WATCHING DUCKS AND GEESE AT BERKELY LAKE, DENVER, COLORADO

by Kenneth Harper Finton 

I am counting my blessings today, one of which is the ability to walk around a nearby lake that is also a bird preserve. The lake is called Berkeley Lake. It lies right off I70 in Denver, just before disappearing into the great Rocky Mountains.  Not only do I get needed daily exercise, but I make some ‘fine feathered friends” along the way ...  not so much close friends, but acquaintances that help to brighten the day. Meeting the other folk that are out to enjoy the day can be as important as the walk, as walkers abound at all times of the day, from wheelchair bound folk carrying oxygen to young mothers jogging with fat-wheeled baby carriages to take off the baby fat. When I was a child, baby carriages had thin rubber wheels and were pushed by sedate women with long summer dresses whose major purpose was to do some shopping or get the child outdoors. These days, healthy young women jog down the manicured sidewalks by the dozens, far outpacing my plodding and deliberate steps.

Regular hikers at our lake include Harry, a white-bearded, fit man who has lived in the neighborhood since childhood and walks around the lake four or five times every day.  He knows all about the birds, the eagles that nest there and the history of the lake since the early 1920s.

One of my precious possessions that were handed down from my parents was my father’s copy of Audubon’s Birds of America. My mother bought the great volume of paintings for my father for Christmas in 1942, three months after I was born. I often wondered how she afforded it, as she was living on her own while my father was drafted and serving in the army during World War II.  I have used is for years to help identify birds that I come across, though many of these species are now rare or extinct. I have always been entranced with his paintings of birds and vividly remember the pictures of scary vultures and condors that so impressed me as a child.

http://kennethharperfinton.me/2015/04/26/john-james-audubon/

THE DOUBLE CRESTED-CORMORANT

The lake has attracted many species of ducks and geese since the City of Denver drained and remodeled it a few years back.  One bird friend has become quite close this spring. I did not know the name of the bird and dubbed it a long-neck goose. Shades of Chantilly Lace, I am sure. For weeks he stood guard over his next on top of a nearby tree. He seemed to be in his tree every time we walked the lake for many weeks. I learned that the bird was a double-crested cormorant. Cormorants and Shags are medium to large seabirds that are found all over the world. Their ancestors were fresh water birds. Though their feet are webbed, they can perch high in trees. They are related to pelicans. Cormorants are diving birds that can dive to as much as 45 meters in search of fish and eels and water snakes. After their dives, they spread their wings to dry, as their feathers are not as waterproof as a duck of a goose. They have an ungainly hooked beak and have been at war with fishermen for centuries, as they compete for the fish in the area.

 

 

THE HOODED MERGANSER

One of the more impressive and lesser known ducks is the secretive Hooded Merganser. “Hooded” is an understatement for this little duck, also called a Crested Merganser. Adult males are beautiful with sharp black-and-white patterns set off by chestnut flanks. Females have their own distinctive elegance drawn from their from their cinnamon crest.

In the winter, the birds nest in holes left in trees like squirrels, but they move to fresh water lakes in the spring and summer while they hatch their broods.

Hooded Mergansers are fairly common in Colorado on small ponds and rivers. They dive for fish, crayfish and other food, seizing it with their thin, serrated bills.

Though they nest in tree cavities, the ducklings leave the nest with a precocious leap to the forest floor when they are only one-day old. Hooded Mergansers are the smallest of the three Merganser species found in the United States.

Males and females of the Hooded Merganser live in monogamous pairs. They remain together until the female has selected a nesting place and completed the laying her clutch. After that, the male leaves the female to incubate and care for the brood. Females will actively seek out cavities in dead trees or artificial nest boxes such as those provided for wood ducks.They prefer cavities four to fifteen feet off the ground. Breeding occurs anytime between the end of February and the end of June, depending on the region.

The female will lay a clutch of seven to fifteen eggs but only begins incubation when the last egg has been laid. This insures synchronous hatching, so all the ducklings are consequently the same size. This evolutionary trait facilitates efficient parental care. During incubation, the female may lose anywhere from 8% to 16% of her body weight.

