Author: Don

Snow leopards, Panthera uncia, beautiful but shy cats, are one of the top predators in their high-altitude habitat.  They are grey to white with large black spots covering their entire body, including the tail.  A short muzzle and large nostrils help the snow leopard inhale large quantities of air in the thin atmosphere of their home range.  Their bodies are short and stocky, ranging from 50 to 150 pounds.  Snow leopards cannot roar, but have a wide range of calls including purring, meowing, grunting, moaning and chuffing. 

Home ranges are generally large, covering from five square miles where vegetation and food are abundant to 150 square miles in sparser areas.  Snow leopards are most active at dawn and dusk, resting near cliffs and ridges that provide shade and good vantage points for hunting.  They are stealthy hunters and can actively pursue prey down mountainsides, dragging the kill to a safe location where they will consume all edible parts. Mainly carnivores, they feed on wild sheep, goats, ibex, and wild boar, but will hunt smaller prey including pika, marmot, and voles.  They eat a large amount of supplemental vegetation such as grass and twigs.  They prefer larger prey and can survive for two weeks on a wild sheep before needing to hunt again.

Snow leopards live in the alpine zones of central and southern Asia, from altitudes of 9,800′ to 14,800′.  They have several adaptations for enduring the cold temperatures including small, round ears minimizing heat loss, fur on the bottoms of their paws to keep them warm while walking on snow and ice, large nostrils to heat and humidify the air they breathe, and a long, flexible tail used as a blanket for their face while sleeping.

A snow leopard reaches sexual maturity between two and three years old.  Their lifespan is 15 to 18 years in the wild, and may exceed 25 years in captivity.  They are solitary cats, except when breeding in late winter.  In late spring, two to three cubs are born blind and helpless, but with thick fur coats at birth.  They can see at seven days and will be walking in five weeks.  They leave the den for the first time in two to four months.  They spend the first 18 months in the care of their mother learning to hunt and will establish their own territories before leaving permanently. 

Snow leopards are listed as vulnerable, with an estimated population of less than 10,000 remaining in the wild.  The main threats to their survival are poaching for the illegal trade in fur and body parts and habitat destruction.  Climate warming trends are causing 30% reductions in alpine zones worldwide, placing snow leopards in competition with predators from warmer habitats who are now able to range into higher altitudes.

The Global Snow Leopard Forum, World Wildlife Fund, the Snow Leopard Conservancy, and other groups are working with local people and countries to help snow leopards survive and to maintain the fragile environment they inhabit.  Protected areas are being established in several countries that encompass their native ranges.  These same areas provide food, resources, and some of the largest freshwater reservoirs on earth for the many species living there, including people. 

Snow leopards were first exhibited in 1872 by the Moscow Zoo.  In 1990, at the Beijing Zoo, the first cat was bred in captivity.  As temperatures cool down for the year, consider a trip to a zoo near you to see these wonderful cats.

Antlers and horns, often referred to interchangeably, are sported by North American species in the deer and cattle families, respectively.  Typically found only on males, except for caribou where both sexes grow antlers, there are distinct differences in growth and usage.

Antlers are found in the deer family, including white-tailed deer found across the continent, elk along the Pacific Coast and across the western U.S. – Canada border, caribou found in Alaska, mule deer located mainly in the western U.S., and moose found along the entire  U.S. – Canada border.  Horns are found on species in the bovine family including bison found in small herds across the grasslands west of the Mississippi River and sheep, goats and cattle found throughout the North American continent.

Caribou by Jacob W. Frank, Oct 2008; Elk by Scott Kinmartin, Jun 2009; Moose by Larry Lamsa, Aug 2021; Mule deer by Mark Moschell, Nov 2016; White-tailed deer by Jeff Bryant, Jan 2017

Antlers are shed at the conclusion of the breeding season each year, and a new pair is grown for the following year.  Antlers grow from the tip, growing faster and larger as adults get older.  Velvet, a layer of fine hair, covers the living bone and provides oxygen and nutrients to the developing antler.  As annual breeding activities begin in late autumn, individuals will rub off the velvet and stop the bone from growing.  After the breeding season ends in mid-winter, normal bone maintenance breaks down dead tissue at the base, and the antlers fall off.

Antlers are proudly displayed by males to attract mates and are a clear indicator of the bull’s health.  Elk are the largest deer species, and a set of antlers may grow an inch a day, contain seven to eight points with a four foot spread, and weigh up to 20 pounds each.  The largest elk bulls attract from five to thirty mates.  Antlers are also used in defense of the herd and for asserting dominance over other herd members, typically for mates or food.

