139 Notes

About Crossbill Bills

John Schmelefske

2001 could certainly be described as on 28 October 2001. By 2 the year of the crossbill in areas of November, there was a small flock Ontario south of the Canadian of six or seven birds hanging Shield. The first nest ofWhite-winged around the feeders. This provided Crossbill (Loxia leucoptera) in the me with a great opportunity to test Greater Toronto Area was discov­ out my new digital camera. ered in the Palgrave Conservation The feeders I use are clear plas­ Area in February of 2001 (Coady tic tubes with tiny teardrop-shaped 2001). In the fall of 2001, as predicted holes for access to the seeds. I by many observers in the north, the remember many years ago when I poor cone crop on the Canadian bought my first niger feeder, I ini­ Shield resulted in a large movement tially thought I had gotten a faulty of finches southward. On my own unit because the holes where so property, approximately 5 km south small it did not seem possible that of Alliston, Ontario, from September the birds could get the seeds out. through November, I observed Of course, it proved to be no prob­ Purple Finches (Carpodacus pur­ lem for finches. This time around I pureus), Evening Grosbeaks wondered whether their crossed (Coccothraustes vespertinus), Pine bills would actually make it harder Grosbeaks (Pinicola enucleator), for crossbills to feed from a niger Pine Siskins (Carduelis pinus),White­ feeder. I soon realized that cross­ winged Crossbills and Common bills could use their tongues very Redpolls (Carduelis flammea) at var­ effectively to manipulate seeds. ious times, along with the usual They would stick their upper American Golfinches (Carduelis tris­ mandible in the feeder and leave tis) and House Finches (Carpodacus the lower mandible pointing to the mexicanus). side. Then they would use their Crossbills have always gotten a tongue to wedge a seed against the lot of attention for their amazing upper mandible and slide it out of bill adaptation, and rightly so. Last the feeder (see Figure 1). Clearly, fall was the first time I had ever had the unusual beak is only one of White-winged Crossbills coming to their assets. It makes sense that my feeder. The first arrivals were while the bill would be helpful in two juveniles, which I first noticed prying cones open, they would need VOLUME 20 NUMBER 3 140 a dexterous tongue to finish the job. resources are low and crossbills Unfortunately, one of my start corning to feeders, as they did White-winged Crossbill visitors had in 2001. My impression was that a terminal encounter with our slid­ these marks were not deep enough ing doors. The autopsy revealed to cause serious damage, but that curious markings on the upper over a whole winter it might be a mandible of the beak (Figure 2). I problem. It may be that, because of wondered if these abrasions might the bill shape, crossbills have to do have been etched into the bill by more maneuvering to access niger the edges of the openings in the feeders and consequently are more bird feeder. I had bought new niger susceptible to bill damage. feeders that year and thought that perhaps the sharp edges of the plas­ Discussion tic were hard enough to cause this I have no way of knowing with any kind of damage. The scratches were certainty whether the bill markings superficial, but potentially this were actually made by the feeder could have a significant impact on openings. I did not notice the marks wintering birds during years when on the beak until I looked at the

Figure 1: White-winged Crossbill removing seeds from niger feeder. Photo by John Schmelefske. o TARIO BIRDS DECEMBER 2002 141