Like most waterfowl, Hooded Merganser hatchlings are precocial. They usually leave the nest within twenty-four hours after they hatch. Once they leave the nest, the young are immediately capable of diving and foraging, but they often remain with the female for warmth and protection The Mergansers are descended from a species of ancient ducks from the Late Pleistocene era. The exact relationship between the ancient birds and the modern species is unknown.

THE AMERICAN WHITE PELICAN

Since 1960, Colorado is also home to the American White Pelican, a huge, lovely bird with black feathers on the tip of their wings and a nine-foot wingspread.  They are also found at Berkeley Lake. If you have never seen a White Pelican, you will be amazed when you finally see one. They fly like gliders in formation and land with a precision that would make the Air Force proud.  Most of them die before leaving the nest, but if they survive that first year they can have a twenty year life span. They now breed in Colorado in the spring and summer and move to the southern coasts when winter comes.

THE MALLARDS

Mallards are plentiful in local lakes. They are dabbling ducks that do not dive, but stand on their heads, butts in the air, to nibble on water plants, insects and roots. The males have a glossy green head, a ring of white feathers on the neck and gray areas on the wings. They males are called Drakes. The females have brown-speckled plumage. They form pairs in the fall that lasts until the female lays the eggs in the spring. Then the male often leaves and forms bonds with other males and lets the female raise the brood until the molting season in June.

Mallards are gregarious birds that love to flock together in groups called ‘sords’. The male will forcibly mate with other females, especially if she has lost her mate. Male Mallards remain sexually potent most of the year. When they pair off with mating partners, often one or several drakes are left out. This lonely group of adolescent ducks sometimes targets an isolated female duck, even if she is of a different species, then they chase and peck at her until she weakens. At this point the males take turns copulating with the female.

On 5 June 1995 an adult male Mallard collided with the glass façade of the Natuurmuseum Rotterdam and died. Another drake Mallard raped the corpse almost continuously for seventy-five minutes. The author of a paper on this occurrence disturbed the scene and secured the dead duck. Dissection showed that the rape victim was of the male sex. It is concluded that the Mallards were engaged in an ‘Attempted Rape Flight’ that resulted in the first described case of homosexual necrophilia in the Mallard.

Mallards are the ancestors to most domestic ducks.

 

YOU OLD COOT

Coots are plentiful at our lake. The American coot is also known as a mud hen. Though commonly thought to be ducks, American Coots belong to a distinct order called Rallidae. Coots do not have the webbed feet of ducks, but sport broad, lobed scales on their lower legs and toes that fold back with each step to facilitate walking on dry land. Groups of coots are called covers or rafts.

The oldest known coot lived to be 22 years old.

The American Coot is a migratory bird that occupies most of North America. It lives in the Pacific and southwestern United States and Mexico year-round and occupies more northeastern regions during the summer breeding season. In the winter they can be found as far south as Panama.

The Coot mating season occurs during May and June if they have enough territory. Coots are monogamous throughout their life. The American Coot typically has long courtship periods. This courtship period is characterized by billing, bowing, and nibbling. Billing is the touching of bills between the male and females. Males generally initiate the billing. As the pair bond becomes more evident, both males and females will initiate billing only with each other and not other males or females.

After a pair bond is decided, the mating pair looks for a territory to build a nest. A pair bond becomes permanent when a nesting territory is secured. First the male chases the female. Then, the female moves to the display platform and squats with her head under the water. The male then mounts the female, using his claws and wings to balance on the female's back while the she brings her head above the water. Sex for the coot usually takes no longer than two seconds, thus the expression, “You old Coot.”

Coots generally build floating nests. The female lays 8–12 eggs per clutch. Females and males have similar appearances, but they can be distinguished during aggressive displays by the larger head plumage on the male. 

American Voots eat primarily algae and other aquatic plants but also animals (both vertebrates and invertebrates) when available.

The American Coot has a mixed reproductive strategy. The female practices a form of brood parasitism, a common alternative reproductive method in some birds. When a parasitic female lays her egg in a host female’s nest, the host female lays about two eggs per day. Host females may recognize parasitic eggs when the egg deposition pattern deviates from the traditional one egg per day pattern. The occurrence of brood parasitism may be influenced by the body size of the potential parasitic female relative to the potential host female. Parasitic females are generally larger than their host counterparts, but on average, there is no size difference between the parasite and the host.

