{"elementGlobalId":103889,"circumscripConfidence":{"id":1,"circumscripConfidenceDescEn":"1 - Strong","circumscripConfidenceDescEs":"1 - Fuerte","circumscripConfidenceDescFr":"1 – Forte"},"classificationLevel":{"id":7,"classificationLevelNameEn":"Species","classificationLevelNameEs":"Especies","classificationLevelNameFr":"Espèce"},"classificationStatus":{"id":1,"classificationStatusDescEn":"Standard","classificationStatusDescEs":"Estándar","classificationStatusDescFr":"Standard"},"iucn":{"id":11,"iucnDescEn":"Least concern","iucnDescEs":"Menos preocupante","iucnDescFr":"Moins préoccupante","iucnCode":"LC"},"nameCategory":{"id":1,"nameCategoryDescEn":"Vertebrate Animal","nameCategoryDescEs":"Animal vertebrado","nameCategoryDescFr":"Animal vertébré","nameTypeCd":"A","nameTypeDesc":"Zoological"},"rankMethodUsed":{"id":4,"rankMethodUsedDescEn":"Expertise without calculation","rankMethodUsedDescEs":null,"rankMethodUsedDescFr":null,"rankMethodUsedExternalDescEn":"Ranked by inspection","rankMethodUsedExternalDescEs":null,"rankMethodUsedExternalDescFr":null},"formattedScientificName":"<i>Chroicocephalus ridibundus</i>","scientificName":"Chroicocephalus ridibundus","scientificNameAuthor":"Linnaeus, 1766","primaryCommonName":"Black-headed Gull","relatedItisNames":"<i>Larus ridibundus</i> Linnaeus, 1766 (TSN 176835)","uniqueId":"ELEMENT_GLOBAL.2.103889","elcode":"ABNNM03040","conceptRefFullCitation":"American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in <i>The Auk</i>]. Also available online: http://www.aou.org/.","conceptName":"<i>Larus ridibundus</i>","taxonomicComments":"Formerly included in <i>Larus </i>but separated on the basis of genetic data (Pons et al., 2005) that indicate that the genus would be paraphyletic if the following species were included: <i>C. philadelphia</i>, <i>C. cirrocephalus</i>, and <i>C. ridibundus</i> (AOU, 2008). Considered conspecific with with South American <i>L. </i><i>maculipennis </i>by some authors. Regarded as monotypic by most authorities. See Nikula (1993) for information on hybridization with other gull species. Formerly named \"common black-headed gull\" (AOU, 1995).","roundedGRank":"G5","conservationStatusFactorsEditionDate":null,"conservationStatusFactorsEditionAuthors":null,"primaryCommonNameLanguage":"EN","recordType":"SPECIES","elementNationals":[{"elementNationalId":167089,"classifConfidence":null,"nation":{"id":38,"nameEn":"Canada","nameEs":"Canadá","nameFr":"Canada","isoCode":"CA","region":"Canada"},"roundedNRank":"N3B,N3N,NUM","elementSubnationals":[{"elementSubnationalId":264936,"subnation":{"id":63,"nameEn":"New Brunswick","nameEs":"New Brunswick","nameFr":"Nouveau-Brunswick","subnationCode":"NB","dnationId":38},"roundedSRank":"S1N,S2M","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1N,S2M","speciesSubnational":{"elementSubnationalId":264936,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":355148,"subnation":{"id":67,"nameEn":"Ontario","nameEs":"Ontario","nameFr":"Ontario","subnationCode":"ON","dnationId":38},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":355148,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":388692,"subnation":{"id":91,"nameEn":"Labrador","nameEs":"Labrador","nameFr":"Labrador","subnationCode":"LB","dnationId":38},"roundedSRank":"S1B,S2N,SUM","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1B,S2N,SUM","speciesSubnational":{"elementSubnationalId":388692,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":341332,"subnation":{"id":69,"nameEn":"Quebec","nameEs":"Quebec","nameFr":"Québec","subnationCode":"QC","dnationId":38},"roundedSRank":"S3B","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S3B","speciesSubnational":{"elementSubnationalId":341332,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":397333,"subnation":{"id":92,"nameEn":"Island of Newfoundland","nameEs":"Isla de Terranova","nameFr":"Île de Terre­Neuve","subnationCode":"NF","dnationId":38},"roundedSRank":"S1B,S3N,SUM","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1B,S3N,SUM","speciesSubnational":{"elementSubnationalId":397333,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":405866,"subnation":{"id":66,"nameEn":"Nova Scotia","nameEs":"Nueva Escocia","nameFr":"Nouvelle-Écosse","subnationCode":"NS","dnationId":38},"roundedSRank":"S3N","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S3N","speciesSubnational":{"elementSubnationalId":405866,"hybrid":false,"exotic":false,"native":true}}],"nrankReviewYear":2023,"nrank":"N3B,N3N,NUM","speciesNational":{"elementNationalId":167089,"exotic":false,"native":true}},{"elementNationalId":163468,"classifConfidence":null,"nation":{"id":225,"nameEn":"United