PINTAIL POPULATION STATUS

Northern pintails (Anas acuta) are still one of North America's most abundant duck species, but their numbers have declined markedly since the mid-1970’s. In the 2003, the US Fish and Wildlife Service’s 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.

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 1990’s. 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 1990’s 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 1950’s and 1970’s 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.

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 BIOLOGY

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.

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

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:

Objectives:

Methodology

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 (3), South Carolina (8), North Carolina (15), Virginia (3), Maryland (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.

Management Implications

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.

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.

STUDY PARTNERS/PARTICIPANTS

Acknowledgments

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.