Skunk

 Skunk: Mammals in the family Mephitidae.

Kingdom: | Animalia

Phylum: | Chordata

Class: | Mammalia

Order: | Carnivora

Family: | Mephitidae

There are 10 living species of skunks. They may be found in the following three genera: Conepatus, Mephitis, and Spilogale.

Size and Weight:

The size of a skunk varies depending on the species. They can range in length from 15.6 to 37 inches, and in weight from about 1.1 to 13 pounds. Spotted skunks are the smallest species. The largest are the hog-nosed skunks.

Appearance:

Skunks have moderately elongated bodies with relatively short, well-muscled legs. They have five toes on each foot, and long front claws for digging. Most skunks have black and white fur, but some may be brown or grey. All skunks are striped. Depending on the species, a skunk may have a single wide stripe along the back and tail, or two thinner stripes, or a series of white spots and broken stripes.

Diet:

Skunks are omnivores. They eat both plant and animal material. Their diet may include insects, rodents, lizards, birds, snakes, eggs, berries, roots, fungi and leaves. When living near human populations, skunks are known to scavenge garbage left by humans. They also may scavenge bird and rodent carcasses left by other animals.

Habitat:

Skunks live in a wide variety of habitats, including deserts, forests and mountains.

Geography:

Skunks inhabit North America and South America.

Breeding:

Early spring is skunk mating season. Skunks are polygynous, meaning successful males may mate with additional females. The female gives birth in a den after a gestation period of about two months. She will give birth to a litter of four to seven kits, which are born blind, deaf and vulnerable. After about three weeks, the kits open their eyes. They are weaned at about two months but will stay with their mother until they are ready to mate at about one year old. Mother skunks are protective of their young and are known to spray at any sign of danger. Males are not involved in raising the young.

Social Structure:

Skunks are crepuscular and solitary animals when not breeding. However, in the colder parts of their range, they may gather in communal dens for warmth. Skunks dig burrows to use for shelter during the day. For most of the year, a skunk’s normal range measures 0.5 to 2 miles. During breeding season males travel an expanded range, 4-5 miles per night.

Although skunks may shelter in their dens for extended time periods in the winter, they are not true hibernators. They go into a dormant stage when they are typically inactive and feed rarely. During the winter months, males often den alone but multiple females may huddle together, returning to the same den year after year.

Lifespan:

In the wild, skunks live two to four years. In captivity, they may live for up to ten years.

Threats:

Skunks are threatened by a long list of predators including humans, coyotes, domestic dogs, red foxes, lynx, bobcats, badgers, mountain lions, and fishers. They also can be prey for aerial predators like eagles, great horned owls and crows. Skunks are highly susceptible to diseases like canine distemper and West Nile Virus, among many others. While skunks have an excellent sense of smell and hearing, they have poor vision and are unable to see objects clearly at a distance of 10 feet or more. This leaves them vulnerable to road traffic.

To protect themselves from predators, skunks have a well-known stink strategy. In response to a threat, a skunk will first try to escape. If escape is impossible, it will hiss and stamp its feet. If the threat persists, a skunk can position itself in a U-shape so that its front and back ends are facing the threat, ensuring that its spray will hit the mark without getting a drop on itself. The skunk then emits a well-aimed cloud of stench.

Most predators are deterred by this tactic, which is one of nature’s most effective defense mechanisms. The skunk spews an oily, yellowish liquid produced by anal glands under its fluffy tail. While the liquid does no permanent damage, its stench may linger for days. And, since one of the spray’s noxious ingredients is water resistant, bathing has little effect on relieving the stench.

Conservation Status:

Eight of the ten skunk species are listed as “Least Concern” by the IUCN Red List of Threatened Species. The pygmy spotted skunk (Spilogale pygmaea) and the eastern spotted skunk (Spilogale putorius) are listed as “Vulnerable.”

Koala

Koala: the koala is an arboreal herbivorous marsupial native to Australia.

Kingdom: | Animalia
Phylum: | Chordata
Class: | Mammalia
Order: | Diprotodontia
Family: | Phascolarctidae
Genus: | Phascolarctos
Species: | cinereus

There are two subspecies of koalas: adustus, the northern or Queensland koala, and victor, the southern koala.

Size and Weight:

On average, koalas are 2 to 3 feet in height. Southern koalas are typically larger than northern koalas. Northern koalas weigh 9 to 19 pounds and southern koalas weigh 15 to 29 pounds. Males weigh about 50 percent more than females.