Figure 2: Dead White-winged Crossbill with abrasions on the bill. Photo by John Schmelefske. pictures later long after tossing the Craig Benkman crossbill remains over the back fence. I went expert and author of the White­ over the 60 other photos that I took winged Crossbill account in The of crossbills at the feeders, and saw Birds of North America (Benkman no obvious similar markings but 1992) kindly examined my photo­ this may be because the pictures graph and considered that the con­ were taken at too great a distance clusions concerning wear on the bill to pick up such details. Are there seem reasonable although I doubt other possible explanations for that such wear even over a winter these marks? Well, I doubt whether would prove harmful to the bird" conifer cones would have the (Craig Benkman, pers. comm.). degree of hardness necessary to Thinking about crossbills got cause such damage. I considered me thinking about crossed bills. whether the marks might have One thing I noticed from my pic­ resulted from the impact on the tures was that some crossed bills go window but they look like etchings top-to-the-Ieft and bottom-to-the­ on the surface not fractures due to right while others go top-to-the­ impact. right and bottom-to-the-Ieft. I won- VOLUME 20 UMBER 3 142 dered whether there is a theory as lower mandible crossing to the left) to why they go either way and in that species (Benkman 1996). whether the ratio of each alterna­ Even more intriguing is whether tive had been measured? one variant spins the cones one way A search of the crossbill litera­ when it eats and the other spins ture revealed that the lower them the opposite way? Craig mandible of the North American Benkman (pers. comm.) stated that subspecies of the White-winged this does not appear to happen, but Crossbill (L. l. leucoptera) crosses that he had not systematically tested to the right approximately three it. Does one approach cones from times more often than to the left the left, and the other from the (Benkman 1988), while the lower right? mandible of the Red Crossbill (L. According to Bent (1968), curvirostra) "crosses to right as based on studies of captive Red often as to left" (Adkisson 1996). Crossbills by Tordoff (1954): "Birds Why the difference? Benkman are either right-handed or left­ (1996) theorized that the 1:1 bill handed in opening cones, according type ratio in Red Crossbills "results to which way the mandibles are from negative frequency-depend­ crossed. In feeding, the birds carry ent selection favouring the rarer pine cones with their bills to a morpho A crossbill always orients perch, hold the cones with their toward closed conifer cones so that feet, and insert the tips of the open its lower mandible is directed mandibles. With the long axis of the towards the cone axis (Benkman bird's head approximately at right 1987). Thus, only part of the cone angles to the long axis of the cone, can be reached easily when cross­ the tip of the lower mandible press­ bills have few perch sites and the es towards the central axis of the cone cannot be removed from the cone and raises a scale against the branch or otherwise turned around. essentially stationary tip of the Since crossbills may visit cones upper mandible. The tongue then which have previously been foraged probes and removes the seeds." on by other individuals, an equal Perhaps even more fascinating frequency of left-to-right mandible is the following account of Red crossings may minimize overlap in Crossbill roosting behaviour in Bent the use of cones and enhance forag­ (1968), again based on research by ing efficiency." In contrast, our Tordoff (1954): "Before going to White-winged Crossbills "forage on sleep birds extend and retract their cones that are easily twisted and tongues, three to five times a sec­ removed from branches", and since ond, for as many seconds. After a they manipulate the cones for effi­ pause, they repeat the process. The cient foraging, there is no selective tongue may project on either side of advantage for the rarer morph (i.e., the mandibles, and it extends well ONTARIO BIRDS DECEMBER 2002 143 beyond the tips. Sizable clusters of Clearly, the crossbill is a bird white frothy bubbles appear at the worthy of observation. In many ways ends of the bills. These clusters soon they remind me of parrots, with their break, leaving the mandibles wet highly evolved and dexterous bill and and shining. Coincident with the tongue. Behaviourally, the way they tongue action the birds open and forage so gregariously in groups, close their bills, but at a slower rate. hanging upside down and stretching Also, they close the bill in the to reach food, makes me think of "wrong" direction, resulting in a them as the boreal parrot. peculiar appearance because the mouth will not close evenly. It is Acknowledgements possible that this procedure brings I would like to thank Craig Benkman about a wearing down of the non­ for his helpful comments on an earli­ occluding edges of the bill by abra­ er draft, and RonTozer for assistance sion, with the moisture acting like with the literature. water on a whetstone."

