Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used simulation methods incorporating measures of demographic uncertainty to evaluate risk of overharvest and prioritize information needs for North American sea ducks (Tribe Mergini). Sea ducks are popular game birds in North America, yet they are poorly monitored and their population dynamics are poorly understood relative to other North American waterfowl. There have been few attempts to assess the sustainability of harvest of North American sea ducks, and no formal harvest strategy exists in the U.S. or Canada to guide management. The popularity of sea duck hunting, extended hunting opportunity for some populations (i.e., special seasons and/or bag limits), and population declines have led to concern about potential overharvest. We used Monte Carlo simulation to contrast estimates of allowable harvest and observed harvest and assess risk of overharvest for 7 populations of North American sea ducks: the American subspecies of common eider (Somateria mollissima dresseri), eastern and western populations of black scoter (Melanitta americana) and surf scoter (M. perspicillata), and continental populations of white-winged scoter (M. fusca) and long-tailed duck (Clangula hyemalis). We combined information from empirical studies and the opinions of experts through formal elicitation to create probability distributions reflecting uncertainty in the individual demographic parameters used in this assessment. Estimates of maximum growth (rmax), and therefore of allowable harvest, were highly uncertain for all populations. Long-tailed duck and American common eider appeared to be at high risk of overharvest (i.e., observed harvest < allowable harvest in 5–7% and 19–26% of simulations, respectively depending on the functional form of density dependence), whereas the other populations appeared to be at moderate risk to low risk (observed harvest < allowable harvest in 22–68% of simulations, again conditional on the form of density dependence). We also evaluated the sensitivity of the difference between allowable and observed harvest estimates to uncertainty in individual demographic parameters to prioritize information needs. We found that uncertainty in overall fecundity had more influence on comparisons of allowable and observed harvest than adult survival or observed harvest for all species except long-tailed duck. Although adult survival was characterized by less uncertainty than individual components of fecundity, it was identified as a high priority information need given the sensitivity of growth rate and allowable harvest to this parameter. Uncertainty about population size was influential in the comparison of observed and allowa...

Populations of greater sage‐grouse (Centrocercus urophasianus; sage‐grouse) have been in a decline since the nineteenth century. We used our research, unpublished reports, and scientific literature to identify which predators kill sage‐grouse and to assess whether lethal control of these predators benefited the species. We also asked state wildlife biologists and scientists whether they had ever witnessed a predator kill sage‐grouse. We identified 266 instances where the predator responsible for depredating nests or killing juvenile or adult sage‐grouse could be ascertained. Most adult sage‐grouse were killed by eagles (Accipitridae), owls (Strigiformes), coyotes (Canis latrans), or red foxes (Vuples vulpes). Based on nest cameras, most depredated eggs are taken by common ravens (Corvus corax), badgers (Taxidae taxus), or coyotes. There are too few studies to conclude that predator removal increases survival rates of juvenile or adult sage‐grouse. No study has been conducted to determine whether badger removal increases nest success of sage‐grouse, and the only study on coyote removal produced ambiguous results. Several studies reported that more sage‐grouse nests are successful (i.e., >1 eggs hatched) in areas where common ravens were removed or in areas where raven densities were lower than in other areas. The data we reviewed did not indicate predators played a role in the decline during the past century, but increasing numbers of ravens since the 1970s may have contributed to the declining sage‐grouse populations in recent decades. We conclude that removing common ravens can increase nest success, although not necessarily sage‐grouse abundance. Without a better understanding of sage‐grouse and their predators, wildlife biologists will be handicapped in their efforts to prevent sage‐grouse populations from continuing to decline. © 2016 The Wildlife Society.

