Posts Tagged ‘mammals’

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A Furry Surprise

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Wednesday, February 15th, 2012

Adult Great Horned Owl, Southeastern © Rick and Nora Bowers/VIREO

When I saw the two ears just above the edge of a large nest forty feet up the cottonwood, I thought to myself “a Great Horned Owl is already on the nest in late January”. I gathered our birding group and set up the spotting scope and was surprised to see the “ears” were not the feathered ear tufts of a Great Horned Owl, but the furry ears of a Gray Fox high in the tree enjoying the winter sun. I had often seen foxes relaxing on low branches of willows and other small trees but this one won the prize for tree climbing.

The Gray fox (Urocyon cinereoargenteus), may be at the top of the tree because it is at the bottom of the canine food chain. A very atypical canid, Gray Foxes are adept climbers and may climb or roost in trees to escape coyotes. Many years ago, as a wildlife rehabilitator, I had the chance to raise both a young Gray Fox and a young Red Fox in North Central Texas. I would let them out in our large nature center auditorium to play and a rousing game of tag often ensued. The Gray Fox was no match for the long legged Red Fox in a straight race, but whenever the Red Fox got close the Gray would go arboreal across chairs and tables and outmaneuver his pursuer.

Gray Fox © Daniel J. Cox, Natural Exposures

Although the overall color is mostly gray, the rufous on the shoulders of Gray Foxes sometimes misleads people into calling them Red Foxes. Gray Foxes seem to be a charming mix of dog and cat. They only weigh about as much as a big house cat, 8-10 pounds, with short legs and a long snout. They make a variety of chirps, barks and yips that sound anything but doglike. Like a Coyote, they are efficient predators on mice, birds, lizards and large insects and will eat fruit in season. Their ability to climb, rare among canids, allows them to reach fruit high in the tree. Since they are mostly nocturnal, I don’t see them often. But now that I have a better search image, I’ll be checking all the old raven’s nests I see for those telltale ears.

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Posted in Tom Wood | 2 Comments »

Stop It – The Burmese Python – Part I

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Monday, February 13th, 2012

Everglades Guide Jason with a Burmese Python

We must do everything we can to rid the Everglades of all invasive plant and animal species. That’s a seemingly impossible task at this point for the supposed invasive species capitol of the world. We must also prevent the importation and introduction of any new species to protect the currently out of whack balance of South Florida’s ecosystem. Having said that, I am enraged by the ignorant media coverage regarding the “big snakes” in the Everglades. In December of 2011 an article titled “Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park” was published and the media-led hysteria that followed offered tabloid style headlines that fed into people’s natural fears.

“Pythons Rule Florida’s Everglades”
“Pythons and Anacondas Dominate Food Chain”
“Burmese Pythons Picking Florida’s Everglades Clean”
“Pythons have stranglehold on Everglades”

A local NBC anchor suggested without a trace of skepticism that the population of the invasive giants was well over 200,000. This is a stunning climb up the food chain from a few years ago when the estimate was 9,000, then 15,000, 30,000 and then inexplicably 150,000. Now 200,000 plus? Stop it.

Burmese Pythons (Python molurus bivittatus) are endangered in their native Southeast Asian range, thanks to poaching and exportation for the pet trade. People buy them as pets because they’re cuddly or they’re constricting. Sometimes it’s hard to tell the difference. They get to be big, growing to lengths over 20 feet. Eventually they’re the ideal pet they once were and owners dump them in the Everglades. Many were thought to have escaped into the swamp in 1992 when Hurricane Andrew devastated Homestead, Florida, home of many reptile breeders and importers.

Northern Raccoon

The scientific paper that has flamed the frenzy claimed that Northern Raccoons (Procyon lotor), Virginia Opossums (Didelphis virginiana) and bobcat sightings (both live and road kill) are down about 99% from a period of time that predated the python infestation. Now one of the co-authors is distancing himself from the suggestion that pythons are to blame. He says it’s possible, but he blames the media for drawing a correlation between the two.

Virginia Opossum with young © Jack Dermid

They did note that top predators like the Florida Panther (Puma concolor coryi) and Coyote (Canis latrans) (an Everglades new comer), populations had increased but did not suggest that they could be culprits in the population declines of prey species such as raccoons and opossums. Nor did they mention the severe drought the Everglades National Park has experienced and what effect that might have on the need for certain species to seek out better habitat.

Florida Panther © Brian Kenney

The analysis of the scientific paper was lacking and the media did not do their due diligence to understand the entire issue. The shocking headline was enough to craft an exciting tale of reptile Armageddon. I’ll explain more about the biology of the pythons, the threat they pose and what we need to do to stop it. Next week.

