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61 Identification and Status of Bald , Golden Eagles, Turkey , and Black Vultures in by Bruce W. Duncan

Introduction the four considered here In flight., Bald Eagles (Haliaeetus have structural differences that leucocephalus) , Golden Eagles influence flight and can assist with (Aquila chrysaetos) , Turkey Vultures identification. The important (Cathartes aura), and Black Vultures differences for large, soaring (Coragyps atratus) all appear large species include wing loading, aspect and black with varying amounts of ratio, and the number of paler or white markings here and emarginated or slotted primaries. there in the . Superficially, The definitions of these terms are: they are similar, but closer Wing Loading: Weight divided by examination reveals differences in wing area; shape, size, flight style, and Aspect Ratio: Ratio ofwing span to markings that usually identifY each. wing width; Two recent books, A Field Guide Emarginated Primaries: Primary to the Hawks ojNorth America by feathers having one or both vanes Clark and Wheeler (1987) and reduced in width from the tip Haw~ inFlight by Dunne et al. inwards. (1988) cover the identification of For a much fuller discussion, see these species very well. This paper Rerlinger (1989), chapter 5. adds or emphasizes certain distinctions and provides How do they affect flight? information on the status ofeach (1) Wing loading: species in Ontario; it is not A soaring with a low wing intended to be a complete loading '(i.e.. less weight per unit of discussion ofidentification features. wing area) is able to more slowly and still remain airborne (i.e., not SOIite helpful terms stall). It also has a smaller turning All are not created equal. In circle, and can soar on weaker spite ofappearing similar in the sky, thermals, an ability that is especially

Bruce W. Duncan, 1049 Kirkwall Road, R. R. #1, Dundas, Ontario L9H 5E1

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helpful early and late in the day. Bortolotti 1988; Brown and One with a high wing loading (Le., Amadon 1968). This means that more weight per unitofwing area) immatures may be slightly less is able to make high speed dives efficient gliders. However, it also and has a lower rate ofsink when provides a technique for aging gliding at high speed. these birds. Older birds will have The Bald has a wing moulted some or all of the wing loading of80.94 N/m2 (Kerlinger feathers and replaced them with 1989) while the others have wing shorter ones. Eagles typically do not loadings that are either unknown have a complete annual flight or unpublished. However, weights feather moult so that the trailing and wingspans are given in Brown edge of the wing has some long and and Amadon (1968), and show some short feathers; it appears Golden and Bald eagles having ragged compared to the even-edged double to triple the weights of immature's wing. This is often the Black and Turkey vultures, while case with the as well. wingspans ofeagles and Turkey The ragged edges are generally Vultures are similar, and Black an indication that an eagle is older Vultures smaller (see Table 1). than immature. On occasion an This means that Turkey and immature will lose a wing or tail Black vultures have low wing feather by accident and replace it loadings and the eagles, higher. before the annual moult. The replacement feather will be shorter. (2) Aspect ratro: Immatures like this are few and far The higher the aspect ratio, the between. longer and narrower the wing and the more efficient it is for (3) Emarginated primaries: continuous gliding. Albatrosses All four species have six emarginat­ have aspect ratios ofabout 20, while ed outer wing feathers, providing the Sharp-shinned Hawk's six slots at the tip ofthe wings. (Accipiter striatus) is 4.57 (Kerlinger These slots do two related things: 1989). A.:spect ratios of the four (a) lower the stalling speed (i.e., species are indicated as similar by the speed atwhich a soaring or Kerlinger and are considered low, gliding bird can stay airborne); and although no figures are given. Bald (b) add more lift to the wings Eagles have a slightly higher aspect without lengthening them. ratio (somewhat narrower wings Since the feathers are "cut" on compared to the other species). both vanes, the slots formed have Immature birds (Le., those in squared ends when the wings are their first oflife) have longer fully spread; this is apparently more wing and tail feathers than adults efficient than one-sided slots for and therefore have slightly lower providing lift to the wing (Brown aspect ratios (Gerrard and 1976).

