Wednesday, December 17, 2014

Avian Senses Part One - Vision


Eyesight in birds is the most developed of all their senses. 

Some species have the ability to capture an entire scene in one look as opposed to putting it together one section at a time as we humans must.  This is called wide-angle vision. 

Notice the placement of the eyes on the far side of the head on this Northern Mockingbird (photo: Gay Schroer)

The eyes of birds vary in shape and can be flat, round or tubular, unlike human eyes, which are uniformly round. The avian eyes fill the orbit completely and are in most cases placed on the sides of the head (usually seen in birds that can be a prey species).  Because of this, these birds see better to the side.  This is the reason that, upon observation, you see birds rapidly bob or turn their head from side to side when looking at an object.  Bobbing the head allows them to compensate by seeing objects from two different angles.  Depth perception should seemingly be limited due to this monocular vision, but since birds move so much faster than most of earth’s animals, they must have excellent depth perception to land smoothly on any perch, avoid obstacles, and catch the items they eat. 
The Eurasian Eagle Owls uses its forward facing eyes to zero in on prey (photo: Gay Schroer)

Not all birds see in a monocular fashion, though.  Some birds use monocular vision for near nearsightedness and forward binocular viewing for farsightedness.  The forward facing alignment of the eyes is common to most predators, especially the owls.

Conversely, humans have strictly binocular vision.  Because our eyes face forward, we are able to use them together to focus on objects. 

The sclerotic ring is made up of small bones that are called ossicles.  There are two banded muscles called Crampton's and Brucke's, that are attached to the ossicles and are used for focusing. The sclerotic ring is what forces the lens into positions that allow for very fast and precise visual acuity, whether the subject is near or far.  Birds have voluntary, or manual control over the rings, just as we can move our fingers and toes when we think about it.

Diagram of the avian eye (photo: wikipedia files)

 The Crampton's muscle adjusts the curvature of the lens and thus controls the way the light bends as it enters the eye. 
 
The Brucke's muscle controls the shape of the lens.  This process is similar to using a pair of binoculars.  Think of looking through the lens and the image being blurred.  As you turn the focusing mechanism, the image becomes either clearer or more blurred.

Cones and rods (named from their actual shapes) are types of photoreceptors, located on the retina at the back of the eye, that allow animals to see light and color. Rods are sensitive to light, but they only create coarse gray images.  Cones are sensitive to color and allow for detail.  The large number of cones in the avian eye enables birds to form very sharp images.

The next time you visit the World Bird Sanctuary be sure to pay special attention to the differences between the eyes of the birds that visit our feeders (prey birds) and the raptors (birds of prey…predators) in our exhibits.

More to come on the topic of avian vision next month.

Submitted by Leigh French, World Bird Sanctuary Naturalist

Monday, December 15, 2014

Owl


World Bird Sanctuary is proud to present another poem by guest author Marge Biermann posing the question "How did the owl get his hoot?"
Wild Barred Owl (photo: Cathy Spahn)
OWL

I didn’t hear my friend, Owl, last night,
Guess he found another tree in which to light.

So many to choose from during his nocturnal cruise,
While other birds are snuggled in their nests having a snooze.

He “Hoots” to the moon and every small star.
His penetrating call is heard near and far….

A solitary voice in the silent night so dark,
I often wonder where he perched on Noah’s Ark.

On the railing, perhaps, overlooking waters deep,
While all the others settled in to find some sleep?

Did he gain his wisdom watching waves lap against the boat….
Is that when the “Hoot” was formed in his throat?

Was it a haunting lullaby Creator used to send his peace,
Assuring his creatures all would pass, the rains would cease?

Maybe Owl is wiser than most….so stoic and calm,
Because long, long ago his voice served as a balm.

To bring serenity and peace to Creator’s traveling ark,
Until it was time for all to disembark.

For a “Job well done” Creator gave Owl his “Hoot”,
Because with his body it just seemed to suit.

And for his patience displayed sitting on that Ark’s rail,
Creator gave him wisdom from his head to his tail!

Submitted by World Bird Sanctuary Guest Author Marge Biermann

Saturday, December 13, 2014

The Crow is Afoot!


