Waterfowl

Introduction

Ducks, geese, and swans belong to the family Anatidae, commonly know as waterfowl. There are about 150 species of waterfowl worldwide. In Maine, 34 species are found:15 species are residents during the breeding season, 18 species winter in Maine, and all 34 species migrate through Maine. Eleven dabbling ducks, 13 diving ducks, 6 sea ducks, and 4 geese comprise the 34 species of waterfowl found in Maine.

Molt. Once birds reach adulthood, they have at least one annual and complete replacement of their plumage (feathers). This process is referred to as the molt. In addition to this annual molt, males of many species of ducks molt into a more colorful plumage prior to the breeding season, and females molt into a duller plumage prior to nesting to be better camouflaged. Geese have only one plumage and molt once a year. During the annual molt, waterfowl have a complete and simultaneous molt of their wing feathers, which leaves them flightless for 2 to 4 weeks. Ducks often desert their breeding grounds, prior to the molt, in search of food-rich waters and areas that provide protection from predators while they are flightless. The molt occurs during the post-breeding period for male ducks, and during the brood rearing period for geese and female ducks.

Did you Know?

  • That breeding female eiders that have lost their eggs or ducklings are called Aunt's. They help protect ducklings of successful breeders from predators.
  • The common eider is the largest duck in North America and has the largest egg.
  • Incubating female eiders cover the eggs with down when they leave the nest to keep the eggs warm.
  • Some waterfowl species will migrate hundreds of miles to areas where they molt their worn feathers.
  • Some species of ducks will lay eggs in the nest of another duck leaving the other duck to incubate the eggs.
  • Red-breasted mergansers do not nest in tree cavities like the common and hooded mergansers; they nest on the ground.

Migration. As a whole, waterfowl make tremendously long migratory flights, traversing thousands of miles from their breeding grounds to their wintering grounds. This migratory nature is affected by the seasonal availability of food resources and favorable climate conditions. During migration, waterfowl often fly continuously and land only when they are exhausted or weather conditions make flying difficult. Most fly at 40-60 miles per hour and fly from a few feet above the water to over 20,000 feet above sea level. The altitude of migration depends on terrain and the distance flown.

Survival. Hunting, predation, starvation, disease, and accidents (e.g. striking power lines, drowning in fishnets, oil spills, etc.) are common sources of mortality for waterfowl. Unhatched eggs, ducklings before they reach flight stage, nesting hens, and flightless birds during the molt are the most vulnerable to predators. Common predators are small mammals (raccoons, skunks, fox, etc.), birds (gulls, owls, eagles, etc.) and snakes. Disease is probably the most important source of non-hunting mortality and can reach epidemic levels. Common diseases associated with waterfowl are botulism, fowl cholera, duck virus enteritis, and lead poisoning.

Longevity. Generally, sea ducks and diving ducks live longer than dabblers and geese are the longest lived of all waterfowl. Maximum life-span recorded from band returns were 23 years for a Canada goose, 8-23 years for dabbling ducks, 12-21 years for diving ducks, and 11-18 years for seaducks. The variation in life span is species dependent. For example, among the dabblers, a European widgeon had the lowest and a mallard had the longest maximum life span.

Historical Management in Maine

Distribution and Population Trends. Records of waterfowl numbers during settlement by Europeans are not available, but, in general, it is believed that waterfowl were more numerous then. In the 1950s, development of surveys, inventories, and banding programs provided indices to the population status of waterfowl. From 1950-1985, productions surveys in Maine have shown variable trends in Maine's common breeding waterfowl. Ring-necked ducks, hooded and common mergansers, mallards, and blue-winged and green-winged teal have increased. However, black ducks, wood ducks, and goldeneyes have been declining.

Harvest Trends/Statistics and Season Changes. Waterfowl harvests in the United States have been declining since 1978. This decline is a result of a combination of factors: hunter numbers have been declining, waterfowl populations were lower during the 1980s, and hunting regulations were more restrictive.

Hunting Tips

  • Set decoys close to your blind with one decoy at least 40 yards out.
  • Be ready to dispatch cripples as soon as they hit the water and before they swim out of range.
  • Know your equipment
    • pattern your shotgun with hunting loads.
    • practice shooting clay-pigeons prior to the
      season.
  • Carry safety and first-aid equipment on all hunting trips.
  • Remain still when birds are approaching your set. Move only at the last moment before shooting.

