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Breeding by a Lesser Black-Backed Gull

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Breeding by a Lesser Black-Backed Gull s ull us on the tlanti JULIE C. ELLIS ß DEPARTMENT OF ENVIRONMENTAL AND POPULATION HEALTH ß CUMMINGS SCHOOL OF VETERINARY MEDICINE 200 WESTBOROROAD ß TUFTSUNIVERSITY ß NORTHGRAFTON, MASSACHUSETTS 01536 MARY CASW[LL STODDARD - DEPARTMENTOF ECOLOGYAND EVOLUTIONARYBIOLOGY - YALEUNIVERSITY ß NEW HAVEN, CONNECTICUT06520 L. WILLIAM CLARKß P. O. BOX71 ß KRESGEVILLE,PENNSYLVANIA 18333 Abstract thepair and their chicks from 30 Mayuntil 3 Island (42 ø 59' N; 70ø 36' W) in the Isles of Thispaper documents the second observation August2007. Additional observations of the Shoalsarchipelago, located approximately 10 of breedingby LesserBlack-backed Gull pairand the surviving juvenile were made in km fromthe coastof New Hampshirein the (Larusfuscus) in NorthAmerica and first for mid-and late August. Gulf of Maine, first on the afternoonof 29 theAmerican Atlantic coast. A singlebird was May 2007,while walking through a Herring discoveredon AppledoreIsland, Maine on 29 Fieldencounters Gull colony(Figure 1, Frontispiece;all pho- May 2007,standing near a HerringGull (L. We observed a Lesser Black-backed Gull tographsby DavidBrown). We discovered the argentatus)at a nest with two eggs.We (Larusfuscus) with a HerringGull (L. argen- LesserBlack-backed Gull standingnext to a recordedbreeding phenology and behavior of tatus)near a nestwith twoeggs on Appledore HerringGull on thetop of a bareledge on the 546 NORTH AMERICAN BIRDS BREEDINGBYALESSER BLACK-BACKED GULLI peripheryo[ the island.We climbedto thetop of theledge and observed a nest with two eggsnear the locationwhere the Lesser Black-backed Gull hadbeen standing. We moved awayfrom the nest to allow the gullsto return;the Lesser Black-backed Gull and the Herring Gull returnedto the two-eggnest. The two gulls stoodvery close together, sug- gestingthat they were a mated pair.We observedthe nest and pair for approximately1.5 hours,took photographs,and left the site. The next day,we construct- ed an observationplatform andblind and placed it in the bestposition for viewingthe nest. Because the nest was lo- cated in a depressionsur- roundedby boulders,it was difficult to see from most an- gles.Thus, the blind had to be situatedapproximately 60 m from the nest site in order to view the nest and pair ade- quately.The nest was observed everyday from 30 Mayuntil 3 Figure1. LesserBlack-backed Gull{right) with incubating Herring Gull at nest on Appledore Island, Maine. œhotoõraph bylTavidBrown. August2007, for a totalof 215 hours.Breeding behaviors of the pair were group. We observedthe nest from 10:30 land. Neitherspecies bred on the Isles of recordedduring incubation,hatching, and through12:30 and again from 13:30through Shoalsat theturn of thecentury, but by 1972, pre-fledgingstages and wfil be describedin 15:00 and observedboth adults at the nest, Herring Gulls had increasedto over 7000 deraftelsewhere (Stoddard and Ellis,unpubl. but thefledgling was not observed. breedingpairs, while Great Black-backed data).Videotape and photographs were taken Gullshad increased to over1100 pairs (Drury throughoutthe observationperiod. Oiscussion 1973). Since1975, the numberof breeding On 22 June, two chicks were observedat Thereis only one otherrecord of a Lesser HerringGulls has steadily declined, while the thenest (Figure 3). Bothchicks survived un- Black-bscked Gull in the Isles of Shoals. One numberof breedingGreat Black-backed Gulls til the week of 30 July, when the chicks individualwas observedin September2006 has increased(Borror and Holmes 1990). Re- movedbehind the boulderssurrounding the near the same location (southeasternside of centsurveys indicate that breedingpopula- nestand were only occasionally visible. Dur- AppledoreIsland) as the bird we discovered in tionsof bothspecies have declined in thelsles ing thisweek, only one of the chickswas ob- 2007 (S. Mirick, pers. comm.).There have of Shoals,and in 2006 therewere approxi- servedbeing fed by theparents, so we assume beensporadic sightings of LesserBlack-bscked mately1427 pairs of HerringGulls and 1266 thatthe second chick had died. On 2 August, Gullsin coastalNew Hampshireand Massa- pairsof GreatBlack-backed Gull in thearchi- we went to the nest and found a fresh carcass chusetts,mainly during the winter months. pelago(Ellis, unpubl. data). nearbythat appeared to be the secondchick; Birds seen during summermonths (June LesserBlack-backed Gull (Larusfuscus) we bandedthe surviving chick. On 3 August throughAugus0 are typically juveniles (S. Mir- breedsprimarfiy in northernand western Eu- 2007 we left the islandand wereno longer ick, pers.comm.), and countsof bothadults ropebut hasundergone a considerablerange ableto observethe nest every day. andjuveniles have increased