Maryland Lt Governor Mike Steele visited Patuxent today to meet the Director, Research Managers, Scientists, and staff. Following an overview of the Research Center by Dr Judd A. Howell, Center Director of Patuxent, Lt Governor Steele met at length with scientists and staff to discuss on-going research at Patuxent. Although his very full schedule would not permit an extended visit, Mr Steele was apparently very pleased at his warm reception and promised to return soon for a more complete tour of our Center. We were fortunate to receive a visit by the Lt Governor so soon after his inauguration which evidences his interest in the environmental science in which Patuxent is engaged. 

Maryland Lt Governor Mike Steele (center) watches a video and discusses Seaduck Research with Edward Lohnes (left) and Dr Matthew C Perry (right).

Patuxent Scientist Guntenspergen is one of Authors of "Differences in Distribution of Modified Basins and Ducks Relative to Roadside Transects"

WETLANDS: Vol. 23, No. 1 - March 2003 DIFFERENCES IN DISTRIBUTION OF MODIFIED BASINS AND DUCKS RELATIVE TO ROADSIDE TRANSECTS Jane E. Austin, Glenn R. Guntenspergen 1, H. Thomas Sklebar, and T. K. Buhl U.S. Geological Survey Northern Prairie Wildlife Research Center Jamestown, North Dakota, USA 58401

E-mail: jane_austin@usgs.gov  U.S. Geological Survey Patuxent Wildlife Research Center University of Minnesota Natural Resources Institute 5013 Millers Trunk Highway Duluth, Minnesota, USA 55811

Abstract: Wetland basins in the Prairie Pothole Region of the U.S. are commonly modified by excavation (e.g., roadside ditches, stock dugouts), partial drainage (ditching), and diking. Differences in the distribution of modified wetlands may affect the predictive accuracy of waterfowl survey data if such wetlands are not distributed randomly in the landscape and if waterfowl are not distributed equally among them. We used data collected on thirty-eight 40-km2 plots in North Dakota to examine the distribution of modified basins relative to roadside transects and their use by five species of dabbling ducks in 1995. The 800-m-wide transects were subdivided into an inner 400-m transect, centered on the road, and the remaining outer transect area. We compared the distribution of modified and natural wetland basins among three sample areas: 1) the inner 400-m wide roadside transect area, 2) the outer transect area, and 3) the remaining area within the 40-km2 plot that was outside of the transects (outer plot). Duck use was compared between the two transect areas. The plots contained 20,582 basins, of which 88.5% were unmodified, 7.5% were excavated, 3.7% were partially drained, and 0.2% were diked. Nearly all excavated temporary (89%) and seasonal (90%) basins occurred in the inner transect area, reflecting the high proportion of basins that would be defined as roadside ditches. Excavated semipermanent basins were more evenly distributed among the outer plot and two transect widths; these basins often were dugouts but also included roadside ditches. Partially drained and diked basins also were fairly evenly distributed among the three sample areas. Semipermanent basins had greater use by mallards (Anas platyrhynchos) and northern pintails (A. acuta) when they were partially drained than when they were excavated or unmodified; pintails also had greater use of partially drained seasonal basins. Use of wetland basins by gadwall (A. strepera), blue-winged teal (A. discors), and northern shovelers (A. clypeata) did not differ among water regimes or modification. We found no evidence to indicate that duck numbers determined from standard 400-m-wide roadside transects were biased relative to the larger landscape. However, pond counts derived from such transects were biased. Correlations of duck numbers to pond counts that exclude ditches or temporary basins would poorly reflect the response of ducks to available water.

Contact: Dr. Glenn R Guntenspergen Voice 218-720-4307 Fax 218-720-4328 glenn_guntenspergen@usgs.gov 

Link and Doherty--Authors of "Scaling in Sensitivity Analysis" in Ecology

Contact: Dr William A. Link 301.497.5631

Canus, a one-winged whooping crane instrumental in re-establishing this endangered species as part of the United States Geological Survey’s (USGS) captive breeding program, died last weekend of natural causes at the agency’s Wildlife Research Center in Laurel, Maryland. Canus was just a few weeks short of his 39th birthday. Scientists believe that the average life span of a whooping crane runs from 25 to 30 years, although captive birds can live much longer.