Literature Cited Adkisson, C S. 1996. Red Crossbill (Loxia Benkman, C.W. 1996. Are the ratios of bill curvirostra). In The Birds of North crossing morphs in crossbills the result of America, No. 256 (A. Poole and F. Gill, edi­ frequency-dependent selection? Evolu­ tors). Academy of Natural Sciences, tionary Ecology 10: 119-126. Philadelphia, and American Ornitholo­ Bent, A.C. 1968. Bent's Crossbill (Loxia gists's Union, Washington, ne. curvirostra benti). Pp. 520-524 in Life Benkman, C.W. 1987. Crossbill foraging Histories of North American Cardinals, behavior, bill structure, and patterns of Grosbeaks, Buntings, Towhees, Finches, food profitability. Wilson Bulletin 99: Sparrows, and Allies (A.e. Bent; compiled 351-368. and edited by o.L. Austin, Jr.). United Benkman, C.W.1988. A 3:1 ratio of mandible States National Museum Bulletin 237, crossing direction in White-winged Part 1, Washington, D.e. Crossbills. Auk 105: 578-579. Coady, G. 2001. First nest record of White­ Benkman, C W. 1992. White-winged Crossbill winged Crossbill in the Greater Toronto (Loxia leucoptera). In The Birds of North Area. Ontario Birds 101-111. America, No. 27 (A. Poole, P. Stettenheim, Tordoff, H.B. 1954. Social organization and and F. Gill, editors). Academy of Natural behavior in a flock of captive, nonbreed­ Sciences, Philadelphia, and American ing Red Crossbills. Condor 56: 346-358. Ornithologists's Union, Washington, ne.

John Schmelefske, R.R. 4, Alliston, Ontario L4R 1V4

VOLUME 20 NUMBER 3 144 J. Bruce Falls: Distinguished Ornithologist

Ron Tasker

I am honoured to present my long­ gun site, used as a 6X30 monocular, time friend and field companion, Dr. which he bought from John Crosby J. Bruce Falls, Professor Emeritus, for $4.00, and an ersatz telescope Department of Zoology, University built out of one of his father's sur­ of Toronto, for receipt of the presti­ veying instruments. gious OFO Distinguished Ornithol­ Most important, birding bud­ ogist Award on 28 September 2002. I dies were scarce. One almost never am honoured, both by being asked saw another person looking at birds, to do so by OFO, in whose institu­ and I at least felt significantly inse­ tion as a distinct organization from cure as to try to hide my activities the FON, I was involved as the FON when I went out. Whereas Bruce Board representative, and by such a was inspired by a neighbour, Gord close identification with Bruce, Giles, teachers and by Sunnyside wearing two of his many hats: that of and High Park, I got turned on by internationally recognized profes­ my father and the DonValley where sional biologist and all round natu­ his Taylor antecedents farmed for ralist and birder. several generations. We both graduated from It was not until I started univer­ Victoria College in 1948 in Honour sity in 1944 that I first met other Science, he in Honour Biology. naturalists, when John Speakman Bruce joined the University of and Joe Wheeler invited me to join Toronto Department of Zoology in them on their raptor nest bicycle 1954, was tenured in 1961, and pro­ expeditions, north of Toronto. In moted to full professor in 1966, serv­ the fall of 1945, I first met Bruce ing as undergraduate secretary from who at the time was returning to 1969 to 1975 and associate chair second year Honour Biology after from 1975 to 1980. He was appoint­ serving his tour in the RCAF from ed Professor Emeritus in 1989. 1943 to 1945. Thinking back to those earlier He took me out to surrounding years, birding was not the big budg­ "hot spots" and very slowly I began et item it is today. We had to rely on to learn how to tell one bird from the Red, Green and Blue Books of another and to distinguish their the Birds ofNorth America (1931). songs. I also bought my first Eastern Nor was good equipment available. Peterson. Bruce introduced me to Where I relied on family opera such luminaries as Terry Short, glasses, Bruce was more inventive Lester Snyder, Ken Mayall, Cliff with a badly scratched World War I Hope and Jim Baillie. He spon- ONTARIO BIRDS DECEMBER 2002 145

