Osprey

 The osprey is a bird that is in a class all its own. Literally, the osprey is the only member of the genus Pandion, which is the only genus in the family Pandionidae. So what makes the Osprey so unique? First off is the fact that they have the ability to rotate one of their toes so that they have two facing forward and two facing back. This adaptation helps them to catch fish, which is their main food source. Most species of owls have this ability but the osprey is the only diurnal raptor, active during the day, that has this unique ability. Their feet also have rough pads on the bottom which helps in grabbing slippery fish.

 Even though the osprey is the only member of its family they are not so alone. Osprey can be found on every con tenant in the world except Antarctica. They are found near water where they hunt for fish, often diving up to two feet under the surface. In the Western Hemisphere Osprey breed primarily in northern sections of North America. The breeding range includes most of Canada, the northern United States, and the Pacific Northwest. These birds migrate south to central and South America for the winter, some traveling over 2500 miles each way. Populations in Florida and the Gulf Coast typically are year round residents.

Osprey

 Now that all of the ice has left the rivers and lakes the osprey have returned to Minnesota. Osprey are found on every continent in the world except for Antarctica. They nest on all continents except Antarctica and South America. Osprey do migrate to South America, from North America, during the winter. However they do not nest in South America.

 The osprey is sometimes called a fishing hawk. This is because their primary food source is fish. However they are not really a hawk. They actually have their own genus, Pandion, and family Pandionidae. This is because Osprey have some unique characteristics and behaviors that differ from other hawks, falcons, and eagles. First off all of their toes are relatively the same size, unlike other diurnal raptors which have a longer toe called a hallux. They also have the ability, like owls, to shift their outer toe so that they can have two toes facing front and two facing back instead of 3 forword and one back like hawks, eagles, and falcons.

 These adaptations to their feet are designed to help them catch fish. Switching their toes to two forward and two back helps them to hold onto slippery fish. They also have rough pads on the bottom to help them to grasp a fish. They are much better at catching fish than the bald eagles are, actually plunging up to a couple of feet below the water surface to catch their prey.

Unfortunately it is dangerous world and a passing eagle or turkey vulture will not hesitate to try and steal the osprey's hard earned meal. Osprey were once rare here in Minnesota due to DDT, which affected many different species of raptors. Through release programs the population has rebounded nicely here and is now stable and healthy. Half of the pictures in this post were taken in Minnesota the other half were taken in south Texas.

Osprey

One of the most interesting raptors is the Osprey. They are often called the fishing hawk but in reality they are not really a hawk at all. The osprey has its own genus (Pandion) and own family (Paninidae) of which it is the only member. So what makes the osprey so unique? The main difference is the osprey's feet. Most diurnal raptors, those that are active in the daytime, have one toe that is longer then the other three. This toe is called the hallux. It usually is the backward facing toe and one one that many raptors use to kill their prey. If you look at the young osprey being banded in the photo above you can notice that all the toes are relatively the same length. Also note that instead of 3 toes forward and one behind ( Anisodactyl) like other diurnal raptors this bird has two toes forward and two behind (Zygodactyl) like an owl. Osprey are able to switch back and forth.

Osprey feet also have pads on the bottom with tiny spines, called spicules, which help them to grasp fish. These adaptations on their feet help them to catch fish which makes up about 98 percent of their diet. Osprey are much better at fishing then bald eagles are, often diving up to 2 feet under the water to catch them. Osprey are found on every continent except for Antarctica. They do not nest in South America but birds from the northern portions of North America, like the birds in these photos which were photographed here in Minnesota, can migrate over 7500 miles a year from Canada down into central South America.

Everglades National Park

 South Florida was once a large series of wetlands that ran from the Kissimme River down to the Biscayne Bay. The numerous ponds, slough, sawgrass marshes, hardwood hammock and forested uplands were the basis of an intricate ecosystem that was home to many unique plants and animals. Unfortunately this amazing wetlands was a nightmare for early settlers that were looking for land to settle, farm, and graze their livestock. As these settles began to drain portions of the wetlands the fragile ecosystem began to suffer. Species at the top of the food chain, like the osprey above, were lead indicators of the damage to the environment.

By 1900 early environmentalists and conservationist became concerned about the impact that people were having on the habitat. Besides draining the wetlands, hunters were also killing millions of the wading birds, like the white ibis above. In 1900 Florida instituted a ban on plume hunting in southern Florida but many people were making a living off slaughtering these birds. The ban lead to tensions that eventually got conservation officers killed. In 1928 Ernest Coe began an effort to create the Everglades National Park and  in 1934 congress finally designated the park. It took supports another 13 years to purchase the land and in 1947 the Everglades National Park was dedicated.