"Canus, the individual may be gone, but his legacy will persist in the ever-growing populations of wild whooping cranes in North America," USGS Patuxent Center Director Judd Howell said. "He was a great symbol for restoration of wildlife populations and he will be missed."

Canus, named as a symbol of cooperation between Canada and the United States, was a long-time participant in both the Fish and Wildlife Service's (FWS) and the USGS efforts to preserve and restore wild whooping crane populations in North America. He sired a large portion of the whooping cranes in captivity and is the progenitor of many that have been released in the wild. The first whooping crane to fledge in the US in 60 years, is a descendent of Canus.

"Although Canus’ role as a sire helped in bringing the whooping crane back from the brink of extinction, teaching us how to keep his species alive and how to breed them was really his most significant contribution," said Kathleen O’Malley, of the USGS’s Captive Breeding Program. " When Canus became a resident at Patuxent, we had to learn what to feed whooping cranes, how to get them to breed, and how to keep their eggs alive. The staff is really shaken up over Canus’ death," said O’Malley, who still finds it hard to talk about.

Canus was rescued from the wild with a fractured wing in 1964 when there were just 42 whooping cranes left in world. The number had dipped as low as 17 before rebounding due to the protection of critical habitat in both the US and Canada, and the joint efforts of both countries to save the birds, including captive breeding efforts. After a period of time in Colorado, Canus was shipped to Maryland in 1966 to become the first whooping crane in the endangered species recovery program at Patuxent, which was then part of the FWS. Today, the whooping crane population stands at approximately 420, ten times what it was when Canus came to Patuxent.

For more information on Whooping Cranes and the Captive Breeding Program at the USGS Patuxent Wildlife Research Center, visit our website at http://www.pwrc.usgs.gov  or visit our regular whooping crane report at: http://whoopers.usgs.gov/ 

See related story in the Washington Post: http://www.washingtonpost.com/wp-dyn/articles/A40701-2003Jan24.html 

CANUS 1964-2003
At Patuxent 1966-2003

Patuxent's Kendall and Nichols are Authors of "Estimating State-Transition Probabilities for Unobservable States using Capture-Recapture/Resighting Data" in Ecology

Kendall, William L., James D. Nichols, 2002: ESTIMATING STATE-TRANSITION PROBABILITIES FOR UNOBSERVABLE STATES USING CAPTURE-RECAPTURE/RESIGHTING DATA. Ecology: Vol. 83, No. 12, pp. 3276-3284.

Abstract: Temporary emigration was identified some time ago as causing potential problems in capture-recapture studies, and in the last five years approaches have been developed for dealing with special cases of this general problem. Temporary emigration can be viewed more generally as involving transitions to and from an unobservable state, and frequently the state itself is one of biological interest (e.g., nonbreeder). Development of models that permit estimation of relevant parameters in the presence of an unobservable state requires either extra information (e.g., as supplied by Pollock's robust design) or the following classes of model constraints: reducing the order of Markovian transition probabilities, imposing a degree of determinism on transition probabilities, removing state specificity of survival probabilities, and imposing temporal constancy of parameters. The objective of the work described in this paper is to investigate estimability of model parameters under a variety of models that include an unobservable state. Beginning with a very general model and no extra information, we used numerical methods to systematically investigate the use of ancillary information and constraints to yield models that are useful for estimation. The result is a catalog of models for which estimation is possible. An example analysis of sea turtle capture-recapture data under two different models showed similar point estimates but increased precision for the model that incorporated ancillary data (the robust design) when compared to the model with deterministic transitions only. This comparison and the results of our numerical investigation of model structures lead to design suggestions for capture-recapture studies in the presence of an unobservable state. Keywords: capture-recapture models, deterministic transitions, model constraints, multi-state models, nonbreeders, robust design, temporary emigration, unobservable state.

Contact: Dr William L. Kendall 301.497.5868

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