Friday, 6 January 2023

Come Catch the Rabbit, He Runs

 

Canada Lynx Quebec
Canada lynx in Quebec.  Photo credit: Lucas Vogel (CC 4.0 License)

Four distinct lynx species live in the world - the Eurasian lynx, the bobcat, the Canada lynx, and the endangered Iberian lynx.  The word "wildcat" most frequently refers to this animal.  The two North American lynxes, the bobcat and Canada lynx, are closely related but largely separated by geography.  Ranges of these two species overlap only along southern Canada near the border and some parts of the northern United States.  You could say that all bobcats are lynx, but not all lynx are bobcats. 

Sizes and weights of both species are similar.  Both are well-camouflaged within their environment.  Canada lynx can be distinguished from bobcats by longer ear tufts, a shorter tail with an entirely black tip, hind legs significantly longer than the front ones, and much larger paws.  These big paws resemble snowshoes - mirroring that of the snowshoe hare, which consists of most of their diet.  The Canada lynx is so specialized at hunting this animal that their numbers dramatically fluctuate in response to the local hare population.  When snowshoe hares become scarce in an area, lynx produce fewer litters until the hare numbers rebound, and many individuals will migrate to another area where their favorite food is abundant.  During these lean times, a female lynx will not breed if she does not have the nourishment to support both herself and nursing a litter.  This natural cycle is an example of carnivores regulating their own population density.  Depending on availability, the amount of snowshoe hare can range from one-third of a lynx's diet to nearly a hundred percent.  They may hunt other animals, ranging in size from voles to caribou fawns. 

This species thrives in northern, snowy environments and dense boreal forests.  The cold climate requires the lynx to conserve more energy when hunting.  A wildcat's greatest weapon is the element of surprise.  When stalking, the Canada lynx attempts to come as close to the prey as possible without alerting it.  In the winter, the lynx's coat becomes a light gray color - another characteristic similar to the snowshoe hare, which is brown in the summer and white in winter.  This trait helps both the hare and the lynx blend in and become hard to see.  Canada lynx often lie in wait along "rabbit trails" where hares are frequently found.  When they sight a hare, they will either stalk and chase after their quarry, or wait for the hare to come to them before ambushing it.  The Canada lynx's lanky build and large paws with fluffy, wide-spread toes allow them to gain traction on ice.  They can run atop deep snow that would be a significant obstacle to bobcats (which is why the ranges of these two rarely overlap).  The hares are most active at twilight and night, so Canada lynx usually hunt around this time.   However, they are not strictly nocturnal.

Bobcat in Arizona.  Photo credit: Lakeworth (CC 2.0)

Considered to be the fiercer of the two species, the bobcat would likely win in a fight.  As adaptable, generalist predators, they make use of a wide variety of habitats and prey.   Rarely seen by humans, bobcats are nevertheless widespread and have survived along the periphery of urban areas in some places.  These wildcats' elusive nature, toughness and versatility are integral to their survival and wide range throughout North America.  

Carnivores must hunt their own food to survive and consider both the size of the prey and the level of risk.  The bobcat is best suited to hunt prey weighing between one and twelve pounds.  This size range overlaps with large rats, rabbits (their most common food), hares, opossums, waterfowl, snakes, and on the upper end, small fawns.  However, mature male bobcats are also capable of taking down full-grown deer, which average 100-150 pounds.  Usually these are does already in poor condition, though bucks are occasionally taken as well.  Given the bobcat's typical 18-35 pound size, this is an impressive feat!  In the eastern United States, these wildcats are one of the few natural predators of white-tailed deer, where the overabundance of the deer has caused problems for the region's vegetation and forests.  (Cougars historically lived in the East, but were hunted to local extinction east of the Mississippi River in the 1800s.  This has contributed to the problem because cougars specialize in hunting deer.) Due to their smaller size, female bobcats are unlikely to hunt adult deer. 

Bobcat in New Hampshire.  Photo credit: UNH

Bobcats are crepuscular, like their prey.  This means they usually hunt at dawn and dusk.  Most activity occurs from three hours before sunset to midnight, and again from dawn to three hours after sunrise.  The wildcats travel along habitual routes through their territory, typically roaming 2-7 miles every night.  While on the prowl, bobcats search for hiding and stalking cover (tall grass, bushes, tree stands, brush piles) where rabbits and rodents are likely.  Lookouts like small cliffs and ledges also make good vantage points to spot prey.  Bobcats sometimes use lookouts for a more passive hunting strategy - to watch and wait for prey to come.  

Keen vision and excellent depth perception help bobcats judge how close their prey is.  The wildcat stalks in silence and remains low to the ground, keeping claws retracted.  At the right moment the bobcat springs, seizing the target with sharp claws.  As mentioned before, male bobcats can successfully hunt adult deer, mostly ones already in poor physical condition.  Deer are wary and capable of self-defense, but can be weakened by parasites, disease, stress/injuries from bucks fighting in the fall, and severe winters.  To hunt this challenging prey, he attempts to catch the deer off-guard, leaping while the deer is resting on the ground.  More frequently, bobcats hunt smaller sized animals like snakes, rabbits, rats, and mice.  To capture small prey, a bobcat pins the rodent beneath his or her paws and delivers a single nape bite.  If the bobcat misses on the initial pounce, he or she chases the quarry.  Sprinting at 30-35 miles an hour, the wildcat runs with long strides thanks to a flexible spine and muscular legs.

bobcat running
Running Bobcat in Florida.  Photo credit: Russ (CC 2.0)
 

Canada lynx and bobcats both show great perseverance.  If the first rabbit escapes, the wildcat doesn't give up the hunt.  He or she finds a lookout near a food or water source, rests and waits.  More opportunities will eventually come to this location.  Patience comes naturally to them.  Between sedentary periods, the wildcat keeps an alert gaze and repeats the process again.  

