THE 2000 FALKNER ISLAND TERN PROJECT REPORT Jeffrey A
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}' ~USGS science for a.changing world THE 2000 FALKNER ISLAND TERN PROJECT REPORT Jeffrey A. Spendelow USGS Patuxent Wildlife Research Center (PWRC) 11510 American Holly Drive. Laurel, MD 20708-4017 USA · 3 February 2001 Pre-season Preparations and Spring Work Weekend · U.S. Fish and Wildlife Service (FWS) Stewart B. McKinney National Wildlife Refuge (NWR) Manager Bill Kolodnicki. and NWR staff Kevin Allen. Jennifer Brown, Patrick Comins, and Deb Trantor visited Falkner Island on 2~ April (4-20) to assess the overwinter damage and survey the island for waterfowl nests. They also boated past Goose Island where they saw both a Harbor Seal and a Gray Seal. Falkner Island Tern Project (FITP) Director Jeff Spendelow and PWRC Biological Technician Peter Osenton arrived in Guilford on 4-26, but didn't make it out until the next day to begin pre-season preparations, put a new line across the harbor, clear net lanes, and set up some nets. UMass/Amherst M.Sc. student Corey Grinnell joined us that night. The next morning we did some banding, set up the 2m-X-2m grid on the north end gravel spit, _remarked the baseline for the beach plots~ finished taking tires and nestboxes out of storage, and placed the boxes on the beach for the habitat enhancement project. Bill Kolodnicki, Kevin Allen and Pam Denmon brought five volunteers out on 4-29 to help move the tires to the spit, set them in place. and load them with gravel, and Jeff,,-Peter. and Corey flagged the top plots that evening. A calm dawn allowed some netting, but increasing winds on 4-30 forced our departure before finishing the nestboxes and beach plot system. Residency, staff, fieldwork, and noteworthy fieldseason events Jeff and Corey returned on 5-15 to begin residency for the summer. The 2000 FITP staff consisted of CAS Research Assistants Jan Amendola (5-15/7-28), Sandy Chan (5-15/8-11), Carrie Dean (5-15/8-13), and Michele Kuter (5-19/8-16). We remarked the beach plots. added gravel to the nestboxes, and put up most of the blinds on 5-16, and we got the remaining blinds up by 5-20. Erin Andros- (5-17/5-19) trapped and marked a few rabbits. Beth Wenzel (5-22/7-26) worked on her M.Sc. study of the nocturnal behavior of terns and night-herons, Bill Kolodnicki made a special trip out to tow in our boat when the engine died (6-07), Arno Reinhardt (6-16/7-01, a_ student from Germany) helped us get through the peal of hatching, Jim Zingo added a (much-appreciated!) light to the outhouse and helped Rick Schauffler (7-11/7-12) plot GIS reference points (in part for recreating the plot system after revetment construction began in September). Kate (7-14/7-16) and Diana Spendelow (7-22/7-23) helped with fieldwork and a Twilight Cruise, respectively, and Crystal Hutchins - (8-02/8-18) helped Corey with his work. We also had other fieldwork/mainte·nance ·assistance from McKinney NWR staff and volunteers Kevin Allen, Tom Caffrey, Patrick Comins. Pam Denmon, Wendy Morgan, and Bob Walsh. The FITP staff worked alternating shifts until residency ended on 8-18, and Michele then moved to PWRC to finish the task of summarizing the observations of colormarked terns and help Jeff get caught up on back-logged database entry and management chores. Other noteworthy fieldseason events included: several fierce storms - one on 6-06 wiped out a large number of Common Tern (COTE) nests, and winds on 6-11 blew over three blihds (including the Beach Blind~ a first!): the rescue by Corey and Carrie of two hapless boaters just before their boat sank on 7-05; and visits by Beth's thesis advisor Sylvia Halkin (6-21/6-22), photographer Cheryl Barnaba (8-02) to take pictures for an article in the Essex, CT Main Street Times, and Monomoy NWR Refuge Biologist Stephanie Koch (8-02/8-03) to check out FITP research procedures. 1. 