James A. Dubovsky

U.S. Fish and Wildlife Service · Division of Migratory Bird Management

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Land-use intensification on arable land is expanding and posing a threat to biodiversity and ecosystem services worldwide. We develop methods to link funding for avian breeding habitat conservation and management at landscape scales to equilibrium abundance of a migratory species at the continental scale. We apply this novel approach to a harvested...

ContextFunding for habitat-management programs to maintain population viability is critical for conservation of migratory species; however, such financial resources are limited and can vary greatly over time. The Prairie Pothole Region (PPR) of North America is an excellent system for examining spatiotemporal patterns of funding for waterfowl conse...

We estimated U.S. and Mexican citizens’ willingness to pay (WTP) for protecting habitat for a transborder migratory species, the Mexican free-tailed bat (Tadarida brasiliensis mexicana), using the contingent valuation method. Few contingent valuation surveys have evaluated whether households in one country would pay to protect habitat in another co...

Many economic studies value birdwatching in general and often do not account for potential differences in viewers’ benefits from observing different species. But, how different are economic values of viewing various bird species? To answer that question, we surveyed Ducks Unlimited (DU) members using an online questionnaire to estimate trip expendi...

Migratory species provide important benefits to society, but their cross-border conservation poses serious challenges. By quantifying the economic value of ecosystem services (ESs) provided across a species’ range and ecological data on a species’ habitat dependence, we estimate spatial subsidies—how different regions support ESs provided by a spec...

Quantification of the economic value provided by migratory species can aid in targeting management efforts and funding to locations yielding the greatest benefits to society and species conservation. Here we illustrate a key step in this process by estimating hunting and birding values of the northern pintail (Anas acuta) within primary breeding an...

The proposed action of the 2013 Final Supplemental Environmental Impact Statement (FSEIS 2013) is to adopt a process for authorizing migratory bird hunting in accordance the Migratory Bird Treaty Act (16 U.S.C. §703-712) and the four bilateral conventions. Regulations allowing the hunting of migratory game birds in the families Anatidae (waterfowl)...

1.Prediction is fundamental to scientific inquiry and application; however, ecologists tend to favor explanatory modeling. We discuss a predictive modeling framework to evaluate ecological hypotheses and to explore novel/unobserved environmental scenarios to assist conservation and management decision makers. We apply this framework to develop an o...

Migratory species provide economically beneficial ecosystem services to people throughout their range, yet often, information is lacking about the magnitude and spatial distribution of these benefits at regional scales. We conducted a case study for Northern Pintails (hereafter pintail) in which we quantified regional and sub-regional economic valu...

Compared to increases recorded in the 1970s, annual indices to abundance of the Mid-Continent Population (MCP) of sandhill cranes have been relatively stable since the early 1980s. The spring 2012 index for sandhill cranes in the Central Platte River Valley, Nebraska, uncorrected for visibility bias, was 259,576 birds, which was significantly lower...

Compared to increases recorded in the 1970s, annual indices to abundance of the Mid-Continent Population (MCP) of sandhill cranes have been relatively stable since the early 1980s. The spring 2011 index for sandhill cranes in the Central Platte River Valley, Nebraska, uncorrected for visibility bias, was 363,356 birds. The photo-corrected, 3-year a...

The mid-continent population of sandhill cranes (Grus canadensis) is the largest population of cranes in North America. Hunting seasons for sandhill cranes were closed in 1916 and gradually resumed in Mexico (1940), the United States (1961), and Canada (1964). As knowledge of the biology of cranes and experience with hunting seasons increased, area...

Unlike other North American prairie-nesting dabbling ducks, northern pintail (Anas acuta) populations have not increased since the early 1990s and remain well below the long-term average for traditional survey areas. Previously reported estimates of annual survival and recovery rates for pintails did not investigate any spatial or temporal factors...