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Posted in Entries by Jungle Pete | 1 Comment »

Gray Wolf

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Thursday, February 9th, 2012

Gray Wolf by Lisa Densmore

Location: Yellowstone National Park

En route to Yellowstone National Park, my sweetheart received a text message from his 15-year-old son who was just leaving the park.

“Saw a wolf!” read the text message.

“Where?” we wrote back.

“Near the gate by Gardner,” came the reply.

An hour later, just after passing under the massive stone arch at the northwestern entrance to Yellowstone, we spied a canine animal stalking something in the snowy sagebrush, a coyote. As we watched the coyote pounce then swallow a dark vole, I realized the reported wolf was likely this coyote, a common misidentification.

Coyote

The Gray wolf (Canis lupus), also known as an Arctic wolf, Common wolf, Mexican wolf, Plains wolf, Timber wolf and Tundra wolf, is much bigger than a Coyote (Canis latrans). The average Coyote stands about 24 inches at the shoulder and weighs less than 50 pounds. The largest Coyote on record weighed less than 75 pounds. By comparison, the average Gray Wolf is 33 inches tall at the shoulder and weighs over 60 pounds. Alaskan and other far-northern wolves often weigh over 100 pounds. The heaviest Gray Wolf on record in North America tipped the scales at 175 pounds! Wolves also have larger, wider snouts, shorter ears, and a proportionately smaller head than coyotes.

Gray Wolf with young © Rita Summers

The next morning, we saw the wolf in the first photo trotting purposefully across a frozen hillside. Resembling a cross between a German shepherd and a Husky, its gray, cream and dark gold winter coat was so lush, I wanted to run my hand over it, but I wasn’t about to get out of the car to pet a wild wolf!

Wolves are apex predators. They are exceptionally strong for their size, able to turn over a dead moose. Their teeth can crush with double the strength of a German shepherd’s teeth. And they can run fast, over 35 miles per hour.
“I wish it were a black one,” said my partner. Wolf fur color can include every shade of white, cream, gray, brown and black. About half of the Yellowstone population is reportedly black. I didn’t care its color. I was happy for the chance to photograph one.

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Posted in Entries by Lisa Densmore | 3 Comments »

In the Year 2000 – The Osprey

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Monday, February 6th, 2012

Osprey by Jungle Pete

By the year 2000 Ospreys and Bald Eagles will be extinct.

That is what my 3rd grade teacher told me in 1978. Chemicals were killing the birds including Brown Pelicans, Cormorants and other fishing eating birds. The year 2000 was a long time away and seemingly in a galaxy far, far away and yet for my eight year old, Star Wars-obsessed brain, the notion of extinction was real and saddening to me.

Brown Pelican - adult, breeding, Eastern © Arthur Morris/VIREO

My teacher had oversimplified the problem but I wouldn’t understand that until years later. In fact the ban on harmful chemicals, such as DDT, years earlier had begun the reversal of misfortunate that many of these birds had endured. DDT, an effective chemical pesticide used in the control of malaria-spreading mosquitoes was considered to be the culprit in the decline of many fish-eating bird populations. The chemical bioaccumulates in fatty tissues of animals as it works its way from the base of the food chain, from plant, to invertebrate, to fish, to bird. When the female birds would lay eggs, the DDT inhibited calcium deposition in eggshells resulting in thin eggs that were often crushed by the incubating adults.

http://audubonguides.com/species/Birds/Osprey.html

After DDT was banned from use in the United States in 1972, the chemical slowly worked its way out of the environment, including wildlife and humans and the affected bird populations began to recover.

Twelve years after my teacher’s apocalyptic prophecy, the sight of an Osprey taking flight over a body of water in Florida is relatively common. I routinely have the opportunity to watch Ospreys swoop down over the water and with spiculed-talons, grab a fish to eat. The spicules are sharp spines that impale their prey and make it easier for them to catch slippery fish. Nests are conspicuous accumulations of hefty sticks in trees, on utility poles or on human-made Osprey nesting platforms.

The population rebound for many of the species affected by DDT and other chemicals is very encouraging. Yet I would say to the children of today, the health of our ecosystems is still in jeopardy and unless we fix drainage issues, stop nutrient overloads and prevent further habitat loss, species such as the Wood Stork, Roseate Spoonbill and Florida Panther will be extinct by 2030.

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The Comfort Zone

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Wednesday, February 1st, 2012

White-tailed Deer by Jack Ballard

The question comes from the back seat of the car, not a critical inquiry about my driving, but a query about a half-dozen white-tailed deer.

“Why are those deer all lying on that hump?”

I swivel my eyes to the side of the street and sure enough, a modest bevy of does and fawns are bedded on a mound of grass, a barren and windswept island in a sea of snow.

“They’re just trying to get comfortable.”

“It looks too cold out there to be comfortable.”

