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Birds

Purple Gallinule – Porphyrio Martinica

Purple Gallinule

General

The Purple Gallinule (Porphyrio martinica) sometimes referred to as a ‘swamp hen,’ is a brightly colored bird that can be found gracefully walking across floating vegetation in southern and tropical marshlands.

Description

Purple Gallinules are chicken-sized birds that reach a mature length of approximately 14”, with a wingspan of 20” to 24”, and a mature weight of 7.3 oz. to 10.2 oz. They have red eyes, a short, triangular red bill with a yellow tip, and a light bluthe Purple Gallinule can be see walking on top of floating vegetation or clambering through dense shrubse or white frontal shield (located on the forehead.) Some of their most unique features are their tall, thin yellow legs and long toes (used to navigate across floating vegetation.) PG’s are perhaps best known for their striking coloration. Purple-blue plumage covers the head, neck, breast, short tail, and underside. The back and wings are green-blue and their undertail coverts are white. Chicks are born covered in black down. Juveniles are buff to brown in color, with some green on their backs, yellow legs, and dull facial features.

Purple Gallinule movements on land have been likened to those of a chicken while in the water, they’re said to move like a duck. Their long toes enable then to gracefully move across floating vegetation, but make it difficult for them to clamber through dense shrubs.1 While walking or swimming, they move their head and tail in a constant jerking motion. The flight of the PG has been described as labored and slow, with dangling legs. Despite this, PG’s have been known to fly great distances from their home ranges and have been sighted as far north as southern Canada and Maine.

Purple Gallinules are vocal and make squawking, cackling, and guttural grunting noises.

Habitat

Purple Gallinue is essentially a tropical marshbird that just makes its way into the United States.PG’s can be found in freshwater marshes, wetlands, lakes, waterways, or bayous where there is a presence of floating vegetation (such as lily pads.)

Location

They are year round residents of northern, central, and eastern-central South America, parts of Central America, southern Florida, and the Caribbean. Breeding ranges reach northward to Texas, Arkansas, the Carolinas, and the Gulf Coast. Some populations migrate short distances and winter along the Gulf Coast of the United States and in Central America.2 Although the PG is not a graceful flier, there have been sightings far from this species normal range (in the northern United States, southern Canada, Europe, and South Africa.)3

Diet

They are ground foragers whose diets consist of aquatic vegetation, grasses, seeds, fruit, water hyacinth flowers, grains, insects, and some invertebrates. They gather plant material while standing atop floating vegetation, climb brush for seeds or fruit, and collect insects off the bottom of lily pads (by rolling the edge over and holding it in place with their foot while collecting the insects with their bill.) Insects are fed to the chicks. PG’s are able to use their feet to hold food while eating.

Reproduction

Purple Gallinules breed between April and September. Nests are built using grasses and other aquatic vegetation and are attached to either a floating mat or a thicket of vegetation. Between 6 to 10 eggs are laid -one per day- that are creamy to buff with small irregular brown spots. Both the male and female incubate the eggs for 18 to 20 days. The chicks hatch over the course of 3 to 4 days, covered in black down. The chicks generally remain in the nest until all the eggs have hatched, but are able to leave the nest within a day of hatching if disturbed (already capable of swimming, diving, and running.) The chicks are fed by both parents for 8 to 9 weeks. By 7 weeks old, the chicks are capable of short flights and by 10 weeks old, they can make sustained flights (by this time the chicks have reached 1/3 their mature size.)4

Notes of Interest

There is a hunting season for PG’s in the United States; however, they are not a common game bird and by the time the season opens, local Purple Gallinule populations have often already started migrating south. For example, the hunting season in Arkansas includes a daily limit of 15 birds and lasts from September 1st through November 15th.5

1. http://www.allaboutbirds.org/guide/Purple_Gallinule/id
2. http://birds.audubon.org/birds/purple-gallinule
3. http://www.allaboutbirds.org/guide/Purple_Gallinule/id
4. http://txtbba.tamu.edu/species-accounts/purple-gallinule/
5. http://thecabin.net/sports/outdoors/2009-08-16/

http://www.allaboutbirds.org/guide/Purple_Gallinule/id
http://birds.audubon.org/birds/purple-gallinule
http://txtbba.tamu.edu/species-accounts/purple-gallinule/
http://thecabin.net/sports/outdoors/2009-08-16/

 

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Birds

Great Blue Heron Information Identification

Great Blue Heron

General: The Great Blue Heron (Ardea herodias) is the largest and most common heron in North America. These wading birds are skilled fishers, thriving in a variety of geographic locations and climates. This species is protected by the United States Migratory Bird Treaty Act despite healthy numbers and stable populations, listed as Least Concern on the IUCN Red List.