The 2012 revision of the North American Waterfowl Management Plan (NAWMP) explicitly recognized the need to increase recruitment and retention of waterfowl hunters, birdwatchers, and other conservationists to maintain support for wetland conservation. The incorporation of human dimensions objectives within the NAWMP has compelled waterfowl and wetland managers to consider whether and to what extent landscape characteristics such as public land access; the type, amount, and location of wetlands; and site infrastructure will increase support for wetland conservation among user groups. Further, it has forced the waterfowl community to consider the possible trade‐offs between managing land to achieve biological versus social objectives. We used publicly available, long‐term data sets to illustrate a method of incorporating human dimensions into waterfowl habitat planning and management. We used United States Fish and Wildlife Service waterfowl harvest survey data, United States Geological Survey band encounter data, and Cornell Lab of Ornithology eBird data to summarize travel characteristics of wetland bird enthusiasts (i.e., waterfowl hunters and birdwatchers) in the Atlantic Flyway. Greater than 90% of all trips by wetland bird enthusiasts occurred within their state of residence. We used data from New York, USA, to demonstrate how to construct discrete choice recreation demand models to identify factors that influence site selection and participation. We demonstrate how model outputs, such as the expected change in the number and geographic distribution of recreational trips (i.e., hunting or birdwatching), can be used as an objective metric to evaluate the benefits of alternative habitat acquisition and restoration projects relative to the human dimensions objective of the NAWMP. These data and methods show promise for incorporating human dimensions objectives into habitat delivery and understanding potential trade‐offs relative to biological objectives. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Management of waterfowl that migrate seasonally across North America occurs within four flyways that were delineated in the early 1900s to include the annual movements of populations. Movements may have changed over the past century since the administrative flyways were established, and may do so while management plans are in use, so information about transitions among flyways through time can illustrate how management assumptions may change. Today there are more than 12 million records from 60 years of migratory waterfowl band recoveries to assess adaptive management approaches that will be most effective when they account for movements within and between flyways. We examined how much the movement of North American waterfowl occurs between flyways, whether those movements have changed through time, and whether movements of mallards are representative of multiple species, as suggested by current harvest management strategies. We estimated the probability a duck would transition from one flyway to another and the strength of migratory connectivity (MC) for each species within and among flyways. We used capture-mark-recovery models to estimate population-specific movement within and among flyways (transition probabilities) for 15 migratory waterfowl species that were banded during breeding and recovered during winter. We developed new functionality in the R package MigConnectivity to estimate the species-specific strength of MC using transition probability samples from the capture-mark-recovery models.We found the regular movement of duck populations among flyways, overall weak MC, and no consistent change in migratory movements through time. Mallard movements were median among all duck species, but significantly different from many species, particularly diving ducks. Despite the significant movement between flyways, our work suggests flyway management of waterfowl matches many of the seasonal movements of these species when considering mid-continent flyway management. We recommend models accounting for all transition probabilities between populations and regularly estimating harvest derivations, transition probabilities, and MC metrics to verify that the current movements match model assumptions.

Waterfowl monitoring, research, regulation, and adaptive planning are leading the way in supporting science-informed wildlife management. However, increasing societal demands on natural resources have created a greater need for adaptable and successful linkages between waterfowl science and management. We presented a special session at the 2016 North American Duck Symposium, Annapolis, Maryland, USA on the successes and challenges of linking research and management in waterfowl conservation, and we summarize those thoughts in this commentary. North American waterfowl management includes a diversity of actions including management of harvest and habitat. Decisions for waterfowl management are structured using decision analysis by incorporating stakeholder values into formal objectives, identifying research relevant to objectives, integrating scientific knowledge, and choosing an optimal strategy with respect to objectives. Recently, the consideration of the value of information has been proposed as a means to evaluate the utility of research designed to meet objectives. Despite these advances, the ability to conduct waterfowl research with direct management application may be increasingly difficult in research institutions for several reasons including reduced funding for applied research and the lower perceived value of applied versus theoretical research by some university academics. In addition, coordination between researchers and managers may be logistically constrained, and communication may be ineffective between the 2 groups. Strengthening these links would help develop stronger and more coordinated approaches for the conservation of waterfowl and the wetlands upon which they depend. Ó 2017 The Wildlife Society.KEY WORDS adaptive harvest management, decision analysis, flyways, waterfowl.