{"elementGlobalId":817032,"circumscripConfidence":null,"classificationLevel":{"id":7,"classificationLevelNameEn":"Species","classificationLevelNameEs":"Especies","classificationLevelNameFr":"Espèce"},"classificationStatus":{"id":1,"classificationStatusDescEn":"Standard","classificationStatusDescEs":"Estándar","classificationStatusDescFr":"Standard"},"iucn":null,"nameCategory":{"id":1,"nameCategoryDescEn":"Vertebrate Animal","nameCategoryDescEs":"Animal vertebrado","nameCategoryDescFr":"Animal vertébré","nameTypeCd":"A","nameTypeDesc":"Zoological"},"rankMethodUsed":{"id":1,"rankMethodUsedDescEn":"Legacy Rank calculation - Excel v3.1x","rankMethodUsedDescEs":null,"rankMethodUsedDescFr":null,"rankMethodUsedExternalDescEn":"Ranked by calculator","rankMethodUsedExternalDescEs":null,"rankMethodUsedExternalDescFr":null},"formattedScientificName":"<i>Hypsiglena ochrorhyncha</i>","scientificName":"Hypsiglena ochrorhyncha","scientificNameAuthor":"Cope, 1860","primaryCommonName":"Coast Nightsnake","relatedItisNames":null,"uniqueId":"ELEMENT_GLOBAL.2.817032","elcode":"ARADB18030","conceptRefFullCitation":"Mulcahy, D.G. 2008. Phylogeography and species boundaries of the western North American Nightsnake (Hypsiglena torquata): revisiting the subspecies concept. Molecular Phylogenetics and Evolution 46:1095-1115.","conceptName":"<i>Hypsiglena ochrorhyncha</i>","taxonomicComments":"Taxonomy of <i>Hypsiglena </i>has received some critical review since Tanner's revision of the genus in 1944. Dixon (1965) and Dixon and Dean (1986) studied a morphological contact zone between northern and southern taxa at the Sonora–Sinaloa border in Mexico, finding that it comprised a narrow zone of hybridization with some taxa existing in sympatry. Hardy and McDiarmid (1969) examined specimens across the range of this presumptive contact and elsewhere in western Mexico and concluded that no morphological characters existed to separate <i>torquata </i>and <i>ochrorhyncha</i>, except maybe nuchal patterns, which they decided (p. 170) was \"a case of pattern dimorphism in a single, otherwise uniform, species.\" Grismer et al. (1994) dismissed the recognition of subspecies in Baja California, stating, without evidence, that the subspecies intergrade widely. Mulcahy (2008) conducted a comprehensive phylogeographic study of <i>Hypsiglena </i>based on an mtDNA analysis of &gt;150 individuals. Mulcahy (2008) recognized six species in what was considered <i>H. torquata</i>, five of which are consistent with previously described lineages (e.g. subspecies), while one represents a unique lineage that remains to be described. Mulcahy (2008) also recommended maintaining the subspecies designations for several of the widespread, polymorphic species, which may represent incipient species. The nominal species <i>H. torquata</i> is now restricted to Mexico, three described forms occur in the USA, and the undescribed form is endemic to the Cochise Filter Barrier area of southeastern Arizona and associated New Mexico (Crother 2017).","roundedGRank":"G5","conservationStatusFactorsEditionDate":"2009-08-12","conservationStatusFactorsEditionAuthors":"Hammerson, G.","primaryCommonNameLanguage":"EN","recordType":"SPECIES","elementNationals":[{"elementNationalId":817033,"classifConfidence":null,"nation":{"id":225,"nameEn":"United States","nameEs":"Estados Unidos","nameFr":"États-Unis","isoCode":"US","region":"United