It is cold. But “comfort” is a relative word and animals seek it as much as humans. Compared to lying in the snow, the deer have found a fairly dry spot to nap that also absorbs solar radiation better than the white stuff. In fact, thinking about an animal’s comfort is often a good way to find them. On windy days, you’ll discover most mammals on the leeward side of slopes where they’re buffered from the breeze. Birds tend toward perching places in sheltered areas as well. When it’s really cold, animals prefer south-facing slopes that maximize their exposure to the sun. In a summer scorcher, they’re just like us, looking for a shady spot to nap.

White-tailed Deer © Mishakoe

As we motor by the napping whitetails, I can’t help but nudge the heat a bit higher in the car. There is one important difference between the comfort-seeking behavior of humans and whitetails: we can adjust the temperature, they can only adapt.

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A Bad Winter for Rodents

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Friday, January 27th, 2012
Great Gray Owl

Adult Great Gray Owl © Brian E. Small/VIREO

It’s been a very mild and almost snow-free winter in Manitoba so far this year. Good news for us. Bad news for mice and shrews and voles. They rely on a thick blanket of snow to survive the winter.

A couple of years ago as I watched a Great Grey Owl along a road in the boreal forest east of Winnipeg, it suddenly left its perch on a hydro pole, swooped over the road-edge, and plunged, talons-first, into the thick snow. It immediately extricated itself and flew back with a small, squirming rodent.

Wow! I wondered. How’d it do that? I knew that owls had great hearing. But the snow was at least a foot thick. That, it seemed to me, was like me hearing a pin drop a block from my house.

Meadow Vole © Rob & Ann Simpson

And what was a rodent doing in a snow-bank? I thought they hibernated all winter or found a warm place like my basement to hang out.

That’s when I first heard about pukak.

Pukak is that small space under the snow and above the ground that forms when the snow piles up more than a foot or so and when the earth’s warmth melts the bottom layer to form passageways for insects, rodents and tiny mammals.

Cinereous Shrew © Audubon Guides

Mice and shrews and voles use these passageways to seek out seeds and grasses and bugs left over from the summer and fall. At irregular intervals vents form to allow gasses to escape. Owls listen to the tiny noises that emanate from these vents.

House Mouse © Rita Summers

With barely three inches of snow on the ground this year, pukak hasn’t yet formed. That means the rodents can’t leave their winter hideouts. They don’t have to worry about owl attacks, but they are in danger of starving. The thicker the snow, the better their chances of surviving the cold.

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Posted in Entries by Gene Walz | 1 Comment »

Moving Snow

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Tuesday, January 24th, 2012

American Bison by Jack Ballard

With a large driveway to clear, I’ve joined the ranks of those indolent souls who have swapped a snow shovel for a snow blower. Well, most of the time. Occasionally, Old Man Winter blows the white stuff into drifts too deep and too hard for my small, single-stage snow blower.

When that happens, out comes the shovel. Moving snow by hand is tough work. When a packed clump breaks loose that fully fills my shovel, it takes a concerted effort to heave it from the driveway.

Humans aren’t the only creatures that need to shove snow around in the winter. Many animal species have their own needs and methods. Deer, elk and bighorn sheep paw away snow to uncover forage. But when it comes to snow removal, these creatures are to the animal world what little snow blowers are to human civilization. Down the street, my neighbor clears his driveway with a burly, two-stage snow blower that clears a three-foot path in a hurry. Out in the wild, his machine might be compared to an American Bison. Using their massive head, bison seem to effortlessly shove a couple feet of snow out of the way in a side-to-side motion. Anyone who has shoveled a driveway can appreciate the raw power it takes to move that much snow. Where does all that power come from? A bison’s hump is composed of muscle, attached to long vertebrae. This muscular mass is particularly adapted to forcefully moving the head from side to side, powering the bison’s winter snow removal. I don’t think I’d look too elegant with the hump, but I’d sure like to harness some of their power to my shovel.

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Bighorn Sheep

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Friday, January 20th, 2012
Bighorn Sheep

Bighorn Sheep by Lisa Densmore

Location: Rocky Mountains

Two days ago, as I turned the corner off Highway 191 onto the access road to the Big Sky Ski Resort in Montana, I saw a Big Horn sheep (Ovis canadensis) grazing placidly beside the road. I always look for Bighorns there, and feel cheated if they’ve meandered elsewhere when I come to Big Sky. There’s another dependable herd of them on a hillside west of Denver above Interstate 70. I’ve also photographed butting bighorns atop a 40-foot cliff in Custer State Park in South Dakota.