Dinner Time

Osprey Banding

 Over the years I have had opportunities to view numerous types of bird banding. Back in the summer of 2010 I was fortunate to be able to photograph osprey banding at several nests around the Twin Cities. Most of the banding took place at nests that were located on osprey platforms. In some cases a climber was hired to climb up to the nest to get the chicks otherwise a basket lift was used. It is important to get the chicks at the correct age, about 5 weeks old. If they are too small the shock of banding may affect their health. If they are too large they might try and escape and hurt themselves or they might try and fight and hurt the bander. This chick had a lot of bravado but it was still young enough for the bander to easily handle.

 While the banders are grabbing the chicks from the nest the parents fly around the nest calling loudly. To them this is an invasion, from a large predator, and their babies are in danger. Besides screaming they also will dive at the bander. They usually do not get close enough to touch the banders but it is important to be careful  because they have very sharp talons. At the end of the day, when the chicks are placed back into the nest and the banders leave, the osprey will be successful and they will have saved their chicks.

 Once on the ground the chicks are kept in the shade. Banding here in Minnesota takes place at the beginning of July so it can be quite warm. Since they are already stressed out because of the banding it is important not to let them get too hot because it might affect their health. The chicks have two bands crimped on to their legs. on their left leg they get a silver Us Fish and Wildlife band. This band number is recorder at the Bird Banding Lab in Washington DC. THE right leg is banded with a colored alpha numeric band which is much easier to read through binoculars or a scope then the silver band. This helps different groups, such as the Audubon Society, Three River Park District or other interested organisations identify the birds in the field.

Although they were at one time plentiful through out the state of Minnesota, the osprey had all but disappeared from the southern half of the state by the early 1900's. In 1984 the Hennepin Parks Association,  now the Three Rivers Park District, began a release program to reintroduce nesting osprey into the Twin Cities Metro area. They set up osprey nesting platforms in suitable habitat and began to release young birds that had been taken from northern Minnesota. Over an eleven year time frame, 1984-1995, they released 144 young osprey into the area and put up around 100 nesting platforms. Many of these birds returned to the Twin Cities after migration and when they reached maturity, 3-4 years, they began to nest in the area. In 2010 their were over 60 active nesting territories in the Twin Cities and the number has continued to grow. Around 85% of the population is banded.

Laguna Atascosa NWR

 The Laguna Atascosa is a refuge that is located along the Gulf coast in south east Texas. It is the largest refuge in the south Texas Rio Grande Valley with around 97,000 acres. The refuge is bordered on the east by the waters of the Laguna Madre which flow out into the Gulf of Mexico. This area was primarily coastal prairie habitat until Spanish settlers came in the 1700's and converted much of the land to grazing land for livestock. In the mid 1800's Texas became a part of the United States and portions of the land were developed for agriculture. During WWII the U.S. War Department acquired portions of what is now the refuge and used it as an aerial gun and bombing range. Some of the bunkers still exist with in the refuge.

 In 1941 the US Fish and Wildlife Service proposed protecting the area because of the large number of waterfowl that wintered in the area, particularly the redhead duck. In March of 1946 the refuge was established by Congress. It has been designated as a "globally important bird area" by the American Bird Conservancy. It is an important migratory stop for numerous species of birds. There have been 417 species of birds recorded in the refuge which is more then any other refuge into the United States. A number of endangered species can also be found in the refuge including ocelots, jaguarundi, Kemp's ridley sea turtle and the Aplomado falcons, which were reintroduced by The Peregrine Fund in the 1980's,

Osprey Eating Fish

 

The osprey is a very interesting raptor. They are sometimes called the fishing hawk, because they are almost 100% fish eaters. However the osprey is not a hawk at all, they are in their own family. They are the only diurnal raptor, one that is active during the day, that has the ability to shift a toe so that they can have 3 toes forward and one back or two facing forward and two facing behind. The only other raptors that have this ability are owls and the Osprey definitely is not an owl.

Osprey Carrying a Fish

 The osprey is a raptor that is found on every continent in the world except for Antarctica. They are commonly called fish hawks however they are not hawks at all. They differ from hawks and other diurnal raptors because their toes are all the same length and their outer toe is reversible, allowing them to have two toes facing forward and two back like owls. Osprey are slightly smaller then eagles and are found in a variety of habitats always near a water source. They almost exclusively eat fish and when in flight turn the fish to face the same way as they are to make them more aerodynamic. 

