Partners in Flight (PIF) is a consortium of professional and volunteer scientists and educators that promotes the conservation of landbird species. Central to the PIF conservation effort is the development of Bird Conservation Plans specific to each physiographic region of the United States. Without a coordinated prioritization of research needs, land managers, researchers, and funding agencies seeking to conserve landbirds lack direction. To address this issue, we (the Research Working Group of Partners in Flight) identified research priorities that have emerged recently as a result of Bird Conservation Plan development. Research priorities for the coming decade focus on habitat, specifically the identification of high-quality habitats and landscapes for breeding, migration, and wintering. Identification of the scale of breeding and natal dispersal and describing linkages between wintering and breeding populations are also research priorities for the coming decade. A summary of research priorities for each of the PIF regions (Northeast, Midwest, West, and South) is also provided. Specific research needs associated with priority species and habitats in each physiographic area can be accessed in a searchable database:  http://www.partnersinflight.org/pifneeds/searchform.cfm.

A main goal of the Forest Bird Monitoring Program (FBMP) is to monitor temporal trends in forest-dwelling bird abundance in Ontario. The program has been running for over a decade. The experience gained from this program can provide methodological recommendations to anyone planning a similar program to monitor trends in bird populations. Power analyses on FBMP data indicated that for species occurring at 50 sites, 10 yr of annual sampling at either three or five locations (stations) per sampling site would provide adequate (80%) power to monitor declines in annual counts of 2–3% (18–26% decline over 10 yr). Obtaining this level of power for species found at fewer than 50 sites requires more time. The FBMP method of two visits to each site per year seems appropriate. The visits provide different information, but there is little indication that one sampling window is superior to the other.

Red-plumaged birds (red species) may behave more visibly in the presence of a red-orange safety vest that field observers must often wear, but species lacking red plumage (non-red species) may behave less visibly (i.e., the species-confidence hypothesis). Such responses may bias many common counting techniques. We experimentally tested if observer clothing color could affect richness and abundance variables derived from point counts. During summer and winter, we surveyed point-count stations while alternately wearing a red/orange vest (vest counts) and not wearing a vest (control counts). Winter estimates of species richness, total abundance, abundance of non-red species as a group, and the White-breasted Nuthatch (Sitta carolinensis) were significantly lower when the vest was worn, but red species were not significantly different. We did not observe any significant effects of the vest during summer counts. Power was high for community-level variables and intermediate for non-red species, but low power and marginally significant results suggested that we might have failed to detect effects on red species. Several factors may account for why we observed effects on non-red species during winter but not summer: species composition varied between seasons, dense summer foliage may have obscured the vest from view, or territoriality and nesting activities may have dampened avoidance behaviors during summer. Although effects of clothing color were significant for the winter season, managers and biologists should avoid risk of bias by restricting observers to dark or drab colored clothing for all seasons and for all avian sampling techniques, not just winter point counts.

Communal breeding has been recorded in a number of New World corvids, mainly among North and Central American jays, but in only one South American species. In this note we present evidence that the Cayenne Jay (Cyanocorax cayanus) is also a communal breeder. Cayenne Jays occur in family-sized groups in forest habitat in southern Venezuela. More than two individuals have access to the nest and feed the nestlings. Members of one group participated in the defense of the nest by mobbing a preserved boa. These observations suggest that Cayenne Jays, like other species of Cyanocorax, form coherent social units and that helpers typically aid in the care of the young or potential young.

Few data are available on seasonal changes in winter diet of Harlequin Ducks (Histrionicus histrionicus), especially in relation to their use of Pacific herring (Clupea pallasi) spawn. We used fecal analyses to determine seasonal changes in Harlequin Duck winter diet at a site where Pacific herring spawn. We measured frequency of occurrence and relative abundance by volume of prey remains in 202 fecal samples collected during four date periods in 1998 and 1999. These two measures were highly correlated. We identified snails, crabs, limpets, and chitons as the principal animal prey, and ranked relative importance of most prey types in similar order as previous studies using stomach analyses. Crabs parts constituted the majority of prey remains during molt, and we concluded that crabs were dominant in the diet during molt because crabs generally have greater organic content and less hard-part remains per unit of body mass than other hard-shelled prey consumed at that time. Snail remains were highest in frequency of occurrence during winter. Herring eggs were not detected in feces until a week after herring spawned, but abrupt changes in other prey types indicated that herring eggs were the principal prey throughout the spawn period. Polychaetes increased in importance in winter and spring, and rated third in frequency of occurrence in spring. We recommend using fecal analyses to determine frequency of occurrence of prey in the diet of other sea-ducks that are known to feed on hard-shelled molluscs and crustaceans. Measures of relative abundance of prey remains can be useful if conversion factors relating hard-part remains to whole-body biomass are available.

Five male Eastern Bluebirds (Sialia sialis) were observed and songs recorded over entire breeding seasons in central Kentucky. Songs consisted of an average of 3.02 notes and the mean time between the beginning of successive songs within a bout was 7.26 s. Most songs (63.7%) given by male bluebirds were low volume, while 14.8% were moderate volume, and 21.5% were high volume. Individual male bluebirds possessed large (x̄ = 59.4) repertoires of song types, and few were shared among two or more males. Singing rates varied among breeding stages, with high rates during the pre-pairing period suggesting that song plays a role in mate attraction. However, male bluebirds also sing during interactions with conspecific males, indicating an aggressive or territorial function, to facilitate the transfer of food to incubating or brooding females, nestlings, and fledglings, and to warn mates, nestlings, or fledglings about the presence of a potential predator. Thus, as reported in an increasing number of species, singing by male bluebirds serves multiple functions.

