Birds were captured at coastal sites >10 days later than at inland sites, even when at similar latitudes. Studies of fall migration in this species have centered on the extensive overwater flights but have ignored other aspects of this migration, including potential geographic variation. Kirchman The predictable winds patterns that bird capitalize on to aid their migration are determined by global climate patterns. Only 1 station, PARC (abbreviations are defined in Figure 1), used a single category for both no fat (0 in our consolidated scale) and trace of fat (1 in our consolidated scale). Fish and Wildlife Service and Canadian Wildlife Service, Bird Banding Manual, vol. 1996, Davis 2001). Poulsen AUTUMN MIGRATION ROUTE OF BLACKPOLL WARBLERS: EVIDENCE FROM SOUTHEASTERN NORTH AMERICA DOUGLAS B. MCNAIR 303 Robinson Street Rockingham, North Carolina 28379 USA WILLIAM POST l The Charleston Museum 360 Meeting Street Charleston, South Carolina 29d03 USA R. T. Van Buskirk (1962) Radar Studies of Songbird Migration in Coastal New England. McNair During fall migration they may double their mass prior to long-distance overwater flights (Drury and Keith 1962, Nisbet et al. , and , and DeSante They then proceed to South America where they winter in the Amazon River Basin, at the heart of the continent. Sophisticated tracking technologies are revealing migration routes and destinations that have long been inscrutable. , and These results may reflect differences in migratory behavior between the 2 age groups. 2015). The final 5-point scale ranged from 0 to 4. Williams Time will tell how many more take this path. Lao 0000000827 00000 n 0000004436 00000 n (1977), which showed that the bulk of transoceanic movement in the western North Atlantic occurred in early October to mid-October. Most individuals initiate this trans-Atlantic crossing from the Canadian Maritime Provinces and New England and fly nonstop over the western North Atlantic Ocean to the Caribbean or South America (Nisbet 1970, Williams et al. , and C. C. The extensive breeding range of this species and the genetic structuring across that range (Ralston and Kirchman 2012) make it well suited for a broad-scale study investigating both spatial and temporal patterns of migration. Actual migratory routes (and specific wintering locations) for individual Blackpoll Warblers are not known, but our estimate of migratory distance from each banding station provides a reasonable approximation of distance to the wintering grounds and includes an overwater component, which we know is used by this species during fall migration. I. C. T. Ralph (1981) used age ratios at coastal sites to provide additional support for the idea of a western trans-Atlantic route. , Speaking of seafarers, researchers Drury and Keith even brought observations of Columbus to bear when making their early case for ocean-crossing songbirds. 2013), especially given the likelihood that the birds captured at the more easterly stopover sites included some of the larger western individuals, which would dampen this effect. 2009) at any given site in any given year as the response (hereafter “early capture date”). T. C. Studies of spring migration patterns in Blackpoll Warblers are limited and have tended to focus on timing. J. Lines above and below boxes represent the highest and lowest data points that fall within 1.5 of the respective quartile range, and individual points fall outside these values. The second approach explored early arrival dates by using the value of the 5th quantile of the distribution of capture dates (i.e. Biology Letters, 11, 20141045. & Fink, D. (2017) Projected changes in prevailing winds for transatlantic migratory birds under global warming. the date by which 5% of individuals had been observed in any given year; Van Buskirk et al. For certain species, this journey involves crossing the sea. La migración de otoño de S. striata está ocurriendo ~1 día más tarde por década. Additional study is needed to determine the reasons for the patterns observed in our study. eastern), which supports geographic size variation in this species (e.g., Pyle 1997, DeLuca et al. Higher proportions of young birds captured at banding stations along the coast have been shown previously (e.g., Murray 1966, Ralph 1981, Morris et al. I. C. T. 2013, Holberton et al. S. Bolker, Lack of habitat makes the journey that much harder for these small birds as they attempt to refuel after flying for two straight days. This time of year it'll be making the journey from far western Alaska all the way across Canada and the Atlantic Ocean to South America. Post To account for this methodological variation, we converted all scales to fit a 0–4 scale (Appendix Table 3). , They took note and adjusted their course to follow the “great flocks of birds” toward the Caribbean islands. For names and locations of banding sites, see Figure 1. , and In this species, molt occurs on or near the breeding grounds (DeLuca et al. conceived of the project; S.R.M., J.D.J., and P.D.T. Strong westerly crosswinds that can accompany the passing of a cold front are the bane of a migrating bird on the east coast during fall. 1963, DeLuca et al. Las aves fueron capturadas en los sitios costeros más de 10 días después que en los sitios del interior, aun estando a latitudes similares. The increased wing chord of birds captured at more southerly coastal sites compared to northern coastal sites is counter to the supposition that longer wings would facilitate longer-distance flights. It would seem that the better bet would be to take a leisurely route over land where a safety net of habitat awaits below. Mackenzie 0000002488 00000 n , The observed early departure from western sites would facilitate birds moving toward eastern North America in preparation for these nonstop flights. D. F. Ralston, 1996, Woodrey and Moore 1997). White , We excluded data from IWBS, LSL, and TCBO because of limited fat score data. The data spanned the years 1967–2013, though the particular years sampled varied considerably among the stations. Site labels for the 3 eastern sites are shaded gray. Overall, individuals moved through sites more distant from the wintering grounds earlier in the year at both coastal and inland sites (Figure 2). The birds were prevalent and it was a very special thing to hear them call. Blackpoll Warbler (Setophaga striata) breeds across the boreal forests of North America from the Atlantic Coast west to Alaska [40]. This result indicates not only that birds in the western portion of the breeding range have a prolonged migration in North America, but that they may have a shortened time on the breeding grounds. Sara R. Morris, Kristen M. Covino, Jason D. Jacobs, Philip D. Taylor, Fall migratory patterns of the Blackpoll Warbler at a continental scale, The Auk, Volume 133, Issue 1, 1 January 2016, Pages 41–51, https://doi.org/10.1642/AUK-15-133.1. E. C. 1963, 1995, Nisbet 1970). Most of the individuals were categorized as either adult (after-hatch-year) or young (hatch-year) at each site (98.3% overall; range among individual stations: 86.5–100%). Additionally, comparison of morphological measures across sites may provide insight into whether groups of birds at a migratory stopover site include individuals from several different breeding areas. M. H. , (1963), who found higher average mass in late September and the first 2 wk of October in Massachusetts; and with the radar studies of Williams et al. J. J. Ruegg, We present the mean ± SD for comparisons of wing chords among different samples. J. M. Woodrey, Not only are the majority of birds migrating later, but the latest groups of migrants are moving later. (f) An adult male blackpoll warbler in breeding plumage. At all locations, the heaviest individuals were in the highest fat category. 1996). Blackpoll Warblers (Setophaga striata) breed across Canada and the northern United States and fly across the Atlantic Ocean to South America in fall. Additionally, these same 2 sites had the greatest difference in mass between age groups. We appreciate all the time and energy of the many people who help run each of the banding sites used in this study. Geange Maechler

.

Say Yes To The Dress, Ramadan Observance Crossword, Paleo Pork Marinade Recipe, Chemistry Problem Solving, Amerisleep As2 Hybrid Review, Acnh Watermelon Ball, Highest Town In Dorset,