Wetland birds – Discover-Nature

Flamingos

The greater flamingo, Phoenicopterus roseus, with its long neck and legs, hooked downward bill, and bright pink plumage can be found on five of the seven continents, not including Australia or Antarctica. Only one of the six species is native to the continental U.S., the American greater flamingo, Phoenicopterus ruber, and its native range encompasses only the far southern portions of Florida. Three additional species are found in the Caribbean and northeastern and southwestern portions of South America, plus two species are native to coastal areas of Europe, Africa , and Asia.

Flamingos are found in all types of shallow water habitats. They forage in both saltwater lakes and coastal lagoons, in addition to freshwater wetlands, ponds, and mudflats. They are able to eat prey found in very alkaline waters that most other avian species cannot tolerate. Feral birds, ones that have escaped captivity and are now breeding in the wild, from the other three species found in North and South America have formed several colonies along the southeastern coast of the U.S.

The name flamingo comes from a Spanish word meaning flame, bright and red in color. Immature birds are gray or brown. They absorb carotene, a reddish-yellow pigment, from their food, which slowly changes their plumage to light pink, deepening to darker shades including reds and oranges. It takes about three years until a bird attains the bright pink adult plumage everywhere except their flight feathers which are jet black and can be seen only when their wings are extended.

^{Greater Flamingo chick in water by JHVEPhoto, Getty Images}

Flamingos have the longest neck and legs of any native bird in the U.S. Wingspans on full-grown adults may reach five feet. Flying in a V-formation, flocks move quickly, with necks extended, taking short, strong wingbeats. Flamingos call is a strong honking, sometimes hard to distinguish from geese, to maintain the group’s cohesion in flight. Webbed feet provide stability on soft sand, mudflats, and in shallow waters along lake bottoms. Flamingos are excellent swimmers, and they use their webbed feet to stabilize their bodies in the water when reaching downward for food growing in deeper lakes and ponds.

^{Flamingo head, by XavierMarchant, Getty Images}

A flamingo’s bill is sharply angled downward in the middle. On most birds, the upper bill is part of the bones of the head, heavier and immovable. On flamingos, this is reversed and the upper bill can be used as a flap against a heavy lower bill. When feeding, the bird lowers its head, turning the bill upside down, sweeping it from side to side through the water. A central groove in the lower bill contains space for a fat tongue, used to push and pull higher volumes of water through the bill. The edges of the bill are lined with rows of horny plates called lamellae that strain out crustaceans, mollusks, and small insects. Flamingos are typically night feeders, resting during the day.

Flamingos roost in single species colonies. They will only breed if they are part of a large group, and breeding occurs for all at the same time. Nest mounds are volcano-shaped, arranged close by one another on a mudflat. Each breeding pair of birds lays only one egg on top of its mound. Parents take turns incubating the egg while the other is foraging. Chicks stay with the parents for four to six weeks after hatching, until they are able to feed themselves. Still unable to forage and in need of protection, all of the chicks in larger colonies may form one group called a creche. The group can be guarded by only a few adults, giving the rest of the colony the opportunity to forage for themselves and bring back food for the creche.

^{Nesting Rose Flamingo with egg in nest, by Artush, Getty Images}

^{Chick and mother, by tane-mahuta, Getty Images}

Toward the end of the 1800s, feather collecting for the millinery markets adversely impacted many bird populations. However, this did not include flamingos because their feathers quickly lose the pink color once they are removed from the bird. Today, flamingo populations around the world are shrinking due to habitat loss. Much of their native habitat is wetland coastal areas being developed. In addition, flamingos do not have the capacity to switch diets, and as more wetlands are drained or polluted, food sources are continually disappearing.

Look for these magnificent birds at your local zoo, or consider a trip to see them in many of the nature areas in southern Florida.

Heronry

Herons, members of the Ardeidae family, have been returning to area nest sites for the past couple of weeks. Herons are mainly tropical birds, but they have spread out during warmer months to every continent except Antarctica. They can be found in all types of habitats except where high and low temperature extremes are the norm, such as high altitudes and dry deserts. Herons build nests in a heronry, a descriptive term for a rookery or colony of herons.