in recentdecades. expansionduring the past century (Post and We returnedto the island11 Augustand Great Black-backedGulls (L. marinus) and Lewis1995). Since1995, the breedingrange observedthe pre-fledglingwith its parents HerringGulls breed on Appledore Island in a of the subspeciesL. fuscus graellsii has ex- nearthe nest.We alsoobtained videotape of varietyof habitats:on exposedinland ridges, pandedsouthward to includethe CanaryIs- the parentsand the pre-fledgling.We ob- cobblebeaches, bare rock ledgeson the is- lands (Grande and Palacios2002). The first served the Lesser Black-backed Gull and Her- land'speriphery, and around shrubs and near record of a Lesser Black-backed Gull in North ringGull at thenest 21 August,but thefledg- buildingsof the ShoalsMarine Laboratory. America (outside of Greenland) was in ling wasnot present.Several fledglings were Trendsin Herringand Great Black-backed coastalNew Jersey in 1934 (Edwards1935). observedin a groupon the waternear shore, Gull populationson the Islesof Shoalsare Recordsof thisspecies in NorthAmerica in- andit ispossible that the fledgling was in that representativeof those throughout New Eng- creasedslowly from 1950 throughthe mid- VOLUME 61 (2007) NUMBER 4 547 IBREEDINGBYALESSER BLACK-BACKED GULL Figure2.Juvenile gulls from nest of Lesser Black-backed Gulland Herring Gull at nest on Appledore Island, Maine; these birds were banded and color-marked forsubsequent study. Photograph byBavidBrawn. 1970s,then increased substantially thereafter; andintermedius have increased, whereas L. f. Bevier about Lesser Black-backed Gulls in by 1994,it hadbeen reported in all 31 states fuscushas decreased significantly throughout easternNorth America.Support for M. C. in theeastern half of theUnited States except its range.L. f. graellsiibreeds in the Faroes, Stoddardwas provided by the NationalSci- for West Virginia (Post and Lewis 1995). British Isles, Iceland, France, the Nether- ence Foundation'sResearch Experience for Maximumnumbers seen in a givenday in- lands,Germany, and morerecently, the Ca- UndergraduatesProgram at theShoals Marine clude 456 individuals observed in March naryIslands in the Macronesianarchipelago Laboratory.This paper is ContributionNum- 2007at LakeNockamixon, Pennsylvania (Bill (Post and Lewis 1995, Grande and Palacios ber 144 of theShoals Marine Laboratory. Etter, pers comm.). Most observationsof 2002). L. J. intermediusbreeds in southern LesserBlack-backed Gulls along the Atlantic Norway,Sweden, Denmark, and the Nether- Literature dted coast of North America occur from October lands.L. f. fuscusbreeds in northernNorway, Borror,A. C., and D. W. Holmes.1990. Breed- throughApril, but increasinglythe species is Denmark, Sweden, Finland, and Russia. ingbirds of theIsles of Shoals.Second edi- observedbetween May and September, partic- Basedon range expansion, increased breeding tion. ShoalsMarine Laboratory.Ithaca, ularlyon the outercoasts, e.g., North Caroli- populations,and migratorypatterns, L. f. New York. na. Winteringbirds may come from lceland, graellsiiwould be mostlikely to occurin Cramp,S., and K. E. L Simmons,eds. 1983. wherebreeding populations of LesserBlack- North America,along with someL .f. inter- TheBirds oJ the Western Palearctic. Volume backedGulls have been increasing (Cramp medius(Post and Lewis 1995; de Knijff and N. 3. OxfordUniversity Press, New York. andSimmons 1983), but theonly firm record van Swelm1998). L. f. Juscushas not been de Knijff,P., and N. vanSwelm. 1998. Band- of a banded Lesser Black-backed comes from conclusivelydocumented in NorthAmerica. ingpoints to originof LesserBlack-backed ColdSpring Harbor, New York; the bird had Putativehybrids between Herring and Less- Gullsin America.Birding 30: 367-368. beenbanded in a Dutchbreeding colony (de er Black-backed Gulls have been observed in Drury,W H. 1973 Populationchanges in New Knijffand van Swelm 1998). someeastern states, including North Carolina, Englandseabirds. Bird Banding 44:267 313. North America'sonly other recordof a Connecticut (<www.fordham.edu/lewis/birds/ Edwards,J. L. 1935. The LesserBlack-backed breedingLesser Black-backed Gull comes comhyb/herxles.html>), and New York Gull in NewJersey Auk 52: 85. from Juneau,Alaska on 12 June 1993 (van- (<www.birds.cornell_edu/crows/lbbgull- Grande,J. M. and C.-J. Palacios.2002. First Vliet et al. 1993): one was observed with a hybrid.htm>).These observations, combined breedingrecord of theLesser Black-backed HerringGull at a nestwith two eggsin the with recordsof largenumbers of wintering Gull in the Macronesicarchipelago, North middleof a smallmixed colony of Herring LesserBlack-backed Gulls and observations of Atlantic; a large spreadin its breeding Gulls and and Glaucous-wingedGulls (L juvenile-plumagedbirds (Ridout 1993), sug- range.Waterbirds 25: 388-389. glaucescens).That nesting
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