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Recolonization of the Flicker and Other Notes from Isla Guadalupe, Mexico

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Recolonization of the Flicker and Other Notes from Isla Guadalupe, Mexico Ornithology Program (HRC) Harry Reid Center for Environmental Studies 2001 Recolonization of the Flicker and other notes from Isla Guadalupe, Mexico Paul R. Sweet American Museum of Natural History George F. Barrrowclough American Museum of Natural History John Klicka University of Nevada, Las Vegas, [email protected] Liliana Montanez-Godoy Universidad Nacional Autonoma de Mexico Patricia Escalante Universidad Nacional Autónoma de México Follow this and additional works at: https://digitalscholarship.unlv.edu/hrc_ornithology Part of the Ecology and Evolutionary Biology Commons, Genomics Commons, and the Ornithology Commons Repository Citation Sweet, P. R., Barrrowclough, G. F., Klicka, J., Montanez-Godoy, L., Escalante, P. (2001). Recolonization of the Flicker and other notes from Isla Guadalupe, Mexico. Western Birds, 32(1), 71-80. Available at: https://digitalscholarship.unlv.edu/hrc_ornithology/34 This Article is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Article in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Article has been accepted for inclusion in Ornithology Program (HRC) by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. RECOLONIZATION OF THE FLICKER AND OTHER NOTES FROM ISLA GUADALUPE, MEXICO PAUL R. SWEET and GEORGE F. BARROWCLOUGH, Departmentof Ornithol- ogy, AmericanMuseum of NaturalHistory, Central Park West at 79th Street, New York, New York 10024 JOHN T. KLICKA, J. F. BellMuseum of NaturalHistory, University of Minnesota,St. Paul,Minnesota 55108 (currentaddress Barrick Museum, University of Nevada,Las Vegas,Nevada 89154) LILIANAMONTAi•IEZ-GODOY and PATRICIA ESCALANTE-PLIEGO, Instituto de Biologia, UniversidadNacional Aut6noma de M•xico, Apartado Postal 70-153, 04510 Distrito Federal, M•xico ABSTRACT:During a visitto IslaGuadalupe from 31 May to 3 June 1996, we documentedthree speciesnew to the island,the Barn Owl, Swainson'sThrush, and HoodedOriole, and establishedfirst breeding records for the EuropeanStarling and WesternMeadowlark. Red-shafted Flickers are now breeding on the island,represent- ing a recentrecolonization from the mainlandfollowing the extinctionof the endemic population.We investigatedthe validityof Colaptes auratus rufipileus and con- cludedthat it doesnot meet the standardfor phylogeneticspecies but differsfrom C. a. collarisat the 75% levelusually associated with subspecificrank. Damage to the cypressforest by goats continues,and all speciesdependent on these trees are threatenedby lossof habitat. IslaGuadalupe is a volcanicoceanic island lying 260 km westof the coast of BajaCalifornia (29 ø 00' N, 118ø 20' W). It is some37 km longwith an areaof 250 km2 and reaches an elevation of 1298 m. Thehistory and status of the avifaunahave been reviewed by Howelland Cade(1954) andmore recentlyby Jehl and Everett(1985). Subsequentobservations have been reportedby Dunlap (1988), Oberbaueret al. (1989), Mellinkand Palacios (1990), Howelland Webb (1992), and Galloand Figueroa (1996). Here we reporton birdsobserved and collectedon a visitto IslaGuadalupe between 31 May and 3 June 1996. Mapsof the island,showing localities mentioned here, have been providedby Jehl and Everett(1985) and Moran (1996). Three of the specieswe recordedrepresent first records for the island;in addition,we confirmedthe breedingof two recentlycolonizing species and notedthe recolonizationof a previouslyextirpated species whose taxonomic status we reexamined. ITINERARY We spenta few hoursat the navalbase (Melp6mene Cove or PuntaSur) upon our arrivalon the islandand then traveledthe dirt road from there to the airstrip(Campo Pista: 29 ø01' N, 118ø 17'W), wherewe spentone night anda morningobserving and collecting.We thencontinued to