In Maine, during the last 20 years, waterfowl hunter numbers have been declining steadily. Since the five year period, 1976-80, a 43% decline in the average number of duck stamps sold has been observed (Table1).
Declines in black duck populations since the mid 1950's, led to a harvest reduction plan in the United States and Canada. Waterfowl hunting season lengths were shortened from 50 days to 30 days between 1985-1993. Bag limits were also reduced from 5 to 3 birds per day, and special individual species restrictions of 1 black duck, 1 pintail, and 1 hen mallard were instituted. Between 1983 and 1987, black duck harvests were reduced in the U. S. by 42% and in Maine by 61%. In 1988, when 30 day seasons were first required, the prohibition on black duck hunting in early October was lifted. Season lengths increased in 1994 to 40 days and again in 1996 to 50 days, but the black duck season remained reduced.

Dabbling Ducks

Description

Dabbling ducks common in Maine are the American black duck,the mallard, green-winged teal, blue-winged teal, and wood duck. Northern shoveler, Northern pintail, gadwall, European widgeon, American widgeon and fulvous whistling ducks also occur in Maine, but are less common. Dabblers feed by dabbling at the water surface or by "upending" submerging their head and pitching their tail up. They will also feed on land in open areas. Several dabblers have bills adapted for straining tiny items out of muddy water. Females are mostly brown with spots or stripes, which helps them blend in when nesting. Males are generally more brightly colored, but some have similar plumage as the female (e.g. black duck). The male wood duck in its breeding plumage has earned the title of the most beautiful duck in North America. The crest of the head is iridescent green in front to purplish in the rear, burgundy feathers are found behind each eye, and the sides of the head are purple, blue-green, and bronze.

Natural History

Habitat and Food Habits. Black ducks, mallards, and pintails utilize a range of habitats (brackish, salt, and freshwater marshes, lakes, rivers, and beaver ponds), which leads to a diverse diet ranging from seeds of aquatic plants, to cultivated crops, to mollusk. Mollusk are less important part of mallards and pintails diet. Wood ducks inhabit streams, rivers, flood plains, lakes, swamps, and beaver ponds. Acorns, when available, are the favored food of wood ducks. Green-winged and blue-winged teal have similar food habits and often feed together on mud flats and shallow marshes. Green-winged teal are primarily vegetarians, whereas, blue-winged teal will eat some animal life.

Reproduction. Dabbling ducks first breed as one-year olds and begin nesting in March and April. The blue-winged teal is the last to reach its breeding grounds and thus nests the latest of all dabblers. Dabbling ducks form short pair bonds that weaken during the onset of incubation. Some pair bonds only last a few days after incubation begins whereas others maintain the bond up to 3 weeks into incubation. Dabbling ducks lay a clutch of 5-15 eggs with the average nest having 10 eggs. Incubation and nest success is variable among species. Hens incubate eggs for 22-30 days. Nest success ranges from 32-75%. Gadwell's have the highest nesting success and green-winged teal have the lowest. Green-winged teal nesting success may be an underestimate, because nests and broods are difficult to observe. Most wood ducks establish pair bonds in late fall and winter and migrate to their breeding areas in pairs. Drake woodies remain with their mates longer than most ducks, allowing them opportunity to renest if their initial nest is lost. Wood ducks incubate their eggs for 28-37 days longer than other dabblers. Like common and hooded mergansers and common goldeneyes, wood ducks nest in tree cavities. A wood duck's average clutch size is 8-10 eggs. However, more eggs may be in a nest due to "dump nesting". Dump nesting refers to the activity of another duck laying her eggs in an established nest and leaving. The hen who established the nest may incubate the eggs or abandon the nest.

Diving Ducks

Description

Diving ducks common in Maine are ring-necked ducks, common goldeneyes, buffleheads, hooded mergansers, and common mergansers. Greater scaups, lesser scaups, Barrow's goldeneyes, red-breasted mergansers, canvasbacks, redheads, and ruddy ducks are less common in Maine. Diving ducks feed by diving from the surface and swimming underwater. They propel themselves through water with powerful strokes of their feet. Some also hold their wings partly open when submerged. Females tend to be evenly colored with shades of brown and, unlike female dabbling ducks, they do not have spots and stripes. Males are strikingly patterned in black and white. Mergansers are the only ducks that specialize in eating fish, and their bills are serrated to help grasp slippery fish.

Natural History

Habitats and Food Habits. The diet of diving ducks consists of aquatic vegetation (pondweeds, wild celery, delta duck potato, bulrus seeds, widgeon grass, eelgrass, etc.) and animal life (aquatic insects, fish, and mollusk). Ring-necks and redheads typically feed in shallower water, sometimes so shallow they do not need to dive. Merganser's diet consist primarily of fish and crustaceans, and the hooded merganser has the most diverse diet among the mergansers. Greater scaup feed on both plant and animal life, but clams constitute a major portion of their diet. Lesser scaup, with the exception of sea ducks, feed in deeper water than any other diver, typically 10-25 feet deep. Lesser scaup feed primarily on animal life.

