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Posts tagged ‘predatory birds’

Spring Has Sprung: Birds of Prey

This is the second post of a three part series of a Florida field trip that this photographer co-coordinated for the South Jersey Camera Club members for the purpose of photographing birds and their behavior. The field trip was conducted over a five-day period in the beginning of March. The first post entitled, ‘Spring Has Sprung: Busy, Busy Birds’, visited the Venice Rookery with an amazing diversity of birds courting, mating and raising offspring. This post travels to various locations in southwest Florida to photograph birds of prey nesting and caring for their offspring.

‘Bald Eagle’ © Larry A Lyons

The Bald Eagle is another success story on the importance of banning harmful chemicals, such as the pesticide known as DDT; enacting laws such as the federal ‘Endangered Species Act’; and providing appropriate measures of wildlife management. In Florida there were only 88 active nests in 1973. Now there are more than 1,300 nests documented as a result of all of these initiatives.

One of these nests is situated high up in a tree in the northern section of Fort Meyers, Florida. Adult ‘Bald Eagles’, known as Ozzie and Harriet, have been coming to this nest since 2006 residing in the nest between the months of October and May. This eaglet was stretching its wings waiting its turn to be fed.

‘Can I Fly Yet?’ © Larry A Lyons

‘Feeding The Eaglets’ © Larry A Lyons

‘Burrowing Owls’, no bigger than 10 inches (25 cm) in height, live underground in burrows. They dig out tunnels in sandy soils often within residential communities, particularly vacant lots preferring areas with low ground cover. Burrows extend for 4 to 8 feet (1.2 to 2.4 m) underground. This pair of owls was guarding its burrow.

‘No Trespassing’ © Larry A Lyons

The Florida burrowing owl is classified as a “species of special concern”. This means burrows, owls, and their eggs are protected from harassment and/or disturbance by state law.

‘Burrowing Owl On Watch’ © Larry A Lyons

The installation of T-perches near the owl burrows is often provided. These perches provide the owls with an elevated view that aids in looking out for predators. The T-perches also make the burrows visible for operators of lawn mowers.

‘Watching Over Burrow’ © Larry A Lyons

Unlike other owls, Burrowing Owls are active during the day. They have a diversified diet feeding on small mammals (moles and mice), insects, birds, amphibians and reptiles.

‘On The Prowl’ © Larry A Lyons

This wise old ‘Great Horned Owl’ was watching over an owlet living in this tree. Two nests of these owls were observed within a suburban community of Cape Coral that was no more than two blocks apart. It is one of the most common owls in North America. They live in a broad range of habitats from deserts, forests, tropical rainforests, cities, parks and suburbs. Like the burrowing owl, it has found a way of adapting to suburban sprawl.

‘The Wise One’ © Larry A Lyons

Great Horned Owls take life-long mates and will raise the young together. It does have a varied diet that can include small to medium sized mammals (foxes, rabbits, raccoons, rodents, etc.), amphibians, birds, fish and reptiles. This owlet is only a few weeks old and still covered with downy feathers.

‘Owlet’ © Larry A Lyons

The osprey has become the symbol of how nature can recover from environmental atrocities. Osprey populations were decimated from the 1950’s to the 1970’s because of the widespread use of an insecticide, known as DDT. Once DDT was finally banned in 1972, recovery of the osprey population began. A previous post entitled, ‘The Osprey Comeback’, provides more information about the how DDT caused the extermination of the osprey populations. The biology and reproduction cycle of the osprey is also provided in this previous post.

‘Osprey Portrait’ © Larry A Lyons

The ospreys were quite active in building their nest. This nest was situated on an osprey platform in the Ding Darling Refuge in Sanibel Island and nesting begins as early as March. The male ‘Osprey’ brought the remainder of a fish to the female who was attending to constructing the nest. Ospreys mate for life and often return to the same nest year after year.

‘Room Service’ © Larry A Lyons

Stay tuned for the final post of this series that will visit birds and other wildlife at Ding Darling Wildlife Refuge and the Corkscrew Swamp Sanctuary.