States","nameEs":"Estados Unidos","nameFr":"États-Unis","isoCode":"US","region":"United States"},"roundedNRank":"N3N","elementSubnationals":[{"elementSubnationalId":376174,"subnation":{"id":26,"nameEn":"Maine","nameEs":"Maine","nameFr":"Maine","subnationCode":"ME","dnationId":225},"roundedSRank":"S1N","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1N","speciesSubnational":{"elementSubnationalId":376174,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":325292,"subnation":{"id":28,"nameEn":"Michigan","nameEs":"Michigan","nameFr":"Michigan","subnationCode":"MI","dnationId":225},"roundedSRank":"SNRN","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNRN","speciesSubnational":{"elementSubnationalId":325292,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":404742,"subnation":{"id":47,"nameEn":"Rhode Island","nameEs":"Rhode Island","nameFr":"Rhode Island","subnationCode":"RI","dnationId":225},"roundedSRank":"S1N","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1N","speciesSubnational":{"elementSubnationalId":404742,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":312865,"subnation":{"id":53,"nameEn":"Virginia","nameEs":"Virginia","nameFr":"Virginie","subnationCode":"VA","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":312865,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":348343,"subnation":{"id":25,"nameEn":"Maryland","nameEs":"Maryland","nameFr":"Maryland","subnationCode":"MD","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":348343,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":407615,"subnation":{"id":56,"nameEn":"Washington","nameEs":"Washington","nameFr":"Washington","subnationCode":"WA","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":407615,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":372702,"subnation":{"id":9,"nameEn":"Connecticut","nameEs":"Connecticut","nameFr":"Connecticut","subnationCode":"CT","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":372702,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":356853,"subnation":{"id":1,"nameEn":"Alaska","nameEs":"Alaska","nameFr":"Alaska","subnationCode":"AK","dnationId":225},"roundedSRank":"S3M","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S3M","speciesSubnational":{"elementSubnationalId":356853,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":391038,"subnation":{"id":41,"nameEn":"New York","nameEs":"Nueva York","nameFr":"New York","subnationCode":"NY","dnationId":225},"roundedSRank":"SNRN","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNRN","speciesSubnational":{"elementSubnationalId":391038,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":796088,"subnation":{"id":55,"nameEn":"Vermont","nameEs":"Vermont","nameFr":"Vermont","subnationCode":"VT","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":796088,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":357683,"subnation":{"id":38,"nameEn":"New Jersey","nameEs":"Nueva Jersey","nameFr":"New Jersey","subnationCode":"NJ","dnationId":225},"roundedSRank":"S4M","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S4M","speciesSubnational":{"elementSubnationalId":357683,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":320810,"subnation":{"id":37,"nameEn":"New Hampshire","nameEs":"New Hampshire","nameFr":"New Hampshire","subnationCode":"NH","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":320810,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":338173,"subnation":{"id":24,"nameEn":"Massachusetts","nameEs":"Massachusetts","nameFr":"Massachusetts","subnationCode":"MA","dnationId":225},"roundedSRank":"S1B,S2N","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"S1B,S2N","speciesSubnational":{"elementSubnationalId":338173,"hybrid":false,"exotic":false,"native":true}},{"elementSubnationalId":340250,"subnation":{"id":34,"nameEn":"North Carolina","nameEs":"Carolina del Norte","nameFr":"Caroline du