Following is a blog post submitted by World Bird Sanctuary Naturalist/Trainer, Leah Tyndall while she and the birds were performing in a Wild West show in Silver Dollar City in October.

As I sit here in Branson, I am both excited and sad.

I’m excited because for September and October 2014 I am part of an incredible Wild West show at Silver Dollar City, surrounded by amazingly talented people and working with an awesome Bald Eagle named Beauford.  WBS was hired to fly Beauford for this show.  I am sad however because I miss the other birds that I usually work with during this time, especially one little guy in particular; a three month old African Pied Crow named Sherlock.
Sherlock, fresh out of his shipping crate (photo: Leah Tyndall)

Sherlock came to us from a breeder in Arkansas and instead of going to World Bird Sanctuary headquarters in Valley Park, he came straight to me at WBS’s Milwaukee County Zoo bird show so that the bird show staff and I could get him used to life as a zoo show bird as soon as possible.

Sherlock’s trip from Arkansas to Wisconsin was not an easy one. The plane he was supposed to travel on needed mechanical repairs and he missed his connecting flight, so he had to take a later one.  After picking him up from the airport a little after nine pm, I took him to the zoo.  I peeked carefully into the crate to check on him and was met by an adorable blue eye followed immediately by a begging call--someone was hungry! I gave him some soaked dog food and tucked him in for the night, making sure to arrive early the next day.

Since Sherlock was hand raised he is very social and loves being around humans.  He stepped right to my hand and after a few tries, treats and some creative body blocking I was able to weigh him. 
Sherlock proved to be a very quick learner (photo: Leah Tyndall)

From that first day Sherlock (named because he figures things out so quickly) excelled at all training.  Stepping to the hand led to flying to the arm on command, perching on command, waiting on a perch (his least favorite behavior), sitting nicely on the scale (which became challenging in its own right since he always wants to sit on the scale, even before you put it down), object retrieval, object placing and of course, crating.

Crate training the little crow was tricky, not because he was afraid of the crate, but because he apparently wants to limbo. When I first started crate training, I had a perch in the crate to help him stay balanced and protect his tail.  In Sherlock’s mind I must have meant this perch to be a limbo pole, because every time I put food in the back of the crate, he went under the perch, which was only a few inches above the floor of the crate.  I had to remove the perch so that he could physically get all of the way into the crate to get his reward. 

Once the perch was gone he started running into the crate all the time, and that was when he made the grand discovery that the carpet on the crate floor could move if he pulled on it.  Being an insanely curious young crow he spent several sessions tugging on the carpet, until he realized tugging carpets did not get him treats, and even worse it meant no object retrieval, his favorite behavior.  He also enjoyed playing tug of war with my Kalem glove tassel and sticking his whole head in my glove when it was clipped to my belt.
Sherlock's first "selfie" (photo: Sherlock the Pied Crow)

Being such a clever and social bird, he discovered that leaping onto the trainer’s shoulder or head prevented the human from leaving and this quickly became his favorite game. We discovered socializing with him in a non-training situation and rewarding him for waiting while we exited curbed this behavior. It also led to hilarious moments such as Sherlock texting (“4”) and taking a selfie while I was trying to get his picture.

Sherlock is a clever, young, social crow able to learn at an incredible rate.  Crows, as a species, are extremely intelligent and staying one step ahead of them can be a real challenge for any trainer.

Even while I am typing this he is continuing his donation box training. Soon he will take dollar bills and place them into a donation box to help our animals and the World Bird Sanctuary’s conservation efforts.  Soon…but for now he believes his task is to twist them or shove them back into my hand.  However, I have no doubt that this extremely intelligent young crow will quickly learn the desired behavior.  Can’t wait to get back to WBS HQ to continue his training! 

Be sure to keep an eye out for Sherlock--coming soon to a bird show near you.  He will be the one accepting your donation dollars at the end of the show.

