PINTAIL POPULATION STATUS
drake pintail trapped with several hens is being aged prior to banding
Northern pintails (Anas acuta) are still one of North America's most
abundant duck species, but their numbers have declined markedly since the mid-1970s.
In the 2003, the US Fish and Wildlife Services May Breeding Population and
Habitat Survey (May Survey), estimated that the pintail population was 39% below
their long-term average (1955 - 2003) of 4.2 million, and 56% below the population
objective of 5.6 million outlined in the North American Waterfowl Management Plan.
breeding population estimates for pintails, surveyed over their traditional prairie
pothole breeding grounds
In the past, ducks in mid-continent North America have waxed and waned in response
to respective periods of wet years and drought. The estimated number of prairie
wetlands in the May Survey reached record highs in the late 1990s. Mallards
(Anas platyrhynchos) reached an all time record high in the May Survey
in 1999, as did gadwalls (Anas strepera) and Northern shovelers (Anas clypeta)
in 1997. In the late 1990s both green-winged (Anas crecca) and blue-winged
teal (Anas discors) increased to more than 40% above the long-term average
and even wigeon (Anas americana) were 20% above the long-term average.
However, pintails did not respond to the wet habitat conditions as expected. The
poor response by pintails is troubling given large populations reached during
previous periods of abundant habitat in the 1950s and 1970s and the
current responses observed by other dabblers.
Biologists have posed numerous reasons for the failure of pintails to recover
to population levels seen in past prairie wet cycles. Pintails have a preference
for shallow-water breeding habitats that are the most susceptible to agricultural
drainage. They have a strong tendency to nest in open habitats, frequently in
grain stubble fields. As such, many pintail nests are destroyed each spring by
farming practices. Pintails also have a tendency to be early nesters and as such
hens and their nests may be more vulnerable to predation.
May breeding population and habitat survey, traditional survey area
Some research suggests that early nesting ducks such as pintails may be more
susceptible to nest zredation than late nesting species such as gadwall. During
the lean times of early spring, predators may home in on the few nesting ducks
available whereas predators may have less of an impact later in the season when
the landscape is swamped with nesting birds. Nests in open habitats may also be
easier for predators to locate. Pintails, like most other dabbling ducks, will
attempt to renest after failing an initial nesting attempt. However, pintails
are less persistent at renesting than other species like mallards. Few pintails
will attempt renesting after a failed second attempt. Add to the poor recruitment,
several recent, severe late summer outbreaks of avian botulism in mid-continent
North America where many pintails have succumbed.
Many of the pintails that fall victim are undoubtedly failed breeders that
tend to concentrate at these molting sites where the botulism events occur. In
addition to these problems identified on the breeding grounds there are exist
problems on key wintering areas. The western United States has experienced losses
of wetlands and water shortages due to development and agriculture. These areas
are critical stop-over sites during migration. In the Gulf states particularly
Texas, a declining rice culture industry is suspected to have reduced the amount
of high quality habitats utilized by wintering pintails.
Pintail pair at Tule Lake National Wildlife Refuge, courtesy of Dave Menke/USFWS
In eastern North America, pintails begin to arrive in September although significant
numbers are not present until October with the peak arriving in November. While
migrating through New Jersey, pintails can often found in association with flocks
of green-winged teal. In New Jersey, pintails are most numerous during the fall
and winter in tidal freshwater, brackish and salt marshes from Camden to Salem.
Along the Atlantic Coast large concentrations of pintails can be seen around the
impoundment's of the Edwin B. Forsythe National Wildlife Refuge. In the Atlantic
Flyway, significant numbers of pintails winter from New Jersey to Florida.
May National Wildlife Refuge manager, Howard Schleigal prepares to release a drake
pintail, where many of the pintails were trapped
Pintails are one of the earliest nesting ducks in North America, and their
presence in New Jersey in late February and March is a sure sign that spring is
on the way. While the fall migration is protracted, the northward, spring migration
is focused into a relatively short period of time between late February and mid
March. During this time, pintails concentrate primarily in tidal freshwater marshes,
which drain into the Delaware River and Bay. Key spring staging areas for pintails
include the Maurice River, Mannington Meadow and the numerous freshwater tidal
creeks from Pedricktown to Woodbury. On an aerial survey conducted by Division
Waterfowl Program personnel in late February 2004, nearly 30,000 pintails were
counted in these marshes. These marshes serve as critical staging areas, where
birds can feed on small seeds, and invertebrates in the muddy substrate, gathering
precious resources needed for the final leg of migration, and reproduction.
Pintails have the widest distribution of any species of waterfowl in the world.
In North America, pintails nest across the northern portion of the continent with
key concentrations found in the US and Canadian prairies as well as in the Alaskan
and Canadian Arctic. They tend to prefer open areas where vegetation is low or
sparse. More than any other species of waterfowl, pintails nest in agricultural
type habitats. Nest sites are frequently located in stubble fields, roadsides,
hayfields, pastures, and grain fields. On average, nest sites are located within
40 yards of water. On average female pintails lay 8 eggs, but clutch sizes range
from 3 to 14.
