This Statistical Guide is intended to aid field biologists wishing to analyze data gathered in standardized monitoring programs for landbirds. It grew out of the needs expressed by the Western Working Group of Partners in Flight, and we thank the members of that group for providing the incentive to develop this document.

Prairie and grassland habitats in central and western North America have declined substantially since settlement by Europeans (Knopf 1994) and many of the birds and other organisms that inhabit North American grasslands have experienced steep declines (Peterjohn and Sauer 1999; Johnson and Igl 1997; Sauer, Hines, and Fallon 2007). The species addressed here, Sprague's Pipit (Anthus spragueii), Grasshopper (Ammodramus savannarum) and Baird's (A. bairdii) sparrows, and Chestnut-collared Longspurs (Calcarius ornatus), are grassland birds that are of special conservation concern throughout their ranges due to declining populations and the loss of the specific grassland habitats required on both their breeding and wintering ranges (Knopf 1994, Davis and Sealy 1998, Davis 2003, Davis 2004, Jones and Dieni 2007). Population-trend data on grassland birds, while clearly showing declines, provides no information on the causes of population declines. Without demographic information (i.e., productivity and survivorship), there are no means to determine when in their life cycle the problems that are creating these declines are occurring, or to determine to what extent population trends are driven by factors that affect birth rates, death rates, or both (DeSante 1995). For migratory birds, population declines may be driven by factors on breeding grounds, during migration, and/or on wintering grounds. Lack of data on productivity and survivorship thus impedes the formulation of effective management and conservation strategies to reverse population declines (DeSante 1992). Furthermore, if deficiencies in survivorship are revealed, management strategies may need to address habitats on both breeding and non-breeding grounds, as well as along migratory pathways. One technique that helps inform management strategies is the biochemical analysis of isotopes and genetic markers, from the sampling of individual feathers from live birds (Smith et al. 2003, Perez and Hobson 2006; Appendix). Determining demographic parameters and effectively sampling feathers to reveal connectivity between breeding and wintering grounds requires detailed knowledge of molt patterns and age determination criteria for the target species, in the hand. For example, productivity, survivorship, and territory acquisition may all be age-dependent, with first-year birds showing different patterns and responses than older birds. In many cases it may be possible to sample both a feather grown on the breeding grounds and one grown on the wintering grounds from a single individual, but knowledge of age-specific molt patterns, as well as an ability to recognize different feather generations, is needed to accomplish such a task. While some information on molt and aging criteria exists for grassland passerine species (Pyle 1997a), these species have been rarely captured during mark-recapture studies (Jones et al. 2007) and this information thus needs refining. There is a need for additional resources to assist field workers in determining molt patterns and age in captured individuals. Our objective is to describe molt and aging criteria for four grassland passerine species with the aid of digital photographs taken in the field. We hope that this document will be useful for researchers studying grassland species through capture and banding of live individuals on either the breeding or the wintering grounds. We present a general section on molt and aging techniques, followed by specific accounts for the four species treated: Sprague's Pipits, Grasshopper and Baird sparrows, and Chestnut-collared Longspur. We also provide a brief protocol on collecting feather samples (Appendix).

The historical breeding range of Long-billed Curlews (Numenius americanus) was the western U.S. and the southern Canadian Prairie Provinces from California north to British Columbia and east to southern Manitoba and Wisconsin, northern Iowa and eastern Kansas. However, this breeding distribution has contracted and Long-billed Curlews have lost about 30% of their historical range. The eastern edge of the current breeding range is the western Great Plains from the Texas panhandle north throughout southwestern and south central Saskatchewan. Long-billed Curlews currently winter along the southwestern U.S. coast from central California, southern Texas and Louisiana south along both of Mexico's coasts to Guatemala, and are casual along the Atlantic coast north to New Brunswick, the southeastern South Carolina and Florida coasts, and the West Indies. Long-billed Curlews are federally protected in the U.S., Canada, and Mexico under the Migratory Bird Treaty Act. In the U.S., they are listed as a U.S. Fish and Wildlife Service Bird of Conservation Concern: nationally, in five U.S. Fish and Wildlife Service regions, and in several Bird Conservation Regions. They are listed as a species of concern in several U.S. states. In Canada, they are on Schedule 1 of the Species at Risk Act as a "Species of Special Concern" and are "Blue Listed" in Alberta and British Columbia. In addition, they are listed as "Highly Imperiled" in both the U.S. and Canadian shorebird conservation plans. Long-billed Curlews are a protected migratory bird species but do not have an official conservation designation in Mexico. The high levels of concern are due to the loss of the eastern third of their historical breeding range and apparent population declines, particularly in the shortgrass and mixed-grass prairies of the western Great Plains. The Breeding Bird Survey does not show any significant trends for Long-billed Curlews throughout much of their range; however, the applicability of BBS to adequately monitor Longbilled Curlews has been questioned. Documented declines have occurred in several portions of their range, including historical population declines, the contraction of breeding range, and reductions in the number of migrants along the Atlantic coast. Initial population declines were attributed to over-hunting and plowing of the native prairies for agriculture. Current threats include habitat loss and destruction due to urban development, grassland conversion for agricultural purposes, changes in the natural fire regime and the spread of exotic invasive species. Predation, grazing practices, energy development, diseases, and pesticides may also threaten Longbilled Curlew populations. Long-billed Curlews breed, migrate, and winter across multiple geographical ranges; therefore, effective conservation actions will require cooperation by local, regional, and international entities. Several important steps have been taken towards identifying limiting factors affecting Longbilled Curlew populations. Current conservation needs include: population monitoring, breeding ground studies that identify local micro-habitat use, and identification of critical wintering and migration areas. The development and use of management recommendations for maintaining native grasslands, invasive species control, and water and wetland conservation are also important to the maintenance of Long-billed Curlew populations. Investigation of the effects of energy development and subsequent operations is increasingly important as the demand for alternative "green" energy sources increases. Public outreach will continue to be an important tool in the conservation of Long-billed Curlew populations. Currently, while there are very few specific Long-billed Curlew management and conservation projects on-going, there are many identified needs. This status assessment and conservation action plan is intended to be a summary of the current state of the species, and a guide to its conservatio