Posts Tagged ‘Sandhill Crane’

Flying Filet Mignon

April 23, 2014

Cranes are North America’s tallest birds.  There are 2 species of cranes that live on this continent–the sandhill (Grus canadensis) and the rare whooping (Grus americana).  The former grows to as much as 4 feet tall, while the latter can grow a few inches taller than its cousin.

Four-Sandhill-Cranes

 

 

 

 

 

 

 

 

 

 

 

 

  

Top photo is of sandhill cranes; the bottom is of whooping cranes.

Cranes inhabit open environments such as savannahs, marshes, and agricultural fields where they can use their keen eyesight to detect and flee from potential threats.  They are omnivorous, feeding upon grains, underground tubers, small vertebrates, shellfish, and insects.  Oddly enough, they don’t usually eat fish.  They were notorious among pre-Civil War planters for digging up leftover sweet potatoes missed by slave harvesters.  Today, they still take advantage of inefficient machine harvesting and feed on leftover grain in farmer’s fields.

Some species of crane has lived in North America for at least 10 million years.  A species resembling the extant crowned crane of Africa lived in Nebraska during the Miocene.  Its fossils were among those found at the Ashfall Fossil Beds located in that state.  Sandhill crane fossils dating to the early Pleistocene (~2 million BP) have been excavated from the Leisey Shell Pits in Florida.  Both species of crane are well represented in Florida’s fossil record, and a crane specimen was also excavated from Bell Cave, Alabama.

Both sandhill and whooping cranes were abundant in southeastern North America when Europeans began colonizing the region.  John Lawson referred to them as “hoopers” because of the loud sound the whooping cranes make.  J.J. Audubon wrote their calls could be heard from 3 miles away, thanks to their 5 foot long vocal cords.  Audubon recounts an humorous experience he had when hunting a crane.  He was traveling on a boat down the Mississippi River when he spotted a flock of cranes.  He jumped off the boat and took a shooting position but was so anxious to show off his marksmanship that he made a bad shot and merely winged one while the rest flew away and escaped.  The injured bird couldn’t fly and Audubon began chasing it across the savannah.  He trapped it against a fallen long, but the bird spread out its wings and charged him.  Audubon, afraid of the long sharp bill, turned around and fled toward the boat with big bird in hot pursuit, a spectacle that caused his companions to laugh heartily.  One of his companions saved him by using a paddle to bludgeon the agressive bird to death.

Like all of North America’s most spectacular species, cranes were nearly overhunted into oblivion.  Hunters especially desire cranes because they are a delicacy known as “ribeye of the sky.”  I’ve never had the chance to eat crane, but I have tried ostrich and it tastes exactly like beef tenderloin, therefore I think “flying filet mignon” might be a more accurate nickname.  Reportedly, crane meat is lean but ribeye is a very fatty cut of steak. (If it was up to me,  all ribeye steaks would be ground into hamburger–that’s all this cut is good for.)

The good taste of crane meat almost doomed whooping cranes to extinction.  Whooping cranes completely disappeared from eastern North America–the last sighting of this species in Georgia was on St. Simon’s Island in 1885.  The entire population fell to just 15 birds, but with federal protection the western population has increased to 270 birds.  They summer in Wood Buffalo National Park Canada, and they winter in the Aransas National Wildlife Refuge, Texas.  An attempt to establish a second western population failed because the birds were hatched using sandhill cranes as surrogate parents.  The whooping cranes in this experimental population imprinted on sandhill cranes and wouldn’t mate with their own kind.  An attempt to re-establish an eastern population has been more successful.  There are now 104 whooping cranes that summer in Necedes National Wildlife Refuge, Wisconsin and winter in St. Marks NWR, Florida (which I visited last summer.  See: https://markgelbart.wordpress.com/2013/06/06/wakulla-springs-shellpoint-beach-and-the-st-marks-wildlife-refuge/).  Scientists used hand puppets resembling whooping cranes to rear the founders of this population, and they got them to imprint on fixed winged aircraft that led them on a migration to their winter habitat.  This population is currently unsustainable because a species of biting black fly is preventing the birds from having successful nesting.  Researchers hope to move the cranes to a different area of Wisconsin where this species of fly doesn’t live. 