Lake Renwick Heron Rookery by Am Bananas

A heronry can include only a few nests or several hundred in one location. Nest sites are often located on islands, especially those created from dredging. These do not typically support other wildlife populations. Predators searching for eggs and young chicks, especially raccoons, find it difficult to access nest sites. Nests can be located near the water’s surface, in reed-beds, or high up in the tops of tall trees, from 40′ to 100′ off the ground. It is not unusual for a single tree to support 8-10 nests. Individual birds tend to colonize with their own species, although a good nest site may support several colonies of different species adjacent to each other.

Black-crowned Night Heron and Great Blue Heron by Eric Heupel

Herons eat a wide variety of foods, but are strictly carnivorous. Their main food comes from aquatic habitats and includes fish, crustaceans, and amphibians. They occasionally hunt in non-wetland habitats, including agricultural fields and grasslands, eating voles, field mice, and other live prey. A primary reason for colony style nesting is the scarcity of nest sites that are safe from predators and still close enough to food sources, typically from one to three miles away. One advantage is that the food source can be shared among many individuals.

Once a suitable location for a heronry is established, nests will be reused from year to year. Returning males arrive first, choose a nest, and then find a mate. Birds may choose different mates each spring, but will remain monogamous for that year. Nests are constructed by weaving together twigs of various lengths and start out about 20″ in diameter. As nests are reused by new pairs of birds, they are continually rebuilt and improved each year. Older nests may reach massive proportions of up to five feet across.

Lake Renwick Heron and Cormorants by Synspectrum

Adult herons are at the top of their food chain, their only predator is humans. As such, they are considered an excellent indicator of the health of our wetlands. Draining wetlands for urban or agricultural development removes them as a food source, and a heronry may be abandoned if there is not enough food available for raising young. Human disturbance can also have negative effects on reproduction. Repeated intrusions into nesting sites results in nest failure and abandonment of eggs or chicks. It is against the law to disturb any rookery or heronry.

To learn more and safely view all of the activity of a heronry, consider a visit to one of Illinois’ premier sites, the Lake Renwick Heron Rookery in Plainfield, Illinois. They have limited days and hours, so before you go, check their website at: https://www.reconnectwithnature.org/preserves-trails/visitor-centers/lake-renwick-heron-rookery-visitor-center

Red-winged Blackbird

Signs of spring continue in many places this month, and one of those is the return of red-winged blackbirds, Agelaius phoeniceus. Males are a glossy black with bright red shoulder patches bordered in yellow called epaulets. Females are dark, streaky brown with an orange-ish face and chin and faint pale orange epaulets. Members of the blackbird family, they have stocky, rounded wings, a short tail, and a thick beak.

Red-winged blackbirds winter in Mexico and migrate in spring to the United States and southern Canada. Wetlands, including marsh, wet meadow, and heavily vegetated shores of small ponds, are their preferred habitat. Nests are built in wet, brushy areas. They are cup-shaped, woven from twigs and grass, and attached to straight, vertical shoots near the water’s surface. They are held together with mud and lined with fine grasses for comfort and insulation.

Red-winged Blackbird song and call recorded on the Cub Lake Trail in Rocky Mountain National Park. Note that an American Robin, Ruby-crowned Kinglet, Wilson’s Snipe, House Wren and the buzz of a hummingbird flying by can also be heard in the recording.

Males arrive first in the spring and select a territory. They have a wide variety of songs for attracting mates and warning other males to stay out of their territory. Many blackbird species have the ability to learn and incorporate new songs into the repertoire. Males use many convoluted flight sequences that show their bright red and yellow epaulets as warning signs for both competitors and potential predators. Experiments studying the red shoulder patch shows that birds use them to establish a rank in the social order of birds in the area. A bird defending its own territory will display the whole epaulet, whereas a bird searching for food outside its established range will keep the red shoulder partially concealed, so as to not provoke an attack.