Figure 1: Dr. Bruce Falls accepting the Distinguished Ornithologist Award at the OFO Annual Convention in Kingston, Ontario, 28 September 2002. Photo by Rory MacKay. sored me for membership in the dune, which in the morning turned TOC and Brodie Club, and most out to be covered by Prickly Pear important, introduced me to his Cactus, now long gone. I cannot friends, including Bob Ritchie, Bob recall a better fallout of especially Lanning, John Crosby, Yorke warblers in the flowering apple Edwards and Alex Cringan, who trees in the orchard, also long gone. was my future wife's (Mary Craig) Entering the park was simple then. cousin. I had never heard of a bird­ The gates were usually open, rarely ing trip until Bruce and his policed by the RCMP, and you entourage took me to Hamilton, could drive and camp anywhere introducing me to Rock Chapel, you liked. No crowds then; birders Lake Medad and then to Long were few on the ground. The trip Point in March 1946. culminated with us all convincing In May of the same year, he ourselves we had found a took me to the ultimate destination, Richardson's Owl among the cot­ Point Pelee. I will never forget the tages near the base. 6+ hour drive in Bruce's father's Although Bruce then went on to car, almost driving off the become an international figure, Leamington dock into Lake Erie in whereas I simply enjoyed natural his­ the dark, camping out on a sand tory, while I was reviewing his VOLUME 20 NUMBER 3 146

Curriculum Vitae with its 126 publi­ known what it was", they said. I will cations, I was struck by the similari­ never forget falling off a log into ties in our lives after undergraduate four feet of muck when birding with days. We both thrilled to our first Bruce and Ann, John Speakman, western birding. While in the RCAP, Mary, and Ron Ridout in La Selva Bruce was posted at Souris, Mani­ in Costa Rica in 1989. It took me toba, Penhold and Calgary, Alberta, half an hour before I could see from whence he hitchhiked to through my binoculars again. Bismark, North Dakota, Banff, Red We both worked at summer Deer and Vancouver. Perhaps you jobs for the Department of Planning did better in uniform because my first and Development under Ken western trip to Heron Lake in south­ Mayall and Fred Ide, doing stream ern Minnesota, while I was doing surveys, in Bruce's case with Andy research with Charles H. Best at Lawrie in the Thames and South Rochester, was not too smooth. We Nation drainages, as well as nearer both belonged to the Intermediate Toronto, and in mine also in the Naturalists, along with Jim Baillie's South Nation as well as in the James daughter, Florence, and Bob Bay watershed. The highlight of the Bateman. latter summer was Kesagami Lake We both experienced similar and River, now a provincial park. embarrassments. While Bruce's In 1947, Bruce's summer work mother unknowingly admonished took him to the Wildlife Research Professor Dick Saunders not to get Station at Lake Sasajewun in snow on her floor when he came Algonquin Park with David Fowle into the house to telephone, after and Jim Bendell. With Norm Bruce had shown him a Bohemian Martin, he worked under Professor Waxwing, the "twitch" that fol­ Dymond in the Park Naturalist lowed Dick (Jim Baillie was away) Program. Bruce stayed with the to see my Varied Thrush at Maple in Wildlife Station, working with such 1961 upset my neighbour by telling people as Yorke Edwards, Cliff him not to come out of his own Hope and Doug Miller, for the rest house for fear he would frighten the of his academic career, eventually bird! Jim Baillie obligingly elimi­ serving as U of T Department of nated the cause of the disturbance a Zoology representative. few days later. We were both influenced by the Bruce recounts his embarrass­ same people, in Bruce's case, mold­ ment when leading a birding group ing his career. "Covers" (A. F. in Toronto in place of Dick Coventry) provided advice and sup­ Saunders, when he could not identi­ port. E. M. Walker brought him into fy a loud warbler song that turned dragonflies, Dymond into fish. It is out to emanate from a Connecticut. hard to forget J. R.'s mnemonic for "Professor Saunders would have the song of the White-crowned ONTARIO BIRDS DECEMBER 2002 147

Sparrow: "poor Jo Jo peed his pants". VVhereas Bruce became a Check out these major part of the VVildlife Station, I great tours! had a briefer but fruitful time at the Fish Lab, now the Harkness Laboratory of Fisheries Research on Lake Opeongo in Algonquin Park, that introduced me to Jack Price and Jake (now Senator) Kenny of Trinidad, as well as