States"},"roundedNRank":"N5","elementSubnationals":[{"elementSubnationalId":817034,"subnation":{"id":7,"nameEn":"California","nameEs":"California","nameFr":"Californie","subnationCode":"CA","dnationId":225},"roundedSRank":"SNR","dataSensitive":{"id":2,"dataSensitiveDescEn":"No","dataSensitiveDescEs":null,"dataSensitiveDescFr":null,"dataSensitiveCode":"N"},"dataSensitiveCategory":null,"srank":"SNR","speciesSubnational":{"elementSubnationalId":817034,"hybrid":false,"exotic":false,"native":true}}],"nrankReviewYear":2008,"nrank":"N5","speciesNational":{"elementNationalId":817033,"exotic":false,"native":true}}],"lastModified":"2026-10-02T22:47:22.565434Z","lastPublished":"2026-10-02T21:32:08.892226Z","promotionalDescription":null,"conceptLineageSummary":null,"nsxUrl":"/Taxon/ELEMENT_GLOBAL.2.817032/Hypsiglena_ochrorhyncha","grankAdjustmentReasons":null,"grankChangeDate":"2008-07-14","grankReviewDate":"2008-07-14","grankReasons":null,"grank":"G5","rankInfo":{"elementGlobalId":817032,"aooPercentGood":null,"enviromentalSpecificity":null,"intrinsicVulnerability":null,"longTermTrend":null,"numberEos":{"id":13,"numberEosDescEn":"81 - 300","numberEosDescEs":"De 81 a 300","numberEosDescFr":"De 81 à 300"},"numberGoodEos":null,"numberProtEos":null,"popSize":{"id":35,"popSizeDescEn":"100,000 to >1,000,000 individuals","popSizeDescEs":"De 100.000 a >1.000.000 de individuos","popSizeDescFr":"De 100 000 à >1 000 000 individus"},"rangeExtent":{"id":33,"rangeExtentDescEn":"200,000-2,500,000 square km (about 80,000-1,000,000 square miles)","rangeExtentDescEs":"200.000 a 2.500.000 kilómetros cuadrados (aproximadamente 80.000 a 1.000.000 millas cuadradas)","rangeExtentDescFr":"De 200 000 à 2 500 000 km carrés (de 80 000 à 1 000 000 miles carrés approximativement)"},"shortTermTrend":{"id":40,"shortTermTrendDescEn":"Relatively Stable (<=10% change)","shortTermTrendDescEs":"Relativamente estable (variación = <10%)","shortTermTrendDescFr":"Relativement stable (variation = <10 %)"},"threatImpactAssigned":{"id":10,"threatImpactAssignedDescEn":"Low","threatImpactAssignedDescEs":"Bajo","threatImpactAssignedDescFr":"Faible"},"rangeExtentComments":"Range extends from northern California southward through western California to southern Baja California (Mulcahy 2008).","areaOfOccupancy":null,"areaOfOccupancyComments":null,"numberEosComments":"This species is represented by a large number of occurrences or subpopulations.","popSizeComments":"Total adult population size is unknown but presumably exceeds 100,000. The species occupies a wide range and is locally fairly common.","viabilityComments":null,"threatImpactComments":"No major threats have been identified. Locally, habitat has been destroyed or degraded, but in many areas the rugged habitat tends to be unsuitable for extensive, incompatible human uses.","shortTermTrendComments":"Trend over the past 10 years or three generations is uncertain, but extent of occurrence, area of occupancy, number of subpopulations, and population size probably have been relatively stable.","longTermTrendComments":null,"inventoryNeeds":null,"numberProtEosComments":"Many occurrences are in national and state parks and other well-protected areas.","protectionNeeds":null,"otherConsiderations":null,"intrinsicVulnerabilityComments":null,"enviromentalSpecificityComments":null},"animalCharacteristics":{"elementGlobalId":817032,"majorHabitat":{"id":3,"majorHabitatDescEn":"Terrestrial","majorHabitatDescEs":"Terrestre","majorHabitatDescFr":"Terrestre"},"nonMigrant":false,"localMigrant":false,"longDistanceMigrant":false,"mobilityMigrationComments":null,"foodHabitsComments":"This snake eats mainly lizards and lizard eggs, sometimes other small animals (Stebbins 2003).","animalPhenologyComments":null,"colonialBreeder":false,"length":null,"width":null,"weight":null,"animalPhenologies":[],"animalFoodHabits":[]},"occurrenceDelineations":[{"eoSpecsDetailId":1142,"locationUseClass":{"id":1,"locationUseClassDescEn":"Not applicable","locationUseClassDescEs":"No se aplica","locationUseClassDescFr":"Sans