27 Notes

Why Do Male Belted Kingfishers Winter Farther North Than Females? by Ron Pittaway

Belted Kingfishers ICeryle alcyon) are arrives, she seems attracted to the cold-hardy and often winter as far nest site and then pairs with the north as open water permits IBent male. The two then defend the nest 1940). During the last four winters site and fishing area" IStokes and 11991-1994), I recorded the sex of the Stokes 1983). Godfrey 11986) states kingfishers observed wintering in that breeding populations in rocky southern Ontario. Observations were areas le.g. Canadian Shield) are made at Bobcaygeon, Lakefield, limited by the availability of nesting Minden, Toronto and Whitby - all sites. Therefore, male kingfishers that situated north of Lake Ontario. Given defend winter territories on or near a good view, it is quite easy to the breeding grounds would have the distinguish males from females in the first choice of the best breeding field IGodfrey 1986). Interestingly, all habitats Inest sites and fishing areas). the kingfishers In = 12) seen well Returning females are apparently enough to classify were males. In most attracted to those males holding Yellowstone National Park, the best breeding territories. Wyoming, Skinner lin Bent 1940) also Of course, there may be other noted that all of the kingfishers equally valid explanations why only wintering along streams kept open by male kingfishers are found at the hot springs were males. The first very northern part of their winter females arrived there on 17 March. range. I would be interested in Why do male kingfishers winter hearing about any winter IDecember­ farther north than females? My February) sightings of female hypothesis is that the number of nest kingfishers in southern Ontario and sites in the northern part of the about other hypotheses. Belted Kingfisher's range is the major factor limiting their populations. Kingfishers usually dig their nesting Acknowledgements tunnels in stream banks and old I thank Bill Crins, Michel Gosselin, gravel pits, often some distance from Jean Iron, Ron Tozer and Mike water IGodfrey 1986). Males arrive Turner for much valuable assistance first on the breeding grounds and and advice in the preparation of this defend a nest site. "When the female note.

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Literature cited Godfrey, W.E. 1986. The Birds of Canada. Bent, A.C. 1940. Life Histories of North Second Edition. National Museum of American Cuckoos, Goatsuckers, Canada, Ottawa. Hwnmingbirds and Their Allies. Part 1. Stokes, D. W. and L.Q. Stokes.. 1983. A Guide to United States National Museum Bulletin 176, Bird Behaviour. Volume II. Little, Brown and Washington, D.C. Company, Boston and Toronto.

Ron Pittaway, Box 619, Minden, Ontario KOM 2KO.

Grasshoppers as Food Source for Black-billed Cuckoo by David Agro

The most frequently noted food items Haldimand-Norfolk, on 1 August of the Black-billed Cuckoo (Coccyzus 1993. The first bird, presumably erythropthalmusJ are caterpillars, feeding for most of the day, had eight particularly the "hairy" species (Bent whole grasshoppers and a number of 1940, Godfrey 1966, Terres 1980J. parts that were identified as a Other animals such as grasshoppers, grasshopper. There was only one part beetles, crickets, mollusks, and fishes that could be determined as being are mentioned as prey, but little has from another insect, identified as a been noted on their importance as caterpillar (LepidopteraJ. The second part of the cuckoo's overall diet. My bird had two whole grasshoppers and examination of gizzards and numerous grasshopper parts, plus a proventriculae of two Black-billed small amount of caterpillar hair. It Cuckoos found short-horned had proportionately less food in its grasshoppers (Order Orthoptera: proventriculus and gizzard than the Family AcrididaeJ to be the major first, possibly due to less feeding food item. time. Both birds were road kills. The The number of grasshoppers in first bird was an adult female, found these birds suggest that cuckoos do barely alive near Nanticoke, R.M. not always depend mainly on Haldimand-Norfolk, in the late caterpillars for the large portion of afternoon on 24 July 1993. The their diet. At times when caterpillars second bird, an adult male, was are not plentiful, the birds found recently killed in the early presumably take advantage of other, morning near the intersection of more abundant food sources such as Highway 24 and Regional Road 10 grasshoppers. (Turkey Point RoadJ R.M.