I’m fascinated by Bighorn Sheep, mainly because of their massive curled horns, the rings of which record their owner’s age. Male Bighorns, or rams, use their signature headgear to vie for dominance in the herd, rearing up on their hind legs and smacking an opponent’s horns with a resounding crash, over and over again, often for several hours. No headaches for the head butters though. Their thick bony skulls usually prevent all but the echo, although a broken horn, nose or more serious injuries sometimes occur if the butt isn’t a bulls-eye. Female Bighorns, called “ewes”, have horns too, but much smaller.

Bighorn Sheep Range Map

Bighorn Sheep Range Map © Audubon Guides

It’s uncanny how an animal weighing over 250 pounds can be so agile on rocky cliffs. A relative of the goat, their split, rough-bottomed hooves grip mountainous terrain with a tenacity greater than a rock climber’s sticky-soled shoes. The ewes give birth on remote ledges each spring to help prevent predation of their lambs by Wolves, Coyotes and Mountain Lions, though Golden Eagles have no problem swooping down for dinner.

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Posted in Entries by Lisa Densmore | No Comments »

Baby New Year – The Gray Squirrel

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Monday, January 2nd, 2012

Half of the Gray Squirrels (Sciurus carolinensis) alive today will not survive to 2013. This does not ease my mind regarding the predicament I find myself in on the day when a small, slightly-furred and sightless creature was found on a boardwalk deep in the heart of the Everglades. What to do?

The lifespan of a Gray Squirrel averages 11 to 12 months which means half of them can live longer and some as long as ten years of age in the wild. It also means that from birth through adolescence there are plenty of hardships that lead to their demise. Poor nut crops and cone production can lead to insufficient food supply, and diseases combine as the two greatest causes of Gray Squirrel mortality. Predators including hawks, bobcats, raccoons and the tree climbing snakes also reduce the population size.

In the cypress forests of the Western Everglades, Gray Squirrels are relatively abundant and more frequently seen than their larger and more colorful cousin, the Big Cypress Fox Squirrel (Sciurus niger avicinnia). Mating season begins earlier in the south with courtship involving routine male competition, chasing of the female and a one-minute mating affair that results in 2-6 pups being born 44-46 days later.

Doe squirrels will build a secluded nest in the cavity or fork of a tree but still must protect their young from nest predators and cannibalistic squirrels. Pups are blind and naked with only the vibrissae whiskers to help them locate their mother in the nest. Within a few weeks they begin to grow fur and by week four they can open their eyes.

After only a week they have doubled their size from half an ounce to an ounce and as the pups grow, space in the nest dwindles. Occasionally they are accidentally pushed from the nest or dropped by the mother while transporting them.

This pup was found in the middle of the Fakahatchee Strand State Park boardwalk. It was seemingly unharmed and breathing fine. My choice was to find a rehabilitator to care for it or delicately move it from harms way and leave it for mama to come and get it. Having seen a squirrel close by, I left the pup and wished it well in 2012, hoping to see it in 2013.

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The Mountain Cottontail

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Friday, December 30th, 2011

Mountain Cottontail by Lisa Densmore

Location: Red Lodge, Montana

Whenever my sweetheart slams on the brakes, I instinctively reach for my camera. A large animal or raptor deserving of a photo is often the reason for the sudden stop. The other day, as we drove through our neighborhood toward our house, my seatbelt suddenly tightened across my chest, but I couldn’t see any big beasts.

“Over by the red osier,” he said, pointing to a small clump of leafless reddish twigs that sprouted in a haphazard clump from the snow.

I peered intently at the clump catching a slight movement its base. A cute little mountain cottontail (Sylvilagus nuttallii) crouched quietly, twitching its nose now and again as it peered cautiously in my direction. Sometimes called “Nuttall’s cottontail”, mountain cottontails have rounded, black-tipped ears with fur inside, and tweedy brown fur. The underside of their tail is white. Mountain cottontails also have a distinctive light brown patch on the back of the head and neck, which, along with their smaller size, is a good way to tell them apart from snowshoe hares (Lepus americanus).

Mountain cottontails are a Rocky Mountain rabbit. Their range begins at the foothills on the eastern side of the Rockies and extends west to the eastern side of Sierra Nevadas. They mainly eat grasses which is probably why I often spot them munching contently near my house. I live near a golf course that used to be ranchland. There are still fields around the houses and fairways. The landscaping shrubs give these little bunnies cover from predators and provide another food source when the snow buries the grass. Cottontails spend over 50% of their waking hours eating!

Click. Click. This mountain cottontail was the perfect photo model, still as stone, though I’m sure he was hoping if he didn’t move we would miss him. Perhaps we would have if he were perched on a pile of sticks or beside a large rock, but not against the white snow. Unfortunately for him, he doesn’t turn white like his jack rabbit cousin.

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Posted in Entries by Lisa Densmore | 2 Comments »

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