2 Common Tern (COTE) nesting and reproductive success Jeff saw a COTE on 4-28, and COTEs began nesting a day earlier in 2000 (first eggs found 5-16) than in 1999. The first complete census of COTE nests was done from 6-08/6-09 and COTE·areas were checked on a 3- to 5-day rotation through 8-15. The first COTE chick was found on 6-10. by 6-15 we had marked 2824 nests. and by 6-30 and 7-16 we had marked 3364 and 3758 nests. about 650 and 500, respectively, less than by those same dates in 1999. There was a similar amount of late nesting in 2000 as in 1999: 85 new COTE nests were found between 7-16/7-31, but no new nests were found after that, and overall we marked 3843 COTE nests ( about 500 less than in 1999) and estimated about 3300-3500 pairs of COTEs nested on Falkner Island in 2000. This year, perhaps in part because th~ grasses grew unusually high by early ~une, there was no increase in the percentage of COTEs nesting on the top of the island (583 nests. 21% of those found) by 6-15, but there were continued small increases in nests as of 6-30 from 1999 and 2000 in Plots 58-66 (17% increase from 397 to 465 nests) and Plots 4-6 (16% increase from 75 to 87 nests). the two major areas where Phragmites control had been done after the 1998 breeding season. This year there did not appear to be a shortage of prey fish in Long Island Sound in June and July as has occurred several times in past years, and there seemed to be only one Black-crowned Night~Heron harassing the nesting terns. Even so. as a result of the combination of storms in early June apd the night-heron's activity, many (especially pipping) eggs and hatchling COTE chicks were destroyed, died, or were predated, and so we banded about 4400 COTE chicks. Also, while a Northern Harrier killed a fledgling, an unknown number of older chicks and near-fledglings were predated by the night-heron, and we found more than 1025 dead chicks, losses in 2000 in July and August seemed much less than in 1999. The maximum potential productivity for COTEs (3346 chicks from 3843 nests), therefore, was greater than in 1996, 1997~ 1998, and 1999 (2117, 2559, 2871, and 2027 chicks from 3935. 3719, 4043, and 4345 nests, respectively). , We trapped, netted and caught by hand 421 adult COTEs of which 109 were unbanded and 312 (74%) were previously-banded birds. As compared to 1999. fewer (only 14) -adult COTEs, but two fledgling COTEs from Great Gull Island. NY, were found dead in 2000, and 10 dead adults and 15 dead COTE chicks were salvaged. Roseate Tern (ROST) nesting, habitat enhancement projects and reproductive success As we have for the past several years, we half-buried 100 tires in the gravel on the north end of the island and added gravel to 176 nestboxes for our 2000 ROST nesting habitat enhancement project. The first ROST nest was found 5-20, but it had a 2-egg clutch, so laying probably began on 5-18, a day earlier than in 1999. The ROST nesting areas were checked virtually daily from 5-20 to 8-14. By 5-31 and 6-15 we had marked, respectively, 102 &119 ROST nests (compared to 91 &116, and 94 &109 nests by these dates in 1998 and 1999, respectively). The first two ROST chicks hatched on 6-11, by which time we estimated that we had 110 pairs of ROSTs breeding on Falkner Island. Only 9 more ROST nests were initiated by 6-30, four by 7-16, and none after that for a total of 132 ROST nests marked. These 132 ROST nests were believed to have been produced by 115 pairs, and 76 (58%) were judged successful in that at least one chick was presumed to have fledged and left the island (see below). The use of sites and productivity of nests in different areas and habitat categories for 2000 are shown in Table 1. Table 2 summarizes nesting, productivity, and adult trapping and resighting data collected since the FITP began in 1978. · ; 3 Table 1. Results of 2000 FITP habitat enhancement projects for Roseate Terns. Nest-site No. sites No. No. No. (%age) No. chi~ks Productivity Plots category available Useda Nests Successful Fl edged . (chicks/nest) 16-19 inside tires 100 40 42 25 (60%) 28 0.67 25-27 inside boxes 20 13 14 6 (43%) 6 0.43 45-46 inside boxes 24 15 16 9 (56%) 11 0.69 49-50 inside boxes 40 13 13 8 (62%) 10 0.77 52-53 inside boxes 20 3 6 1 (17%) 1 0.17 56-58 inside boxes 72 27 28 19 (68%) 22 0.79 ----------------------------------------------------------------------- 45-58 inside boxes 156 58 63 37 (59%) 44 0.70 46-58 natural sites ? 12 12 7 (58%) 7 0.58 all modified sites 276 ( 111 119 68 (57%) 78 0.66 all natural sites ? 13 13 8 (62%) 8 0.62 a "No. Used" includes all nest sites with unincubated clutches. Some nest sites were used more than once whe~ earlier ~lutches failed. Of all 132 nests, 42 (32%) were inside the rims of tires in Plots 16-19, 15 (11%) were in the northeastern area in Plots 25-27, and 75 (57%) were on the southern end.