Horns are living bone on the inside, covered by a sheath of keratin composed of specialized hair follicles.  Horns grow from the base where they meet the skull and grow continuously throughout the life of the animal.  They are often curved in shape and covered with ridges or fluting.

Horns are used to establish dominance within a herd, marking those males that control the actions of the herd.  They are used in defense of territory from individuals of other herds and as defensive weapons when interacting with predators.  Horns are also used to dig roots for food and strip bark for marking territory.

As you walk the forest paths, keep watch for white-tailed deer growing their antlers at this time of year, and observe the transition as velvet is removed in the coming few months.

The pronghorn, Antilocapra americana, is the only living species in the family Antilocapridae.  All of the animals in this family are native to North America, having diverged from a common ancestor in the giraffe family during the Early Miocene period about 14 million years ago.   During the late 1800s, populations were estimated to be between 50 and 100 million animals, roaming from southern Canada to Arizona and eastern California to the Rocky Mountains.  Fencing of land for ranching and farming severely impacted migration and breeding opportunities.  These restrictions, along with hunting, reduced pronghorn populations to 20,000 by 1925.  Establishing open range areas, including National Park land, and limiting hunting helped the pronghorn population grow back to about a half-million by the late 1900s.

Pronghorns are deer-like mammals with bright white cheeks, bellies, and rumps against a reddish-tan body.  Their short mane stands erect at 3″-4″ high.  Bucks have a black neck patch and a broad black band running from their eyes to a black nose.  Black horns grow to 12″ for females and up to 20″ on males, curving backward and inward with one prong jutting forward.  Their eyes are large and set out  from the skull allowing them to detect movement at distances of up to four miles.  Teeth grow continuously in response to wear from eating rough grasses and brush.  Pronghorns have hollow-core hairs covering their bodies.  When the hair lies flat, it provides excellent insulation for colder temperatures.  The hair can also stand erect, allowing cooler air to circulate next to the skin during summer heat.

Pronghorns live in herds, a lifestyle that has several advantages for non-hunting animals living in flat, open terrain with large predators.  Defense against predators is better when there are more pairs of eyes watching.  More animals together in a herd also means there is the possibility of many fighting back against a predator.  Herds keep males and females in closer contact at breeding time helping to synchronize mating cycles so that all young are born at the same time and can be cared for by many adults.  Pronghorns warn distant herd members of predators by flaring long white hairs on rump patches  that give a flash that is visible over long distances.

Dominant males establish territories early in the spring and defend these using loud snorts, chasing away competitors, and butting with their horns.  Mating takes place in autumn, followed by seven months of gestation, with one or two fawns born in late spring.  Newborn fawns lie quietly in tall grass, while mother feeds some distance away so as not to give away the fawn’s location to predators.  She will visit each fawn several times a day to nurse.  After 7-10 days, the fawns are strong enough to join the herd.  Pronghorns are active night and day, catching snatches of sleep whenever possible while feeding.  Herds migrate annually, following no set path, but going where food sources are available.  While they avoid mud, rivers and streams are easily crossed as they are excellent swimmers.

Pronghorns are a unique native species of North America.  The biggest threats to pronghorn today are oil exploration and strip mining as well as roads and fences across migration routes from spring breeding to winter grazing locations.  They have the longest land migration of any species in the United States.  Pronghorns are the second fastest animal on land, able to run at 70 mph for three to four minute bursts,  while the cheetah is faster for short distances, pronghorns are the long distance champs, able to sustain 30 mph for distances in excess of 15 miles.  You can see them at many zoos across the United States, or keep your eyes open as you travel their favorite range in southwestern Wyoming.

The giraffe, Giraffa camelopardalis, is the tallest animal in the world.  Currently, it is classified as one species with nine subspecies, although taxonomists do not all agree on this.  A group is properly called a “tower” of giraffes unless they are observed in motion, in which case we refer to them as a “journey” of giraffes.  Giraffes have several interesting characteristics that we will explore.

Giraffes have a black prehensile tongue about 18″ long.   The upper lip, also prehensile, in combination with the tongue, is used for grasping, holding, and pulling whole branches through their mouths to strip off all of the leaves and thorns.  Their preferred food includes leaves, fruits, and flowers of woody species.  The thorny acacia tree is a special favorite.  Giraffes are ruminants, using strong stomach muscles to bring food back up to their mouths for chewing multiple times. For complete digestion, food makes its way through a giraffe’s four stomachs. 

Adult giraffes may reach heights of 14′ to 19′ and weigh from 1800 pounds to 2600 pounds.  Their necks, up to eight feet long, have the same number of vertebrae as other mammals.  As calves grow, cervical vertebrae grow longer.  The neck is very long, yet too short to reach the ground, so a giraffe must spread and bend its front legs in order to drink.  Giraffes do not need to drink more than once every few days, though, getting most of their water from their food.