These remarkable animals play an important role in keeping rodent and rabbit populations in balance.  While their influence as carnivores is not as known or well-studied as that of larger animals like wolves, the wildcats have even played a role in habitat restoration projects.  A prominent example is Cumberland Island in Georgia.  In absence of any predators, the island's plant communities were damaged due to overbrowsing and grazing by deer.  After 32 bobcats were reintroduced in 1989, deer had a check on their numbers and eventually stabilized.  This allowed native oak trees to regenerate.  Green tree shoots are a deer's preferred food, and the renewal of oak proved beneficial for the island's deer that had previously been underweight.  Over an eight-year period, average deer body mass increased by 11 kg (24.25 pounds) to a healthier weight.  As of 2021, the island is currently home to 24 bobcats.  Cumberland Island continues to be monitored and is now used as a case study to determine ways to conserve the genetic viability of an isolated population - perhaps by reintroducing one bobcat from the mainland every four or five years.  Similar ecological research occurs on South Carolina's Kiawah Island, located near the city of Charleston.  The local bobcat population is currently trending in the right direction thanks to a reduction in rat poisons on the island.    

Canada Lynx in Alberta (CC 3.0)

Wednesday, 4 January 2023

A Jaguar Conservation Collaboration

 

The jaguar (Panthera onca) is a species well-renowned for strength and hunting prowess.  Their powerful jaws exert a bite force of 1,500 pounds per square inch, enabling them to pierce a turtle shell or the scaly hide of the formidable caiman crocodile.  In North and South America, jaguars are the titans of the feline world.  Worldwide, only lions and tigers are bigger.  Excellent swimmers, jaguars frequently take to the water to hunt, and can cross wide rivers.  Yet jaguars face threats to their survival - key among them are habitat loss, poaching and human intolerance due to livestock predation.  In northern Mexico, jaguars are also blocked off from returning to their historical U.S. range by the border wall. Listed as Near Threatened on the IUCN Red List, they are in need of conservation attention.

jaguar

Initiated in 2003, the Northern Jaguar Project aims to conserve the northernmost breeding population of jaguars and the wilderness ecosystem where they reside.  In addition to habitat protection, fostering the value of living wildlife (especially large carnivores like the jaguar) and creating safe areas of coexistence with local communities is paramount.  Located in a remote, rural region of Sonora, Mexico near the town of Sahuaripa, the Northern Jaguar Reserve covers 55,000 acres, or about 86 square miles.  The reserve is strategically located in the center of a 1500 square mile region of prime jaguar turf.  This protected canyon habitat, located along the Sierra Zetasora foothills range, includes forest, riparian and scrub vegetation. 

Through the conservation of the jaguar as an "umbrella species", the rich biodiversity of species on the reserve benefits from the protected habitat.  The Northern Jaguar Reserve is home to three other wild feline species: pumas (another name for the cougar), bobcats, and ocelots, as well as the coyote and smaller carnivores such as river otters, badgers, and gray foxes.  Herbivores include white-tailed deer and javelina (the two primary jaguar prey animals in the area), jackrabbits, and rodents.  A large variety of reptile and amphibian species, including the Gila monster, and 215 different resident or migratory birds have been documented in the area.  You can view more photos of plants and wildlife on the jaguar preserve here


Key to the Northern Jaguar Project's work is the Viviendo con Felinos program, which translates from Spanish to "living with cats".  Agriculture and cattle ranching are the main sources of income for people within the Sahuaripa region.  Loss of cows to jaguar predation has led to rancher retaliation and poaching, both major threats to the big cats.  Through Viviendo con Felinos, jaguar conservationists work directly with local ranches, encouraging and rewarding coexistence with wildlife.   

Landowners participating in the program sign a contract agreeing to not hunt, poison, or otherwise harm wildlife on their land.  In return, they receive a cash reward for each photo of a jaguar, puma, bobcat, or ocelot on that property.  Jaguar photos earn the largest payouts.  Individual jaguars on the reserve can be identified through these photos by their spot patterns.  Sustainable land management practices, such as pasture rotation and keeping cattle away from riparian zones, also improved the jaguar's habitat.   

The initiative has been a success, with one rancher even stating that the cats on his ranch were more economically valuable than the cattle.  "[I am] going to buy more of those cats; they are worth more than cows," he said jokingly.  At least twelve ranches surrounding the Northern Jaguar Preserve participate in the program.  Thanks to this collaborative effort, the wild felines now enjoy an expanded area where they can roam free from persecution. 

Support the Northern Jaguar Project here.