HARVARD UNIVERSITY Library of the Museum of Comparative Zoology 1974-1977 Mus. COMP, library 73 OCT 3 1 wr harvard UNIVEB®!^^' PROCEEDINGS OF THE LINNAEAN SOCIETY OF NEW YORK For the Three Years Ending March 1977 Date of Issue: August 1977 The Linnaean Society of New York The regular meetings of the Society are held at 8:00 p.m. on the second and fourth Tuesdays of each month from September through May at the American Museum of Natural History and are open to the public. Informal meetings are held at 8:00 p.m. on the third Tuesday of the month during June, July, and August. Persons interested in natural history are eligible for membership in the Society. Annual dues for Active Members are $8.00, for Associate Mem- bers $3.00, and for Supporting Members $20.00. Life Memberships are $200 . The Society conducts regular field trips and maintains a small circulat- ing library for its members. It regularly publishes the News-Letter nine times a year and the Proceedings, which contains articles and notes on regional natural history. At irregular intervals, longer papers and mono- graphs called Transactions are issued. Communications about membership and inquiries about publications should be addressed to: Secretary, Linnaean Society of New York % American Museum of Natural History Central Park West at 79th Street New York, New York 10024 U. S. A. 1974-1977 No. 73 PROCEEDINGS OF THE LINNAEAN SOCIETY OF NEW YORK For the Three Years Ending March 1977 Date of Issue: August 1977 Editorial Committee Members who participated in editing this issue of the Proceedings were: Berry Baker, Eugene Eisenmann, John Farrand, Jr., and Mary LeCroy. The Committee wishes to thank Alice Oliveri for typing manuscripts. Catherine Pessino, Editor Contents Page Breeding Populations of Terns and Skimmers on Long Island Sound and Eastern Long Island, 1972-1975. David Duffy .... 1 Low Productivity of Terns on Hicks Island, 1975. Peter Houde . 49 Gull-Tern Interactions on Hicks Island, 1975. Peter Houde 58 A Water Bird Study of a Limited Area: Jerome Park Reservoir. Walter Sedwitz 65 General Notes Incipient Distraction Displays of the Least Tern. Michael Gochfeld 80 Hoary Bat in Niantic, Connecticut, in January. Cordelia T. Grimm 84 Report of the Secretary for the Year 1974-1975 87 Report of the Secretary for the Year 1975-1976 91 Report of the Secretary for the Year 1976-1977 95 Report of the Treasurer for the Year 1974-1975 100 Report of the Treasurer for the Year 1975-1976 102 Report of the Treasurer for the Year 1976-1977 104 In Memoriam 106 Memorials 106 • f rjr^ ,^^. I:x\.- r j;,-! n, L : .,..vW S,^J V I'.- H-XC'. • '01 i.' -*5 :^|.'M Jr I.j’ ' .'''' ’i^v,, V. ,-/l 4 .j-,/.. , tvq/' • i .. .»f I : , f?t4.'r., r ifti ^iJ ' ' n.i ; 1 "to -'*‘ ' '•^S , ‘(c( )ji» .'»•> tfjipi?. * . / . .\ !f<r.C6CV‘>t5^ I!’ A' i % r VV^"« •‘KrtiJiHf! a iX i s ’ J Breeding Populations of Terns and Skimmers on Long Island Sound and Eastern Long Island: 1972-1975* David Duffy By 1972, it had become apparent to many working on colonial sea- birds that the nesting terns and skimmers of Long Island were being increasingly exposed to a broad spectrum of pressures that might be causing severe changes in their populations. Polychlorinated biphenyls (PCB’s) had been implicated in birth deformities of Common and Roseate Terns (Sterna hirundo and S. dougallii\ Hays and Risebrough 1972). Mercury had been linked to feather loss in young terns (Gochfeld 1971). Egg shell thinning had been noted at several colonies in the area (Hays, pers. com.; pers. obs.); such thinning is believed to be caused by deriva- tives of DDT (Wiemeyer and Porter 1970; Peakall 1970). Further pressure on tern populations had come from invasions of nesting sites by rats, development of recreational beaches, human harassment, and natural suc- cession rendering colony sites unfit for nesting. For all of these factors there were only scattered and often anecdotal accounts of acute situations. What, if any, long-term effect there might be for the tern populations was unknown. Were Common and Roseate Terns holding their own? Or were they, instead, retreating to a few, safe colonies as their populations declined? Little as we knew of Commons and Rose- ates, we knew even less of what was happening to Least Terns (Sterna albifrons) and Black Skimmers (Rynchops niger). It was evident that population estimates were necessary to assess the health of the four species and to determine which pressures were most severe and most needed alleviating. In 1972, A. Poole and I undertook a survey which covered tern and skimmer colonies on Long Island, N.Y.