Whooping cranes following fixed wing aircraft they imprinted on.

Sandhill cranes populations are in much better shape than those of their cousins, though they have been much reduced compared to their former abundance.  A year round population of sandhill cranes lives in south Georgia and Florida.  This population is augmented by winter migrants that spend summers in northern states and Canada.  Some nothern migrants also winter in Louisiana and Texas.  Last year, Tennessee opened a hunting season on sandhill cranes.  When I first heard about this, I thought it was a mistake, but I changed my mind.  An estimated population of 87,000 sandhill cranes migrate through Tennessee but the state only issued a total of 1200 permits, and to be eligible, hunters have to take a coarse proving they can tell the difference between a sandhill crane and the rare protected whooping crane.  I doubt such a conservative limit will put much of a dent in the population.  Moreover, sandhill cranes are difficult to approach and not every hunter is guaranteed to bag one. 

Andrew Zimmern and the hunters who bagged a sandhill crane for an episode of Bizarre Foods on The Travel Channel.

I like Andrew Zimmern, host of the Travel Channel’s Bizarre Foods.  However, I take issue with the excuse he used when justifying his hunt for sandhill cranes.  He joined some hunters in Tennessee in order to bag one for his show.  He claimed the birds ravaged farmer’s fields and drove away ducks and geese.  Supposedly, these factors were a sound reason for controlling their numbers.  This is pure bullshit.  Farmers have already harvested most of their crops by late fall–the time of year when cranes travel through Tennessee.  Ducks and geese co-existed with cranes for millions of years before man ever entered North America.  Hunting cranes is not a necessary policy for managing their numbers.  Why can’t Zimmern just be honest and admit he wants to kill the birds because they taste good?

Another pet peeve I have is hunters who claim they are “harvesting” an animal.  Harvest means picking an apple or an ear of corn.  Using the word “harvesting” as an euphemism for killing is just dishonest.  To “harvest” an animal usually means shooting it, and I’m pretty sure the animal feels lots of pain when the bullet or shotgun pellets are tearing through their nerves.  I’m not against hunting for food.  I enjoy the flavor of wild game meat and would eat nothing but this healthy alternative, if I had the opportunity.  Why can’t people just be honest about it?  Hunting is killing…not “harvesting.”

Fire Suppression = A Decline in Biodiversity (Part 2–The Animals of Longleaf Pine Savannahs)

June 29, 2011

Fox Squirrels come in several color phases–orange, black, and gray.  Some have white or gray masks as well.

Fox Squirrel–Sciurus niger

I love these big colorful squirrels.  I lived in Niles, Ohio until 1975, and our home was bordered by oak woods on 2 sides.  Big orange fox squirrels were the playful denizens there.  But since I’ve lived in Georgia, I’ve only seen one–a black masked fox squirrel foraging with a group of gray squirrels (Sciurus carolinensis) in a pecan orchard in Burke County.

This range map is bullshit.  No statewide survey of fox squirrels has been done in at least 50 years, if ever.  It’s likely an accurate range map would show a much patchier distribution.

Southern fox squirrels differ in their habitat requirements from northern fox squirrels, despite being the same species.  The former prefer mature longleaf pine savannahs with fingers of oak forests, while the latter thrive in oak/hickory woods.  Fox squirrels are declining in Georgia because longleaf pine savannahs were largely replaced with shorter rotation loblolly pine tree farms.  Lumber companies harvest loblolly pines every 50 years which is not enough time for trees to develop snags.  The Trees are also planted closely and fire is suppressed.  Gray squirrels are more abundant today in state because they’re well adapted to the dense young forests that have sprouted on abandoned agricultural lands.  Gray squirrels escape predation by jumping from tree top to tree top, while fox squirrels prefer to dash on the ground as far as they can before retreating to a tree.  Though clumsy in trees compared to their smaller cousins, their larger size allows them to put up more of a fight, if a predator catches up to them.  This difference in behavior explains why gray squirrels occur in closed canopy forests, and fox squirrels prefer open parkland forests.  For this reason I think fox squirrels were more abundant in this region during the Pleistocene when open environments were common.  Areas managed for red-cockaded woodpeckers should benefit fox squirrels.  Forest managers used longer rotations and fire to maintain the bird’s required habitat.