ONTARIO BIRDS APRIL 1994 29

Acknowledgements Literature cited I would like to thank M.E. Gartshore, Bent, A. C. 1940. Life Histories of North R.W. Knapton and J.D. McCracken American Cuckoos, Goatsuckers, Humming­ who made helpful comments on the birds, and Their Allies. Part 1. United States National Museum Bulletin 176. manuscript, and the Long Point Bird Washington, D.C. Observatory for its support. Godfrey, W. E. 1966. The Birds of Canada. National Museum of Canada Bulletin 203. Ottawa. Terres, J. K. 1980. The Audubon Society Encyclopedia of North American Birds. National Audubon Society, New York.

David Agro, Long Point Bird Observatory, Box 160, Port Rowan, Ontario NOE 1MO.

Mourning Doves Wintering in Ontario by Ron Tozer

Introduction production" (Armstrong and Noakes The Mourning Dove (Zenaida 1981). The number of overwintering macroura) occurred only sparingly in Mourning Doves in southern Ontario settled areas of southern Ontario 150 continues to increase today. Where years ago (Snyder 1957), but had agricultural land has been taken over become a common breeding species by urban development, the species of the southwestern part of the has adapted through extensive use of province by early in this century winter bird feeders (Tozer and (Baillie and Harrington 1936). For Richards 1974; Alison 1976). In many of these early years the recent years, the Mourning Dove has Mourning Dove was migratory in begun to winter even farther north in Ontario (Saunders and Dale 1933). central Ontario, away from Overwintering apparently developed agricultural areas. This note examines in agricultural areas due to the some of the data which illustrate availability of waste and stored corn these trends in wintering by (Alison 1976; Armstrong and Noakes Mourning Doves in Ontario. 1983). It was not until the early 1950s that wintering populations in Southern Ontario southern Ontario "increased rapidly Freedman and Riley (1980) trac;ed and in a linear fashion" (Armstrong population trends of various bird 1987), apparently correlated with species wintering in southern Ontario "corresponding increases in corn through an analysis of annual

VOLUME 12 NUMBER 1 30 Christmas Bird Count (CBq data was 1987. Two southern Ontario from seven locations (Hamilton, CBCs have actually reached totals of Kingston, Kitchener, London, Ottawa, more than 2000 Mourning Doves (Le. Pickering and Toronto) during the 2016 at Cedar Creek in 1987, and period from 1929 to 1977. Their 2001 at St. Catharines in 1988j! findings for the Mourning Dove indicated that "essentially no birds Central Ontario were recorded prior to 1950", In 1966, it was reported that the followed by relatively low (but Mourning Dove wintered in Ontario, increasing) numbers during the next "north rarely and precariously to two decades. Then "a spectacular Ottawa" (Godfrey 1966). Since then, increase" occurred from 1970 to however, the species has been regular 1977, with the combined totals for all (with increasing numbers) throughout seven sample counts averaging about the twenty years from 1973 to 1992 1350 birds per year (Freedman and on CBCs at Ottawa-Hull, Pakenham­ Riley 1980). Using the same method Arnprior, and Carleton Place. During on CBC results reported in American the 1980s, wintering by Mourning Birds from the seven selected Doves spread to various sites on the locations over the next fifteen years Canadian Shield. For example, they (1978 to 1992), I found an average of have become regular (with increasing 3479 Mourning Doves per year numbers) on the following CBCs (ranging from 1288 in 1982, to 5226 since the year shown in parentheses: in 1988). These sample count results Pembroke (1981); North Bay, Sault were standardized to "birds per Ste. Marie, and Gravenhurst­ observer" in order to compensate for Bracebridge (1982); Deep River, and increasing observer effort over time, Minden (1987); Sudbury (1988); and as suggested by Raynor (1975). Burks Falls, and New Liskeard Freedman and Riley (1980) found a (1989). Mourning Doves have been peak of about six birds per observer regularly observed on an unpublished in 1976, while I calculated that there winter bird count at Huntsville since were 10.2 Mourning Doves per 1984 (Huntsville Nature Club observer by 1988. The dramatic records). increase in wintering by Mourning Wintering by Mourning Doves at Doves in southern Ontario has these Shield communities is obviously continued. apparently linked to increases in local I examined all Ontario CBC data breeding populations (Alison ::. 976), reported in American Birds during the and the provision of food at winter twenty years from 1973 to 1992 in feeding stations adjacent to dense order to further investigate the coniferous cover for roosting. Dow magnitude and timing of the increase (1994) has suggested a similar in Mourning Dove numbers. In dependency on feeders as "a factor southern Ontario (south of the critical to maintaining local Canadian Shield), there were fully 15 populations as breeding entities" in Christmas Counts which achieved outlying areas of the Northern totals of 1000 birds (or more) during Cardinal's (Cardinalis cardinalis) range the 1980s. The average year of these in Ontario. Many Mourning Doves counts first reaching that "plateau" attempting to winter on the Canadian