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Table 1: Weights and wingspans ofselected species

Species Wingspan (em) Weight (g)

Bald Eagle 1~244 3000-6300 152-204 2900-5800 Turkey 180 (average) 1400-1800 137-150 1181-19401

1 Brasiliensis race, which is about 7% smaller. Information for the atratus race ofour region is not available.

The flight styles of the birds in a generally uphill direction under consideration are affected by (Brown 1976). all three of these factors together. The two vultures search for Identification over large areas and so need to be The following briefnotes may add efficient soarers and gliders, and to or emphasize some aspects of may need to fly very slowly over an identification. For a complete area in order to detect food. Low treatment, see the two books wing loadings and six emarginated mentioned at of this primaries allow the vultures to do article. this over land, including fairly early and late in the day when thermals (1) Flight are too weak for eagles. The vultures, Turkey Vultures fly with wings Turkey Vultures in -particular, uptilted in a pronouced dihedral, seldom flap, an activity that moving slowly, and rocking as they requires more energy than soaring. go. They frequently give a half-flap The two eagles, having higher with the outer half of the wings, wing.loadings, are able to make then straighten them out again high speed dives, essential when quickly. Golden Eagles have slightly chasing prey, but with six slotted uptilted wings, but not nearly so primaries can also soar more pronounced a 'V" as the Turkey efficiently, important when Vulture. Bald Eagles and Black searching for food and migrating. Vultures soar on flat wings. In fact, The higher aspect ratio of the Bald Bald Eagles look like flying planks Eagle also makes it a more efficient because of their long, narrow wings. glider, helpful when migrating. When flapping, Black Vultures Because oftheir weight (and higher give halfa dozen stiff, jerky flaps at wing loading), the two eagles can a time; Turkey Vultures and eagles glide or dive at much higher speed have much slower, more deliberate than either vulture. A Golden Eagle wingbeats. was once timed flying at 195 km/h When g1iding, all species tuck

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their wings back more or less Golden Eagles. However, in Golden depending on wind and strength of Eagles, the white is a clear band rising air. The eagles are able to with no dark sides on the outer tail glide more rapidly than the vultures feathers. In Bald Eagles, the white is but this may not be apparenL ordered all around (tips and outer Watch carefully any single, fast­ tail feathers) with dark. Usually the gliding, big black bird - Turkey white is marbled with dark like a Vultures are most often seen in Harlan's Hawk ( jamaicensis flocks. It may be a Golden Eagle harlani) tail; in Golden Eagles the migrating at the same time as white appears immaculate. vultures and looking very similar GOLDEN EAGLE when in a half-tucked gliding The tawny and golden neck and position; so similar, in fact, as to be head feathers of the Golden Eagle dismissed as a can appear white (like the head of without close scrutiny. The Black an adult ) when in full Vulture as the rarest of these sun. The extensive white in an species in Ontario will be seen immature Golden Eagle's tail alone or with a group ofTurkey. coupled with sun-lightened gold on Vultures. the head can bear a superficial resemblance to an adult Bald Eagle. (2) Plumage: At distances, the bird may easily be BLACK VULTURE passed off as the wrong species. This species is only two-thirds the Nicoletti (1989) also pointed out size of a Turkey Vulture and half something interesting about the size ofeagles. At a distance, it immature Golden Eagles: some may may be confused - not with the show little or no white at the bases distinctive dihedral of the other of the flight feathers. One of this vulture species - but with an plumage was caught and banded at eagle's fairly flat profile. However, Hawk Cliff, Ontario, on 12 its distinctive white primary patches November 1990; there was no white will give it away. at all on the underwing flight or covert feathers. These two white TURKEY VUITURE patches, in conjunction with the There is nothing new to add to the white patch in the tail, are plumage descriptions already in the considered standard field marks. guides. Obviously, one must use great care BAlD EAGLE and more than one or two field In immature and some subadult marks when identifYing or , the Bald Eagle has attempting to age this species. extensive white tipped with black­ Nicoletti also added that on brown in the tail. This pattern is the birds in later plumages than same for immature and subadult immature there is a tawny bar

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Table 2: Dates and locations of Black Vulture sightings in Ontario