objet","displayOrder":1},"eoSpecGroupName":"Medium And Large Colubrid Snakes","subtypes":null,"inferredExtentDistance":0.5,"inferredExtentNotes":null,"minimumEoCriteria":"Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals (including eggs) in or near appropriate habitat where the species is presumed to be established and  breeding.","mappingGuidance":null,"separationBarriers":"Busy highway or highway with obstructions such that snakes rarely if ever cross successfully; major river, lake, pond, or deep marsh (this barrier pertains only to upland species and does not apply to aquatic or wetland snakes); densely urbanized area dominated by buildings and pavement.","separationDistanceUnsuitableHabitatat":1.0,"separationDistanceSuitableHabitatat":10.0,"altSeparationProcedure":null,"separationJustification":"Available information on movements of colubrid snakes is limited to a small minority of species. These data indicate that nearly all species have home ranges smaller or much smaller than 25 ha (e.g., less than 3 ha, <i>Pituophis catenifer</i> in California, Rodriguez-Robles 2003), with some up to about 75 ha (<i>Heterodon platirhinos</i>, average 50 ha, Plummer and Mills 2000), and the largest up to 225 ha in the biggest colubrids (<i>Drymarchon</i>, summer mean 50-100 ha, USFWS 1998). <br><br>Radiotelemetry data for <i>Pantherophis </i>indicate that residents of hibernacula that are 1-2 km apart (with suitable intervening habitat) probably interbreed (Prior et al. 1997, Blouin-Demers and Weatherhead 2002). However, \"evidence of genetic structure even over short distances (e.g., 2-20 km) implies that gene flow among rat snake populations can be easily disrupted\" (Prior et al. 1997). Loughheed et al. (1999) found evidence of substantial genetic exchange among local hibernacula (< 6 km apart), but gene flow over distances of 10s of km appears to be substantially less. Based on extensive radio-tracking data, Blouin-Demers and Weatherhead (2002) found that home range size of <i>Pantherophis </i>averaged 18.5 ha and ranged up to 93 ha; based on the most mobile individuals, <i>Pantherophis </i>from hibernacula up to 8 km apart can come together for mating. <i>Pantherophis </i>and probably other colubrids exhibit high fidelity to hibernacula and shift even to nearby sites only rarely (Prior et al. 2001). <br><br>Many of the several studies that report small home ranges for colubrids did not employ methods (e.g., radio telemetry) suitable for detecting full annual or multi-annual home range size, dispersal, or other long-distance movements, so these may have yielded underestimates of home ranges or activity areas.  <br><br>At least some colubrids, including medium-sized species such as garter snakes, not uncommonly move between areas up to a few kilometers apart, and several species make extensive movements of up to several kilometers, so separation distances of 1-2 km for suitable habitat are too small for medium-sized and large colubrids.<br><br>A separation distance of 10 km for suitable habitat was selected as most appropriate for snakes assigned to this Specs Group because it seems generally unlikely that two locations separated by less than 10 km of suitable habitat would represent distinct occurrences.<br><br>For the purposes of these occurrence specifications, upland habitat is regarded as unsuitable habitat for aquatic and wetland snakes. For upland snakes, shallow or patchy wetlands are treated as unsuitable habitat whereas large deepwater habitats (subjective determination) are barriers.","versionDate":"2013-02-12","versionAuthor":"Hammerson, G.","versionNotes":"Separation distance for suitable habitat was changed from 5 km to 10 km based on comments from Dale Jackson (12 Feb 2013).","lastModified":"2020-04-30T02:04:05.987846Z"}],"plantCharacteristics":null,"elementManagement":{"elementGlobalId":817032,"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":181240,"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":"2020-05-14T05:28:33.873651Z"}],"references":[{"id":621810,"citation":"Crother, B. I. (editor). 