Reproduction. Diving ducks typically first breed at 1 year of age, however scaup do not breed until 2 years of age. Diving ducks begin pairing in late winter, and pair bonds are generally established by early spring. Diving ducks have a strong homing ability with a large percentage of them returning to the same breeding areas each year. Hens begin nesting as early as April and as late a June with lesser scaup nesting late. The average nest has 9 eggs and hens incubate their eggs for 21-29 days. The hatching rate of eggs is variable among diving ducks ranging from 25-70%. Both scaup species have the lowest nesting success rate. Nest failure is caused by predation, flooding, and desertion. Predation is the greatest factor attributed to nest failure. Diving ducks may renest if they lose their nest early in the breeding season; but mergansers do not renest after loosing their initial nest, because males leave the breeding areas early. Mergansers breed later (2 years), have longer incubation period (22-37 days), and nest earlier (Feb. to April) than other divers. Like other diving ducks, they have strong homing instincts and produce similar clutch sizes.

Geese

Description

The snow goose, white-fronted goose, Canada goose, and Atlantic brant occur in Maine. The white-fronted goose, snow goose and Atlantic brant are only observed in Maine as they migrate through. The Canada goose is the only goose that breeds, winters, and migrates through Maine. Unlike ducks, a goose's plumage does not differ between males and females and subadult and adult geese. Canada geese have a black bill, black legs, black feet, and black neck. Their head is also black with a white cheek patch, and their wings and back are brown.

Natural History

Food Habits. The Canada goose, more than any other species of waterfowl, has benefited from the production of crops. Geese browse on grasses and the leaves of clovers and consume cultivated grains. Clover, barley, wheat, rye, alfalfa, timothy, fescues, corn, oats, buckwheat, grain sorghums, and soybeans are among the most preferred. Large and open grain fields with an undisturbed body of water nearby to provide security, are essential.

Reproduction. Most Canada geese return to the same breeding area year after year and nest the earliest of any waterfowl. Birds begin nesting as early as March to as late as May, depending on the latitude of breeding areas.Canada geese form life-long pair bonds with their mate, but if their mate dies, the survivor will seek a new mate. Some Canada geese breed as early as two years of age, but most breed for the first time at three years of age. The average clutch size is five eggs, but can range from 1-12 eggs per nest. The female incubates the eggs and may leaves the nest periodically to feed. The male watchfully guards the hen while she is on and away from the nest. The hen incubates her eggs for 25-30 days. About 70% of nesting pairs successfully hatch their eggs. Nest failures are caused by desertion, destruction of nest by predators, and destruction of nests by natural agents (e.g. flooding). Desertion and destruction of nest by predators account for about 90% of all failed nests. Some geese will renest after losing the first nest.

Survival. There is a wide range in mortality rates for geese due to the degree of shooting pressure. Immature birds have a higher mortality rate (39-65%) than adults (23-46%), and males have a higher annual mortality rate than females.

Historical Management in Maine

Distribution and Population trends. Prior to 1960, a breeding populations of geese was not present in Maine. The Department began a trap and transfer program of Canada geese from New Hampshire, New York, and Connecticut to establish a breeding population of geese in Maine. Also, the United States Fish and Wildlife Service trapped and transferred geese and raised them in pens on the Moosehorn National Wildlife Refuge. The young of these captive geese where released on the refuge to establish a local population. Due to these efforts, a resident goose population has been established and is increasing in Maine.

Season Changes. In 1995, the regular goose season was closed due to low production on the breeding areas coupled with overharvest. In 1996, a special early season was established to allow some harvest of resident Canada goose populations. This early season allows hunting between September 1 and September 25 in northeastern states.

Past Management Goal and Objectives. During the 1980 planning period, the goal was to increase the distribution and abundance of Canada geese in remote portions of the State in order to provide increased use opportunity. The objective was to establish naturally sustaining flocks at 20 new locations in remote portions of the State.

Current Management in Maine

Current Distribution. Based on observations from brood counts, Canada goose populations have increased in all regions.

Current Management Goals and Objectives. During the 1985, 1991, and 1996 planning periods, the goal was to increase breeding waterfowl populations to maximize fall populations. To meet this goal, two Abundance Objectives, a Harvest Objective, and a Habitat Objective were established. The first Abundance Objective is to increase the distribution of Canada geese in WMU's 1,2, and 3 by 50% by 2001. The second Abundance Objective is to reduce the non-legal mortality of waterfowl populations by 25% by 2001. The Harvest Objective is to provide Maine hunters the maximum annual hunting opportunity through 2001, which will allow for achievement of the abundance objectives and be consistent with the Federal framework. The Habitat Objective is to maintain the quantity of wetland habitat at current levels (1990).

Management Challenges. Because the regular goose hunting season is closed to allow migrant stocks to recover from earlier over-harvest, the Department's biggest challenge is to provide hunting opportunity for Maine goose hunters and control expanding flocks of resident Canada geese.