Submitted by Leah Tyndall, World Bird Sanctuary Naturalist/Trainer

Thursday, December 11, 2014

Tawny Eagles


Tawny Eagles derive their name from the color of their feathers, a subtle rusty brown. 
Juvenile Tawny Eagle (photo: the wikipedia files)

They can be found in eastern and southern Africa but also in southern Asia.  They are scavengers, mostly eating things that are already dead.  However, they have been seen catching prey up to the size of large rabbits.  They also often steal food from other birds, such as storks and hornbills. 
Tawny Eagle feeding on roadkill (photo: the wikipedia files)

Tawny Eagles are smaller than most old-world vulture species, and eat the same food.  Often times the vultures will find carrion first.  Tawny Eagles will wait for the vultures to eat, and then drive them away by repeatedly flying and “barking” at them (their call does sound like a dog barking).  Once the vultures are scared, they will vomit to be light enough to fly away.  Tawny Eagles then use this opportunity to devour the vomit as a warm “fresh” meal. 

During the dry season in Africa they build very large flat nests for raising their young.  This nest will be used for many years.  They usually lay two eggs, which take a little over a month to hatch.  Usually only one of the chicks survives. 

In the wild, a Tawny Eagle will live for upwards of sixteen years.  In captivity we can usually about double their lifespan. 
Diablo - Watch for him in Milwaukee next summer (photo: Gay Schroer)

Max and Diablo, the two Tawny Eagles here at the World Bird Sanctuary, were raised in captivity for educational purposes.  You can usually find Max in the weathering area behind the visitors’ center if he is not traveling to one of out outreach programs in the area.  Diablo can be seen at the Milwaukee County Zoo during the summers flying in our Bird of Prey shows.

In the wild Tawny Eagles are a common sight, and are listed as a species of Least Concern on the IUCN (International Union for Conservation of Nature) Red List. At this time the species seems to be doing well and there are no specific conservation efforts for them.
Max is one of the most photogenic birds at WBS (photo: Gay Schroer)

The next time you visit the World Bird Sanctuary look for Max in the weathering area.  You may get lucky enough to see him playing with his tennis balls or hear him barking at someone or something he perceives to be a threat within his territorial boundaries. 

And don’t let the plain brown feathers fool you…Tawny Eagles are one of the most photogenic birds at WBS.  Be sure to bring your cameras. 

As with all our animals, Max and Diablo are available for adoption as part of our Adopt A Bird Program.

Submitted by Mike Cerutti, World Bird Sanctuary Naturalist/Trainer

Tuesday, December 9, 2014

Feed The Birds


Winter is upon us, and many species of birds have gone south for the winter months.
A Nuthatch just inches away from a kitchen window (photo: Gay Schroer)

Your backyard will not be devoid of birds, though. There are quite a few species of birds that spend the winter in the area, as well as northern migrants passing through, but surviving freezing temperatures requires a reliable, high energy food source. For those of you with bird feeders, here are some tips for feeding your backyard birds during the winter.

Birds have a higher metabolic rate than mammals.  To maintain this rate birds need to eat foods that are high in calories and fat. Three simple high calorie/high fat foods are perfect for feeding songbirds during the winter: oil sunflower seeds, suet, and peanuts. As the name suggests, oil sunflower seeds have a higher oil content than other sunflower seeds, giving them higher fat and protein amounts, and double the calories of other types of seeds. Furthermore, oil sunflower seeds are easier for the birds to eat because of the thinner, smaller shells.
A Catbird enjoying some suet (photo: Gay Schroer)

Suet is another popular winter bird food. Made largely of animal fat, suet is not often used in summer because it can melt in warmer temperatures and can become rancid, but this extremely fatty, high-energy food is perfect for the winter months. Many kinds of suet have other foods mixed into the fat, such as fruit, nuts, or birdseed. Since the ingredients are very simple, it is possible to make and mold your own suet if you do not wish to purchase it.
A Bluejay feeding on squirrel-proof hot pepper suet (photo: Gay Schroer)

Peanuts can also be mixed into suet, but are nutritious enough to be fed to birds as is. Whether shelled or whole, peanuts are a high protein, high fat food that will not freeze. Their large size, however, can make peanuts difficult for some of the smaller backyard birds to eat. To help them out, you can chop the peanuts up into smaller pieces. If you don’t have any peanuts, smearing dabs of peanut butter in a small dish or on the bark of a tree will work just as well. The drawback with peanuts is that they also attract squirrels. If you’d rather save the peanuts just for the birds, you might have to consider looking into squirrel-proofing your bird feeder, or purchasing a separate squirrel feeder.
Carolina Wrens feasting on tree nuts (photo: Gay Schroer)