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37:1-84. Online with updates at: http://www.ssarherps.org/pages/comm_names/Index.php","shortCitationAuthor":"Crother","shortCitationYear":2008,"referenceCode":"B08CRO01NAUS","lastModified":"2020-02-25T14:38:20.142383Z"},{"id":722484,"citation":"Crother, B. I. (editor). 2012. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 7th edition. SSAR Herpetological Circular 39:1-92.","shortCitationAuthor":"Crother","shortCitationYear":2012,"referenceCode":"B12CRO01NAUS","lastModified":"2020-02-25T18:11:51.08501Z"},{"id":943912,"citation":"Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]","shortCitationAuthor":"Crother","shortCitationYear":2017,"referenceCode":"B17CRO01EHUS","lastModified":"2020-02-25T18:11:53.413199Z"},{"id":1067057,"citation":"Dixon, J. R. 1965. A taxonomic reevaluation of the night snake <i>Hypsiglena ochrorhyncha</i> and relatives. The Southwestern Naturalist 10(2):125-131.","shortCitationAuthor":"Dixon","shortCitationYear":1965,"referenceCode":"A65DIX01NAUS","lastModified":"2020-11-11T03:23:39.159401Z"},{"id":1067059,"citation":"Dixon, J. R., and R. H. Dean. 1986. Status of the southern populations of the night snake (<i>Hypsiglena</i>: Colubridae) exclusive of California and Baja California. The Southwestern Naturalist 31(3):307-318.","shortCitationAuthor":"Dixon and Dean","shortCitationYear":1986,"referenceCode":"A86DIX01NAUS","lastModified":"2020-11-11T03:23:39.159401Z"},{"id":468751,"citation":"Grismer, L. L., J. A. McGuire, and B. D. Hollingsworth. 1994. A report on the herpetofauna of the Vizcaino Peninsula, Baja California, Mexico, with a discussion of its biogeographic and taxonomic implications. Bulletin of the Southern California Academy of Sciences 93:45-80.","shortCitationAuthor":"Grismer et al.","shortCitationYear":1994,"referenceCode":"A94GRI02NAUS","lastModified":"2020-11-11T03:23:39.143794Z"},{"id":159457,"citation":"Hardy, L.M. and McDiarmid, R.W. 1969. The amphibians and reptiles of Sinaloa, México. University of Kansas Publications, Museum of Natural History 18:39-252.","shortCitationAuthor":"Hardy and McDiarmid","shortCitationYear":1969,"referenceCode":"A69HAR02NAUS","lastModified":"2020-11-11T03:23:39.143794Z"},{"id":627897,"citation":"Mulcahy, D.G. 2008. Phylogeography and species boundaries of the western North American Nightsnake (Hypsiglena torquata): revisiting the subspecies concept. Molecular Phylogenetics and Evolution 46:1095-1115.","shortCitationAuthor":"Mulcahy","shortCitationYear":2008,"referenceCode":"A08MUL01EHUS","lastModified":"2020-02-25T19:38:43.398642Z"},{"id":1067060,"citation":"Tanner, W. W. 1944. A taxonomic study of the genus <i>Hypsiglena</i>. Great Basin Naturalist 5(3&amp;4):25-92.","shortCitationAuthor":"Tanner","shortCitationYear":1944,"referenceCode":"A44TAN01NAUS","lastModified":"2020-11-11T03:23:39.159401Z"}],"otherCommonNames":[{"id":144817,"name":"coast nightsnake","language":"EN"}],"speciesGlobal":{"elementGlobalId":817032,"cites":null,"cosewic":null,"fwsRegion":null,"genusSize":{"id":3,"genusSizeDescEn":"Small genus","genusSizeDescEs":"Género pequeño","genusSizeDescFr":"Petit