Compared to increases recorded in the 1970s, annual indices to abundance of the Mid-Continent Population (MCP) of sandhill cranes have been relatively stable since the early 1980s. The spring 2010 index for sandhill cranes in the Central Platte River Valley, Nebraska, uncorrected for visibility bias, was 451,024 birds. The photo-corrected, 3-year a...

Observers counted 5,265 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during January and February 2009, which was a 14% increase from the 4,637 counted during winter 2008. The number of white birds (4,377) and cygnets (888) increased 15% and and 10%, respectively, from counts last year. In the tri-state area, t...

Observers counted 459 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2008, 13% lower than the count from last year (527). The number of white birds in the tri-state region (379) was about the same as in 2007 (383), but the number of cygnets declined 58% and was the low...

Compared to increases recorded in the 1970s, annual indices to abundance of the Mid-Continent Population (MCP) of sandhill cranes have been relatively stable since the early 1980s. The Central Platte River Valley, Nebraska, spring index for 2009, uncorrected for visibility bias, was 460,000 sandhill cranes. The photo-corrected, 3-year average for 2...

Observers counted 4,637 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during January and February 2008, which essentially was unchanged (-1%) from the 4,701 counted during winter 2007. The numbers of white birds (3,818) increased 4%, but the number of cygnets (808) decreased 12% from counts last year. However,...

Observers counted 527 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2007, 4% higher than the count from last year (507) and the highest count since 1992. The number of white birds in the tri-state region was about the same as in 2006, but the number of cygnets was 40%...

Since 1975, annual harvest estimates for Mid-Continent sandhill cranes (Grus canadensis) have been collected in all states for which a hunting season has been authorized by the U.S. Fish and Wildlife Service (Service). Although these data have been used to monitor the harvest of the Mid-Continent population, analyses to promote understanding of the...

The Rocky Mountain Population (RMP) of greater sandhill cranes (Grus canadensis tabida) was not hunted in the U.S. from 1916 until 1981, when Arizona initiated the first modern-day season. Hunting programs in the U.S. were subsequently expanded to 6 states for the RMP and have been guided by a cooperative flyway management plan, including a harvest...

Sport hunting for the Mid-continent population of sandhill cranes (Grus canadensis) in the United States resumed in New Mexico in 1961 after a 45-year moratorium. Interest in crane hunting continued to increase and by 1975, 8 states were participating in sandhill crane hunting. Currently, hunting seasons have been established in all Central Flyway...

Observers counted 4,701 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during January and February 2007, a decrease of 14% from the 5,484 counted during winter 2006. However, in Montana, aerial surveys were conducted only in a portion of the survey area; ground counts were conducted on remaining areas. The numbe...

Compared to increases recorded in the 1970s, annual indices to abundance of the Mid-Continent Population (MCP) of sandhill cranes have been relatively stable since the early 1980s. The Central Platte River Valley, Nebraska, spring index for 2007, uncorrected for visibility bias, was 302,600 sandhill cranes. The photo-corrected, 3-year average for 2...

We estimated the detection ratio for Rocky Mountain Trumpeter Swans Cygnus buccinator that were counted during aerial surveys made in winter. The standard survey involved counting white or grey birds on snow and ice and thus might be expected to have had low detection ratios. On the other hand, observers were permitted to circle areas where the bir...

The abundance of the Mid-Continent Population of Sandhill Cranes has been relatively stable since the early 1980s, compared to the increases that were recorded in the 1970s. The Central Platte River Valley, Nebraska spring index for 2004, uncorrected for visibility bias, was 356,850. The photo-corrected 3-year average for 2001-2003 was 370,300, whi...

Observers counted 507 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2006, slightly below the count from last year (510) but the second-highest count since 1992. The numbers of white birds in the tristate region increased 6%, but the number of cygnets was 16% lower com...

Observers counted 5,484 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during February 2006, an increase of 2% from the 5,361 counted in February 2005 and the third consecutive record-high count for the Mid-winter Survey. The numbers of white birds (4,261) and cygnets (1,223) increased 1% and 6%, respectively, f...