Appearance:

Koalas are known for their teddy bear-like appearance. They are often referred to as “koala bears,” but koalas are actually marsupials, not bears. Marsupials are an infraclass of mammals most commonly known for their pouches, which includes wombats and kangaroos.

Koalas are arboreal, or tree-dwelling, marsupials and have a number of adaptations for tree living. Their bodies are lean with long, muscular front and hind limbs and large, sharp claws to help with gripping tree trunks, and rough skin on the bottom of their feet to provide friction good for climbing. The koala has five digits on their front paws, two of which are opposable, which would be like a human having two thumbs. This allows the koala to grip branches as it moves from tree to tree. The koala has thicker fur on its rump, which provides a cushion when sitting on branches.

Diet:

Koalas are folivores or leaf eaters. They primarily eat eucalyptus leaves, but will occasionally branch out to non-eucalypt plant species. They eat approximately a pound of leaves daily and rarely drink water, as they obtain water from their leafy diet.

Eucalyptus leaves are highly toxic to most mammals, but koalas’ digestive systems are specially adapted to detoxify the poisonous chemicals in the leaves. Eucalyptus leaves are high in fiber and low in nutrition, so they take a while to digest. To conserve energy, koalas spend anywhere from 18 to 20 hours of their day sleeping. Koalas are nocturnal and do the vast majority of their eating at night.

Habitat:

The species lives in tall eucalypt forests and low eucalypt woodlands. They also live in coastal and island woodlands.

Geography:

Koalas are native to Australia and are found in the eastern and southern regions of the country. The majority can be found in the four Australian states: South Australia, Victoria, Queensland, and New South Wales.

Breeding:

The koala gestation period is only 34 to 36 days. The joey is born blind, furless, earless and only about an inch long. Immediately after being born, it crawls up from the birth canal into the mother’s pouch. There, the joey attaches to one of two teats. It will not emerge from the pouch for approximately six months. After six to seven months of solely feeding on milk, the joey starts consuming its mother’s protein-rich pap, which inoculates the baby’s gut with the necessary microbes for eucalypt digestion.

At about a year old, the young koala no longer drinks milk or fits in its mother’s pouch. Female koalas do not always reproduce annually, in which case, the yearling joey may stay with its mother longer. Once independent, the joey remains near its mother’s territory before claiming its own. Koalas become sexually mature at around two or three years, but non-alpha males are far less likely to breed successfully.

Social Structure:

Koalas are generally solitary animals and live in well-defined home ranges. Each home range is often controlled by a single alpha male, with a number of females also living inside that area, These females will mate almost exclusively with the dominant male, who will defend his territory against outside males that may move into the area. Females generally want to reproduce with the largest male and rely on male vocalizations to assess the potential mate’s size.

Although home ranges may overlap, koalas are mostly solitary animals that avoid confrontations and interactions whenever possible. When males aren’t bellowing to attract mates, communication through sounds and scents is often meant to alert wandering koalas of their presence and prevent encounters. Males are generally more vocal than females, but females will communicate vocally with their young, and both sexes make a variety of noises when in distress.

Lifespan:

Koalas generally live an average of 13 to 17 years. Females often live longer than males, whose life expectancy is often less than 10 years due to injuries during fights, attacks by dogs and being hit by cars.

Threats:

Habitat loss and climate change are among the largest threats to koalas. Human activity, such as agricultural and urban development, have led to the destruction and fragmentation of koala habitat. They are spending more time on the ground moving from tree to tree. While on the ground, koalas are much more vulnerable to being hit by cars and attacked by predators like dogs. They also have elevated levels of stress, which makes them more prone to diseases like chlamydia.

Increasing evidence links the changing climate to lower to significant koala range contractions in western Queensland and New South Wales. Climate change is linked to reduced nutrient levels in Eucalyptus leaves, rendering them of lower quality. Droughts and extremely high temperatures will likely increase in incidence and severity, which will likely have an impact on koala populations.

From late 2019 to early 2020, deadly wildfires raged throughout parts of Australia, largely as a result of high temperatures and severe drought. Billions of animals are estimated to have died in the fires, including other unique Australian species like wombats and kangaroos. These massive bushfires burned more than 26.4 million acres, including koala habitat. Thousands of koalas as officials estimate up to 30% of their habitat was destroyed by the fires.