genre"},"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":7,"level1":"Animals","level2":"Vertebrates","level3":"Reptiles","level":3,"hasChildren":false,"parentId":2,"distributionStatus":"complete","displayOrder":1100},"parentSpecies":null,"infraspecies":false,"kingdom":"Animalia","phylum":"Craniata","taxclass":"Reptilia","taxorder":"Squamata","family":"Colubridae","genus":"Hypsiglena","americanFisheriesStatus":null,"americanFisheriesStatusDate":null,"saraStatus":null,"saraStatusDate":null,"cosewicDate":null,"interpretedCosewic":null,"cosewicComments":null,"usesaDate":null,"interpretedUsesa":null,"usesaComments":null,"completeDistribution":true,"synonyms":[{"id":128903,"synonym":"Hypsiglena torquata ochrorhyncha","synonymAuthor":"Cope, 1860","formattedSynonym":"<i>Hypsiglena torquata ochrorhyncha</i>"}],"infraspeciesList":[],"ebarId":null,"ebarCanadianScope":false,"ebarGlobalScope":false,"ebarKbaGroup":"Amphibians and Reptiles","caGeneralStatusId":null},"speciesCharacteristics":{"elementGlobalId":817032,"reproductionComments":null,"ecologyComments":null,"habitatComments":"This snake generally inhabits arid and semiarid plains, canyons, and hillsides, usually in rocky, dissected or hilly terrain with sandy or gravelly soils, including areas dominated by desert, grassland, shrubland, savanna, or woodland (Stebbins 2003). Periods of inactivity are spend under rocks or other surface cover, in crevices, or underground.","generalDescription":null,"diagnosticCharacteristics":null,"speciesMarineHabitats":[],"speciesTerrestrialHabitats":[{"cagTerrHabId":-112647,"terrestrialHabitat":{"id":4,"terrestrialHabitatDescEn":"Woodland - Hardwood","terrestrialHabitatDescEs":"Lote de madera - Madera dura","terrestrialHabitatDescFr":"Terrain boisé — Feuillu","displayOrder":6}},{"cagTerrHabId":-112648,"terrestrialHabitat":{"id":5,"terrestrialHabitatDescEn":"Woodland - Conifer","terrestrialHabitatDescEs":"Lote de madera - Conífera","terrestrialHabitatDescFr":"Terrain boisé — Résineux","displayOrder":7}},{"cagTerrHabId":-112649,"terrestrialHabitat":{"id":6,"terrestrialHabitatDescEn":"Woodland - Mixed","terrestrialHabitatDescEs":"Lote de madera - Mixto","terrestrialHabitatDescFr":"Terrain boisé — Mixte","displayOrder":8}},{"cagTerrHabId":-112650,"terrestrialHabitat":{"id":7,"terrestrialHabitatDescEn":"Shrubland/chaparral","terrestrialHabitatDescEs":"Matorral/Chaparral","terrestrialHabitatDescFr":"Fruticée/Chaparral","displayOrder":9}},{"cagTerrHabId":-112651,"terrestrialHabitat":{"id":8,"terrestrialHabitatDescEn":"Savanna","terrestrialHabitatDescEs":"Sabana","terrestrialHabitatDescFr":"Savane","displayOrder":10}},{"cagTerrHabId":-112652,"terrestrialHabitat":{"id":9,"terrestrialHabitatDescEn":"Grassland/herbaceous","terrestrialHabitatDescEs":"Pastizales/cobertura herbácea","terrestrialHabitatDescFr":"Prairie/couverture herbacée","displayOrder":11}},{"cagTerrHabId":-112653,"terrestrialHabitat":{"id":11,"terrestrialHabitatDescEn":"Desert","terrestrialHabitatDescEs":"Desierto","terrestrialHabitatDescFr":"Désert","displayOrder":13}},{"cagTerrHabId":-112654,"terrestrialHabitat":{"id":17,"terrestrialHabitatDescEn":"Bare rock/talus/scree","terrestrialHabitatDescEs":"Roca viva/pendiente de roca/piedras sueltas","terrestrialHabitatDescFr":"Éboulis","displayOrder":20}}],"speciesRiverineHabitats":[],"speciesPalustrineHabitats":[],"speciesLacustrineHabitats":[],"speciesSubterraneanHabitats":[],"speciesEstuarineHabitats":[]},"primaryReference":{"id":943912,"citation":"Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]","shortCitationAuthor":"Crother","shortCitationYear":2017,"referenceCode":"B17CRO01EHUS","lastModified":"2020-02-25T18:11:53.413199Z"},"predecessors":[{"predecessorId":102181,"elCode":null,"name":"Hypsiglena torquata","formattedName":"<i>Hypsiglena torquata</i>","classficationCode":null,"uniqueId":"ELEMENT_GLOBAL.2.106077","lineageDate":null,"nsxUrl":null}],"elementGlobalThreatAssessments":[]}