Observers counted 510 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2005, the highest count since 1992. The numbers of white birds and cygnets in the tri-state region increased 22% and 4%, respectively, compared to counts in 2004. The number of young produced in Monta...

Observers counted 5,361 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during February 2005, an increase of 17% from the 4,584 counted in February 2004 and the second consecutive record-high count for the Mid-winter Survey. The numbers of white birds (4,206) and cygnets (1,155) increased 10% and 53%, respectivel...

Annual indices to abundance of the Mid-Continent Population of Sandhill Cranes has been relatively stable since the early 1980s, compared to the increases that were recorded in the 1970s. The Central Platte River Valley, Nebraska spring index for 2005, uncorrected for visibility bias, was 412,000. The photo-corrected 3-year average for 2002-2004 wa...

Observers counted 417 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2004, a count identical to that from comparable areas last year. The numbers of white birds and cygnets in the tri-state region were essentially unchanged from respective counts in 2003. The numbers o...

Observers counted 4,584 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during February 2004, an increase of 15% from the 3,974 counted in February 2003 and a record-high count for the Mid-winter Survey. The numbers of white birds (3,831) and cygnets (753) increased 12% and 38%, respectively, from counts last yea...

The abundance of the Mid-Continent Population of Sandhill Cranes has been relatively stable since the early 1980s, compared to the increases that were recorded in the 1970s. The Central Platte River Valley, Nebraska spring index for 2004, uncorrected for visibility bias, was 356,850. The photo-corrected 3-year average for 2001-2003 was 370,300, whi...

Observers counted 417 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2003, an increase from 371 counted from comparable areas last year. The increase was attributable mostly to an increase in production (+60%) from that in 2002; the number of white birds (321) was slig...

Observers counted 3,974 swans (white birds and cygnets) in the Rocky Mountain Population of trumpeter swans during February 2003, a decrease of 10% from the 4,415 counted in February 2002. The number of white birds (3,427) declined 11% from that of last year, while the number of cygnets (547) was essentially unchanged from the count last year (553)...

Observers counted 371 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain Population of trumpeter swans during fall of 2002, a decrease from 475 counted from comparable areas last year and the lowest count since 1993. The number of white birds (311) declined 23% from that of last year, while the number of cygnets (60)...

In 1995, the United States Fish and Wildlife Service adopted a protocol for the adaptive management of waterfowl hunting regulations (AHM) to help reduce uncertainty about the magnitude of sustainable harvests. To date, the AHM process has focused principally on the midcontinent population of mallards (Anas platyrhynchos), whose dynamics are descri...

The set of population models used for the adaptive harvest management (AHM) of eastern mallards has been reviewed and revised. The revised set of six models: (1) rely solely on federal and state waterfowl surveys rather than the Breeding Bird Survey to index breeding-population size; (2) allow for the possibility of a positive bias in estimates of...

Historically, the statistical complexity of modeling spatial relationships in band-recovery data has limited the use of spatial models in the management of waterfowl populations. Consequently, managers have assumed simplified spatial relationships (e.g., by stratification and pooling data over large geographic areas) to obtain spatially explicit es...

Requests to increase military aircraft activity in some training facilities in the United States have raised the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We hypothesized that habituation was a possible proximate factor influencing the low proportion of free-ranging ducks reacting to military...

Requests to increase military aircraft activity in some training facilities in the United States have prompted the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We quantified behavioral responses of wintering American black ducks (Anas rubripes), American wigeon (A. americana), gadwall (A. streper...

Those charged with regulating waterfowl harvests must cope with random environmental variations, incomplete control over harvest rates, and uncertainty about biological mechanisms operative in the population. Stochastic dynamic programming can be used effectively to account for these uncertainties if the probabilities associated with uncertain outc...

Food restriction during winter may subsequently affect waterfowl reproduction. Therefore, we tested the effects of restricted and ad libitum (control) food availability during winter 1987-88 on reproductive performance of captive wild-strain and game-farm female mallards (Anas platyrhynchos) in Mississippi. Females fed restricted diets weighed less...