Wednesday, August 9, 2017

An Eagle Against the Odds

By Sheena Patel
Wildlife Rehabilitator

Here's a remarkable story about a Bald Eagle on its last breath who, against all odds, was able to be nursed back to health and rejoin the wild:

On February 20th, the Vermont Institute of Natural Sciences (VINS) Center for Wild Bird Rehabilitation received a call about a Bald Eagle found lying face down in a slurry of ice on a snowmobile trail in Brattleboro, Vermont. The concerned caller had stumbled upon an eagle surrounded by piles of its last meal, which were regurgitated all around its face. Initially believing it to be deceased, the caller was awestruck after seeing the eagle take a small breathe. The local game wardens carefully brought the eagle to VINS' rehabilitation center, where it was put into the ICU and given an enclosure with a heating pad to try and warm it up. Throughout the day, the eagle continued to regurgitate food, indicating it may have ingested something poisonous or toxic. The treatment plan for the eagle was to administer IV fluids in an effort to flush out whatever harmful substances were in its body. 

Upon entering the exam room, the staff noticed that the eagle was banded with the United States Geological Society (USGS). After looking up the band information, the eagle was determined to be a female from Canada banded by biologist Dr. Guy Fitzgerald on November 21st, 2013, the year it was hatched. This remarkable information came as a great surprise to many of the staff in the rehab department, because often times it is impossible to tell the sex of an adult bird, let alone know the year it was born or where it originally came from. Upon ICU intake, she was too weak to stand and could only lie face down in her enclosure with her eyes closed. She continued to regurgitate her last meal while rehab staff looked on unable to aid her any further - all desperately hoping that she’d make it through the night. When the staff arrived the next morning, they immediately checked on her and discovered she was no longer lying face down on the ground, but standing up on her own power. Although she still lacked the strength to perch, her small triumph was a glimmer of hope for everyone that had seen her in her previous state. She continued receiving IV fluids and soon after began a liquid supplemental diet in addition to the fluids. 

Over the next few weeks she slowly gained the strength and energy to begin perching a few feet off of the ground in her ICU enclosure. She was also transitioned off of her liquid diet to one of solid food. This meant being force fed rat and fish as opposed to the liquid feeding tube she had previously received her nutrients from. The force feeding soon turned into hand feeding and she eventually was able to move out of the ICU and into an outdoor enclosure where she quickly began to eat on her own. After continuing to do well in her outdoor enclosure, she was finally moved to our largest enclosure, the flight cage, in which she had space to fly back and forth for longer flights and perch high up in the air. Once she completed flight physical therapy, which involved encouraging her to fly and bank around corners, she eventually regained the muscle strength she would need to be released back out into the wild. 

On May 10th, the eagle was released back into the wild in Windsor, VT where she took flight and eventually caught a great thermal pocket of air that gave her plenty of lift and she continued to ascend high into the sky. She was even greeted by a wild Bald Eagle that soon joined her and flew beside her!

Her rehab story is remarkable, not only because VINS doesn't often get calls about Bald Eagles needing medical attention, but also because she was banded which provided us with a wealth of information on her. When reaching out to bander, Dr. Guy Fitzgerald, to let him know about her story and her release, he explained that back in 2013 the eagle had been found in a slurry pit after having inhaled a lot of fumes. Concerned for her safety and well being, she had x-rays and an endoscopy exam which confirmed that she was indeed a female. After clearing her of any overall health issues or internal damage to her respiratory system she was returned back to the wild by a volunteer and over the years must have made her way down to Vermont. We can now proudly and successfully say that she is back out in the wild where she belongs - thanks to the help of all staff, supporters, and volunteers who made her recovery possible.

Monday, July 24, 2017

A Change of Feathers: The Molt

By Anna Autilio
Lead Environmental Educator

Feathers are one of the defining characteristics of birds. They produce the brilliant red of the Northern Cardinal, and the shocking blue of an Indigo Bunting. Though one purpose of feathers is to be flashy and attractive, especially to a potential mate, feathers have a host of other functions. From helping a bird keep warm, to protecting it from UV rays, to masking the sounds of flight, to the act of flying itself, feathers allow birds to survive in nearly every ecosystem on Earth. And yet, they are not permanent fixtures on a bird’s body.

Northfield, the Broad-winged Hawk, growing in some new tail feathers.
Contrast the 2 white-striped on the right with the duller brown on the left.
The process of losing and replacing feathers is called the molt, and it is a uniquely bird event. Though snakes shed their skin, dogs their fur, and insects their exoskeletons, a bird’s molt is timed, ordered, and an astounding physiological process.

The function of the molt is to replace last year’s feathers that have been damaged by wear and exposure, to ensure the thermoregulatory and aerodynamic properties remain reliable. In North America, most birds go through a molt of all of their flight and body feathers each summer, a process that can take weeks or months. Most wouldn’t want to drop all of their feathers at once, then spend a week grounded while regrowing them all! Instead, the pattern of molting in each species is unique, but ordered. Some, like the hawks, lose their innermost primary flight feather first, and proceed outward. Some start in the middle and proceed in both directions, like the falcons. Some owls molt synchronously, losing all the feathers on their tails in the space of a few days, but it does not appear to impede their mobility.

Molting body feathers: the reddish bars on Northfield's flanks are replacing
the brown, tear-drop splotches.
Our ambassador Broad-winged Hawk, Northfield, is an excellent molting educator, and this summer is helping visitors visualize the molt in action. As a second-year bird, Northfield came to VINS in June 2016, still with a coat of down. By late August he had grown in the full set of feathers that was his “juvenal plumage”, characterized by mottled brown on his back and wings, a brownish tail with multiple thin stripes, and most noticeable of all, heart-shaped brown splotches on his flanks and legs. This summer, Northfield is undergoing what ornithologists call the “prebasic molt” into his adult or “basic plumage”. His brown mottling is becoming darker and more reddish as new body feathers grow in. His tail feathers are being replaced by wide, starkly black-and-white stripes, and sadly, his "heart-pants" are giving way to russet horizontal bars on his chest.

Broad-winged Hawks are long-distance migratory birds, and so Northfield's wild counterparts often have trouble fitting the entire molt in before September, when they must soar down the Appalachians to Central America. As such, some Broad-wings suspend the molt mid-summer, and finish it on their wintering grounds. 

Molting birds can be hard for the casual observer to identify--a strange mix of two radically different birds in one—but understanding molting patterns can help scientists learn much about a particular bird’s age and lifestyle. Within each feather is the story of when and where it was grown.

What should you do if you find a molted feather? Enjoy looking at it, then leave it be.