Nord","subnationCode":"NC","dnationId":225},"roundedSRank":"SNA","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNA","speciesSubnational":{"elementSubnationalId":340250,"hybrid":false,"exotic":false,"native":true}}],"nrankReviewYear":2003,"nrank":"N3N","speciesNational":{"elementNationalId":163468,"exotic":false,"native":true}}],"lastModified":"2026-10-02T21:42:43.203105Z","lastPublished":"2026-10-02T21:32:08.892226Z","promotionalDescription":null,"conceptLineageSummary":null,"nsxUrl":"/Taxon/ELEMENT_GLOBAL.2.103889/Chroicocephalus_ridibundus","grankAdjustmentReasons":null,"grankChangeDate":"1996-11-27","grankReviewDate":"2016-04-07","grankReasons":null,"grank":"G5","rankInfo":{"elementGlobalId":103889,"aooPercentGood":null,"enviromentalSpecificity":null,"intrinsicVulnerability":null,"longTermTrend":null,"numberEos":null,"numberGoodEos":null,"numberProtEos":null,"popSize":null,"rangeExtent":null,"shortTermTrend":null,"threatImpactAssigned":null,"rangeExtentComments":"BREEDING: Iceland, Faroe Islands, Eurasia, southeastern Canada, northeastern U.S. European population expanded northward since the mid-1800s, probably due to amelioration of climate, increase in food supply resulting from human activities, and reduced persecution (Nikula 1993). Increasing numbers occurred in the 1900s in southeastern Canada and the northeastern U.S., where nesting has occurred in several areas (Labrador to Maine and Massachusetts) beginning in the 1970s; U.S. nestings have been unsuccessful and population expansion does not seem to be on-going (Nikula 1993). See also Brown and Nettleship (1984). NON-BREEDING: in North America along Atlantic coast from Labrador, Newfoundland, New Brunswick, and Nova Scotia south to New York (Long Island), rarely farther south and west, and in Old World. In North America, the largest numbers occur in the St. John's/Conception Bay area, Newfoundland, where a peak of a couple hundred occurs in November, and in Nova Scotia around the Sydney/Glace Bay area and around Halifax (Nikula 1993). Casual in Hawaii, Puerto Rico, and along Pacific coast of North America. Regular in spring in Aleutian and Pribilof Islands.","areaOfOccupancy":null,"areaOfOccupancyComments":null,"numberEosComments":null,"popSizeComments":"See Evans (1984) for status in Greenland, Evans (1984) for status in northwestern Europe.","viabilityComments":null,"threatImpactComments":null,"shortTermTrendComments":null,"longTermTrendComments":null,"inventoryNeeds":null,"numberProtEosComments":null,"protectionNeeds":null,"otherConsiderations":null,"intrinsicVulnerabilityComments":null,"enviromentalSpecificityComments":null},"animalCharacteristics":{"elementGlobalId":103889,"majorHabitat":{"id":3,"majorHabitatDescEn":"Terrestrial","majorHabitatDescEs":"Terrestre","majorHabitatDescFr":"Terrestre"},"nonMigrant":false,"localMigrant":false,"longDistanceMigrant":true,"mobilityMigrationComments":"Some may spend summer in winter range along east coast (Terres 1980). Often returns to same wintering locale in successive years (Nikula 19930.","foodHabitsComments":"Highly opportunistic. Hawks for insects, searches muddy places for worms, plunges and dips into water for food, eats weed seeds and waste grain in fields, grasslands, and marshes, scavenges in harbors or mudflats where sewage discharged (Terres 1980).","animalPhenologyComments":null,"colonialBreeder":true,"length":41,"width":null,"weight":284,"animalPhenologies":[{"animalCagPhenologyId":102718,"animalPhenology":{"id":3,"animalPhenologyDescEn":"Diurnal","animalPhenologyDescEs":"Diurno","animalPhenologyDescFr":"Diurne","displayOrder":3},"adult":true,"immature":true}],"animalFoodHabits":[{"animalCagFoodHabitsId":105007,"foodHabits":{"id":1,"foodHabitsDescEn":"Carnivore","foodHabitsDescEs":"Carnívoro","foodHabitsDescFr":"Carnivore","displayOrder":1},"adult":true,"immature":true},{"animalCagFoodHabitsId":105008,"foodHabits":{"id":2,"foodHabitsDescEn":"Piscivore","foodHabitsDescEs":"Piscivore","foodHabitsDescFr":"Piscivore","displayOrder":2},"adult":true,"immature":true},{"animalCagFoodHabitsId":105009,"foodHabits":{"id":3,"foodHabitsDescEn":"Invertivore","foodHabitsDescEs":"Invertívoro","foodHabitsDescFr":"Invertivore","displayOrder":3},"adult":true,"immature":true},{"animalCagFoodHabitsId":105010,"foodHabits":{"id":5,"foodHabitsDescEn":"Granivore","foodHabitsDescEs":"Granívoro","foodHabitsDescFr":"Granivore","displayOrder":5},"adult":true,"immature":true}]},"occurrenceDelineations":[{"eoSpecsDetailId":1093,"locationUseClass":{"id":2,"locationUseClassDescEn":"Breeding","locationUseClassDescEs":"En reproducción","locationUseClassDescFr":"Reproduction","displayOrder":2},"eoSpecGroupName":"Gulls and Terns","subtypes":null,"inferredExtentDistance":null,"inferredExtentNotes":"Inferred extent not appropriate, since foraging areas often separated by a considerable distance from breeding colony.","minimumEoCriteria":"Evidence of historical breeding, or current and likely