ONTARIO BIRDS APRIL 1994 31

Shield are totally dependent on body temperature and, feeding stations, with no access to correspondingly, their metabolic agricultural land for corn or weed expenditures" when exposed to low seeds. ambient temperatues and absence of food (as during winter stormsl. Northern Ontario Successful overwintering by Very recently, a few Mourning Mourning Doves in Ontario allows Doves have been detected on CBCs them to "avoid the hazard of even farther north. These counts, migration and hunting" and to "take with the number of birds in advantage of favourable early spring parentheses, were as follows: conditions that may increase the Timmins in 1992 (6); Thunder Bay in length of the breeding season" 1987(21, 1991 (11, and 1992 (11; (Armstrong and Noakes 19831. Dryden in 1992 (11; and even Moosonee in 1992 (31. Indicative of Acknowledgements this species' continued advance Discussions with Doug Tozer and northward in Ontario was the Ron Pittaway were very helpful in presence of at least 12 birds at the preparation of this note. Moosonee during the 1991 breeding season, with "courting and copulating Literature cited pairs" observed and breeding Alison, R.M. 1976. Mourning Doves wintering strongly suspected (Wilson and in Ontario. Canadian Field-Naturalist 90: McRae 19931. The Clay Belt was 174-176. considered to be the northern Armstrong, E.R. 1987. Mourning Dove. boundary of breeding through the pp. 196-197 in M.D. Cadman, P.F.J. Eagles, late 1980s (Peck and James 1983; and F.M. Helleiner (Compilers). Atlas of the James 19911. Breeding Birds of Ontario. University of Waterloo Press, Waterloo, Ontario. Wintering Capability Armstrong, E.R. and D.L.G. Noakes. 1981. Food habits of Mourning Doves in southern Even with available food and Ontario. Journal of Wildlife Management 45: cover, severely cold winter weather 222-227. often causes injury, and sometimes Armstrong, E.R. and D.L.G. Noakes, 1983. even mortality, among Mourning Wintering biology of Mourning Doves, Doves attempting to winter in Zenaida macroura, in Ontario. Canadian northern areas such as Ontario Field-Naturalist 97: 434-438. (Nickell 1964; Alison 1976; Whelan Baillie, ].L. and P. Harrington. 1936. The distribution of breeding birds in Ontario. 19941. Frost damage to the feet, Transactions of the Royal Canadian Institute including loss of toes, is a common 21: 1-50. injury (Alison 197.6; Armstrong and Dow, D.D. 1994. The Northern Cardinal in Noakes 19831. However, birds Southern Ontario. pp. 291-297 in M.K. sustaining such injuries can McNicholl and J.L. Cranmer-Byng (Editors). apparently still function. Studies of Ornithology in Ontario. Special Publication No.1, Ontario Field Ornithologists. captive birds (Ivacic and Labisky Hawk Owl Publishing, Whitby, Ontario. 19731 have actually suggested that Freedman, B. and].L. Riley. 1980. Population Mourning Doves may ,'possess a trends of various species of birds wintering physiological mechanism that allows in southern Ontario. Ontario Field Biologist them to substantially reduce their 34: 49-79.