Another food that has appeared on the market lately is marketed as tree nuts.  This is a mixture of various types of nuts, such as peanuts, cashews, walnuts, pecans, Brazil nuts and almonds.  The almonds do not seem to be particularly attractive to the birds, as they leave these until the very last.  This nut mixture is very popular with the Woodpeckers, Chickadees, Titmice, and many other backyard birds—as well as the squirrels.  These can be fed in peanut feeders and should be hung out of the reach of the squirrels.  They are a perfect food to be hung under the eaves of your house directly in front of your window for a really close-up view of birds which are normally only viewed from a distance. 
Even the Mockingbirds love the tree nuts (photo: Gay Schroer)

Other than food, you can help out your backyard birds in the winter by providing open water. Most birdbaths freeze over in the winter, but there are heating elements and heated birdbaths to prevent the water from freezing over.

Even though the summer months have come to an end, there is still plenty of bird watching to be done!  Place a few of these nutritious foods in your backyard, sit back with a steaming mug of hot chocolate, and enjoy the show

Submitted by JoHanna Burton, World Bird Sanctuary Naturalist

Sunday, December 7, 2014

Eagle Team Visits Boston College


 There are a lot of great things about working at World Bird Sanctuary.  However, without a doubt, one of my favorite things about working there is when I get to handle our national symbol, the Bald Eagle.


Recently I had the honor to travel to Boston College with one of our Bald Eagles.  Their team name is the Eagles, so it made a lot of sense to be there with one.  I went during a home football game.  The eagle and I attended a pre-game activity.
Beauford, one of our free flying Bald Eagles (photo: Erika Fenske)

For three wonderful hours I got to talk to amazing fans about our national symbol.  I am always captivated when listening to people tell stories of when they have seen Bald Eagles in the wild, whether it is sitting in a tree, flying overhead, or even fishing in a lake or river.  There is absolutely nothing more emotional or moving than when someone talks to me about how when they were younger they remember that our national symbol was so rare.   
Beauford enjoying some time in the sun between performances (photo: Mike Cerutti)

The Bald Eagle became endangered due to overuse of pesticides, but now it can be a common sight in so many places in the United States.  You see, when DDT and other pesticides were introduced to kill mosquitoes it made its way into the rest of the environment as well, and eventually made its way into the fish.  When Bald Eagles ate those fish, the pesticides gave them a calcium deficiency.  That deficiency caused their eggshells to be so thin and brittle that they would break as the mom and dad eagles tried to incubate their eggs.  This meant that there were not many new baby Bald Eagles to replace the older ones when they passed away.  Eventually this caused Bald Eagle numbers to plummet, and in 1963 there were only 487 nesting pairs of Bald Eagles in our lower 48 states.

Thankfully DDT and other pesticides have been banned, and because of breed and release programs (including those done at World Bird Sanctuary), Bald Eagles have made a monumental comeback.  According to the U.S. Fish and Wildlife Service, there are now about 20,000 nesting pairs in the lower 48 states.
Lena, a young Bald Eagle in training (photo: Leah Tyndall)

Young and old alike should all be thankful for the recovery of this great nation's national symbol.  If you would like to see a bald eagle up close or learn more about them, please come see them at World Bird Sanctuary, free to the public and open every day of the year except Thanksgiving and Christmas (barring closures for inclement weather).

Submitted by Mike Cerutti, World Bird Sanctuary Naturalist/Trainer

Friday, December 5, 2014

The Pileated Woodpecker


The Pileated Woodpecker is by far my favorite of the woodpeckers. 

A Pileated Woodpecker at a suet feeder (photo: Gay Schroer)

It is a large bird, about the size of an American Crow, with a large red head crest, a long neck and the black and white body that characterizes the woodpeckers.  There is no doubt when identifying this beautiful bird.  The most wondrous characteristic of this bird is its high, clear series of piping vocalizations that lasts several seconds.  For me, it can be easy to confuse the Pileated Woodpecker vocalization  with the Northern Flicker’s loud, rolling rattle that rises and falls in volume.