PINTAIL SATELLITE STUDY
Paul Castelli examines a hen, checking the fit of the satellite transmitter
Waterfowl hunters in the Atlantic Flyway have long regarded pintails as "trophy"
birds. This status can be attributed to the pintails' striking plumage, their
exceptional wariness and difficulty in decoying, exceptional table quality, and
their relative low abundance when compared to other ducks in eastern North America.
However, despite the high regard that exists for this species, relatively little
is known about the status of pintails that winter in the Atlantic Flyway. Less
than 4% of all pintails banded in Canada and less than 8% of all pintails banded
in the United States during 1966-1999 were harvested in the Atlantic Flyway.
The small proportion of band recoveries in the east calls to question the
relationship of pintails wintering in the Atlantic Flyway to the entire continental
population. For mallards, banding studies have revealed that only a small portion
of the mid-continental population is recovered in the Atlantic Flyway, particularly
in northern states. The question became: Is it plausible to assume that the same
relationship may apply to pintails?
To augment the knowledge gap that exists for pintails that winter in the Atlantic
Flyway, researchers and managers at USGS New York Cooperative Wildlife Research
Unit at Cornell University and the South Carolina Department of Natural Resources
launched a pilot pintail satellite telemetry study during the winter of 2003.
After working out a few of the glitches in the pilot study it was expanded in
the winter of 2004 to include marking 39 adult female pintails with satellite
telemetry transmitters in the six Atlantic Flyway states of New Jersey, Maryland,
Virginia, North Carolina, South Carolina and Florida. Females were chosen over
males for being telemetered with the 20-gram, backpack type transmitters, since
females have a higher propensity to return to natal breeding areas. Adult females
were chosen over juveniles since the larger bodied adults would be more likely
to handle any stress associated with the added weight of the transmitter. The
primary objectives of the current study are to:
- To assess the breeding ground affiliations of female pintails wintering in
the Atlantic Flyway
- To describe the chronology of pintail migration
- To identify spring and fall staging and/or stop over areas used during migration
close-up of of the backpack satellite transmitter on hen #39562
Satellite tracked radio transmitters were placed on adult female pintails trapped
at wintering locations between New Jersey and Florida. Each transmitter weighed
approximately 20 grams and was attached by a backpack style harness made of Teflon
ribbon. Each unit also included a 0.5-gram UHF transmitter designed to facilitate
retrieval if death or transmitter failure occurs prior to the birds departure
on migration. Each transmitter was programmed to provide a location fix (coordinate)
once every 6 days over a 10-month interval. This allows the determination of weekly
movements to and from breeding and wintering sites and establishes time and location
fixes for all major areas used during the year.
We began capturing pintails after the waterfowl hunting season closed. In New
Jersey, we employed baited funnel traps and rocket nets for capturing them. Pintails
were captured and marked in Florida
Carolina (8), North
Carolina (15), Virginia
(4), and New Jersey (6). Participating states have indicated that they may develop
a web site plotting the movement of birds telemetered in their state.
In 1995, the U.S. Fish and Wildlife Service adopted the concept of adaptive
resource management for regulating duck harvests in the U.S. Now termed, adaptive
harvest management (AHM), the process tests alternative hypotheses of population
dynamics as a basis for setting harvest regulations. The mid-continent mallard
population is the principle species for the models used in AHM. In 2000, model
sets for eastern mallards were incorporated into the AHM process because significant
differences were found in the breeding ground derivation and recruitment of this
group of birds.
#39561 is being released at Cape May National Wildlife Refuge
Sufficient data does not exist for application of the AHM process to other
duck species, including the northern pintail; although model sets for pintails
have been developed and are being tested. These species generally are exposed
to: 1) a common hunting season based on criteria established for mallards, and
2) somewhat arbitrary species-specific restrictions based on efforts to account
for variation in the ability of different duck species to support harvest without
adverse impact (USFWS 2002).
Stocks of pintail ducks and other dabbling duck species wintering in the Atlantic
Flyway therefore remain poorly defined in terms of their breeding ground affiliation
and relationship to present harvest management strategies as influenced by the
dynamics of mallards. This study will provide new data to better address harvest
management of pintails in the Atlantic Flyway.
The North American Waterfowl Management Plan remains the most ambitious continental
effort to restore waterfowl populations. Numerous Joint Venture initiatives involving
public and private sector partnerships are making tremendous strides toward the
conservation and management of wildlife habitat. This project offers an opportunity
to look at movement patterns of pintails sampled over a broad expanse of the wintering
habitat used in the Atlantic Flyway. Data gathered during this study will have
specific application in the east to the Atlantic Coast Joint Venture and could
impact the knowledge base for other Joint Ventures across the continent.
The New Jersey Division of Fish and Wildlife would like to thank the New
Jersey Waterfowlers Association for donating funds for the purchase of satellite
telemetry unit used in this research. We would also like to thank the staff from
Cape May National Wildlife refuge staff for their assistance in capturing pintails.