their introduction may have been part of a larger effort to revitalize the local eastern gray squirrel population whittled down by human hunting.

By the 1960s,

The black morphs had spread beyond the parks that surrounded the National Mall,

Although were largely contained by the Capitol Beltway.

In 2005,

It was estimated that black morphs comprised between 5 and 25% of all eastern gray squirrels in that area.

The present population of black eastern gray squirrels in Battle Creek,

Michigan was reportedly introduced in 1915 by John Harvey Kellogg,

Who wanted to repopulate the area with the species after their populations were devastated in the previous centuries by predators and human hunters.

He reported they received 400 eastern gray squirrels from Kent County,

Michigan,

Including some black morphs,

And released them into the community.

Researchers north of Battle Creek at the Kellogg Biological Station later trapped some black morph eastern gray squirrels in 1958 and 1962,

And released them on the East Lansing campus of Michigan State University at the behest of the university's president.

Black morphs were once present in Ohio,

Although the color morph was extirpated from the state by 1930.

However,

An initiative to reintroduce the black morphs into the squirrel population was undertaken in 1961 by Kent State University,

Based in Portage County.

The university,

In coordination from the Canadian and U.

S.

Governments,

Released 10 black squirrels from London,

Ontario,

Onto its campus grounds in an effort to reintroduce the black morphs into the area.

By 1964,

The population of the squirrels had increased to 150,

According to the record courier.

The black morphs of the eastern gray squirrels have since expanded through northeastern Ohio.

Several populations of black morph squirrels were introduced into the area by accident.

Some of these black morph populations have been embraced by their communities,

Although others have viewed as an invasive species to the local ecosystem.

The introduction of black squirrels in the Quad Cities occurred in the 19th century.

According to one story,

Recounted in the book The Palmers,

They were first introduced on the Rock Island Arsenal by either the Palmer family or the base commander.

According to the story,

Some of the black morphs later escaped the arsenal by jumping across ice flows on the Mississippi River when it was frozen,

And populated the other areas on Rock Island.

Eastern gray squirrels,

Including their black morphs,

Were introduced into British Columbia during the early 1900s.

The species was also later introduced into other areas of Canada,

To which it was native,

Such as Calgary,

Alberta.

The majority of the eastern gray squirrels in Calgary originated as pets,

Or zoo animals,

That escaped captivity during the 1930s.

As in Ontario,

Black eastern gray squirrels are now the predominant morph of the species found in Calgary.

Reviews

My dogs were Very interested and give this reading a four paw salute (no thumbs 😅). Thank you!

So helpful to get to sleep! Love all the tidbits about these adorable creatures, but it does the trick as I’ve yet to make it to the end. Thank you! 🐿️💕

This is a favorite and a regular go-to when I wake and can't get back to sleep. I could probably recite the whole thing by now along with you to the end....if I could stay awake long enough!
This podcast never fails me
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Awesome 😎 squirrels 🐿️ are so cute and boring 😴 🤭

Benjamin's soothing voice is perfect for helping a high energy kiddo - and his exasperated mom - fall fast asleep. (Thank you, Benjamin!)