—east from Lloyd Neck on the ‘This paper is dedicated to three members of The Linnaean Society, Roy Latham, Christopher McKeever, and LeRoy Wilcox, who pioneered in the study of Long Island’s colonial seabirds. 1 north shore and east from Watch Hill, Fire Island, on the south shore, as well as much of the north shore of Long Island Sound. The survey was made by car, with a small boat to reach islands. In all but one case, counts were made of colonies renesting after Hurricane Agnes, which washed out many nests on 22 June. Following the storm, we visited 11 colonies in the second week of July, four in August, and four in both July and August. Other workers helpfully provided information on 11 colonies we either did not visit or visited only after the peak of breeding. During 1973 and 1974 there was no organized census. Data are in- cluded whenever gathered in the course of other work. In 1975, W. Webb and I surveyed the same area using a high speed boat. During the last two weeks in June we visited most of the colonies of eastern Connecticut, Peconic Bay, Block Island Sound and Napeague Bay. During the third week in July we surveyed the south shore of Long Island west to Watch Hill, and during the last week of July the north shore of Long Island and parts of western Connecticut. Again, other investigators provided us with additional information on colonies we could not visit. We used a variety of methods to census colonies, depending on the species involved, the weather, the time available and the stage of the breeding cycle at each colony. These methods are presented in the Appen- dix. The sections following contain estimates for each colony based on the census material in the Appendix. Additional information on the type of substrate, extent of vegetation, evidence of predation, and sources of disturbance are presented when available. For convenience in mapping and presenting the data, the colonies are divided into five groups (Fig. 1). This is not to suggest that these divisions represent discrete subpopulations. We still know little of the movement of nesters between colonies or geographic areas. I. The Connecticut Coast and Fishers Island II. North Shore of Long Island, east of Centre Island III. South Shore of Long Island, east of Watch Hill, Fire Island IV. Peconic Bay, Long Island, east to Shelter Island V. Extreme eastern Long Island and western Block Island Sound, except Fishers Island In the following sections, each colony is proceeded by an arabic number corresponding with the colony’s location on the detailed map of each region (Figs. 2—6) 2 — The Colonies I. The Connecticut Coast and Fishers Island (Figure 2a, b) /. Sandy Point, Little Narragansett Bay. Colony Size, 1973: Com- mons—five pair; 1975: Leasts— 15 pr. This sand island is the site of a large gull colony as well as a favorite stop for boaters. Attempts by terns to nest are likely to be brief and unsuccessful. 2. Rock Island, Fishers Island Sound. Colony Size, 1974: Commons 15 pr. Haeni (in litt.) thought that gulls probably preyed on the young soon after they hatched as there were few chicks on this bare island. 3. Lyddy Island, Fishefs Island Sound. Colony Size, 1974: Com- mons—35 pr. “The island is of glacial origin; sand and gravel surrounded by large boulders in the water.” (Haeni, in litt.) Haeni also mentions that by early July in 1974 the island was almost completely overgrown with Black Mustard (Brassica nigra); this heavy growth would prevent terns from renesting. One Herring Gull (Larus argentatus) nest was found in 1974. The island was deserted in 1975. 4. Hay Harbor, Fishers Island. Colony Size, 1974: Commons— 15 pr.; 1975: Commons—30 pr. The colony is on the far side of a barrier island protecting a salt pond. The substrate is pebble, the nests being placed on debris and old storm-tide lines. A pair of Oystercatchers (Haematopus palliatus) and about 20 pr. of Herring and Great Black-backed Gulls (Larus marinus) also nest on the island. The site is privately owned and disturbance is generally light. If the gulls do not drive out the terns, this would be a good site to preserve. 5. Ocean and Oyster Ponds, Fishers Island. Colony Size, 1974: Leasts—four pr.; 1975: Leasts—two pr. The site is isolated and little disturbed. Horning (in litt.) states: “Least Terns have nested in a very small colony on the island for as long as I have been birding, at least 15 years.” 6. Blujf Point State Park. Colony Size, 1975: Leasts—five pr. Accord- ing to Craig (in litt.) the terns nest in at least two groups along the beach. The Mumford Cove area with four pr. is the largest: relatively undisturbed in 1975, it will be protected as a sanctuary with snow-fencing by the state in 1976.