The American Coot, unlike other parasitized species, has the ability to recognize and reject conspecific parasitic chicks from their brood. Parents aggressively reject parasite chicks by pecking them vigorously, drowning them or preventing them from entering the nest. They learn to recognize their own chicks by imprinting on cues from the first chick that hatches. The first-hatched chick is a reference to which parents discriminate between later-hatched chicks. Chicks that do not match the imprinted cues are then recognized as parasite chicks and are rejected. Hunters generally avoid killing American Coots because their meat is not as sought after as that of ducks.

Much research has been done on the breeding habits of American coots.

 

THE CANADIAN GEESE

Non-migratory Canadian Goose populations are on the rise. They are a species that is frequently found on golf courses, in parking lots and urban parks. Owing to its adaptability to human-altered areas, it has become the most common waterfowl species in North America. In many areas Canadian Geese are now regarded as pests by humans. They pollute beaches and leave their staining feces in many an unwelcome place. An extended hunting season, deploying noise makers, and hazing by dogs have been used in an attempt to disrupt flocks.

The Canadian goose is a large, wild species with a black head and neck, white patches on the face. It has a brown body and beautiful markings. It was originally a native to the arctic and temperate regions of the far north, but through migration it has reached into northern Europe as well.  Like most geese, the Canadian goose is primarily herbivorous and normally migratory; it tends to be found on or close to fresh water.

These birds are extremely successful at living in areas that humans have altered greatly. Because Canadian geese have been able to establish breeding colonies in urban and cultivated areas, which provide food and few natural predators, they are well known as a common park species. Their success has led to them being considered a pests. Their destruction of crops, their constant honking noise, their copious droppings and aggressive territorial behavior – along with their and their nasty habit of begging for food –  has made them unwelcome in many areas.

Canada geese are also among the most commonly hunted waterfowl in North America.

By the early 20th century, over-hunting and loss of habitat in the late 19th century and early 20th century had resulted in a serious decline in the numbers of this bird in its native range. The giant Canadian Goose subspecies was believed to be extinct in the 1950s, In 1962, a small flock was discovered wintering in Rochester, Minnesota by Harold Hanson of the Illinois Natural History Survey.

During the second year of their lives, Canada geese find a mate. They are monogamous. Most couples stay together all of their lives. If one dies, the other may find a new mate. The female lays from two to nine eggs with an average of five per clutch. Both parents protect the nest while the eggs incubate, but the female spends more time at the nest than the male.

Two years ago, I knew little about ducks and geese. With camera in hand and a love of nature in my heart, I began to gain a new appreciation of the birds that populate our world. According to some estimates, there are about ten thousand different species of birds on Earth presently. Total populations for birds number about two to four hundred billion birds living today, excluding domestic chickens and turkeys.

This is much less than in past ages. We have lost about 500 species since 1500 and 129 known species have become extinct.  This is bad news for the planet, as birds help to pollinate crops and destroy pests. Scavenger birds clean uop the landscape and help with the decomposition of organic materials. Their decline even helps diseases to spread in human populations.

Estimates are that there are ten billion birds in the United States in the spring and twenty billion in the fall.

Winter and hunters kill about ten billion birds in the United States per year.

The American Bird Conservancy estimates that cats kill around two hundred million birds per year in the US alone.

ECLIPSE FOLIAGE

by Kenneth Harper Finton, photos by author

After mating, drake Mallard ducks shed their feather and look like the female. It is called “eclipse plumage”. Above is a Mallard beginning to shed for his eclipse phase.

The Mallard drakes cannot fly when they molt their wing feathers. This period lasts a month or more until they grow new feathers. The hen-like feathers help to protect and conceal them during this flightless period. By late summer, they again molt and grow the spectacular plumage they use fro attract a mate in the mating season.