recurring breeding, at a given location, minimally a reliable observation of one or more breeding pairs in appropriate habitat. Be cautious about creating EOs for observations that may represent single breeding events outside the normal breeding distribution.","mappingGuidance":null,"separationBarriers":"None.","separationDistanceUnsuitableHabitatat":5.0,"separationDistanceSuitableHabitatat":5.0,"altSeparationProcedure":null,"separationJustification":"Occurrences include nesting areas and associated nesting-season foraging areas (regardless of how far apart they are), but separation distance pertains to nesting areas (breeding colonies). Thus different breeding occurrences may overlap if birds from different nesting areas forage in the same area. Separation distance is not intended to delineate demographically independent populations or metapopulations (such units would be quite large). Instead, separation distance is a compromise between the high mobility of these birds (see following) and the need for occurrences that are of practical size for conservation/management use. <br /><br />California Gulls foraged an average of 17.4 kilometers from colony (Baird 1976); maximum foraging distances ranged from 32 to 61 kilometers (Rothweiler 1960, Baird 1976). Ring-billed Gulls foraged an average of 11 km from colony (Baird 1977). Least Terns foraged up to 3-12 kilometers from nests (summarized in Thompson et al. 1997). Forster's Terns has a reported feeding radius of 3.2 kilometers (Van Rossem 1932). Black Terns foraged up to 10 kilometers from nests, over continuous suitable but unoccupied habitat (M. A. Stern, pers. comm. 1998). Caspian terns in a colony at the mouth of the Columbia River: 90% of adults foraged within 21 kilometers (Collis et al. 1999).","versionDate":"2004-07-21","versionAuthor":"Cannings, S., and G. Hammerson","versionNotes":null,"lastModified":"2020-04-30T02:05:56.849048Z"},{"eoSpecsDetailId":1095,"locationUseClass":{"id":3,"locationUseClassDescEn":"Nonbreeding","locationUseClassDescEs":"No reproducción","locationUseClassDescFr":"Non-reproduction","displayOrder":3},"eoSpecGroupName":"Gulls and Terns","subtypes":"Foraging Concentration Area","inferredExtentDistance":null,"inferredExtentNotes":null,"minimumEoCriteria":"Evidence of recurring presence of wintering flocks (including historical); and potential recurring presence at a given location, minimally a reliable observation of 25 birds in appropriate habitat. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 20 days annually. Be cautious about creating EOs for observations that may represent single events.","mappingGuidance":null,"separationBarriers":"None.","separationDistanceUnsuitableHabitatat":5.0,"separationDistanceSuitableHabitatat":5.0,"altSeparationProcedure":null,"separationJustification":"Separation distance somewhat arbitrary; set such that occurrences are of managable size for conservation purposes. Occurrences are defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.","versionDate":"2002-04-16","versionAuthor":"Cannings, S.","versionNotes":"Includes all inland-nesting gulls and terns, in the genera LARUS, STERNA, and CHLIDONIAS.","lastModified":"2020-04-30T02:05:56.849048Z"},{"eoSpecsDetailId":1094,"locationUseClass":{"id":4,"locationUseClassDescEn":"Migratory stopover","locationUseClassDescEs":"Parada migratoria","locationUseClassDescFr":"Halte migratoire","displayOrder":5},"eoSpecGroupName":"Gulls and Terns","subtypes":null,"inferredExtentDistance":null,"inferredExtentNotes":null,"minimumEoCriteria":"Evidence of recurring presence of migrating flocks (including historical); and potential recurring presence at a given location, minimally a reliable observation of 50 birds in appropriate habitat. Occurrences should be locations where the species is resident for some time during the appropriate season; it is preferable to have observations documenting presence over at least 7 days annually. Be cautious about creating EOs for observations that may represent single events.","mappingGuidance":null,"separationBarriers":"None.","separationDistanceUnsuitableHabitatat":5.0,"separationDistanceSuitableHabitatat":5.0,"altSeparationProcedure":null,"separationJustification":"Separation distance somewhat arbitrary; set such that occurrences are of managable size for conservation purposes. Occurrences are defined primarily on the basis of areas supporting concentrations of foraging birds, rather than on the basis of distinct