Hidden Habitats! Who Knew?

Never underestimate what a nature park can offer and teach you. Take for example a nature park situated in New Jersey just across from the City of Philadelphia.

‘View of Philadelphia’ © Larry A Lyons

The Palmyra Cove Nature Park (www.palmyracove.org) is a 350 acre site located within a highly developed urban and commercial area in southern New Jersey. The park is bordered along the Delaware River just south of the Tacony-Palmyra Bridge.

‘Tacony-Palmyra Bridge’ © Larry A Lyons

Five field trips to the Palmyra Cove Nature Center during the spring of 2013 provided an opportunity to observe and photograph an amazing diversity of organisms and their behavior.

‘Great Horned Owl and Fledging’ © Larry A Lyons

Let’s begin with the Great Horned Owl. This owl is one of the largest owls in North America and one of the most ferocious birds of prey. Both sexes tend to look similar, but the female is 10 to 20 percent larger than the male.

‘Female Great Horned Owl’ © Larry A Lyons

Distinguishing features of the great horned owl are long ear tufts, intimidating stares with their yellow eyes, and densely feathered toes with dark horned claws. General coloration does vary between the owls.

‘Male Great Horned Owl’ © Larry A Lyons

A pair of Great Horned Owls selected a nesting site high up in the crotch of a cottonwood tree. Nesting begins as early as January or February and the female will typically lay two eggs. After hatching the nestlings are unable to fly for ten to twelve weeks, but the owlets will venture to nearby trees.

‘Owlet One’ © Larry A Lyons

One of the owlets remained in the original nesting site while the other owlet had moved to a lower a branch.

‘Owlet Two’ © Larry A Lyons

Both owlets are being cared for by both parents and remain dependent for food until the fall.

‘Ferocious Predator’ © Larry A Lyons

Great horned owls are ferocious predators and will hunt and eat all sorts of small and medium sized mammals (mice, squirrels, opossums, bats, and skunk). It will also eat small and large birds, including Canada geese, herons, ducks, and turkey. Owl prey can also be raccoon.

‘Young Raccoon’ © Larry A Lyons

It was amazing but only 20 feet away from the tree where the owlets were being raised were raccoons residing within a tree hollow.

‘Raccoon Sleeping’ © Larry A Lyons

Raccoons, like great horned owls, are nocturnal and tend to sleep during the daytime. This one was resting in a vertical position in the hollow of the tree.

‘Tree Hollow Home’ © Larry A Lyons

Trekking around the ponds at Palmyra Cove Nature Park can provide some great opportunities to observe birdlife and some interesting and bizarre behaviors. One such encounter involved a courting encounter amongst blue-winged teals.

Blue-winged teals are known to be the last duck to migrate north in the spring throughout most of the United States. Once they arrive in their northern breeding areas, pairs of teals will settle in vegetated wetlands and ponds to begin the next generation.

‘Pair of Blue-Winged Teals’ © Larry A Lyons

Blue-winged teals are monogamous during the mating season and are known to have some exaggerated behavior when courting. One such encounter was when another male attempted to intrude upon this pair of teals.

‘One Male Too Many’ © Larry A Lyons

The paired male quickly made it quite clear by grasping the beak of the intruder.

‘The Attack’ © Larry A Lyons

The intruder was able to pull its beak away from the grasp and then was aggressively chased away.

‘The Chase’ © Larry A Lyons

Blue-winged teal are so named because both sexes have some blue feathers on their forewings, but really cannot be seen until they are taking off or in flight. The male, on the other hand, is distinguished with slate gray head and neck and white crescent in front of the eyes.

‘Phew! Got Away’ © Larry A Lyons

Palmyra Cove Nature Center has a frog pond that is inhabited or utilized by several different amphibians. One unusual amphibian that only visits the pond once a year to breed is the Fowler’s Toad. The Fowler’s Toad is generally terrestrial and nocturnal except when this amphibian is in breeding mode. So, come spring to early summer, Fowlers’ Toads will venture out from the nearby woods to a wetland or shallow pond to breed. The male toad, measuring about two to three inches in size (5.1 to 7.5 cm.), will produce a call to attract the females.