“Feathers are a marvel of natural engineering, but they require constant care and must be replaced periodically to maintain peak performance. Waterfowl spend a couple hours each day just caring for their feathers. An oil gland at the base of the tail secretes a preening fluid that keeps feathers soft and pliable, which in turn prevents them from breaking, keeps them waterproof, and enhances their aerodynamics. Waterfowl use their bills to distribute this fluid throughout their feathers while preening. Ducks and geese also use their bills to realign their feathers and reconnect any Velcro-like barbules that have become separated.” http://www.ducks.org/conservation/waterfowl-biology/waterfowl-feathers/page2

Ducks and geese rely on their feathers to keep warm. Down and feathers have been a used to keep humans warm for millennia.

The Mallard’s head is usually green but its iridescent feathers reflect and absurd caring amounts of light creating a lustrous shine and changes color depending upon the sunlight and the angle at which it is viewed.

Like anything else, feathers wear out. Plucked and lost feathers are replaced right away, but broken and worn feathers are kept until they molt. All the species are flightless during the molting season until the new feathers replace the old.

“Female ducks molt as well, but differences between their basic and alternate plumage are far more subtle. Hens molt into their basic plumage just before nesting and keep this plumage until after the wing molt and brood-rearing activities are complete. Geese typically undergo just one complete molt a year, which has a much less noticeable effect on the birds’ appearance.” – http://www.ducks.org/conservation/waterfowl-biology/waterfowl-feathers/page2http://www.ducks.org/conservation/waterfowl-biology/waterfowl-feathers/page2

https://www.allaboutbirds.org/guide/Mallard/lifehistory

Cool Facts

•The Mallard is the ancestor of nearly all domestic duck breeds (everything except the Muscovy Duck). Domestic ducks can be common in city ponds and can be confusing to identify—they may lack the white neck ring, show white on the chest, be all dark, or show oddly shaped crests on the head.

•The widespread Mallard has given rise to a number of populations around the world that have changed enough that they could be considered separate species. The “Mexican Duck” of central Mexico and the extreme southwestern United States and the Hawaiian Duck both are closely related to the Mallard, and in both forms the male is dull like the female. The Mexican Duck currently is considered a subspecies of the Mallard, while the Hawaiian Duck is still given full species status.

•Mallard pairs are generally monogamous, but paired males pursue females other than their mates. So-called “extra-pair copulations” are common among birds and in many species are consensual, but male Mallards often force these copulations, with several males chasing a single female and then mating with her.

•Mallard pairs form long before the spring breeding season. Pairing takes place in the fall, but courtship can be seen all winter. Only the female incubates the eggs and takes care of the ducklings.

•Ducks are strong fliers; migrating flocks of Mallards have been estimated traveling at 55 miles per hour.

•The standard duck’s quack is the sound of a female Mallard. Males don’t quack; they make a quieter, rasping sound.

•Mallards, like other ducks, shed all their flight feathers at the end of the breeding season and are flightless for 3–4 weeks. They are secretive during this vulnerable time, and their body feathers molt into a concealing “eclipse” plumage that can make them hard to identify.

•Many species of waterfowl form hybrids, and Mallards are particularly known for this, hybridizing with American Black Duck, Mottled Duck, Gadwall, Northern Pintail, Cinnamon Teal, Green-winged Teal, and Canvasback, as well as Hawaiian Ducks, the Grey Duck of New Zealand, and the Pacific Black Duck of Australia.

•The oldest known Mallard was a male, and at least 27 years, 7 months old when he was shot in Arkansas in 2008. He had been banded in Louisiana in 1981.

Credits

•Drilling, N., R. Titman, and F. McKinney. 2002. Mallard (Anas platyrhynchos). In The Birds of North America, No. 658 (A. Poole and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.

•Dunne, P. 2006. Pete Dunne’s Essential Field Guide Companion. Houghton Mifflin, New York.

•Ehrlich, P. R., D. S. Dobkin, and D. Wheye. 1988. The birder’s handbook. Simon & Schuster Inc., New York.

•North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.

•U.S. Fish and Wildlife Service. 2015. Waterfowl Population Status, 2015. U.S. Department of the Interior, Washington, DC.

•USGS Patuxent Wildlife Research Center. 2015. Longevity Records of North American Birds.

•USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.