Date Location 16-17 Feb 1984 Long Point 31 Mar 1984 PointPelee 2-3July 1986 Walsingham and Turkey Point, Haldimand­ Norfolk 29July 1982 Highway 402, east Lambton County 17 Aug 1981 Point Pelee 24 Aug 1974 Cayuga, Haldimand-Norfolk 20 Sep 1979 near Kingsville, Essex County 26 Dec-3Jan 1987-88 Aldershot, Halton across the upper wing coverts. This In the Black Vulture's breeding bar fades over time and is very range further south, it is considered pronounced in spring migrants. By a permanent resident although that time, immatures may have a individuals wander or withdraw slightly pale area here due to seasonally from the northern areas fading; however, the bar is a very (Palmer 1988a). It is currently good mark to aid in aging Golden spreading northward east of the Eagles. Mississippi .

Status of the species in Ontario Turkey Vulture Black Vulture McTIwraith· (1894) reported that the This is the rarest of these species Turkey Vulture "...is a rare visitor to reported in the province, with eight the southwest of Ontario, and to records accepted by the Ontario the east I have not heard ofits Bird Records Committee Games being observed." Today it is a 1983; Wormington 1985, 1986, common nesting species across the 1987; Coady and Wormington south and west of the province 1989). The dates are listed in (Cadman et at. 1987), and the Table 2. number seen in migration is There appears to be no pattern steadily increasing, with 12 365 to the times of the sightings, sighted at Holiday Beach in the fall al though four may have been ofl988 (Benoit 1989). wandering non-breeders during The Turkey Vulture enters summer. The locations were all in Ontario beginning around mid the southwest of the province, close March, and peaks during the spring to Erie in most cases, migration in the last week of that J\ldershot being the furthest north month and the first two weeks of and west (at the western end of April (pers. obs.). These dates apply ). to the extreme south of the

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province. reached a low ofseven active During the nesting season it can in 1983 (McKeating 1985) from be seen almost daily in rural areas which it is slowly recovering away from unbroken foresL Mter (Cadman et aL 1987; Gerrard and the breeding season, the movement Bortolotti 1988). outofOntario begins in early The migration of Bald Eagles is September to the north and late complicated by the fact that September along the Lake Ontario irnmatures and subadults from the and Lake Erie shores. These birds southeastern also exit in largest numbers from about move into the province in spring 5 to 20 October, with the last few and out in faU. Ontario (and going in mid November. However, probably some ) breeders in the past five , there have move into the province fairly early, been a number ofsightings of in March and April (Nicoletti and Turkey Vultures in December, Dodge 1986, 1987). Younger January, and February in southern cohorts return north later in Ontario, an indication, perhaps, of general (Palmer 1988a), although its expanding population. With occasional adults are seen even in more birds in the province, it is June - a few might be southern more likely that there will be some breeders. For example, at Braddock unable to move south because of Bay on the south shore of Lake illness or injury, along with an Ontario in June 1987, one adult, additional few who may inherit a one four-year old, five subadult defective migratory orientation that (two- and three-year olds), seven results in them migrating to one-year olds, and two of unknown southern Ontario rather than with age were sighted. Although outside the rest of the population. Ontario, many of these birds may have been on their way into the Ba/dEag/e province. The Bald Eagle had declined in Southern birds of the year Ontario due to habitat loss, direct (immatures) from , as well persecution and DDT poisoning. In as west along the Gulf , and as the late 1970s and throughout the far north as , become 1980s, however, its numbers have independent oftheir parents from slowly increased with the March toJune. Palmer (l988a) stated elimination ofDDT and 'Their northern movement is reintroduction programs. Ontario's rapid, and they spread out from western population in the Rainy near the Atlantic coast to inland River District has remained quite .well west of the main axis of the large even though reproductive Appalachians ... The young, in success declined during the DDT their first calendar year, are years (Grier 1985), but the dominated by older cohorts. By southern Ontario population going north, presumably they