Pileated Woodpeckers are common year round in the extreme northwestern United States, all lands east of Texas, and across Canada where there are trees big enough for Pileateds to drill a nest cavity.  They are forest birds that can be found foraging primarily for carpenter ants, as well as other insects and a great deal of fruits and nuts, in standing dead trees and downed wood.  They live in mature deciduous or mixed deciduous-coniferous forests.  In the west, they are often found in old growth forests, where in the east they are found in young forests as well as partially wooded suburbs.
A Pileated Woodpecker at another type of suet feeder (photo: Gay Schroer)

This species is monogamous and a pair will defend its territory against other Pileateds all year round, but it will allow some trespassers during the winter non-breeding months.  When an individual dies, the other will go in search of a new mate. 

During nesting season the males will excavate a nest cavity, but the female will assist in lining the nest with woodchips.  This process takes approximately 3-6 weeks.  Nest entrances are not circular like other woodpecker holes; rather they are oblong.  Clutch size ranges from 3-5 eggs,.which take 15-18 days to incubate.  The chicks take approximately a month to fledge, or fly from the nest.  Nests are rarely used again after the breeding season, but other birds and mammals will often use them.

Dead trees are an excellent source of food and shelter; therefore, there is a great deal of competition for territory with other animals.  Not only do other woodpeckers feed on insects from dead trees, but these nesting sites are highly prized.  Wood Ducks, European Starlings, Eastern Bluebirds, and Great Crested Flycatchers will compete for nest sites and, at times, a Pileated Woodpecker will be found sharing a nest with bats or swifts.

The next time you visit the World Bird Sanctuary keep your eyes and ears open for the sight or sound of the Pileated Woodpeckers that inhabit our woods.

Submitted by Leigh French, World Bird Sanctuary Naturalist/Trainer   

Wednesday, December 3, 2014

Birdlore: Northern Cardinal The Romantic Bird


Imagine you are in a blustery, white, clearing, the sun glaring balefully down on you and the surrounding snow reflecting the intensity of the harsh light into your squinching eyes. 

You wonder what life could possibly exist in such a cold, dreary and disheartening place as you trudge through the knee deep hardened snow.  You continue to glance about, shading your straining eyes from the bright light with a hand, when what to your wandering eyes should appear...a dart of red bobbing across your path, a Northern Cardinal!

In some Native American cultures, the sighting of a Cardinal is considered a good omen.  The Cardinal is a symbol of relationships, courtships, and faithfulness to one’s partner.  For a Cardinal to cross your path may be a sign that a romantic relationship is going to start soon or the renewing of an already existing relationship.

This traditional belief lends from the Cardinal’s monogamy and courtship behaviors in the wild.  A male Cardinal will mainly seek out a single female and attract her attention with his bright, vibrant, red plumage.  He will sing to her with a musical whistle-like call, “cheer cheer cheer” and bond to his prospective mate with courtship feeding.
The male cardinal shares seed with the female in order to bond with his prospective mate.
Cardinals are dedicated to protecting their mates and territories from other Cardinals with incredible ferocity.  It is not unheard of to see a male cardinal try to fight off his own reflection in windows or mirrors!  (I’ve often seen male cardinals perch on my work truck raising a fuss, simply because the truck was the same bright red as the bird himself!)

One Choctaw tale tells us how a Cardinal plays the role of matchmaker during his vast travels.  Cardinal finds a lonely and virtuous maiden.  Later, he also encounters a lonely Indian warrior.  Befriending the Indian brave, the Cardinal lures the warrior to the home of the maiden.  Uniting the pair, they find, at last, friendship and a lasting relationship.

So, if you ever find yourself outside and alone, and you hear a Cardinal singing his song of ‘cheer’, just image that he is singing it to you, his beloved.

The next time you visit the World Bird Sanctuary find time to rest on one of the benches near the feeders.  Chances are very good you may spot one of these beautiful birds.

Submitted by Jessica Bunke, World Bird Sanctuary Naturalist/Trainer

Monday, December 1, 2014

365 Photo Project-October 2014


October at the World Bird Sanctuary has been a very busy month.  With special events and a busy travel schedule I have not had that many photo opportunities. 