Osprey Chicks

Since it is now June it should not be long before all of the osprey platforms around the city are littered with chicks. When they first hatch they are pretty small and mom has to stay on the nest to make sure that they stay warm so it usually takes a week or two before you begin to see little down covered heads peaking over the sides of the nest.

 By the beginning of July they are big enough to be banded. Back in 2010 I was fortunate enough to attend several osprey banding sessions around the cities. These pictures were taken from the banding at the Wargo Nature Center, which is a nest that I have been watching for Osprey-Watch. They brought in a boom truck to take the thee chicks down from the nest. Then they give them 2 bands, one from the Department of Fish and Wildlife and the other which is a tracking band to help identify the bird when looking at it through a scope or binos. As you can see mom and dad were not too thrilled about the crazy people taking their babies. But soon the babies are back and the osprey win in the end.

Osprey

This week I signed up for Osprey-Watch. This is a new project that is sponsored by Center for Conservation Biology that is looking to collect information about nesting osprey around the world. They hope to use this information to address three current issue facing aquatic ecosystems, global climate change, depletion of fish stocks and environmental contamination's. The osprey is a good subject for studying these three issues because they are at the top of the food chain in many aquatic environments and can be found all around the world, with nesting occurring in the northern hemisphere and many osprey wintering in the southern hemisphere.
Back in 2010 I helped watch nests around the Twin Cities with the Metro Osprey Watch Project. This was a small group of people, I think about 3 or 4, that we watching osprey nests here in the Twin Cities. That summer I ended up watching about a dozen nests. It was a cool experience but it took up so much time that I was not able to get out and photograph many of the other things that I wanted to. Last year I tried to help out but I just did not have the time. So when I signed up at Osprey-Watch I only registered two of the nests that I had watched in the past. One is from a pair that has nested in a ball field that is close to work, the top photo is one of the adults from that nest. Since it is so close it shouldn't be to hard to run out and check on them at lunch or after work. The second nest is not close or convenient but it is one of the best nests in the Twin Cities to photograph. It is located in a nature center and there is a blind located just south of the nest. The photograph above was taken at the second nest. With only two nests to watch I can help out with some important citizen science, get to watch and photograph some real cool raptors, and still have time to get out and do other stuff so it looks like it is going to be a fun summer.

Tuesday Tweets

Welcome to the inaugural edition of Tuesday Tweets. The rules are very simple. Just post a photo or drawing of any type of bird on your blog then come here and enter your info in the inlinkz tool below. Make sure to include a link back here from your post. Feel free to copy the jpg above and use it with your post or any where else on your site. Then please visit other sites that link up to see their great bird posts.

To Fly

Have you ever wondered how birds fly? This is a subject that has fascinated mankind for ages. In many ancient cultures they viewed a birds ability to fly as something magical or associated it with the supernatural. The truth is that through many many centuries birds have evolved several adaptations which have assist in their ability to fly.
In order to fly birds need to be light weight. Instead of having heavy bones and teeth like we do most birds have hollow bones and a light weight beak. They also have a much more efficient cardiovascular system then we do. Their lungs process oxygen more quickly efficiently and their heart beats much faster. This is necessary because it takes a lot of energy to fly.
Perhaps the coolest adaptation for flight though are their feathers. Birds have between 1,000 to 25,000 feather. Feathers are made of a substance called keratin. Even though they are strong and durable they are also very light. The spine of the feather is called a shaft. The shaft runs the length of the feather and it is hollow inside. Connected to the shaft are branches called barbs. The barbs connect to each other giving the feather a solid appearance however there is space between them which helps to keep the feather light. Each bird has several different type of feathers each serving a different purpose. It is important for the bird to keep their feathers in good shape so they spend a significant part of each day preening. Once or twice a year, depending on the type of bird, they will lose their feathers and new replacements will grow in. This is called molting. Most birds only molt a couple of feathers at a time so that they can continue to fly while their feathers are being replaced. However some waterfowl molt all their feathers at once leaving them flightless for a week or two.

Fishing Hawk

The osprey is a large raptor that is found through out the world. They are commonly referred to as fishing hawks because the majority of their diet consists almost exclusively of fish. Unlike most sea or fishing eagles the osprey often dives down into the water, submerging itself up to two feet deep in search of prey. Eagles usually only get their feet wet which is why osprey are much better at catching fish then a sea eagle such as a bald eagle. Unfortunately most eagles are larger then osprey and they are not against bullying or stealing an easy meal.

Osprey