ONTARIO Bums AUGUST 1990 67

can find room to feed where they Grand River), usually below dams at are free ofaggression from their rapids or falls where open water own kind; those still surviving in produces injured or dead and fall return south and enter roost­ birds. ing assemblies ofother pre­ breeders - a better social situa­ Golden Eagle tion that prevails until reproduc­ Cadman et aI. (1987) showed only tive maturity, when the birds three breeding locations in the become territorial province and, of these, only one was (pp.204-205)." a confirmed Golden Eagle nesting Palmer also noted that banding site. Like the Bald Eagle, it is listed evidence indicates that only a under the Act fraction of second-year and older ofOntario. To the west in Bald Eagles migrate in the manner mountainous country, its typical of the immatures. These southern­ habitat, it becomes much commoner. hatched birds probably comprise During spring migration, the bulk of early spring immatures Golden Eagles, like all the other seen on migration while birds species described here, are most hatched the previous year in Ontario readily seen along the south and Quebec come north later. shoreline ofone of the Great . During the fall migration, Bald Spring passage along Lake Ontario Eagles are seen from early September runs from 10 March to 5 May at to late November along the Lake Derby Hill at the eastern end Erie north shore. There are two (Palmer 1988b); 5 March to 26 May peaks, in mid September and early at Braddock Bay near Rochester, to mid October (Benoit 1987, 1988, (Nicoletti and Dodge 1989), perhaps indicating returning 1986,1987; Dodge 1989, 1990); and southern-hatched immatures early 24 February to 23 May at Beamer in the season followed by northern Conservation Area near Grimsby, birds. later. However, the evidence Ontario at the western end (Dodge available does not include ages and. 1989, 1990; Grimsby Hawkwatcher is based on 122 birds over only 1981-88; unpublished data three autumns at Holiday Beach, 1975-80). The majority pass Ontario. It is known, according to through from 21 March to 5 May Palmer again, that in general, but there is no clearly-defined peak. young northern birds go south In the fall, based on Holiday earlier than their elders - a Beach data, Golden Eagles are first pattern typical of many birds of seen in early October but few pass prey. by until late in the month. From 24 A few Bald Eagles winter in October to 11 November, 102 of the Ontario (e.g., along the Niagara three seasons' total of 129 were River, near Peterborough, in seen. The IS-year average and Hamilton Harbour, along the lower range at Holiday Beach (1974-88)

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is 27 per year (0-58). Some of these Literature cited could be immatures from the west Bmoit, D. 1987 Eastern Great Lakes report. that have wandered to Ontario after Newsletter ofthe Hawk Migration As5ociation of North America 12: 42-44. dispersal from the nesting area. Bmoit, D. 1988 Eastern Great Lakes report. It is ofinterest to note that Newsletter of the Hawk Migration during both spring and fall A550ciation of North America 14: 52-54. Bmoit, D. 1989 Eastern Great Lakes report. migrations, almost all Golden Newsletter ofthe Hawk Migration Eagles are seen from 1100 to 1400h A550ciation of North America 15: 71-74. (Nicoletti and Dodge 1987; pers. Brown, L H. 1976. Eagles ofthe World. obs.). This is a more restricted time Univer5e Books. New York. Brown, L H. and D. Amadon. 1968. Eagles. than that ofBald Eagles and Hawks. and Falcons ofthe World. Country vultures, and probably indicates the Life Books. London. need this species has for thermal Cadman, M. D., P. FJ. Eagl8s, and F. M. H,l1Iiner. 1987. Atlas ofthe Breeding Birds lift during migration. ofOntario. University ofWaterloo Press. Few Golden Eagles are sighted Waterloo. during winter in the province, Clarlt, W. S. and B. K W/wltr. 1987. A Field although two areas do report them Guide to Hawks of North America. Houghton Mimin Company. Boston. with some regularity: Petroglyphs Goady, G. and A. Wormington. 1989. Ontario Provincial Park and Sault Ste. Bird Records Committee report for 1988. Marie. Ontario Birds 7: 43-54. Dodgw,j R. 1989. Eastern Great Lakes Region report. Newsletter ofthe Hawk Migration Conclusion A550ciation of North America 14: 46-51. Of these four species, three are D()(/.gw,j R. 1990. Eastern Great Lakes Region known to have increasing report. Newsletter of the Hawk Migration As5ociation of North America 15: 75-84. populations, and will probably Dumu, P., D. Sibley and C. Sutton. 1988. Hawks spread to areas of the province in Flight. Houghton Mimin Company. where they have previously been Boston. uncommon or absent. The fourth eer.,a.,d,j M. and G. R. BD"ftolotti. 1988. The Bald Eagle: Haunts and Habits ofa species, the Golden Eagle, has a Wilderness Monarch. Western Producer population that in Ontario is not Books. Saskatoon. well known at any season. on,." J 1985. The status ofBald Eagles nesting in northwestern Ontario. pp. 49-51 In Gerrard,J. M. and T. N. Ingram (eds.). Acknowledgements The Bald Eagle in : Proceedings of My thanks to all my friends at Hawk Bald Eagle Days. 198~. White Horse Plains Cliff and Beamer who over the Publishers, Headingly, . Ja'lf&lS, R. D. 198~. Ontario Bird Records years have made raptors ever more Committee report for 1982. Ontario Birds fascinating for me. Special thanks 1: 7-15. to Margaret Bain, who suggested I &rlin~ P. M. 1989. Flight Strategies of put these thoughts in writing for Migrating Hawks. University ofChicago PreS5, Chicago. Ontario Birds, and to Bob Curry and Mcllzmaith, T. 1894. The Birds ofOntario. Alan Wormington for providing Second Edition. William Briggs Company, information on Black Vultures. Toronto. McKeating, G. 1985. Charles Broley: Eagles then and now in southern Ontario.