Murray Speirs, Professor A. G. Willow Ptannigan - Richard Knapton Huntsman, and of course, Professor Harkness, Fred Fry and Ray Dominican Republic/Puerto Rico: March 21 - 31 with Colin Jones & Elado Langford. Jack and Jake led me to Fernandez my first exotic trips to Florida and Tour focuses on endemics; includes two days in Pedernales area. Featured birds include the Everglades in 1945, and Broad-billed Tody, Hispaniolan Trogon, Trinidad in 1952, very different Palm Chat, Bay-breasted Cuckoo, Yellow­ shouldered Blackbird, Elfin Woods Warbler. places in those days to what they are now. Both Bruce and I were Churchill & Southern Manitoba: June 2 - 14 with Richard Knapton influenced by Bill Gunn, this lead­ Includes overnight train ride to Churchill. We ing to Bruce's recognition as an hope to see such specialties as Ross's Gull, international figure in animal com­ Northern Hawk Owl, Willow Ptarmigan, Smith's Longspur, Connecticut Warbler, munication and behaviour, with the Hoary Redpoll, Sprague's Pipit and Black­ first publication in 1959, and espe­ backed Woodpecker. cially his interest in bird song. He The High Arctic: went on to work out the anatomy July 2 - 13 with Richard Knapton Tour covers Aspen Parklands, Boreal forests and physiology of bird song as well, and the exquisite high Arctic tundra.. Great using Great Tits, meadowlarks, and close-up viewing/photography opportunities ofbreeding birds and wonderful flora, plus a of course, VVhite-throated Sparrows, unique Inuit cultural experience. as subjects. Well-organized, quality tours with Both of us love the wilderness, exceptional leaders and great itineraries. Bruce with his Apsley property in Peterborough County, and we with our tract of Lake Huron shoreline, alvar and pseudoboreal forest on Manitoulin Island. But whereas we had our neighbour Ivan Bailey reconstruct two pioneer log houses 1-800-373-5678 on the site, Bruce built his own 19th P.O. Box 94672, Richmond, Be V6Y 4A4 century Ontario Victorian horne at www.eagle-eye.com Apsley with his own two hands. He E-mail: [email protected] also built his own cottage on Go VOLUME 20 NUMBER 3 148