populations.","versionDate":"2004-04-26","versionAuthor":null,"versionNotes":null,"lastModified":"2020-04-30T02:05:56.849048Z"},{"eoSpecsDetailId":156346,"locationUseClass":{"id":6,"locationUseClassDescEn":"Staging","locationUseClassDescEs":"Entorno","locationUseClassDescFr":"Rassemblement","displayOrder":7},"eoSpecGroupName":"Gulls and Terns","subtypes":null,"inferredExtentDistance":null,"inferredExtentNotes":null,"minimumEoCriteria":"Evidence of flocks resting, roosting, and/or feeding young at a given location prior to breeding or after breeding has been completed. Staging may occur near the breeding site, preceding or following major migratory movements such as oceanic crossings, or it may occur after individuals have departed on migration, but before they have arrived at their final destination (a \"stopover\"). Staging may occur at sites also used for breeding, but often does not. Staging habitat may be ephemeral. For Common/Roseate Terns in Massachusetts, a minimum of 100 individuals in appropriate habitat is used.","mappingGuidance":null,"separationBarriers":null,"separationDistanceUnsuitableHabitatat":5.0,"separationDistanceSuitableHabitatat":5.0,"altSeparationProcedure":null,"separationJustification":"In Massachusetts, staging areas are separated somewhat arbitrarily, often by jurisdictional or property boundaries, as are nesting areas for coastal birds.","versionDate":"2017-01-10","versionAuthor":"Mostello, C. S.","versionNotes":null,"lastModified":"2020-04-30T02:05:56.849048Z"},{"eoSpecsDetailId":156347,"locationUseClass":{"id":15,"locationUseClassDescEn":"Adult foraging area","locationUseClassDescEs":"Zona de alimentación de adultos","locationUseClassDescFr":"Aire d’alimentation adulte","displayOrder":15},"eoSpecGroupName":"Gulls and Terns","subtypes":null,"inferredExtentDistance":null,"inferredExtentNotes":null,"minimumEoCriteria":"Applies to both adults and juveniles. Evidence of one or more individuals seeking food in suitable habitat. Evidence of prey capture is not a prerequisite, as importance of a given location for foraging may vary temporally with shifting prey.","mappingGuidance":null,"separationBarriers":null,"separationDistanceUnsuitableHabitatat":5.0,"separationDistanceSuitableHabitatat":5.0,"altSeparationProcedure":null,"separationJustification":"Scientific basis for assigning foraging separation distances is weak because terns are widespread across the Massachusetts coast and highly mobile. Most gaps in foraging observations likely reflect lack of survey effort.","versionDate":"2017-01-10","versionAuthor":"Mostello, C. S.","versionNotes":null,"lastModified":"2020-04-30T02:05:56.849048Z"}],"plantCharacteristics":null,"elementManagement":{"elementGlobalId":103889,"eoManagementGroupName":null,"stewardshipOverview":null,"impacts":null,"restorationPotential":null,"siteConservationPlansConsidered":null,"managementMethods":null,"monitoringMethods":null,"managementProgramContacts":null,"monitoringProgramContacts":null,"managementResearchPrograms":null,"managementResearchNeeds":null,"biologicalResearchNeeds":null,"additionalTopics":null},"occurrenceViabilities":[{"eoRankSpecsDetailId":105352,"eoRankSpecsGroupName":null,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"excellentViability":null,"goodViability":null,"fairViability":null,"poorViability":null,"viabilityJustification":"Use the Generic Guidelines for the Application of Occurrence Ranks (2008).<br>The Key for Ranking Species Occurrences Using the Generic Approach provides a step-wise process for implementing this method.","versionDate":null,"versionAuthor":null,"versionNotes":null,"lastModified":"2020-05-14T02:25:12.789953Z"}],"references":[{"id":153779,"citation":"American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.","shortCitationAuthor":"American Ornithologists' Union (AOU)","shortCitationYear":1983,"referenceCode":"B83AOU01NAUS","lastModified":"2020-02-25T14:38:12.689104Z"},{"id":143467,"citation":"American Ornithologists' Union (AOU). 