A giraffe’s circulatory system includes several adaptations to accommodate its height.  The heart is one of the largest muscles in the body at two feet long and weighing 25 pounds.  It must generate almost twice the blood pressure of a human.  With a resting heartbeat of 150 beats per minute, it pumps sixteen gallons of blood each  minute.  To prevent fainting, a network of veins and muscles along with several one-way valves, regulate blood flow, keeping it from rushing to or away from the head when it is lowered or raised.  Giraffes have smaller red blood cells and many capillaries making oxygen absorption quicker to supply the energy needs of the muscles.

Giraffes sleep less than an hour each day, taking several short naps while standing.  They give birth while standing and calves can stand and walk within an hour of being born.  Their hooves, up to twelve inches in diameter, are made for comfortable walking and running.  Adults can sprint short distances at 40 miles per hour or sustain a loping speed for several miles at 20-30 miles per hour.  Their speed and size keeps adults safe from most predators, although calves are susceptible to lions, hyenas, leopards and wild dogs.  Their  normal life span is 25 years in the wild, but almost 50% of all calves are lost to predation before reaching adulthood.

Giraffes are listed as vulnerable on the IUCN Red List, with 90,000 individuals living in central and southern Africa, down from a population of 150,000 thirty years ago.  The main threats are habitat loss and killing for the bushmeat market.  As human populations expand, the need for firewood and livestock grazing areas results in shrinking forests and savannas.  Another factor negatively impacting populations is climate change, including a severe drought across much of the central plains in 2017.  Private game reserves and national parks offer protection, but they are limited in size and are being used by many species.  Giraffes are vital to keeping ecosystems in balance, eating browse unreachable by other species, opening new areas, and promoting growth of grasses and brush for food for many smaller species.

A marsupial is a mammal with young that are born not fully developed and are subsequently carried in a pouch on the abdomen of the mother where the young can attach to a teat and complete their development.  The most well-known animals in this group are kangaroos, but we also have one species in Illinois, the Virginia opossum, Didelphis virginiana.  The opossum is native to Illinois and is common in all parts of the state.  The oldest remains found in Illinois date back 100,000 years ago, while worldwide, opossums are one of the oldest known mammals, with remains dating back about 20 million years ago to the Miocene period.

An adult opossum has coarse gray hair covering its body with white facial hair and a long, pointed snout with a pink nose.  They are about the size of a house cat with hairless ears and a one to two foot long hairless tail.  Their tails are prehensile, adapted for seizing, grasping, or holding, and used for balancing and climbing.  The hind feet have no claws, but do have an opposable toe used for climbing and grasping.  They can appear fearsome when baring their teeth, having fifty of them, more than any other land mammal.  They live in urban or edge habitats, finding shelter in old dens, rock crevices, hollow logs, and under wood or stone foundations.

Females give birth to one or two litters each year, the first in mid-winter and a possible second litter in early spring.  Young are born about two weeks after fertilization.  A newborn, the size of a bumblebee, must crawl to the mother’s pouch where it will attach to a nipple and stay attached for two to three months to complete its development.  Up to twenty young, called joeys, are born in each litter, but the female adult only has 13 teats and the remainder of the young do not survive.  Young are weaned at about three months.  Usually nocturnal and solitary animals, young will often strike out on their own but may return to the family group for the winter. 

Opossum are omnivores eating a wide variety of food including fruit, grain, seeds, pet food, garbage, carrion, eggs, insects, frogs and other small animals.  Ticks, found on many Illinois mammals, are a favorite food item.  It is estimated that an adult opossum consumes several thousand annually.  Opossum are scavengers, seed dispersers, and a control for small mammal and insect populations.  In turn, they are prey for larger birds and mammals. 

When threatened, an opossum may respond by hissing, growling, baring its teeth, or playing dead.  Playing dead, an autonomic response, occurs when the opossum faints.  They lay on the ground with lips drawn back, teeth bared, eyes half or fully closed, saliva drooling, and a foul-smelling liquid excreted from their anal gland.  Individuals can be poked, turned over or picked up and carried away with no response.  They will recover by slowly regaining consciousness after several minutes or up to four hours.  In the wild, their average life span is two years, and the leading cause of death is being hit by a vehicle. 

Opossum are protected under Illinois law as a furbearer.  Hunting licenses are available each year with no limits.  Permits may also be issued for nuisance animals that may be trapped for removal to another area.  Adults are often infested with parasites, but carry none that are known to affect humans.  They are rarely encountered or seen, but you may be able to observe them in the evening, especially under bird feeders or where pet food is left outside.