VOLUME 12 NUMBER 1 32

Godfrey, W.E. 1966. The Birds of Canada. Saunders, W.E. and E.M.S. Dale. 1933. History National Museum of Canada Bulletin 203. and list of the birds of Middlesex County, [vacic, D.L. and R.P. Labisky. 1973. Metabolic Ontario. Transactions of the Royal Canadian responses of Mourning Doves to short-term Institute 19: 161-248. food and temperature stresses in winter. Snyder, L.L. 1957. Changes in the avifauna of Wilson Bulletin 85: 182-196. Ontario. Pp. 26-42 in F.A. Urquhart (Editorl. James,. R.D. 1991. Annotated Checklist of the Changes in the Fauna of Ontario. University Birds of Ontario. Second Edition. Life of Toronto Press, Toronto. Sciences Miscellaneous Publications. Royal Tozer, R.G. and].M. Richards. 1974. Birds of Ontario Museum, Toronto. the Oshawa-Lake Scugog Region, Ontario. Nickell, W.P. 1964. The effects of probable Published by the authors. frostbite on the feet of Mourning Doves Whelan, P. 1994. Mourning Doves cling to life. wintering in southern Michigan. Wilson Globe and Mail (15 January 1994). Bulletin 76: 94-96. Wilson, N.C. and D. McRae. 1993. Seasonal Peck, G.K. and R.D. James. 1983. Breeding and Geographical Distribution of Birds Birds of Ontario: Nidiology and Distribution. for Selected Sites in Ontario's Hudson Bay Volume 1: Nonpasserines. Life Sciences Lowland. Ontario Ministry of Natural Miscellaneous Publication. Royal Ontario Re~urces. Moosonee. Museum, Toronto. Raynor, G.S. 1975. Techniques for evaluating and analyzing Christmas Bird Count data. American Birds 29: 626-633.

Ron Tozer, R.R. I, Dwight, Ontario POA IHO.

Successful Hybridization of Common Raven and American Crow by E.A. (Beth) Jefferson

Since 1985, a single Common Raven At that time there was no sign of a (Corvus corax) has frequented an mate (Jefferson 1989). urban environment approximately Many observations during 1990 145 kIn south of its usual range. It indicated that the raven had paired has been observed pursuing, killing with an American Crow (c. and feeding on Rock Doves (Columba brachyrhynchos). During April 1990 livia) and Gray Squirrels (Sciurus the r

ONTARIO BIRDS APRIL 1994 33

observed flying into a Norway Spruce On several occasions - 3, 5 and 8 (Picea abies) to alight beside a crow. May 1993 - after consuming several The raven fed the crow what pieces of squirrel, the raven flew to appeared to be fresh "meat", and the nest where it remained for 40-60 then mounted the crow. The raven seconds. Precise activity at the nest and crow were subsequently was obscured by the dense evergreen observed allopreening (D. branches. McClement, pers. comm.; Bent 1946). On 14 June begging calls were Since 1990, the raven and crow have heard from the nest vicinity (A. been seen flying together frequently Fairbridge, pers. comm.). The next (Jefferson 1991). day the author observed much In 1990, the raven began to activity around the nest, with a crow mimic the calls of a crow, which and raven repeatedly calling to each might have led to its acceptance by other. What were later deemed to be the crow. Vocal interactions between two recently fledged hybrids made the crow and raven have been heard short flights between nearby - a pattern of two caws coming from deciduous trees. On 18 June 1993 the crow answered by three deeper positive confirmation was made of caws from the raven. the two hybrids. They were almost In late April 1993, the Common raven-sized, with the wedged-shaped Raven was observed actively tail of a raven and the head of a constructing a nest in a crotch of a crow. Their bills appeared very thin, spruce tree on the above site. The shorter than that of a crow, with a nest was approximately 60 em in small amount of yellow at the gape. diameter and 40 em deep, one metre The two hybrids were photographed from the top of a nine to ten metre several hundred meters south of the high tree. During the next two nest in the crowns of large maple months the raven was occasionally trees (see Figure I). seen on the nest; invariably it was Repeatedly, both the crow and observed perched nearby, well­ raven flew away from the young concealed in the spruce branches. In birds making loud distracting noises a few instances, when intruders came whenever these fledglings were rather close to the nest, it flew from approached; a few minutes later the elsewhere on the property into adults would silently appear from neighboring trees. behind the observers. This behaviour A crow was thrice seen leaving was noted frequently over a 90 the nest, but all nests were too deep minute period. Begging calls from the for any observations of a crow sitting young were silenced when the crow there. On 29 May 1993, the crow was flew into the trees where the young viewed leaving the nest area to remained. Dense foliage prevented confront a high-flying Turkey Vulture precise observations of behaviour (Cathartes aura). Three minutes later, from our position 10 m to the north. as the crow dropped back down, the Later, cawing from these fledglings raven flew up to meet it; both corvids sounded more highly pitched then returned to the nest site (G. compared to that of the crow, which Fairfield, pers. comm.). in turn made calls which were higher