Description: As the largest of the North American herons, the Great Blue Heron may reach an adult size of 4.5’ tall but only 4.5 to 7.5 lbs, due in part to their hollow bones. Their rounded wings span 5.5’ to 6.5’ in width. Males reach an adult size that is approximately 10% greater than females1. In addition to their overall size, Great Blue Herons may be identified by their long necks, long, tapered yellow bills and long, thin legs that are dull green in color. Their legs terminate in narrow, wide-set toes that allow these birds to walk on soft ground. Great Blue Herons have an overall dull blue-gray coloration, with white, black and brown streaking along the neck. Their white faces and white head-caps are accented with black eye-stripes that merge with black plumes on the back of the heads. Additional features include a shaggy grey ruff on the back of the neck, short tails, and tan feathers on the thighs. Juveniles are similar in color, but lack the plumes and shaggy feathers of adults. A juvenile may also be identified by its dark crown and mottled neck2. There may be as many as seven subspecies of Great Blue Herons, distinguished by size, color, and geographic location.

During flight, a Great Blue Heron will fold its neck and slowly beat its wings, reaching speeds of 20 to 30 mph3.

On average, a Great Blue Heron will live to 15 years of age in the wild. The oldest known Great Blue Heron lived to be 23 years old. Like many species, Great Blue Herons experience a high mortality rate in the first year of life, losing over half of juveniles to predation and starvation. Great Blue Herons are generally a solitary species and typically forage along. However, this species does nest in single-species colonies that may contain up to several hundred nests. Great Blue Herons are most active in the morning and at dusk to maximize fishing success. During the day they are inactive, sleeping with single-species flocks of up to 100 individuals. Great Blue Herons are a territorial species and have been known to be aggressively defensive.

Great Blue Herons are capable of producing seven distinct noises but relative to other species, they are fairly quiet. Sounds are made in response to disturbances or threats and to greet other herons. They also use physical gestures to communicate during courtship4.

Habitat: Great Blue Herons live in a variety of temperate and tropical habitats located in close proximity to water, often seen wading in marshes, sheltered bays and inlets, streams, ponds, swamps, wet meadows, along saltwater coastlines and at the edges of rivers and lakes. They may be found in fresh, salt or brackish water. East coast populations typically avoid shores, preferring to live inland5. Great Blue Herons tend to locate their nesting colonies away from human disturbances, in quiet areas including mature forests and islands.

Within their habitats Great Blue Herons are efficient at controlling insect and fish populations. These habitats place eggs and chicks at risk of predation by crows, ravens, eagles, bears, cultures, hawks, and raccoons. Adults may fall prey to larger predators. If a juvenile or adult is killed in close proximity to a colony, the colony will be abandoned. Great Blue Herons face other threats within their habitats, include collisions with wires, and loss of habitat due to land development and forestry.

Location: Great Blue Herons inhabit nearctic and neotropical regions. During the spring and summer, breeding colonies may be found across North and Central America, the Caribbean and the Galapagos Islands. Populations living in extreme northern climates may migrate south in the winter to Central and South America in search of food supplies. These migratory populations do not breed in their winter habitats. However, this species is highly adaptable (more so than other species of herons) and populations have been known to winter in environments as far north as British Columbia, the Alaskan coast, and New England.

Diet: Great Blue Herons are carnivorous. They usually hunt alone, seeking a variable diet of fish (making up the majority of their diet,) small mammals, insects, crustaceans, and reptiles, such as frogs and salamanders. They wade slowly or stand still, waiting for their prey to come within reach of their long necks and bills. They attack fast, grab their prey with their bills, and swallow their meals whole, causing some herons to choke to death if the prey is too large for their slender throats. In deep water environments, Great Blue Herons exhibit a variety of methods to locate and catch food. They may hover above the water, swim, or dive below the surface in pursuit of food.

Reproduction: Great Blue Herons form mating pairs that last for the duration of one breeding season. Northern populations breed between March and May and southern populations breed between November and April. Each season new pairs will form. Great Blue Herons nest in single-species breeding colonies containing from several to several-hundred breeding pairs. Isolated breeding and nesting is very rare for this species. Nesting begins in February when males choose a site and begin an elaborate display of courtship including flight, stretching, twig shaking, and physical shows. Great Blue Herons prefer to nest in tall trees but will also select locations in shrubs or on the ground as long as there is a nearby source of water. Colonies are usually situated in undisturbed wetlands, far from human activity and roads, at elevations up to 4900’6. Males collect the materials for the nest, constructed of sticks and lined with bark, pine needles, and small sticks. Females lay anywhere from two to seven pale blue-green eggs that are incubated for an average of 28 days by both parents. Females in northern environments tend to lay more eggs. In the event that a nest is destroyed or abandoned (adults may abandon a nest due to human intrusion or extreme noise,) a female may lay a second clutch. Both parents feed chicks by regurgitating food, showing preference for the largest chick. After two months the chicks reach fledging age, able to fly and survive on their own. However, fledglings will continue to return to the nest to be fed by their parents for several additional weeks. Male chicks generally experience faster growth rates, reaching a fledgling size up to 13% larger than females7. Great Blue Herons reach sexual maturity at 22 months old.

