Analysis of Banding and Recovery Data for Sharp-shinned Hawks at Whitefish Point, Michigan, 1984-1987

Spring Sharp-shinned Hawk (Accipitcr striatus) migration at Whitefish Point, Chippewa County, Michigan, was summarized by Devcreux ctal.(1985) and included all banding data through 1983.This paperexamines banding data from 1984-1987 and expands upon these previous findings.METHODS Sharp-shinned Hawks banded in this study were captured during spring migration in mist nets placed in Jack Pines (Pinus banksiana) at the tip of Wlfitefish Point, or by luring (see Clark 1970 for a description of luring).Banding was done from early April to late May, the duration of the Sharp-shinned Hawk migration period at Whitefish Point (Dcvcreux ctal.1985).Coverage was most extensive during late April and early May, the peak migration period for Sharp-shinned }tawks (Dcvcreux ctal.1985), when several bandors were present.At other times, usually only a single bander was present.Thus, many banders contributed to this project in addition to the authors (see acknowledgments ).Encounter data through May 1988 were obtained from the Bird Banding Laboratory for Sharp-shinned Hawks banded at Whitefish Point.RESULTS There were 4830 Sharp-shinned Hawks banded at Whitefish Point from 1984-1987.An average of 11.1% ofthe Sharp-shinned Hawks seen on standardized counts (see Peacock 1987, 1988) during April and May were banded (Table 1).From 1984-1987, 47 Sharp-shinned Hawks banded at Whitefish Point were encountered elsewhere; 43 (91%) were females.About 20% of the Sharp-shinned Hawks banded at Whitefish Point are males (Dcvcreux ct al. 1985) so the number of males encountered does not differ significantly from the numbc rcxpccted based on the proportion banded (Chi-square = 3.19, df = 1, P<0.1, Yate's correction, Zar 1984:48).Thirty-four (79%) of the females encountered were SY (second yea0 birds when banded.The time span between banding and encounter date varied from the same day to four years, six months and 14days.From 1956-1987, there were 12,882 Sharpshinned Hawks banded at Whitefish Point; and as of May 1988, 86 have been encountered elsewhere, an overall encounter rate of 0.67%.Twenty-two of the 47 encounters occurred during spring and summer (March-August).Twelve of these 22 birds were encountered within 21 days from their banding date.Only three were encountered north of Whitefish Point: one 370 km NNE in northern Ontario, and two 250 km WNW in the Kcwecnaw Peninsula of Michigan (Figure 1).The remaining nine birds were encountered WSW to ESE of Whitefish Point; three (two females and one male) were ASY (alter second year) birds (Figure 1).One SY female traveled 500 km to the SE in 20 days and was encountered in the SE comer of the Lower Peninsula of Michigan (Figure 1).Another SY female traveled 825 km ESE, being encountered in southern Quebec nine days following banding (Figure 1); the average distance traveled per day was 91.6 kin.Ten birds were encountered during a subsequent spring or summer.Most were encountered in eastern Wisconsin, the western side of the Lower Peninsula of Michigan, or in the Kcwccnaw Peninsula of Michigan (Figure 1).The recoveries from Paris, Tennessee and Mexico were found dead on an unknown date; the information was received by the Bird Banding Laboratory in June but .probablythese birds died during spring or winter.The Nicaragua encounterwas on 15 March, the SE Wisconsin encounter near the Illinois border occurred on 7 March, and the northem Ontario encounter occurred on 9 June.The remaining encounters occurred during April and May.Twenty-three birds banded at Whitefish Point returned during 1984 to 1987 one to six springs later; 22 (96%) were females.Twelve of the 23 birds were SY when originally banded; they were subsequently recaptured at a significantly earlier date (P<0.025,1-tailed Wilcoxon

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.