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pp. 2>341n ~rrllrd,J. M. and T. N. Pal""" R. S. 1988a. Handbook of North Ingram (ed!l.). The Bald Eagle in Canada: American Bird!l. Volume 4. Diurnal Proceedin~ofBald Eagle Days, 198~. Raptors (Part 1). 'hie University Press, White Horse Plains Publishers, Headingly, New Haven. Manitoba. Pal-. R. S. 1988b. Handbook of North NicoUUi, F. 1989. A caution to beware when American Bird!l. Volume 5. Diurnal aging Colden Eagles in flight. Hawk Raptors (Part 2). Yale University Press, Migration Studies 14: 22-24. New Haven. Nicolltti, F. and) Dodge. 1986. Summary WOnIIingwn, A. 1985. Ontario Bird Record!l report of the 1986 spring raptor count at Committee report for 1984. Ontario Birds Braddock Bay, New York. Braddock Bay ~: 2-17. Raptor Research. Unpublished. 56 pp. WOnIIingwn, A. 1986. Ontario Bird Record!l NicoUUi, F. and) Dodge. 1987. Summary report Committee report for 1985. Ontario Birds of the 1987 spring raptor countat 4: ~18. Braddock Bay, New York. Braddock Bay Wonningwn, A. 1987. Ontario Bird Record!l Raptor Research. Unpublished. 50 pp. Committee report for 1986. Ontario Birds 5: 42~~. Nesting ofWhite-winged Crossbills in Oxford County by James M. Holdsworth and Don S. Graham

The White-winged Crossbill (Loxia spruce (Picea spp.) plantations leucoptera) normally breeds in the located at the eastern end of Boreal Forest zone. However, Wildwood Lake. As spring arrived, breeding has been confirmed as far breeding behaviour became south as Presqu'ile Provincial Park, apparent. On 17 March 1989, Victoria County, and the Waterloo Holdsworth observed several males area (Smith and Lumsden 1987; performing the species' Weir 1989a). This article details a characteristic flight song and breeding attempt by White-winged displaying strong territorial Crossbills in Oxford County. The behaviour. By 29 March 1989,20 nesting was at Wildwood Lake, an White-winged Crossbills remained, artificial reservoir in Oxford's all ofwhich appeared to be paired northwest corner, and is among the and very sedentary. These pairs most southerly known records could be found in the same small in the province. spruce plantation for several days. In the win ter of 1989-90, On 7 April, Holdsworth and Holdsworth and Graham . Graham observed a female White­ repeatedly observed about 40 winged Crossbill carry nesting White-winged Crossbills feeding in material into a Norway Spruce

James M. Holdsworth, R. R. #1, Woodstock, Ontario N4S 7V6 Don S. Graham, P. O. Box 1719, Atikokan, Ontario POT 1CO

VOLUME 8 NUMBER 2