First Nesting Record of the Cattle Egret (bubulcus Ibis) in Canada

It appears probable that, when food supply is superabundant as it seems to have been in Tuxedo in 1962, jays may prey less on the nests of other birds and the aggressive interspecific defense of nest area by Robins may also be diminished.The consequent greater number of birds feeding in the area would have increased predation on the Erranis larvae.This implies that, when food is superabundant, reduced interspecific (and probably intraspecific) strife among predators may facilitate local control of forest insect outbreaks by permitting a greater population density of predators.I thank my sister, Forsyth, who found the three nests.--GEoRcEE. WATSOn, U.S. National Museum, Washington 25, D.C. First nesting record of the Cattle Egret (Bubulcus ibis) in Canada.•Thefirst nesting record of the Cattle Egret in Canada was established on 4 June 1962 at Luther Marsh, Wellington County, Ontario, 22 miles (35.2 km) west of the town of Orangeville.Prior to 1962, only one other sighting of the Cattle Egret near Luther Marsh was recorded, when on 25 May 1961 A. T. Cringan and M. R. Wolfe saw a single bird in a wetland area situated one mile west of Luther Marsh, on Concession 7, in the Township of West Luther, Wellington County.The bird was not in breeding plumage.The authors saw nine Cattle Egrets in breeding plumage on 25 May 1962 on a large island in the western part of Luther Marsh.Nesting was not suspected until five Cattle Egrets wcrc observed in a hcronry there on 1 June 1962.This hcronry is located 150 yards (about 135 meters) south of the island on which the nine birds wcrc seen.The heronry is situated in dead, flooded cedars (Thu}a occidentalis) and elms (Ulmus spp.).It occupies about two acres, and lies within the protecting arms of two adjacent islands.Nesting species of the hcronry, up to the discovery of the Cattle Egrets, included Black-crowned Night Herons (Nycticorax nycticorax), Great Bluc Herons (Ardea herodias), and Green Itctons (Butorldes virescens).Layering of nests was evident and can bc described thus: first layer, 1 to 5 feet, Green Herons; second layer, 5 to 15 feet, Black-crowned Night Herons; third layer, 15 to 30 feet, Great Bluc Herons.Two occupied nests of Cattle Egrets wcrc found in the hcronry on 4 June 1962, located in the second layer.They wcrc flimsy and meager in construction.The first nest contained one egg and the second had three.On 9 June 1962, we showed these nests to a group including J. L. Baillie, of the Royal Ontario Museum, and A. T. Cringan, of the Ontario Agricultural College.At this time, the first nest contained two eggs and the second contained four eggs.A fresh egg collected from nest number one is in the collection of the Royal Ontario Museum.We found a third nest, containing four eggs, on 13 June 1962, and construction of a fourth was suspected to be under way at this date.The daily range of the Cattle Egrets about the marsh has not been established definitely, but birds were observed on small islands and on the east shore of the marsh, up to a little over a mile from the heronry, apparently feeding on insects in grassland.With the recording of these nests, the known breeding range of the Cattle Egret is extended by 250 miles from the Columbus, Ohio, nesting area listed by D. E. Davis (Auk, 77: 421-424, 1960).A list of observations of Cattle Egrets in Ontario compiled by J. L. Baillie includes all sight records reported to the Royal Ontario Museum to 15 June 1962.

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