Fall Vagrancy of the Indigo Bunting in Northern Ontario by Alan Wormington

104 Fall Vagrancy of the Indigo Bunting in Northern Ontario by Alan Wormington As a nesting species, the Indigo are presented along with Bunting (Passerina cyanea) is found additional records, principally throughout southern Ontario, obtained from other observers who ranging north in northern Ontario live in northern Ontario. Probable to approximately Smooth Rock origin and a discussion of these Falls (Cochrane District), Kenora records is also given. (Kenora District) and Thunder Bay (Thunder Bay District). The Records Although the Indigo Bunting is a A total of 20 records involving 20 widespread and common nesting birds have been assembled which species in the south, in northern pertain to late fall occurrences of Ontario it is absent from large Indigo Buntings in northern areas between the above listed sites Ontario (Table 1). Of seven birds (Figure 1), and is very uncommon that could be aged and/or sexed, and local even within much of the four were immatures, two were specified range. As a fall migrant immature females and one was an in southern Ontario, the species is adult male. Birds observed in the a well-known early migrant, with field were considered immatures if the majority of birds having they showed fairly obvious, buffy departed by late September (see wingbars and/or diffused streaking Beardslee and Mitchell 1965:416 below, while the bird identified as 417; Sprague and Weir 1984:124). an adult male (in winter plumage) In northern Ontario, most lacked wing bars and streaking breeding birds probably depart below, but showed obvious blue before early September, but actual tones on the rump and flight observations have rarely, if ever, feathers. been reported. The 20 birds were found on dates As a result of numerous fall field ranging from 20 September to 24 trips to northern Ontario by the November, with 19 of these birds author and others, a number of first recorded between 20 September Indigo Bunting observations have and 1 November. It should be been obtained that represent birds noted that for the three birds that that were at, or well beyond, the stayed after 1 November, and for known breeding range of the the single bird first recorded on 11 species, and were observed on November, all were at bird feeders dates which are very late for the and, as such, had probably been species. In this paper, these records artificially induced to linger. Alan Wormington, R.R. #1, Leamington, Ontario N8H 3V4 ONTARIO BIRDS DECEMBER 1986 105 N ). ,\\~, {q 111.3... .. ~ ---~~/I' ..'.. " !,:r-£ '-l :. ,-,-...-fa c··....... r "-----~3~~"---_:p_. J Figure I: Distribution of the 20 late fall occurrences of Indigo Bunting in northern Ontario. The broken line represents the approximate northern limit of the species' breeding range (after Denis 196 L James et al. 1976:50; Godfrey 1986:502; and unpublished data). The 20 birds were found in a are: (1) the birds were "over variety of locations, but almost all shooting" spring migrants and were associated with human simply remained until discovered, influenced habitats or situations. (2) the birds nested at the sites These include birds found in small where they were found, (3) the towns at weedy or disturbed sites birds' appearances were the result (eight birds), at bird feeders in of post-breeding dispersal! small towns (seven birds), and on wanderings, or (4) the birds were gravel-based campsites in provincial reverse fall migrants and arrived parks (two birds). Only the three shortly before they were discovered. remaining individuals were found Over-shooting spring migrants-This at totally natural sites (i.e., two on theory can quickly be ruled out as shorelines and one on a small several of the birds recorded were island). immatures (young-of-the-year). Also, spring records far north of Possible Origin of the Birds the breeding range (excluding the There are several potential sources numerous records for Lake for the vagrant Indigo Buntings Superior) are possibly limited to seen in northern Ontario. These the observation of a male bird on 6 VOLUME 4 NUMBER 3 106 May 1986 at Moosonee, Cochrane and the first fall vagrants (late District (American Birds 40:466). September, this study) are factors Nesting birds-This theory is which clearly argue against this unlikely, as most of the vagrants viewpoint. recorded were at, or beyond, the Reverse fall migration- It is felt th at known breeding range. Further this is the most probable source of more, it seems unlikely that the late fall Indigo Buntings in singing, territorial birds would be northern Ontario, namely that the overlooked while, at the same birds are disoriented reverse location, silent, fall birds would be migrants and arrived from the found. south shortly before they were Post-breeding dispersal-This theory discovered. is more difficult to dismiss and is a possible source of the birds. Analysis and Discussion However, the apparent total lack of In comparing the northern Ontario Indigo Bunting observations observations to other areas of the anywhere in northern Ontario continent, fall observations of between late August (breeding vagrant landbirds at three Nova birds within their known range) Scotia islands (McLaren 1981) Table I: Late fall occurrences of Indigo Bunting in northern Ontario. Date Location #, Age & Sex Observer(s) 20-21 Sept. 1961 Dorion, Thunder Bay Dist. one- Rita Taylor 26 Sept. 1986 Red Rock, Thunder Bay Dist. one imm.