Science Center Objects

Patuxent has a long history of research activities supporting the management and conservation of waterbird populations. Current research interests include studying the movements and migration ecology of sea ducks and other waterbirds along the Atlantic Coast, a long-term demographic study of Roseate Tern populations, and the use of restored island habitats by nesting terns. Patuxent scientists developed many analytical tools used to develop estimates of demographic parameters of waterfowl populations, critical support for the management of these important gamebirds. These tools are now employed for demographic analyses for waterbird populations around the world. In addition to research projects, Patuxent scientists compiled historic colonial waterbird survey data to support efforts to manage these species of conservation concern.

Banding a Least Common Tern Chick

A member of the field crew holds a recently banded least tern chick, displaying both its metal permanent band and its plastic field readable band. (Public domain.)


Productivity of Species of Concern – Least Tern and Common Tern on Poplar Island Restoration Site

Concern has been raised over productivity of two important tern species that have colonized Poplar Island Environmental Restoration Project (PIERP): the Maryland state-listed Least Tern (Sternula antillarum) and Common Tern (Sterna hirundo). Over the 14 year monitoring period at PIERP (beginning 2002), hatching and fledging success of these species has been variable, believed to be linked with natural stressors including avian and mammalian predators and severe weather events.





Black Duck, Anas rubripes, Breeding Range Map

Black Duck, Anas rubripes, Breeding Range Map (Public domain.)

Population Change and Abundance of Black Ducks and Mallards in Eastern North America

Over the last half of the 20th century, the breeding range of American black duck (Anas rubripes) has contracted from central Canada and the Northeastern United States toward eastern Canada. This reduction in size of the breeding range has been reflected in a steady decline of black ducks counted during winter surveys, both the midwinter Waterfowl Survey conducted by the U. S. Fish and Wildlife Service and the Christmas Bird Count. The causes of the declines are unclear. Hunting regulations have been restricted to decrease the harvest. To improve our understanding of black duck population dynamics and of the role of harvest in population change, a variety of surveys, banding studies, and research activities have been conducted for this economically important species. Patuxent staff have been active participants in these activities, and have served on the Technical Committee and Management Board of the Black Duck Joint Venture of the North American Waterfowl Management Plan. Here, we describe Patuxent’s role in assisting with development and analysis of surveys for black ducks in eastern Canada.


American Black Duck.  Photo by Jonathan Fiely.

(Credit: Jonathan Fiely, USGS Patuxent Wildlife Research Center. Public domain.)


Vulnerability Assessment of Available Habitat for Wintering Black Ducks within the Refuge System in the Chesapeake Bay

Executive order 13508 Chesapeake Bay Strategy requires a three-year average wintering black duck populations in the Chesapeake Bay watershed of 100,000 birds by 2025. Recent average at 37,158 black ducks in the Chesapeake Bay. By 2017, National Wildlife Refuges will increase by 10 percent the availability of food resources to support energetic carrying capacity for wintering black ducks on refuge lands located within the Chesapeake watershed. The increase of food resources on refuges will be accomplished through active wetland restoration and management, habitat protection, invasive species control and potential expansion of refuges.



Surf Scoter:  Male surf scoter instrumented with silicone harnesses GSM transmitter being held by Sarah Fitzgerald.

Surf Scoter: Male surf scoter instrumented with silicone harnesses GSM transmitter being held by Sarah Fitzgerald.  (Credit: Jonathan Fiely, USGS Patuxent Wildlife Research Center. Public domain.)






Effects of Dorsally Mounted Solar-powered Cellular GPS Transmitters on Diving and Foraging in Surf Scoters and Red-throated Loons

Numerous proposals for construction of offshore wind farms have scientists racing to determine seabird migration routes and habitat use throughout coastal waters. Two common species of primary concern are redthroated loons (Gavia stellata) and surf scoters (Melanitta perspicillata). While much valuable data has been collected on these species through the use of implantable satellite transmitters, a solution is needed to address poor location estimates (>250 m) and large time gaps between location approximation (~3days). Additionally, mortality rates are above desired levels with implantation of satellite transmitters. In contrast, Solar-powered GPS transmitters allow for almost continuous location collection with location estimates within 18 m. However, to date, little success has been seen with the development of a longterm attachment method of external transmitters in sea birds.







Canada Geese from the National Capital region

Bacteria from the gut of Canada Geese from the National Capital region are being identified using next-generation DNA sequencing.  (photo credit: (Public domain.)




Analyzing the Gut Microbiome of Urban Canada Geese

The Canada Goose, Branta canadensis, was historically a highly migratory species.  However, this species has recently established resident populations in urban, suburban, and agricultural areas in many parts of the U.S., including the Chesapeake Bay region.  The enormous success of these populations has led to consideration of this species as a nuisance, largely due to its excessive droppings and aggressiveness towards humans.  Large amounts of droppings in urban and suburban environments, especially on parks, lawns, and golf courses, are potential sources of bacteria, archaea, and viruses and thus may represent a significant health hazard to human populations in these areas.



Colorbanded Roseate Tern, Sterna dougallii

Color banded Roseate Terns that can be identified repeatedly at distances up to 50 meters or more are providing a wealth of new information about the movements, behavior, and population dynamics of this endangered species. (Public domain.)





Modeling Sex-specific Demographic Rates in Metapopulations

Research that integrates population dynamics and ecological studies is needed to identify the causal factors involved in population declines and viability. For highly mobile organisms such as birds, “between-patch” movements and the use of different geographic sites and habitats at various stages of the annual cycle can make it difficult to measure the effectiveness of “within-patch” site-specific management activities. These local restoration activities must be evaluated within the context of overall population changes on a regional or metapopulation scale. The major objective of this study is to develop new multistate capture-recapture/resighting and ultrastructural models to examine sex- and age- specific regional survival, movement, and recruitment rates. Once developed and tested with data collected from a long-term regional metapopulation study of a suitable species, these general types of models can be adapted for widespread use on a variety of other species.





Northern Pintail, Anas acuta

Northern Pintail, Anas acuta (Public domain.)




Integrating Habitat and Harvest Management for Northern Pintails

Several blue-ribbon panels have challenged the waterfowl management world to recognize the linkages between the two primary management frameworks: harvest management under the Migratory Bird Treaty Act, and habitat management under the North American Waterfowl Management Plan. Because these two frameworks seek to manage the same populations, there needs to be better coordination, in planning, in modeling, in monitoring, and in decision-making.




Mallard (Anas platyrhynchos) post-sampling and ready for release (Public domain.)






Avian Influenza

Avian influenza outbreaks can result in significant economic loss, as in 2014-2015 when the Congressional Research Service estimated losses of $3.3 billion dollars from the death and culling of domestic poultry due to an outbreak of this disease.  Patuxent’s avian influenza research seeks to answer such questions as “How far can a bird carrying this virus travel?” and “What influences the transmission of this disease between wild birds and poultry?”