Conservation

Bald Eagle

When talking about conservation as it pertains to the raptor order the Bald Eagle is the bird that most comes to mind. The Bald Eagle is extremely sensitive to human activity and prefers to live in isolation. In 1940, Congress passed the Bald Eagle Protection Act.  This act made it illegal to hunt, harass, or sell Bald Eagles.  Over the next twenty years the species population saw a rapid decline.  So much so that by 1967 the eagle was official declared an endangered species under the Endangered Species Protection Act.  In 1995, due to various conservation efforts including, outlawing of DDT pesticides, banning the use of lead bullets for waterfowl hunting, and strict regulations regarding disturbing their natural habitat, the eagle is reclassified from "endangered" to "threatened."  Finally in 2004, the Bald Eagle is officially delisted and taken off the threatened species list.  Their numbers have increased from 450 pairs in 1963 to approximately 7,700 currently in the U.S. 

There are a number of current measures in place to ensure the population is sustained.  Strict rules are in place regarding protection of their habitats.  For instance, it is illegal to build within 330 feet of an eagle's nesting site. The U.S. Fish and Wildlife services names a few measures people should take to avoid disturbing the eagle:

1. Protect and preserve potential roost and nest sites by retaining mature trees and old growth stands, particularly within ½ mile from water.

2. Where nests are blown from trees during storms or are otherwise destroyed by the elements, continue to protect the site in the absence of the nest for up to three (3) complete breeding seasons.  Many eagles will rebuild the nest and reoccupy the site.

3. To avoid collisions, site wind turbines, communication towers and high voltage transmission power lines away from nests, foraging areas, and communal roost sites. 

4. Employ industry-accepted best management practices to prevent birds from colliding with or being electrocuted by utility lines, towers and poles.  If possible, bury utility lines in important eagle areas.
4. Do not intentionally feed bald eagles.  Artificially feeding bald eagles can disrupt their essential behavioral patterns and put them at increased risk from power lines, collision with windows and cars, and other mortality factor
4. Use pesticides, herbicides, fertilizers, and other chemicals only in accordance with Federal and state laws.

Sources


http://www.fws.gov/midwest/eagle/conservation/baea-moreconserve.html
http://lib.colostate.edu/wildlife/eagle.html
http://animals.howstuffworks.com/endangered-species/bald-eagle-conservation1.htm

Reproduction

Bald Eagle

The Bald Eagle is monogamous and mates for life returning to the same nest year after year.  Both parents take part in caring for the young with the male foraging for food as the mother incubates the young. They usually build nests in large trees near a body of water.  Their nests can reach up to nine feet in diameter.  The female chooses their mate.  Male displays (courting) often involve aerial acrobatics and diving and locking talons between competing males.  The Bald Eagle has a slow life history ("K selected") and may live up to 30 years in the wild allowing it an ample amount of time to produce offspring.  Bald Eagles become sexually mature at 5-6 years of age. Breeding Bald Eagles lay one to three eggs per year which hatch after about one month.  The chicks are altricial at birth as the young eaglets cannot take care of themselves.  They are born with a coat of down and have poor vision.  It will take roughly 2-3 months before a juvenile will attempt to fly and therefore relies entire on its parents for food during that period.  Approximately 70% of juvenile eagles survive their first year of life.  Often times the larger eaglet in the nest will kill its sibling.  

Turkey Vulture

Turkey Vultures breeding season begins in the warmer months and they lay between one and three eggs.  As part of pair matching, several birds gather in a circle and perform hopping movements around the perimeter of the circle with their wings spread.  They nest in the ground or in caves.  Their nests are untraditional in the sense that they do not use sticks and brush, but rather dig out an indentation in the land. Both parents share responsibilities of incubating and caring for the young.  The eggs incubate about 40 days before hatching.  The chicks are altricial at birth and thus do not care for themselves.  The juvenile vulture fledges the nest at around 10 weeks.  They have a slow life history as the birds are sexually mature at 2 years and live between 15-20 years in the wild.  

Sources

http://www.baldeagleinfo.com/eagle/eagle4.html

http://www.peregrinefund.org/subsites/explore-raptors-2001/eagles/baldeagl.html

http://vulturesociety.homestead.com/TVFacts.html

The Red-tailed Hawk's vocalization is hard to mistake.  It is a very loud high pitched scream.  It sounds like a shriek that you might associate with a Pterodactyl dinosaur.  We have had a chance to see a number of these birds on our trips; however, I don't believe we have ever been close enough to hear one make their call.  Hopefully before the end of the class we will have a chance to get a closer look at one of these majestic birds. Here is a link to hear for yourself.... 


http://www.allaboutbirds.org/guide/red-tailed_hawk/sounds 

Accipitriformes Morphology

These prey birds are all characterized by strong legs and feet with sharp talons and an opposable hind claw.  The bills of these birds are sharp and hooked as they are used to tear flesh.  


The birds have slotted high lift wings in order to provide them with increased lift and gliding ability.  They often have light wing loads and are best suited for soaring.  

Here is a picture of a Bald Eagle in flight.  Notice the distinct slotting on its primary flight feathers. 






The plumage of these birds normally utilize duller colors of grey, brown and black. 
The Old World Vultures have bare heads without feathers, which is thought to aid in thermoregulation. 

Old World Vulture (Accipitridae)

Not to be confused with the New World Vultures which belong to their own family Cathartidae.  A picture of this bird can be seen on my previous post.  




Accipitriformes are one of the most diverse orders of birds. One aspect of this order that varies among species is size.  An example of this variation is size in seen in the difference between the a Pearl Kite (3oz, left) and the Bald Eagle (~12lbs, right).   

Here we can see the striking difference in size between these two birds.  Despite their differences they both share the same hooked talons, bill, and opposable hind claw.  These birds also share the same family- Accipitridae. 








These birds were previously considered in the order Falconiformes.  However, Falcons (Falconidae) has been since removed from this order and has taken the ordinal name along with it. 




Sources
Wikipedia
Tree of Life

RU-Accipitriformes

Raptors


Representative Birds

• Hawks
• Eagles
• Vultures
• Kites
• Osprey
• Harriers
• Secretary-bird

The order Accipitriformes is composed of 4 families consisting of 72 genera and 242 species.  There are 3 families (Accipitridae, Pandionadae and Carhaetidae) and 27 species found in Eastern NA.   The birds in this order include mostly large diurnal prey birds.  Aside from the Secretary-bird, Accipitriformes reside near bodies of water. They feed on a variety of animals including fish, rodents, and snakes.  They are identified by large broad wings suitable for soaring flight.  They typically have sharp hooked bills and talons.  According to Peterson, eagles, hawks, kites, harriers and ospreys, vultures are found almost worldwide.  There are a number of each of these species found in NJ. The secretary-bird is a large terrestrial bird endemic to Africa. 

                                                                                                    

Turkey Vulture

              

Osprey

Bald Eagle

Secretary-Bird






Sources
Wikipedia