- Wormington, WiUiam Lamond I Oct. 1976 Moose Factory, Cochrane Dist. one- Mark W. Jennings 6 Oct. 1984 Moose Factory, Cochrane Dist. one imm. Mark W. Jennings 7 Oct. 1980 Marathon, Thunder Bay Dist. one- Nicholas G. Escott II Oct. 1980 Neys Provo Park, Thunder Bay Dist. one imm. Wormington 12 Oct. 1979 Caribou Island, Thunder Bay Dist. one-- Wormington, Robert G. Finlayson 12 Oct. 1985 East Point, Cochrane Dist. one- R.D. McRae 13 Oct. 1976 Marathon, Thunder Bay Dist. one- Nicholas G. Escott 13 Oct. 1982 Moosonee, Cochrane Dist. one imm. R.D. McRae 13-16 Oct. 1986 Terrace Bay, Thunder Bay Dist. one- Wormington et at. 15 Oct. 1973 Winisk, Kenora Dist. one imm. Q Michael Hunter, Sr.; ROM #126213 18 Oct. 1982 Rossport, Thunder Bay Dist. two-_ I Wormington, Mark W. Jennings 19 Oct. 1984 Marie Louise Lake, Thunder Bay Dist. one adult (f Wormington 23 Oct. 1979 Marathon, Thunder Bay Dist. one -- Wormington 25 Oct.- 3 Nov. 19592 Dorion, Thunder Bay Dist. one imm. Q Rita Taylor 1-6 Nov. 1979 Atikokan, Rainy River Dist. one-- David H. Elder, Wormington 28 Oct.- 24 Nov. 1978 Marathon, Thunder Bay Dist. one-- Nicholas G. Escott (two birds present 11-14 Nov.) I considered as two separate records since birds were not together and likely arrived independantly of each other. 2 bird captured on last date, successfully kept indoors over the winter and released the following May. ONTARIO BIRDS DECEMBER 1986 107 provide excellent comparative and cover. However, sites such as data. When discussing the pattern weedy, overgrown sections of small of 'southern species in fall', towns, for example, located in McLaren lists Indigo Bunting as otherwise extensive tracts of boreal the fourth commonest fall vagrant forest, would attract and induce to Brier, Sable and Seal islands these birds to remain. (with a total of 102 records), after The above suggestion can be Dickcissel (Spiza americana) (119 supported by comparing Indigo records), Field Sparrow (Spizella Bunting data for Thunder Bay pusilla) (139 records) and Brown with those from elsewhere on Lake Thrasher (Toxostoma rufum) (164 Superior. There are no known late records). Through 1984, fall fall occurrences for the area records of vagrant Indigo Buntings immediately surrounding Thunder on these same three islands (I. Bay (N.G. Escott, pers. comm., McLaren, pers. comm., 1985) now 1986), even though the species is total 177 birds. Remarkably-and an uncommon nester here and very closely paralleling the there is a long history of bird northern Ontario occurrences observation from this locality. In fully 175 of the 177 birds occurred contrast, the shoreline east of from 21 September to 27 October Thunder Bay does not support inclusive, with but one bird breeding birds, but the records of recorded before these dates (14 late fall vagrants are numerous. August) and only one after There is no reason why late fall (November 13), both from Sable vagrants would not occur at Island. (Interestingly enough, a Thunder Bay, but since the city is bird recorded at St. John's, large and urbanized, with Newfoundland, on 21-22 October extensive areas of farms and 1982 (Bruce D. Mactavish, pers. farming communities surrounding comm., 1982), also fits neatly into the city, birds would certainly be this pattern of fall vagrancy.) difficult (and not likely) to be Looking at where in northern discovered. Lake Superior's north Ontario the records occurred (see shore to the east of Thunder Bay Figure 1), it is probably more than consists of extensive wilderness coincidence that most of the birds tracts with only scattered small found were in areas known to towns or tiny pockets of disturbed concentrate migrants (e.g., shore areas, thereby providing the ideal line areas of Lake Superior and situation for finding vagrant James Bay), indicating that Indigo Buntings. migration by the birds had recently The fall occurrence in northern taken place. Furthermore, as Ontario of birds originating from shown, the majority of birds southern or southwestern areas occurred in areas influenced by (and late in the season) is not humans. At the time of year when unique to the Indigo Bunting. The these birds occur, vast areas of pattern is also known for a number northern Ontario are generally not of other species; examples include favourable to Indigo Buntings in the many records of Clay-colored terms of providing preferred food Sparrow (Spizella pallida) and VOLUME 4 NUMBER 3 108 Vesper Span-ow (Pooecetes gramineus) as a vagrant in northern Ontario (unpublished data), the less during fall migration, and in frequent occurrences of Scissor comparison to these other species tailed Flycatcher (Tyrannus is one of the most frequent.

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