18 lems would certainly be exacerbat­ Literature Cited ed if the gulls began to nest as Blokpoel, H. and GD.Tessur. 1986. The well. Several large colonies Ring-billed Gull in Ontario: a review of a new problem species. Canadian (>10,000 nests) exist on the lower Wildlife Service Occasional Paper 57. Great Lakes and there is little suit­ 341'1'. able nesting habitat left. This BucJcJey, P.A. and F.G. BueJcJey. 1980. Population and colony-site trends of makes a change to roof-nesting Long Island waterbirds for five yean in even more likely. the mid 1970s. Transactions ofthe Linnaean Society of New York IX: 23­ Acknowledgements 56. Cramp, S. 1971. Gulls nesting on build­ We thank D. Armchuck, R.M. ings in Britain and Ireland. British Bollengier, R. Jackson and T. Birds 64: 476-487. Moulton for providing unpub­ Fisk, EJ. 1978. The growing use of roofs lished infonnation and H. Boyd by nesting birds. Bird-Banding 49:134­ 141. and S.G. Curtis for commenting on Monaghan, P. andJ.C. Coulson. 1977. an earlier draft Status oflarge gulls nesting on build­ ings. Bird Study 24: 89-104. Paynter, R.A., Jr. 1963. North American Herring Gulls nesting on a building. Wilson Bulletin 75: 88. Early Nesting by House Finches in Ontario by Daniel R. Kozlovic The breeding season of the House dential area of St. Catharines, Finch (Carpodacus mexicanus) Regional Municipality of Niagara, commences in late February to Ontario, I observed a male House late April from the southern to the Finch singing from eaves directly northern extreme of the species' above a small Chinese juniper range (Harrison 1978). In (Juniperus chinensis). Soon there­ Ontario, the majority of nesting after, a female finch emerged from activities take place in May and the tree and the pair flew off. June. Here, I report on early nest­ Suspecting a nesting site, I exam­ ing, in March, by Ontario House ined the tree closely and discov­ Finches and comment on the fac­ ered a complete nest positioned tors that may promote early nest­ about 104m from the ground. The ing in this species. cup-shaped nest was composed of On 19 March 1987, in a resi- coarse grasses and rootlets, its rim Daniel R. Kozlovic, 574 St Clarens Avenue, Toronto, Ontario M6H 3W7 ONTARIO BIRDS APRIL 1988 19 House Finches drawing by Ian Jones. Originally published in the Atlas of the Breeding Birds ofOntario. fringed with leaves of dusty miller Two nests were located in Chinese (Centaurea sp.), and lined with junipers and two were in eastern finer grasses, a frazzled cigarette red cedars (J. virginiana). These filter, and more leaves of dusty nests ranged in height from 1.9 to miller. On 21 and 23 March the 202m and were being constructed nest contained one and three eggs, of grasses and rootlets. respectively. During the same The weather during March period I scouted three other neigh­ 1987 at St Catharines was mild, bourhoods ofSt Catharines, with an average temperature of which in previous years had been 2.7°C. The week of 16 to 22 particularly active nesting areas, March had abundant sunshine and and found four additional nests in the minimwn and maximurn daily various stages ofconstruction. temperatures ranged from -7.1 to VOLUME 6 NUMBER 1 20 -O.8°C and 3.5 to 12.8°C, respec­ which fresh eggs had been noted tively. From 23 to 30 March the previously in the province was 26 weather was mainly overcast and April (Kozlovic 1987a) in 1985 at 27.6mm ofrain fell, although tem­ Sl Catharines. Four nests, two peranrresincr~,wimmim­ with three eggs each and two with mum and maximum daily ranges one egg each, were found on this of -2.0 to 4.5°C and 10.2 to date. Another early nesting record 19.5°C, respectively. On 31 for the species was a nest, contain­ .March, however, a cold front ing five nestlings 11 to 12 days passed over southern and central old, found at St Catharines on 26 Ontario that brought snow, sleet May 1983 (pers. obs.). Since the and strong winds. The S1. modal incubation period of Catharines area received 18.8cm Ontario House Finches is 13 days ofsnow and the temperature (Kozlovic 1987b), the last egg in dropped to a low of -5.0°C. this nest was probably laid on 2 On the day after the storm four May. of the five nests, including the one In New Jersey, Leek (1987) first discovered on 19 March, were reported cases of House Finches found filled with wet, packed nesting earlier (in April and even snow. One nest contained four March) in recent years and sug­ eggs, two nests held three eggs gested that these nesting records each and one nest had two eggs. could be indicative ofan advance­ Remarkably, the remaimng nest ment of the nesting season. had survived the ravages of the Similarly, House Finches in stonn and contained four dry eggs