1995. Fortieth supplement to the American Ornithologists' Union Check-list of North American Birds. Auk 112:819-30.","shortCitationAuthor":"American Ornithologists' Union (AOU)","shortCitationYear":1995,"referenceCode":"A95AOU01NAUS","lastModified":"2020-02-25T18:12:12.663519Z"},{"id":134424,"citation":"American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in <i>The Auk</i>]. Also available online: http://www.aou.org/.","shortCitationAuthor":"American Ornithologists' Union (AOU)","shortCitationYear":1998,"referenceCode":"B98AOU01NAUS","lastModified":"2020-02-25T14:38:12.673494Z"},{"id":119830,"citation":"Baird, P. 1976. Comparative ecology of California and Ring-billed Gulls (<i>Larus californicus</i> and <i>L. delawarensis</i>.)Ph.D. dissertation, University of Montana, Missoula.","shortCitationAuthor":"Baird","shortCitationYear":1976,"referenceCode":"N76BAI01NACA","lastModified":"2020-02-25T18:12:51.288882Z"},{"id":153308,"citation":"Baird, P. A. 1977. Feeding ecology of ring-billed and California gulls (<i>Larus delawarensis</i> and <i>L. californicus</i>). Pacific Seabird Bulletin 4:16-17.","shortCitationAuthor":"Baird","shortCitationYear":1977,"referenceCode":"A77BAI01NACA","lastModified":"2020-02-25T18:12:51.288882Z"},{"id":119232,"citation":"Barrett, R. T., and W. Vader. 1990. The status and conservation of breeding seabirds in Norway. Pages 323-333 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Barrett and Vader","shortCitationYear":1990,"referenceCode":"A84BAR03NAUS","lastModified":"2020-02-25T18:11:59.475593Z"},{"id":463505,"citation":"BirdLife International. 2004b. Threatened birds of the world 2004. CD ROM. BirdLife International, Cambridge, UK.","shortCitationAuthor":"BirdLife International","shortCitationYear":2004,"referenceCode":"N04BIR0100LA","lastModified":"2020-02-25T14:38:12.704742Z"},{"id":152351,"citation":"Brown, R. G. B., and D. N. Nettleship. 1984. The seabirds of northeastern North America: their present status and conservation requirements. Pages 85-100 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Brown and Nettleship","shortCitationYear":1984,"referenceCode":"A84BRO01NAUS","lastModified":"2020-02-25T18:12:30.945016Z"},{"id":104085,"citation":"Evans, P. G. H. 1984a. The seabirds of Greenland: their status and conservation. Pages 49-84 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Evans","shortCitationYear":1984,"referenceCode":"A84EVA01NAUS","lastModified":"2020-02-25T14:38:21.111106Z"},{"id":127893,"citation":"Evans, P. G. H. 1984b. Status and conservation of seabirds in northwest Europe (excluding Norways and the USSR). Pages 293-321 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Evans","shortCitationYear":1984,"referenceCode":"A84EVA02NAUS","lastModified":"2020-02-25T14:38:21.111106Z"},{"id":463493,"citation":"Given, A. D., J. A. Mills, and A. J. Baker. 2005. Molecular evidence for recent radiation in Southern Hemisphere masked gulls. Auk 122:268-279.","shortCitationAuthor":"Given et al.","shortCitationYear":2005,"referenceCode":"A05GIV0100LA","lastModified":"2020-02-25T18:21:12.405823Z"},{"id":147495,"citation":"Golovkin, A. N. 1984. Seabirds nesting in the USSR: the status and protection of populations. Pages 473-486 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Golovkin","shortCitationYear":1984,"referenceCode":"A84GOL03NAUS","lastModified":"2020-02-25T18:11:59.475593Z"},{"id":155592,"citation":"Howell, S. N. G., and S. Webb. 1995.  A guide to the birds of Mexico and northern Central America. Oxford University Press, Oxford, UK.","shortCitationAuthor":"Howell and Webb","shortCitationYear":1995,"referenceCode":"B95HOW01NAUS","lastModified":"2020-02-25T14:38:14.376662Z"},{"id":142804,"citation":"James, P. C. 1984. The status and conservation of seabirds in the Mediterranean region. Pages 371-375 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"James","shortCitationYear":1984,"referenceCode":"A84JAM01NAUS","lastModified":"2020-02-25T18:13:31.789525Z"},{"id":149971,"citation":"Melville, D. S. 1984. Seabirds of China and the surrounding seas. Pages 501-511 in Croxall et al., eds. Status and conservation of the world's seabirds. ICBP Tech. Pub. No. 2.","shortCitationAuthor":"Melville","shortCitationYear":1984,"referenceCode":"A84MEL01NAUS","lastModified":"2020-02-25T18:14:40.103023Z"},{"id":141759,"citation":"Nikula, B. 1993. Common black-headed gull. Birding, February 1993, pp. 54-60.","shortCitationAuthor":"Nikula","shortCitationYear":1993,"referenceCode":"A93NIK01NAUS","lastModified":"2020-02-25T18:21:12.405823Z"},{"id":158423,"citation":"Parker III, T. A., D. F. Stotz, and J. W. Fitzpatrick. 1996.  Ecological and distributional databases for neotropical birds. The University of Chicago Press, Chicago.","shortCitationAuthor":"Parker et al.","shortCitationYear":1996,"referenceCode":"B96PAR0100LA","lastModified":"2020-02-25T14:38:12.689104Z"},{"id":619382,"citation":"Pons, J. M., A. Hassanin, and P. A. Crochet. 