. Distribution and abundance of winter populations of bald eagles in Illinois. Bald eagle. February 1988 Havera and Kruse: Winter Populations of Bald Eagles 1986. However, the mean number of eagles seen per inventory was the most logical method of presenting the data. Upper Mississippi River Region. The Upper Mis- sissippi River Region extends from the Illinois- Wisconsin border southward to approximately Rock Island, Illinois (Fig. 6). This region was surveyed from October through March during the three winters of 1980-1983 and substantial numbers of eagles were counted. The floodplain in thi
. Distribution and abundance of winter populations of bald eagles in Illinois. Bald eagle. February 1988 Havera and Kruse: Winter Populations of Bald Eagles 1986. However, the mean number of eagles seen per inventory was the most logical method of presenting the data. Upper Mississippi River Region. The Upper Mis- sissippi River Region extends from the Illinois- Wisconsin border southward to approximately Rock Island, Illinois (Fig. 6). This region was surveyed from October through March during the three winters of 1980-1983 and substantial numbers of eagles were counted. The floodplain in this area provided attract- ive winter habitat for bald eagles (Fig. 7).. Fig 7 - 1 vpual iivcniie habitat of the L'ppcr Mississi] gion. The seasonal pattern of eagle use of the Upper Mississippi River Region is shown in Figure 8. Annual peak population counts occurred between 2 February and 23 March. Substantial numbers of birds were still present when counts were terminated each spring. The greatest 1-day count was 213 eagles on 23 March 1983. Southern (1964) observed peak numbers of 268 and 225 eagles in this region on 2 February 1962 and on 5 February 1963, respectively. A total of 2,663 eagle sightings was recorded in this region; of those were immatures. The proportion of immature ISO â 140- 130 - 70 â 60 â 50- iO â IMMATURES TOTAL. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Havera, Stephen P; Kruse, Glen W. [Champaign, Ill. ] : Illinois Natural History Survey
Size: 2263px × 1104px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, bookcontributoruniv