Notes of Interest: A subspecies of the Great Blue Heron living in southern Florida and the Caribbean is often mistakenly called a Great White Heron because of a color mutation resulting in pure white plumage8.

In 1999, Great Blue Heron colonies in Seattle, WA experienced a 40% abandonment rate in the middle of the breeding season. Experts now believe this exodus resulted from an increased presence of Bald Eagles in the area, known to harass herons and feed on their young. Crows may have also contributed, known to feed on nests after Bald Eagles.
In recent years, breeding colonies in Washington State were once again impacted by threats. Colonies that numbered in the hundreds were replaced with colonies containing only 30 to 40 nests. In addition to the presence of predators, forestry, land development, and the associated noises are believed to have contributed to this decline9.


Footnotes
1. http://www.arkive.org/great-blue-heron/ardea-herodias/
2. http://www.birdweb.org/birdweb/bird/great_blue_heron
3. http://animals.nationalgeographic.com/animals/birds/great-blue-heron/
4. http://animaldiversity.ummz.umich.edu/accounts/Ardea_herodias/
5. http://animaldiversity.ummz.umich.edu/accounts/Ardea_herodias/
6. http://animaldiversity.ummz.umich.edu/accounts/Ardea_herodias/
7. http://www.sms.si.edu/irlspec/Ardea_herodi.htm
8. http://animals.nationalgeographic.com/animals/birds/great-blue-heron/
9. http://www.birdweb.org/birdweb/bird/great_blue_heron

http://animals.nationalgeographic.com/animals/birds/great-blue-heron/
http://animaldiversity.ummz.umich.edu/accounts/Ardea_herodias/
http://www.fcps.edu/islandcreekes/ecology/great_blue_heron.htm
http://www.birdweb.org/birdweb/bird/great_blue_heron
http://www.sms.si.edu/irlspec/Ardea_herodi.htm
http://www.arkive.org/great-blue-heron/ardea-herodias/

Birds

Great Egret Information Identification

Great Egret

The great egret is a summer visitor to upstate New York. Each summer they come up in spring and stay until late October/early November. The great egret is also known as the common egret, large egret or great white heron. It is a widely distributed egret, with four subspecies found in Asia, Africa, the Americas, and southern EGreat egreturope.

Great Egret populations have increased across most of their range from 1966 to 2014, according to the North American Breeding Bird Survey, though there appears to have been a decline in Canadian populations. The North American Waterbird Conservation Plan estimates that there are over 180,000 breeding birds on the continent, and rates them at least a 5 out of 20 on the Continental Concern Score. Great Egret is not listed on the 2014 State of the Birds Watch List. During the 19th century great egrets were hunted for their plumes.

What I find interesting is that for such a beautiful bird, its call is usually a low hoarse croak when disturbed, and at nest sites. It can also give a loud croaking cuk cuk cuk and higher-pitched squawks.

Description:

Great egret flying - notice he "S" curve in its neck
Great Egrets are tall, standing about 3 ¼ feet tall. They are also long-legged, which helps them wade in shallow water. As can be seen from the pictures, the great egret has an S-curved neck and long, narrow yellow bill. In flight, the long neck is tucked in and the legs extend far beyond the tip of the short tail just like a blue heron. The egret’s wingspan can measure 52” – 70”.

As can be seen, great egrets are white. Their bills are yellowish-orange, and the legs black. If you are out bird watching and come across a white egret, the yellow bill with black legs is the important identifier.

In breeding plumage, delicate ornamental feathers are on the bird’s back. Males and females are identical in appearance; juveniles look like non-breeding adults.

Habitat:

Great egrets live in freshwater, brackish, and marine wetlands. During the breeding season they live in colonies in trees or shrubs with other waterbirds, ranging across the southeastern states and in scattered spots throughout the rest of the U.S. and southern Canada. The colonies are located on lakes, ponds, marshes, estuaries, impoundments, and islands.

Territory:

The great egret range has expanded as far north as southern Canada. However, in some parts of the southern United States, its numbers have declined due to habitat loss. The great egret is partially migratory, with northern hemisphere birds moving south from areas with colder winters

Diet:

The great egret feeds in shallow water, marshes and even land. They feed mainly on fish, frogs, small mammals, and occasionally small reptiles and insects, spearing at them with its long, sharp bill most of the time by standing still and allowing the prey to come within its striking distance. Just so it is clear, they do not spear with the bill, they quickly thrust forward and catch the prey in their mouth.

Nesting:

Great egrets are colonial nesters Believe it or not they usually build their stick nests high in trees. You can find them often on islands that are isolated from predators. The nest is up to 3 feet across and 1 foot deep.

The female will lay approximately 1 – 6 smooth, pale greenish blue eggs that are roughly 2” – 2 1/2” long and about 1 1/2” wide. The incubation period is between 23 – 27 days. The young hatch as long and colored white with down covering the back with their eyes open.

Not all young that hatch survive the nestling period. Aggression among nestlings is common and large chicks frequently kill their smaller siblings.