2005. Phylogenetic relationships within the Laridae (Charadriiformes: Aves) inferred from mitochondrial markers. Molecular Phylogenetics and Evolution 37:686-699.","shortCitationAuthor":"Pons et al.","shortCitationYear":2005,"referenceCode":"A05PON01EHUS","lastModified":"2020-02-25T18:12:33.21046Z"},{"id":110533,"citation":"Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele. 1998. A guide to the birds of the West Indies. Princeton University Press, Princeton, NJ. 511 pp.","shortCitationAuthor":"Raffaele et al.","shortCitationYear":1998,"referenceCode":"B98RAF01NAUS","lastModified":"2020-02-25T14:38:14.376662Z"},{"id":158709,"citation":"Ridgely, R. S. 2002. Distribution maps of South American birds. Unpublished.","shortCitationAuthor":"Ridgely","shortCitationYear":2002,"referenceCode":"M02RID0100LA","lastModified":"2020-02-25T14:38:14.361032Z"},{"id":117098,"citation":"Rothweiler, R. A. 1960. Food habits, movements, and nesting of gulls, Freezout Lake, Teton County, Montana. Montana Fish and Game Department, Helena. Paper No. 494. 26pp.","shortCitationAuthor":"Rothweiler","shortCitationYear":1960,"referenceCode":"N60ROT01NACA","lastModified":"2020-02-25T18:12:51.304479Z"},{"id":158716,"citation":"Sibley, D. A. 2000a. The Sibley guide to birds. Alfred A. Knopf, New York.","shortCitationAuthor":"Sibley","shortCitationYear":2000,"referenceCode":"B00SIB0100LA","lastModified":"2020-02-25T14:38:14.361032Z"},{"id":148565,"citation":"Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.","shortCitationAuthor":"Terres","shortCitationYear":1980,"referenceCode":"B80TER01NAUS","lastModified":"2020-02-25T14:38:12.657866Z"},{"id":629315,"citation":"The American Ornithologists' Union (AOU). Banks, R.C., R.T. Chesser, C. Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz, and K. Winker. 2008. Forty-ninth supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 125(3):758-768.","shortCitationAuthor":"The American Ornithologists' Union (AOU)","shortCitationYear":2008,"referenceCode":"A08AOU01EHUS","lastModified":"2020-02-25T18:12:33.21046Z"},{"id":711643,"citation":"Thompson, B. C., J. A. Jackson, J. Burger, L. A. Hill, E. M. Kirsch, and J. L. Atwood. 1997. Least Tern (<i>Sterna antillarum</i>). In A. Poole and F. Gill, editors, The Birds of North America, No. 290. Academy of Natural Sciences, Philadelphia, and American Ornithologists' Union, Washington, DC. 32 pp.","shortCitationAuthor":"Thompson et al.","shortCitationYear":1997,"referenceCode":"A97THO02NAUS","lastModified":"2020-02-25T18:12:51.304479Z"},{"id":101024,"citation":"Van Rossem, A. J. 1933. Terns as destroyers of birds' eggs. Condor 35:49-51.","shortCitationAuthor":"Van Rossem","shortCitationYear":1933,"referenceCode":"A33VAN01NACA","lastModified":"2020-02-25T18:12:51.304479Z"}],"otherCommonNames":[{"id":104152,"name":"Gaviota Encapuchada","language":"ES"},{"id":112422,"name":"Mouette rieuse","language":"FR"}],"speciesGlobal":{"elementGlobalId":103889,"cites":null,"cosewic":null,"fwsRegion":null,"genusSize":null,"jurisEndem":{"id":5,"jurisEndemDescEn":"occurs (regularly, as a native taxon) in multiple nations","jurisEndemDescEs":"Se encuentra en varias naciones (de manera regular, como un taxón nativo)","jurisEndemDescFr":"Se trouve dans plusieurs nations (de façon régulière, tel un taxon indigène)"},"nomenclaturallyEst":null,"usesa":null,"informalTaxonomy":{"informalTaxonomyId":4,"level1":"Animals","level2":"Vertebrates","level3":"Birds","level":3,"hasChildren":false,"parentId":2,"distributionStatus":"complete","displayOrder":1070},"parentSpecies":null,"infraspecies":false,"kingdom":"Animalia","phylum":"Craniata","taxclass":"Aves","taxorder":"Charadriiformes","family":"Laridae","genus":"Chroicocephalus","americanFisheriesStatus":null,"americanFisheriesStatusDate":null,"saraStatus":null,"saraStatusDate":null,"cosewicDate":null,"interpretedCosewic":null,"cosewicComments":null,"usesaDate":null,"interpretedUsesa":null,"usesaComments":null,"completeDistribution":true,"synonyms":[{"id":112997,"synonym":"Larus ridibundus","synonymAuthor":"Linnaeus, 1766","formattedSynonym":"<i>Larus ridibundus</i>"}],"infraspeciesList":[],"ebarId":null,"ebarCanadianScope":null,"ebarGlobalScope":null,"ebarKbaGroup":"Birds","caGeneralStatusId":"GS000942"},"speciesCharacteristics":{"elementGlobalId":103889,"reproductionComments":"Lays clutch of 3 eggs. Incubation reportedly 20-24 or 23-26 days. Young first fly at about 35-40 days. One banded bird lived over 32 years. Usually nests in large colonies in Eurasian range.","ecologyComments":"In North America, often associates with