Ontario have nested progressively that were being incubated. The earlier in the past few years. Such surviving nest was supported by a a trend, however, need not imply a tall (3.2m) Chinese juniper that seasonal advance of nesting. had been bound with twine in a Since the eastern population has helical fashion in order to mini­ been increasing rapidly (Robbins mize snow damage to its branches. et al. 1986), House Finches have Apparently, the tight binding of recently become numerous in the branches had prevented snow many regions of their new-found from being blown into the tree and range. In any large population nest On 14 April there were four there will be variation in the onset nestlings two to three days old in of nesting, and more finches may the nest now be nesting early in the season. Although House Finches have Weather conditions, particular­ been observed carrying nesting ly temperature, appear to have a material as early as March at strong influence on House Finch Niagara-on-the-Lake, Regional nesting activities. In Colorado, Municipality of Niagara, Ontario during spells of warm weather in (James 1978), the earliest date on autumn and winter, Bergtold ONTARIO BIRDS APRIL 1988 21 (1913) observed House Finches phoeniceus) and other species (see searching for suitable nesting sites, Ewald and Rohwer 1982). gathering nesting material and Therefore, I suggest that food set actively building nests. out at feeding stations may also Furthennore, males, which were promote early nesting in House relatively silent during the cold Finches. Since their introduction months, often began to sing on to eastern North America in 1940, mild, sunny days. However, these House Finches have depended on behaviours stopped upon the feeders during the winter months return ofcold weather. The (Elliott and Arbib 1953), and with extremely early nesting activities the growth of the population, sur­ of House Finches at St Catharines veys have recorded a marked seem to have been induced by a increase in the number offinches spell of warm weather. In 1987, attending feeding stations (Burtt southern and central Ontario expe­ and Burt11984; Dunn 1986). For rienced the warmest March since instance, flocks of more than 100 1977, with the average tempera­ birds have been reported at one ture being two degrees above nor­ feeding station at S1. Catharines mal (Scholefield 1987). The total (Foley 1983). Thus, early in 'the hours ofbright sunshine was well season, when natural food items above normal and precipitation such as seeds of weeds and grasses amounts were below normal for are not abundant, feeders may pro­ the month. These "early spring" vide the critical food resources weather conditions persisted long necessary for egg production. enough to allow finches to reach This notion is supported by the 'the egg-laying stage. fact that three of the nests found Unfortunately, most of the clutch­ were in the proximity ofknown es froze after a sudden return of feeding stations. inclement weather, a consequence To date, these observations rep­ ofearly nesting that has been resent the earliest records of nest­ reported elsewhere (Nice 1957) for ing for the House Finch in Ontario. this species. The unusually mild weather condi­ In addition to favourable weath­ tions in March 1987, in concert er conditions, food availability is with readily available food offered believed to be important in the at feeders, appear to have provided timing ofbreeding, since females a favourable environment for may be cued to breed when they breeding much earlier than is usual have acquired sufficient nutrients in the season. to fonn eggs (Perrins 1970). Experimental supplementation of Acknowledgements food abundance has been shown to I thank the people of St seasonally advance breeding in Catharines, Ontario for kindly Red-winged Blackbirds (Agelaius allowing me access to their proper- VOLUME 6 NUMBER 1 22 ty. Meteorological data were pro­ James, RD. 1978. Nesting of the House vided by K. McConkey of the Finch (Carpodacus mexicanus) in Ontario. Ontario Field Biologist 32:30­ Niagara District Weather Office. I 32. also thank R.D. James for his con­ Kozlovic, DR. 1987•. House Finch, structive comments on an earlier Roselin familier, Carpodacus mexi­ eanus. pp. 492-493 ill Atlas of the version of this manuscript. Breeding Birds of Ontario (M.D. Cadman, P.FJ. Eagles and F.M. Literature Cited Hel1einer, Eds.). University of Bergtold, WH. 1913. A study of the House Waterloo Press, Waterloo. Finch. Auk 30:40-73. Kozlovic, DR. 1987b. Differentiation of Burtt, HE., and BP. Burtt. 1984. Changes morphology and reproductive traits in in the House Fmch population in central the House Finch (Carpodaeus men­ New York.