I did however take one morning in between storms to take a leisurely walk on WBS property.  As staff, sometimes we get so focused on the area where we work (such as the Nature Center) that we do not stop and look at the other amazing birds we work with on a daily basis, at least from a photographer’s perspective.  I have to admit it is a very challenging process to pick just a few photos to feature here.
Sole, the Peregrine Falcon (photo: Cathy Spahn)

My first favorite photo is of one of the newest birds on our education team; Solo, the Peregrine Falcon.  Solo is a juvenile Peregrine Falcon whose egg was laid in a nest in Clayton, Missouri.  Before the eggs were hatched the female falcon suffered a severe wing injury and did not survive.  WBS rescued the three eggs and hatched all three in our incubators.  One baby did not survive; one was placed in the nest of another wild falcon pair and was fostered by them.   Unfortunately, Solo was hatched with a few deformities that do not allow him to use his feet properly and his beak is slightly askew; therefore, he has difficulties tearing food.  Because he could not be released he will spend his life as an education bird.  He is a great bird and can teach everyone so much.  On this particular morning when Solo was put outside in the Weathering Area at the Nature Center, he started flapping his wings, and I took the opportunity to get some photos.  I managed to take this photo of him with his wings out.  This photo was my favorite from my morning walk.
Rochester, the Common Buzzard (photo: Cathy Spahn)

The next photo I took a few minutes after photographing Solo is a beautiful photo of Rochester.  Rochester is a Common Buzzard that is in training to join our education team.  Rochester is a sibling to Rodrigo a Common Buzzard that’s in training for the programs WBS presents at Zoos, theme parks and aquariums around the nation.  WBS recently also acquired Rochester’s and Rodrigo’s parents. Their parents are interestingly colored; one light colored bird and one dark, almost charcoal bird.  Rodrigo looks like one of the parents, while Rochester is a very rufous colored bird.  His beautiful color just gets more striking to me by the day.  We are currently training him to fly and he is really becoming an amazing performer.
Tsavo, the Bateleur Eagle (photo: Cathy Spahn)

The last photo I want to include is of Tsavo, the Bateluer Eagle.  The Bateluer Eagle is considered to be one of the most colorful eagles in the world.  This head shot shows off just some of that coloration.  It also captures his personality perfectly.

I find that at times, since I see these birds every day, I sometimes take them for granted.  This kind of walk gives me a chance to step back and appreciate the beauty of the animals that I work with every day.

Submitted by Cathy Spahn, World Bird Sanctuary Naturalist

Saturday, November 29, 2014

WBS Winter Migration


As the leaves start to fall off the trees and the temperatures drop, some of the birds on the World Bird Sanctuary exhibit line will be moved to the lower site for the winter—a winter migration of sorts.

The birds that will be moved to the lower site are older individuals, birds with special needs, and species that can’t take the cold temperatures that we have here in Saint Louis.  The birds moving to the lower site will be with us until the nights are in the mid 40’s so it could be around early May before they are back on display.
Skinner is one of the birds that will be moved to a more protected location (photo: Gay Schroer)
The individual birds that will be moved for the winter are our three Turkey Vultures Skinner, Icky, and Turk.  They are all birds that are around twenty years old and need to be indoors because the three of them have arthritis and the cold temperatures are hard on their joints.   They will be in an enclosure that is blocked from the wind and covered so snow and ice can’t bother them.  Rodney the Harris’s Hawk and Timigen the Red-tailed Hawk are birds that also have arthritis and will need to come down to the lower site for the cold months ahead of us.