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Figure 1: Recent fledgling resulting from the hybridization of Common Raven and American Crow at the former Etobicoke Lakeshore Psychiatric Hospital, Metropolitan Toronto, Ontario, Canada, 18 June 1993. Photo by Beth Jefferson. than the deep resonating caws from descriptions and the other direct the raven. The crow, raven and two observations cited above, it has been hybrids continued to be seen flying concluded that the raven is a male together until the end of June (D. and that the crow is a female. McClement, pers. comm.). During the fall of 1993, the two hybrids wen If fledging took place 14 June frequently observed with the raven. 1993, the eggs would have hatched in On 27 October, all of them were seen early May during which time the briefly by the author chasing 'Rock raven was observed making frequent Doves. trips to the nest after ingesting squirrel meat. If the crow laid the Both sexes of crow take an active eggs as is speculated, it would have part in nest building. Both sexes of occurred approximately 18 days prior ravens also contribute to the building to this in the second week of April. of a nest and both sexes of crow may These dates have been deduced using help incubate (Bent 1946: Goodwin averages cited in Ehrlich et al. (1988). 1976). With ravens, the male is not This appears to be the first reported to incubate but only to cover known documentation of successful the eggs when the female leaves the hybridization of Common Raven X nest. In corvids the male feeds the American Crow in North America. In female during incubation and the Britain, three reports of hybridization female sometimes leaves the nest to of Common Raven X Carrion Crow be fed by the male nearby (Bent (c. carone) are cited in Gray (1958). 1946: Goodwin 1976). From these

ONTARIO BIRDS APRIL 1994 35

But these records date from 1897 to a raven. Identification could be quite 1936. If undocumented raven X crow tricky, especially if they leave their hybridization has occurred, it would natal area. be virtually impossible to distinguish in any of their offspring. (For Acknowledgements example, visual hybrid features I appreciate the continued would not be as apparent as in encouragements from Alvaro Lawrence's and Brewster's Warblers.) Jaramillo and Jim Rising, Zoology The atypical location of this Dept., University of Toronto, and particular raven, and the from Don McClement, who have distinguishing silvery-gray cast to its commented on earlier drafts of this back and wings creating a two-toned note and have offered many insights effect in flight, have enabled this respecting hybridization possibilities. particular raven to be subjected to intense scrutiny. Thus details of its Literature cited behaviour have been noted by many Bent, A. C. 1946. Life Histories of North birdwatchers. American Prior to the spring 1993 Jays, Crows and Titmice. United States National Museum Bulletin 191, Washington, observations described above, in May D.C. 1992 (G. Coady, pers. comm.) and Ehrlich, P.R., D.S. Dobkin, and D. Wheye. during the winter of 1992-1993, 1988. The Birder's Handbook. A Field Guide "small ravens" were seen in the to the Natural History of North American vicinity of the hospital. In addition, Birds. Simon & Schuster. New York, N.Y. on 13 November 1993, a small raven­ Goodwin, D. 1976. Crows of the World. Cornell shaped bird was observed being University Press, Ithaca, New York. chased by two crows, several km Gray, A.P. 1958. Bird Hybrids - A Checklist northwest of the hospital grounds, with Bibliography. Commonwealth above High Park. This corvid was Agricultural Bureaux. Farnham Royal, only slightly larger than the pursuing Bucks, England. crows (B. Yukich, pers. comm.). It is Jefferson, B. 1989. Observations of Common speculated that these smaller Raven in Metropolitan Toronto. Ontario "ravens" might possibly be hybrids Birds 7: 15-20. from previous years. The 1993 adult Jefferson, B. 1991. Evidence of pair bonding between Common Raven (Corvus corax) and hybrid "cravens", as they have been American Crow ICorvus brachyrhynchosl. unofficially dubbed, closely resemble Ontario Birds 9: 45-58. E.A. (Beth) Jefferson, 41 Lake Shore Drive, Apt. 404, Etobicoke, Ontario M8V 1Z3

Red-Shouldered Hawk Survey In 1994 and 1995, volunteers are needed to hours to complete (starting just after sun­ play taped recordings of this rare raptor's rise). Surveyors are given a tax receipt for calls, and note the number and age of those mileage and out-of-pocket expenses. individuals which respond along selected Contact: Lisa Enright, Long Point Bird survey routes in south-central Ontario Observatory, Box 160, Port Rowan, Ontario during late April. Routes consist of 20 NOE 1MO. Telephone (5191 586-3531. stations over 19 km, and take about four

VOLUME 12 NUMBER 1