flocks of migrant and wintering Bonaparte's gulls or other gulls (Nikula 1993).","habitatComments":"ALL SEASONS: Lakes, rivers, bogs, moors, grasslands, swamps, and coastal marshes. NON-BREEDING: seacoasts, estuaries, and bays (AOU 1983). In Europe, also city parks and agricultural fields (Nikula 1993). Strongly attracted to sewer outfalls (Nikula 1993). BREEDING: Nests usually on ground along seacoast, coastal islands, or in freshwater marshes (Terres 1980).","generalDescription":null,"diagnosticCharacteristics":null,"speciesMarineHabitats":[{"cagMarineHabId":-100664,"marineHabitat":{"id":3,"marineHabitatDescEn":"Near shore","marineHabitatDescEs":"Cercano a la costa","marineHabitatDescFr":"Côtier","displayOrder":3}}],"speciesTerrestrialHabitats":[{"cagTerrHabId":-110233,"terrestrialHabitat":{"id":9,"terrestrialHabitatDescEn":"Grassland/herbaceous","terrestrialHabitatDescEs":"Pastizales/cobertura herbácea","terrestrialHabitatDescFr":"Prairie/couverture herbacée","displayOrder":11}},{"cagTerrHabId":-110234,"terrestrialHabitat":{"id":19,"terrestrialHabitatDescEn":"Cropland/hedgerow","terrestrialHabitatDescEs":"Tierras cultivadas/cerco vivo","terrestrialHabitatDescFr":"Terre cultivée/haie","displayOrder":22}}],"speciesRiverineHabitats":[{"cagRiverineHabId":-105677,"riverineHabitat":{"id":1,"riverineHabitatDescEn":"BIG RIVER","riverineHabitatDescEs":"RÍO GRANDE","riverineHabitatDescFr":"GRANDE RIVIÈRE","displayOrder":1}},{"cagRiverineHabId":-105678,"riverineHabitat":{"id":2,"riverineHabitatDescEn":"MEDIUM RIVER","riverineHabitatDescEs":"RÍO MEDIANO","riverineHabitatDescFr":"MOYENNE RIVIÈRE","displayOrder":2}}],"speciesPalustrineHabitats":[{"cagPalusHabId":-102941,"palustrineHabitat":{"id":2,"palustrineHabitatDescEn":"HERBACEOUS WETLAND","palustrineHabitatDescEs":"HUMEDAL HERBÁCEO","palustrineHabitatDescFr":"TERRE HUMIDE HERBACÉE","displayOrder":2}},{"cagPalusHabId":-102939,"palustrineHabitat":{"id":4,"palustrineHabitatDescEn":"FORESTED WETLAND","palustrineHabitatDescEs":"HUMEDAL BOSCOSO","palustrineHabitatDescFr":"TERRE HUMIDE FORESTIÈRE","displayOrder":4}},{"cagPalusHabId":-102940,"palustrineHabitat":{"id":5,"palustrineHabitatDescEn":"Bog/fen","palustrineHabitatDescEs":"Pantanoso","palustrineHabitatDescFr":"Tourbière oligotrophe/marais","displayOrder":5}},{"cagPalusHabId":-102942,"palustrineHabitat":{"id":6,"palustrineHabitatDescEn":"Riparian","palustrineHabitatDescEs":"Ribereño","palustrineHabitatDescFr":"Riverain","displayOrder":6}}],"speciesLacustrineHabitats":[{"cagLacusHabId":-100882,"lacustrineHabitat":{"id":1,"lacustrineHabitatDescEn":"Deep water","lacustrineHabitatDescEs":"Aguas profundas","lacustrineHabitatDescFr":"Eau profonde","displayOrder":1}},{"cagLacusHabId":-100883,"lacustrineHabitat":{"id":2,"lacustrineHabitatDescEn":"Shallow water","lacustrineHabitatDescEs":"Aguas poco profundas","lacustrineHabitatDescFr":"Eau peu profonde","displayOrder":2}}],"speciesSubterraneanHabitats":[],"speciesEstuarineHabitats":[{"cagEstuarineHabId":-101261,"estuarineHabitat":{"id":1,"estuarineHabitatDescEn":"Bay/sound","estuarineHabitatDescEs":"Bahía/Estrecho","estuarineHabitatDescFr":"Baie/détroit","displayOrder":1}},{"cagEstuarineHabId":-101262,"estuarineHabitat":{"id":2,"estuarineHabitatDescEn":"River mouth/tidal river","estuarineHabitatDescEs":"Desembocadura del río/río de marea","estuarineHabitatDescFr":"Embouchure/rivière à marées","displayOrder":2}},{"cagEstuarineHabId":-101263,"estuarineHabitat":{"id":3,"estuarineHabitatDescEn":"Lagoon","estuarineHabitatDescEs":"Laguna","estuarineHabitatDescFr":"Lagune","displayOrder":3}},{"cagEstuarineHabId":-101264,"estuarineHabitat":{"id":4,"estuarineHabitatDescEn":"Tidal flat/shore","estuarineHabitatDescEs":"Marea plana/orilla","estuarineHabitatDescFr":"Replat de marée/rivage","displayOrder":4}},{"cagEstuarineHabId":-101265,"estuarineHabitat":{"id":5,"estuarineHabitatDescEn":"Herbaceous wetland","estuarineHabitatDescEs":"Humedal herbáceo","estuarineHabitatDescFr":"Terre humide herbacée","displayOrder":5}}]},"primaryReference":{"id":629315,"citation":"The American Ornithologists' Union (AOU). Banks, R.C., R.T. Chesser, C. Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz, and K. Winker. 2008. Forty-ninth supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 125(3):758-768.","shortCitationAuthor":"The American Ornithologists' Union (AOU)","shortCitationYear":2008,"referenceCode":"A08AOU01EHUS","lastModified":"2020-02-25T18:12:33.21046Z"},"predecessors":[],"elementGlobalThreatAssessments":[]}