Home Lake. Anyone who tires of the his Visiting Scientist appointments in summer crowding of Georgian Bay 1964 at CSIRO in Canberra, should let Bruce take them on a nat­ Australia, as well as in 1973 at UBC, uralist's tour away from the madding Visiting Scientist appointment at crowd to see such wonders as the Rockefeller University in 1980 and botany of the old Champlain Sea. Visiting Fellowship at Wolfson Bruce was a member ofthe com­ College Oxford, 1981 and 1988, mittee that established the Nature sculpted his professional career. But Conservancy of Canada, was NCC they also contributed to his birding Chair from 1971 to 1974, and has abilities. He was as much at home in remained a major figure in that Europe when Mary and I visited him organization, on which I also served there as he would be at Long Point, as a Board member. We both served finding Curlew Sandpipers, as I in the Conservation Council of recall, and easily distinguishing, to Ontario, and we both had Long Point me apparently identical, migrant connections. Bruce was President of Phylloscopus warblers. the Federation of Ontario Naturalists He is ingenious in the field, as from 1962 to 1964. demonstrated during an early With Don Smith and Witek Birdathon to raise money for the Klawe in 1950 and 1951, Bruce Long Point Bird Observatory. We camped out near the lighthouse at began to get inundated with rain, the tip of Long Point to begin his and with no alternative to start over long career studying deer mice, at on another day, Bruce fashioned a that time for his Ph.D. thesis. There green garbage bag rain cape for they met Lorne Brown, the naturalist each of us, carefully cutting out the lightkeeper, who in 1948 gave me a eye and mouth holes, allowing us to lighthouse-killed Kentucky Warbler continue counting! skin he had prepared. Jim Baillie said In addition to our Costa Rica it was Ontario's seventh record. trip mentioned above in 1989, we Both of us became involved with had great trips together to the Long Point Bird Observatory. Venezuela in 1993, India in 1996 Bruce was already an Honourary and Brazil in 1997. Many of you will Director, since 1970, and chaired the have seen his beautifully edited Program Committee from 1991 to video, for example, of our trip to 1992. Both of us served as Chairman Kazaranga in Assam, particularly of the Board. Bruce played a major elephant rides through marshes to role in the conversion of the former closely approach fighting Asiatic Long Point Bird Observatory to its one horn rhinoceros. national and even more scientific But Bruce will be immortalized successor, Bird Studies Canada. by especially his work on White­ Obviously, his post-doctorate throated Sparrow morphs, Eastern fellowship at Oxford, 1953-1954, and and Western meadowlark song, and ONTARIO BIRDS DECEMBER 2002 149 of course, deer mice. Journal of Zoology from 1982 to However, more important is his 1989, Chair to the Scientific influence on younger scientists. Just Program Committee of the 19th as Baillie, Mayall, Dymond,Walker, International Ornithological Con­ Ide, Coventry and others left their gress in Ottawa, and involved in impressions on him, he has left his others before and after (good mark on 36 graduate students in the chances to do exotic birding!), and field, as Bruce succinctly puts it, of President of the Society of "behavioural mechanisms con­ Canadian Ornithologists, 1991 to tributing to population regulation, 1993. Bruce is a member of the dispersion and use of resources by Laboratory of Ornithology at wild species". His work continues, Cornell, the Ecological Society of with 15 publications currently in America, and the Wilson Ornitho­ preparation or press in the past five logical Society (Council member years. 1962-1964), and a Fellow of the He has been honoured previ­ American Ornithologists' Union ously many times, in Canada, the and the Deutsche Ornithologen USA, UK, and Germany in particu­ Gesellschaft. And now, OFO has lar, and in addition to important most appropriately presented him posts already mentioned, he was with its Distinguished Ornithologist associate editor of the Canadian Award.

Ron Tasker, 12 Cluny Drive, Toronto, Ontario M4W 2P7

The Distinguished Ornithologist Award is granted to individuals who have made outstanding and authoritative contributions to the scientific study of birds in Ontario and Canada, who have been a resource to OFO and the Ontario birding communi­ ty, and whose research on birds has resulted in many publications and a significant increase in new knowledge. Previous recipients were the late Earl Godfrey (1997), Ross James (1998), the late Murray Speirs (2000), and George Peck (2001).

VOLUME 20 NUMBER 3 150 American Crow Nesting on Building

Mark K. Peck

On 2 April 2002, an American Crow twigs and some dried grasses. On 15 (Corvus brachyrhynchos) was ob­ April, no activity was observed at or served carrying several sticks to an near the nest. The nest appeared interior corner of an upper ledge on damaged and the ground below the the northwest side of the Royal nest contained additional twigs, Ontario Museum (ROM), Toronto, grasses and the broken remains of Toronto. The ledge was 21 m above three crow eggs. The area was ground and 3 m from the roof of the rechecked on 17 April, and no activ­ Museum. During the next 30 min­ ity was seen at the nest site or in the utes, a pair of crows made three vis­ surrounding vicinity. its to the site. Sticks were seen On 17 April, a pair ofAmerican being collected on the ground or Crows was observed carrying twigs taken from trees within 100 m of the and trying to place them in various nest. The birds then flew to a large locations on the rooftop along the Northern Catalpa (Catalpa speciosa) south side of the Legislative located in front of the ledge, before Building at nearby Queen's Park. proceeding to the nest site (ONRS The birds tried to place the twigs in 168785). Although difficult to see several locations but, after approxi­ from the ground, the amount of mately 20 minutes, flew off to the material on the ledge suggested that southeast. On 19 April, a nest under nest-building had been initiated a construction (ONRS 168790) was day or two earlier. located in a nearby White Pine Nest-building continued on 3 (Pinus strobus). Large young were (Ron Pittaway,pers. comm.), 4 and 5 seen in this nest on 16 June 2002. April 2002. On 9 April, an adult was seen sitting on the nest. On 12 April, Discussion a crow was seen near the nest, call­ The American Crow is a common ing loudly and flying at a Grey summer resident throughout most Squirrel (Sciurus carolinensis) as it of Ontario. It has been found moved along the upper branches of breeding in a wide variety of habi­ the catalpa. The crow continued to tats including woodland, agricultur­ follow the squirrel until it had al and residential areas. Nests are moved into a nearby tree. The bird usually well hidden in coniferous then returned to the nest. The nest and deciduous trees and occasional­ appeared intact and the ground ly in bushes. But crows have also below the nest contained numerous shown some versatility in nest site