Females choose their mates, based in part on the amount of territory a male can hold and defend and by habitat quality. If there is enough vegetation to support multiple nest sites and insect populations for food, this is a clear indication of a highly desirable breeding partner and more than one female may choose to mate with the same male. Timing of egg laying is tied to availability of food. Females will have two broods each year, with three to four eggs in each.

Red-winged Blackbird eggs by Iowa Cooperative Fish&Wildlife Research

Red-winged blackbirds are extremely bold birds. They are not afraid to attack predators much larger than themselves. Any potential threat close to a nest site is subject to warning calls, displays showing the red epaulets, and dive bombing from a male willing to use his beak as a weapon. Threats may include crows, hawks, raccoons, and people.

Red-winged Blackbird song and call recorded in Moraine Park in Rocky Mountain National Park. Note that Western Chorus Frogs and the buzz of a hummingbird flying by can also be heard in the recording.

The red-winged blackbird is one of the most prolific species in the U.S., and yet their populations have declined an estimated 30% in the last 50 years. Some of this is due to intentional poisoning of large flocks that have often been perceived as a threat to corn and wheat granaries. Urban development continues to contribute to loss of habitat. Other causes for this decline are climate-based including late spring cold snaps that may kill off expected insect populations used for food and additional acreage under threat of wildfires due to warming temperatures.

In spring, the males sing several melodies followed by their signature drawn-out, raspy trill. If you have any wetland areas nearby, visit these to observe their courting and breeding behaviors or attract them to your backyards with their favorite foods. They generally feed on the ground or from a platform feeder. In early spring, they like sunflower seeds, cracked corn, millet, oats and peanut hearts. As insect populations arrive, birds will move into wetland areas to lay eggs and raise their young.

Herons

It is bird migration season, and there are a great many birds returning from their wintering grounds farther south. Two of my favorites are the Great Blue Heron, Ardea herodias and the Great Egret, Ardea alba. These tall birds, 36″-48″ in height, can be seen in ponds, lakes and rivers where they are searching for their favorite foods: fish, crustaceans and small amphibians. At this time of year, before the growing season has started, they can also be found in dry agricultural fields hunting for small mammals such as field mice.

The long curved neck is a modification of one vertebrae that allows the neck to easily flex. In addition, muscles can pull the neck into a tight coil and spring the head and beak forward at incredible speed allowing the bird to quickly snatch a meal from the water. Both of these species are stealthy hunters, moving slowly on long, slender legs through shallow water. They may be seen moving their heads from side to side, crouching or standing upright, or pointing their bills straight down at the water. All of these behaviors are thought to be used to reduce glare on the water surface and allow the birds to better see their prey.

Great Blue Heron, *Ardea herodias*, by DonArnold

Over the summer, these birds will find a mate and raise a family in our area. Nesting usually takes place in colonies, large gatherings of birds that can number between a couple dozen to a few hundred birds. Nests are usually built at the tops of tall trees standing in water. This may be a defensive strategy against ground and climbing predators. You can easily spot these nests sites in the early spring before the trees have leafed out. Colonies of nests are called a rookeries, and there are many to be observed in our area. A rookery that you may want to visit to learn more is at Lake Renwick Preserve in Plainfield. Hours are limited, so please see their website at: https://www.reconnectwithnature.org/preserves-trails/visitor-centers/lake-renwick-heron-rookery-visitor-center

Other herons that are found in our area include the Black-crowned Night Heron, Nycticorax nycticorax and the Green Heron, Butorides virescens. These smaller birds, typically 16″-24″ in height, can also be found foraging near open water, but are often seen in the early morning or early evening. Both species use bait such as insects, seeds, leaves or feathers as well as bread put out by people for ducks and other waterfowl, to attract fish to swim within their reach.

Black-crowned Night Heron, *Nycticorax nycticorax*, by DonArnold

Green Heron, *Butorides virescens*, by DonArnold

You should be able to observe these birds as you visit any area that includes shallow water containing fish or other small aquatic species. They will be here until late autumn when ponds start to freeze over. Heron and egret migration routes depend on continually finding open water for hunting, so winter feeding grounds may include much of Illinois, depending upon our winter temperatures.