‘Fowler’s Toad Calling’ © Larry A Lyons

The toads will proceed into what is referred to as amplexus, also known as the “Latin Embrace”. This embrace is a form of pseudocopulation where the male grasps the female with his front legs. The male then releases a fluid with sperm into the water and externally fertilizes the female eggs. The female lays eggs in clutches up to 25,000 eggs.

‘Latin Embrace’ © Larry A Lyons

There were hundreds of toads in the pond participating in this breeding ritual on this particular day. However, on a return trip of the following week, there was not a single toad to be seen, but there must had been thousands of tadpoles (about one half inch in size) swimming in the pond. Metamorphosis from tadpole to young toad occurs within two months.

The frog pond is also shared with other amphibians, such as, the green frog. This green frog surely would have found the eggs and the tadpoles of the Fowler’s Toad a tasty meal. It is all part of nature.

‘Green Frog’ © Larry A Lyons

Canada geese are so common that their increasing populations have become a nuisance at some locations. However, even though their presence is often taken for granted, their behaviors and their life history are quite interesting.

‘Canada Goose’ © Larry A Lyons

Canada geese do pair for life and will remain together over the entire year. In the spring, pairs of Canada geese will separate from their flocks and establish territories to start the next generation.

When a goose intrudes into a pairs’ territory, a lot of commotion will evolve in which the male will aggressively challenge the intruder by honking loudly, hissing with their beaks open wide and will even grab and collide between each other.

‘No Intruder Allowed’ © Larry A Lyons

The female is responsible for building the nest and incubating the eggs while the male will be nearby guarding the nest. After the goslings hatch they will remain close to their parents.

‘Canada Goose Goslings’ © Larry A Lyons

Canada geese are herbivores and will feed on grasses, sedges, berries, etc. This gosling has learned quickly what is good to eat.

‘Gosling Browsing’ © Larry A Lyons

White-tailed deer is another common resident not only at the Palmyra Cove Nature Center, but also throughout the woodlands and suburbs particularly within northeastern United States. The deer are usually best seen in the early morning or at dusk when they are browsing along the edges of woodlands.

‘Young White-Tailed Deer’ © Larry A Lyons

Their winter or early spring coats are brownish grey but they will turn to reddish-brown in the summer. The female deer (doe) stands at about 3 feet at shoulder height and will weigh up to 100 pounds.

‘White-Tailed Deer’ © Larry A Lyons

White-tailed deer are herbivores and will forage on a wide diversity of plants, including agricultural crops, at a rate of 2 to 7 lbs. per 100 lbs of body weight each day.

‘Doe Close-up’ © Larry A Lyons

White-tailed deer populations do present significant concerns that have caused negative effects to the deforestation of woodlands. Deer-related collisions with vehicles have also been an increasing problem with the overpopulation of deer. Attempting to maintain or manage deer populations at densities that will not be detrimental has become more and more challenging.

‘Drake Mallard’ © Larry A Lyons

No nature park is without mallards, the most common duck in the United States. The female mallard lays an average of nine eggs and is responsible for incubating the eggs and taking care of the ducklings.

‘Female Mallard and Ducklings’ © Larry A Lyons

To reiterate the take home message of this post: Don’t underestimate what a nature park can offer and teach you. Here was a nature park situated in a highly dense urban area that provided an incredible assortment of habitats. The combination of these habitats allowed for the propagation and sustainability of a diversity of wildlife from amphibians to owls, ducks, songbirds and geese to deer and raccoons.

Let’s get our children outdoors and away from their electronic devices. Let them find hidden habitats and enjoy the many wonders of nature. It is “our” next generation that will be responsible for continuing efforts to protect wildlife and maintain a commitment for preserving habitats.

Observe, enjoy, learn and, if you are so inclined, photograph them.