ONTARIO BIRDS DECEMBER 2002 151 selection. Within the province, Peck have been found are usually in and James (1987) reported crows abandoned buildings, where less nesting rarely in dead trees, on top human disturbance would be of dead stubs, and in a cliff face expected. The nest on the ROM crevice. Throughout North Amer­ was certainly high enough to avoid ica, there have been reports of birds disturbance from humans but may nesting on the ground (Mitchell have failed for other reasons. 1915), in tules over water, in hollow Squirrels are very common in the stubs, on telephone poles and even vicinity of the Museum and they are on the chimneys of an abandoned often seen using the ledges and house and a church (Bent 1946). walls to move around the area. A Many of the unusual nest sites men­ nest blocking a well-used route may tioned by Bent were found on the have been disturbed to re-open a prairies where the treeless land­ path. Another possible explanation scape might have been responsible for the nest failure may have been for some of the nest sites selected. the difficulty securing the nest to A more extensive literature search the building. The nest was built on failed to reveal additional nests an interior corner of a flat ledge, sites on buildings. A search of the and although well protected from internet, however, turned up photo­ the south and east, it would still be graphs of an American Crow nest open to winds from the northwest. positioned on a wooden ledge along Nesting on buildings might pro­ one of the lower lock gates of the vide advantages for crows. To a upper lock at Jones Falls, Leeds and corvid, the ledge on a building may Grenville, Ontario (Watson 2000). be akin to a crevice in a cliff, offer­ While it is not surprising to ing protection from both predators think ofAmerican Crows and other and the weather. It may also be corvids nesting in close association more advantageous in areas where with people, it is rare to find them deciduous trees predominate, and nesting on buildings. It has been where birds initiate nest construc­ reported for White-necked Raven tion before the leaves have budded (C. cryptoleucos; Baicich and Harri­ in the spring. son 1997), and there was also a nest­ ing attempt of a Common Raven Acknowledgements (Corvus corax) x American Crow Many thanks to Ron Pittaway for pairing on the former Etobicoke his independent corroboration of Lakeshore Psychiatric Hospital, the nest and his follow-up report. Toronto (Jefferson 1994). Nests that

VOLUME 20 NUMBER 3 152

LiteraturelReferences Cited Bent, A.C. 1946. Life Histories of North Mitchell, H.H. 1915. Crows nesting on the American Jays, Crows, and Titmice. ground. Auk 32: 229. United States National Museum Bulletin Peck, G.K. and R.D. James. 1987. Breeding 191. Part II. Washington, nc. Birds of Ontario: Nidiology and Distri­ Baicich, P.J. and c.J.O. Harrison. 1997. A bution. Volume 2: Passerines. Life Guide to the Nest, Eggs and Nestlings of Sciences Miscellaneous Publication, North American Birds. Second Edition. Royal Ontario Museum, Toronto. Academic Press, San Diego, California. Watson, K. 2000. A Rideau Image. Jefferson, E.A. 1994. A successful hybridiza­ www.rideau-info.com/canal/images/img­ tion of Common Raven and American n-crows.html Crow. Ontario Birds 12: 45-58.

Mark K. Peck, Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6

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3350 FAIRVIEW ST. 951. GORDON ST. BURLINGTON ONT. GUELPH,ONT. 1.-905-634-7700 1.-51.9-821.-2473 E-Mail: [email protected] E-Mail: [email protected]

ONTARIO BIRDS DECEMBER 2002