Although reports of Brown-headed Cowbird (Molothrus ater) parasitism have increased in the Southeast over the past 30 yr, the cowbird's status, distribution, and host relations within this region remain largely unknown. We collected information on cowbird abundance and cowbird/host interactions (parasitism frequency and intensity, hatching success of cowbirds, and host anti-parasite strategies) in an old field in the South Carolina coastal plain from March through August 1997 and 1998. We located 346 nests, representing 16 species, within the study area (Dill Sanctuary, James Island, Charleston Co., South Carolina). Female cowbird abundance (1.2% of all songbird territories) was low within the avian community; however, cowbird eggs were discovered in nests of 12 of 16 species found nesting within the study area. Although cowbird young were successfully fledged from 67% of host species' nests, five species exhibited an anti-parasite strategy (nest abandonment, cowbird egg burial, or egg ejection). The presence of these behaviors is possibly the result of gene flow into the population from areas of longer co-existence with the parasite. However, we present an alternative theory that southeastern, early-successional hosts may have retained rejection behaviors from ancestors previously exposed to cowbird parasitism.

Surveys of vocalizing individuals are useful in detecting widely dispersed species that are hard to locate visually. We determined whether conspecific density affects spontaneous vocalizations of territorial Eagle Owls (Bubo bubo) and thus creates a bias in passive auditory surveys. We mainly listened to dusk call displays of 17 males breeding in two areas of high and low density from the beginning of call activity in October to the start of egg-laying in February. We detected differences in call behavior between males breeding in high density vs. low density. The nearest neighbor distance between breeding males strongly and positively affected call duration. Low density caused low detectability of male Eagle Owls, and later timing of the first call after sunset. Failing to incorporate conspecific density and nearest neighbor distances in surveys of territorial species may reduce the accuracy of population estimates.

I constructed track-plates resembling short pine branches and attached them to pairs of neighboring pine trees distributed over a 1000-ha area in the Colorado Front Range. I checked track-plates after four and eight days between 24–31 August 2000 and scored each for the presence or absence of tracks. Half of all track plates were marked within four days. I found a positive correlation between scores of paired trees, indicating that track-plating accurately reflected the relative abundance of birds among habitat patches. A power analysis showed that to test for a 15% difference in bird visitation among habitats with a power of 0.75 required a sample size of 25 trees.

We studied the reproductive biology of a population of Blue-fronted Amazons (Amazona aestiva) in the Pantanal of Mato Grosso do Sul State, Brazil, between 1997 and 1999. Nesting occurred from August to December. We monitored 94 nests which were found in trees of different sizes. Nesting trees were distributed in all major vegetation associations (floodplains, grasslands, scrub savanna, savanna, arboreal savanna, riparian forests, and pastures). We found about half of nests (53%) in an open and disturbed area of 34 km², yielding a density of 0.5 nests/km². In the remaining 486 km² of the study area, we estimated a mean density of 0.03 nests/km². This could reflect preferences towards open and anthropic-influenced habitats or simply visibility bias. We found most of the nests in Palmae, Leguminosae, and Bignoniaceae, but the proportion of successful nests did not differ between tree types. Average clutch size varied little among the three years of study, but nest survival and the proportion of fledglings per female were lower in 1998 than in 1997 and 1999. The cause of the lower fledging success in 1998 was not determined, but deforestation, an early onset of the rainy season, and higher rates of nest visitation by researchers may have been involved.

An adult Red-shouldered Hawk (Buteo lineatus) was observed capturing and consuming an adult Pied-billed Grebe (Podilymbus podiceps) in Louisiana. Pied-billed Grebes, which regularly dive to escape predators, are rarely captured by raptors.

We studied Wilson's Warbler (Wilsonia pusilla) and Yellow Warbler (Dendroica petechia) habitat use in allopatric and sympatric populations in the Rocky Mountains of northern Colorado and southeastern Wyoming in order to better understand the different habitat needs and interactions of these two species. Foraging Wilson's Warblers and Yellow Warblers used very similar habitat, both selecting larger, more open shrubs. In spite of similar foraging habitat, comparisons of habitat use by the two species at the sympatric sites yielded no evidence of foraging habitat partitioning or exclusion. There was evidence of nesting habitat partitioning. Wilson's Warblers nested on the ground, with some evidence that they used smaller, more densely stemmed shrubs under which to nest. Yellow Warblers are shrub nesters and selected larger, more open shrubs in which to nest. Results provide no evidence that Yellow Warblers can be blamed for population declines in Wilson's Warblers.

Males of socially monogamous species may benefit from using behavioral tactics to ensure their paternity of the young produced by their social mates. We tested whether male Hooded Warblers (Wilsonia citrina) use mate guarding and high song output in an attempt to prevent extra-pair copulations (EPC) by their mates. In this species, most EPC intrusions occur when females produce conspicuous chip vocalizations. Using radiotelemetry, we tracked the male response to female chipping throughout her fertile and non-fertile periods. Our results show that males do not intensively guard their mates by closely associating with them or by increasing their song rate. Mate guarding was not influenced by male age or their own EPC behavior. Female influence on fertilizations and male pursuit of EPC may render mate guarding an ineffective strategy for ensuring paternity in Hooded Warblers.