There are a few species that are on the display line that are found in warmer climates that will have to spend the winter at the lower site as well. The four brown pelicans and the Laughing Kookaburra will spend the winter in the ETC (WBS’s Education Training Center) so they can be in a controlled environment.
Chadder the Laughing Kookaburra will be moved to a heated building (Photo: Gay Schroer)

Lastly our special needs bird Elida the Bald Eagle who has an injured leg will need to be housed in an enclosure that can be blocked from the wind and covered to keep out the snow and ice, so her injured leg doesn’t get too cold.
Ookpik the Snowy Owl loves the cold and snow and will remain on display (Photo: Gay Schroer)

Even with the Turkey vultures, Harris’s hawk, Red-tailed hawk, Brown Pelicans, Kookaburra, and the Bald eagle Elida at the lower site, the exhibit line will have many species of birds for the public to see.  Some of my personal favorites that will be out all winter include our Golden Eagles, Andean Condor, and the Snowy Owls who have no problem in the winter.  We will of course have many Bald Eagles for you to see!

Geronimo and her friend Remington will remain in their enclosure on the exhibit line (Photo: Gay Schroer)

I encourage you all to come out and enjoy the birds on the exhibit line this winter.

Submitted by Adam Triska,  former World Bird Sanctuary Director of Lower Site Management   
   


Thursday, November 27, 2014

Happy Thanksgiving 2014


ALL OF US AT THE WORLD BIRD SANCTUARY


 (HUMANS AND ANIMALS ALIKE)


ARE THANKFUL FOR ALL OF YOU—OUR SUPPORTERS.

HAPPY THANKSGIVING!

Tuesday, November 25, 2014

Eagles of the World: The African Fish Eagle


The African Fish Eagle (Haliaeetus vocifer), not to be confused with the Bald Eagle which looks similar in appearance, largely resides in areas of Sub Saharan Africa that are in close proximity to large bodies of water.  This is due to the fact that these large birds of prey mainly gorge on fish and rely on the abundant food supply that these bodies of water provide.
  
An adult African Fish Eagle (photo: the wikipedia files)

A female African Fish Eagle can weigh upwards of 7-8 pounds, making these eagles one of the larger species of raptor.  Males have an average wingspan of 6 feet, whereas females average about 8 feet.  These birds are characterized by their white head, chest, and tail.  In contrast, their wings, body, and eyes are dark in color.  They have a hook-shaped beak that is yellow with a dark tip and a bright yellow face.  Juveniles have a similar appearance with scattered brown plumage and lighter coloration in their eyes.  Vocalizations from the African Fish Eagle are aweeh-ah, hyo-hyo, or a hee-ah, heeah-heeah.

An African Fish Eagle dragging a heavy fish across the water (photo: the wikipedia files)

The African Fish Eagle mainly feeds on fresh water fish.  The pads on the bottoms of their feet and toes have rough spiracles, which allow them to grasp fish and other slippery prey.  The birds swipe prey out of the water and then carry their catch to a safe place to feed.   When catching prey that is large these eagles will drag their catch across the surface of the water to the shore.  In the event these birds are unable to drag the heaviest of prey they will drop into the water and paddle to the shore with the catch using their wings.  These raptors have also been known to feed on waterfowl, baby crocodiles, lizards, monitor lizards, frogs, hyraxes (small mammals whose closest relative is the elephant), monkeys, carrion, and occasionally domestic chickens.

African Fish Eagles are a monogamous species that are known to mate for life.  The breeding season for these raptors is during the dry season when water levels are low.  These birds usually maintain two or more nests, which they often reuse time and time again.  Because of this these nests, made up of mostly sticks and other pieces of wood, can grow to be quite large.  Some reach almost six feet across and four feet in depth.

An African Fish Eagle egg (photo: the wikipedia files)

Females lay about 1-3 white eggs with red speckles.  Eggs are usually incubated by the female for anywhere between 42-45 days before hatching.  The chicks will depend on their parents for upwards of three months after leaving the nest.  The total time spent in the nest from hatch to fledge is approximately 70-75 days.

A juvenile African Fish Eagle (photo: the wikipedia files)

Under the IUCN (International Union for Conservation of Nature) , these raptors are listed as “least concern”, giving these birds a healthy reputation for thriving in their environment.  Today, their population number sits at about 300,000 throughout their range.

The next time you visit the World Bird Sanctuary be sure to take a walk down the exhibit line just past the wildlife hospital.  Even though we do not have African Fish Eagles, we do have a number of their cousins, the Bald Eagle and also a White-tailed Sea Eagle from northern Europe.

Submitted by World Bird Sanctuary Outreach Coordinator, Callie Plakovic