“A Birder’ © Larry A Lyons

References:

http://www.palmyracove.org

http://animaldiversity.ummz.umich.edu/

http://srelherp.uga.edu/anurans/buffow.htm

http://njaes.rutgers.edu/pubs/fs1202/white-tailed-deer.asp

http://www.allaboutbirds.org/

The Osprey Comeback

Osprey populations were decimated from the 1950’s to the 1970’s resulting primarily from the widespread use of a persistent insecticide, known as DDT. There were regions in the United States where 90 percent or more of the breeding pairs disappeared. Over 500 osprey nests were present in New Jersey prior to the effects of DDT. By 1974 only 50 nests remained in New Jersey.

The osprey has become the symbol of how nature can recover from environmental atrocities. DDT was banned in New Jersey in 1968 and banned almost entirely in the United States by 1972. Recovery of the osprey populations began once these bans were implemented.

The mechanism of toxicity resulting from DDT to predatory birds, like the osprey, is quite complex that ultimately affects their reproductive success. DDT is a persistent organic pollutant that tends to concentrate as it moves through the food chain. Fish that could be contaminated with DDT from eating shrimp or crabs would further magnify the concentration of DDT in predatory birds, like the osprey. The accumulation of DDT and its metabolites in the osprey prevents calcium metabolism causing the thinning of the eggshells. As a result of the eggshell thinning, the osprey would crush the eggs when sitting on them during incubation.

The 1962 landmark book “Silent Spring” authored by Rachel Carson clearly expressed how important it is to maintain a vigilance on the use of chemicals and their fate in the environment. This book is often attributed to the environmental movement that was initiated in the 1960’s.

'Birds of Prey Socializing' © Larry A Lyons

All of the osprey images were photographed at the Edwin B. Forsythe National Wildlife Refuge located on the southern coastline of New Jersey. This refuge, situated just north of Atlantic City, NJ, encompasses 47,000 acres of coastal habitat and is an important sanctuary for a wide diversity of birds and other wildlife. A future post will present many other birds that utilize this refuge.

The osprey, also referred to as the fish hawk, has a diet that is almost entirely made-up of fish.

Ospreys have gripping pad on their feet that aids in plucking the slippery fish from the water with their long curved talons. The osprey will orient the fish head first to reduce wind direction when carrying the fish in flight. Here a flounder is being carried back to the nest.

The osprey stands between 21 to 23 inches (53 to 58 cm.) and has a wingspan of up to six feet (1.8 meters).

They do require suitable tall structures for building their nests. Platforms are often constructed to allow a suitable structure for nest building.

Osprey nests are built of sticks and lined with grasses or seaweed. The male usually fetches most of the nesting material and the female arranges it. At the Forsythe refuge there are at least eight to ten platforms for the ospreys to build their nests.

Males and females do appear similar in appearance, but there are some slight differences that can distinguish between the sexes. Males have a slimmer body and narrower wings. Also, the coloration of the breast band is either lighter or not present in the males.

Ospreys mate for life and return to the same nest year after year. They migrate back north in the Spring usually around the beginning of March.

The female typically lays three eggs and both parents help to incubate the eggs. Osprey eggs do not hatch all at once, but rather hatching is staggered in time so some siblings are older and more dominant. The pair works together to raise the young.

The young fledge at about eight weeks of age and then remain in the area of the nest for about two months.

Juvenile ospreys have buff fringes to the plumage of the upper parts, a buff tone to the underbody, and streaked feathers on its head. Juveniles also have orange pupils that turn yellow when they reach adulthood.

The adults and the juvenile ospreys will begin their southern migration by the end of August or beginning of September to their wintering grounds in Florida, the Caribbean, Central America and South America.

'Are You Ready To Head South?'© Larry A Lyons

Ospreys are a conservation success story. Both the pesticide bans and the construction of artificial nest sites continue to allow for the comeback and growth of osprey populations.

Leave you with a quote by Rachel Carson: “The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.”

References:

http://www.fws.gov/refuge/edwin_b_forsythe/

http://www.conservewildlefenj.org/

http://en.wikipedia.org/wiki/osprey

http://www.allaboutbirds.org/guide/osprey/id

http://animals.nationalgeographic.com/animals/birds/osprey/

http://www.fws.gov/chesapeakebay/osprey.html