Red Cockaded Woodpecker–(Picoides borealis)

Photo of a red cockaded woodpecker from google images.  All the photos in this entry are borrowed from there.

Thirty years ago, this bird was on the verge of extinction, despite having formerly been common throughout the south.  Fire suppression and short forest management rotation nearly caused the death of this species.  Young pine trees never develop the soft rot that red cockaded woodpeckers need for boring nesting cavities.  As a defense mechanism, red cockaded woodpeckers constantly peck wells below their nesting cavities from which pine sap continously flows.  The pine resin repels rat snakes–their number one predator.  For this defense mechanism to work, live trees are a must.  And without fire hardwood understory reaches the level of the nesting cavity allowing flying squirrels, and other predators easy access.  Flying squirrels will decimate red cockaded woodpecker nests.

In a successful effort to save the birds, scientists identified habitat requirements and some suitable land was set aside and managed using prescribed burns and longer tree harvest rotations.  Birds were relocated to the best habitat, artificial nesting boxes were installed to supplement the shortage of good nesting trees, and flying squirrel exclusion devices were used.  In many protected areas red cockaded woodpecker family groups (family groups consist of 2-10 individuals) have increased dramatically to the point where it’s no longer necessary to provide artificial nests or to protect them from flying squirrels.  At SRS for example the population grew from 1 family group in 1987 to 30 by 2003.

Sandhill Crane–(Grus canadensis)

These impressive birds grow to 5 feet tall.  They prefer to nest in grassy marshes adjacent to prairies or savannahs.  The real life version of Sesame Street’s Big Bird used to be common, but since grasslands and wetlands have declined so have the birds.  Georgia’s population includes a permanent one consisting of small family groups, and large congregations of winter migrants.  They’re omnivorous feeding on insects, crayfish, mice, snakes, frogs, worms, acorns, fruit, roots, and farmer’s crops.

Bachman’s Sparrow–(Peucaea aestivalis)

Another inhabitant of open pine savannahs that is declining in abundance.  I heard this bird’s song on a youtube video and recognized it as one I’ve heard.  Evidentally, the sparrow still occurs in Augusta.

Indigo Snake–(Drymarchon corais)

This snake grows to 9 feet long, making it the longest serpent in North America.  They’re rare because their habitat has been fragmented, and they need large ranges.  They hunt during the day and retreat into gopher tortoise burrows at night.  A wide variety of prey is taken–other snakes including venemous ones, small mammals, birds, frogs, and fish.  Indigo snakes don’t kill by constriction or envenomation, but instead bite the head of their prey and thrash, breaking the spines of the small creatures.  Their metabolism is faster then that of most other snakes.

Gopher Tortoise–(Gopherus polyphenus)

 

Gopher tortoises depend on a frequent fire regime to spark the growth of the kinds of plant they eat.  They also like sandy soil that makes it easy for them to dig their elaborate tunnel systems.  They’re a keystone species–over 60 vertebrates and invertebrates depend on their burrows for shelter.  (See also my article–“The Giant Extinct Tortoise, Hesperotestudo crassicutata, must have been able to survive light frosts” from my April or March archives)

Popular game animals such as white tail deer, turkey, and quail thrive in longleaf pine savannahs.  Savannahs were a favored habitat of many extinct Pleistocene species as well including mammoth, long horned bison, horses, llamas, Harlan’s ground sloth, hog nosed skunks, giant tortoises, and others.