the cypress grove(29 ø 07' N, 118ø 20'W, 1165m),near the highest point on the island, where we spent two nights.One night was spent at the fishingvillage (CampoTepey•c or Campo Oeste).We returnedto the naval baseby launch. Western Birds 32:71-80, 2001 71 NOTES FROM ISLA GUADALUPE CONSERVATION Unfortunatelythe decimationof the island'svegetation by feral goatsis continuing;we saw large numbersof goatsthroughout the island.They appearedto be most numerousin the centraland northernportions of the island,nearer the major sourceof freshwater. Moran (1996) reviewedthe historyof goat damage to the flora of the islandand estimatedthat the youngestof the endemicGuadalupe Cypress (Cupressus guadalupensis) were well over 100 yearsold. Apparently,in excessof 20,000 goatswere removedfrom the islandin 1971, reportedlyleaving only 239 animalsat that time (AgrazGarcia 1978). Moran (1996) estimatedthat the population had reboundedto at least7000 in 1994. Low-intensityhunting by fisher- men and marineshas had littleimpact on the populationin recentyears. In addition,attempts at protectingthe remainingcypress forest fragment with a wire fence have failed.The fenceis breachedin many places,and a gate is missing;large herds of goats were observedtrooping through the cypressesat all hours,leaving virtually no vegetationof consequencewithin the understoryof the grove(Figures 1 and 2). In addition,the bark of many of the treesshowed evidence of damageby goats.Clearly only the complete removalof goatsfrom the islandor a securefence with a full-timewarden will guaranteelong-term survival of the cypressesand the birdsdependent on them. We also saw feral dogs and cats on the island,but only in small numbers. ANNOTATED LIST LaysanAlbatross (Phoebastria immutabilis). First recordedbreeding on IslaGuadalupe in 1986 (Dunlap1988). Its statusup to 1992 was reviewed by Gallo and Figueroa(1996). We brieflysurveyed the rockyplateau above the naval base and observedsix full-grownchicks and one adultbird. The youngbirds were closeto fledgingwith down remainingonly on the head and neck. Brandt'sCormorant (Phalacrocorax pencillatus). A pair was seenflying past IsloteZapato at the southanchorage. American Kestrel (Falco sparverius). Fairly common and observed throughoutthe island. Western Gull (Larus occidentalis).A few were seen along the coast between Campo Tepeyficand Melp6mene Cove. Mourning Dove (Zenaida macroura). Common throughoutthe island. Many were observedcoming to drink at the freshwater springbelow the north end of the cypressgrove. Barn Owl (Tyto alba). A singleflank feather(Colecci6n Nacional de Aves 25550) found near the airstrip providesthe first documentationof the occurrenceof this specieson the island,although we saw or heard none. There have been severalanecdotal reports of large owlson the island,and previousauthors assumed that theserefer to the Great Horned Owl (Bubo virginianus). DuringEdward Palmer's initial study of the avifaunaof the island(Ridgway 1876), two unidentifiedspecies of owls were observedbut not collected. 72 NOTES FROM ISLA GUADALUPE Accountsof B. virginianuson the islandappear to originatewith Palmer's assistant(Bryant 1887) who reporteda "HornedOwl (Bubo)"and that "the Mexicans"reported a "largeowl ("Tecolote")."It is possiblethis represents a misunderstandingon behalfof the assistant:tecolote in MexicanSpanish couldrefer to any smallowl, buho (interpretedas Bubo?)to any large owl. Presumablythe tecoloteis the BurrowingOwl, and Bryant(1887) assumed that the largeowl wasa Great Horned. However,it now appearsplausible that theseearly reports refer to the Barn Owl, a speciesthat is knownfor its abilityto colonizeislands, including Isla Socorro some 500 km from the southerntip of Baja California.No Great Horned Owlswere heardduring our visit. BurrowingOwl (Athene cunicularia).Fairly common; several pairs were seenbetween the southend and the cypressgrove. Anna'sHummingbird (Calypte anna). Commonin the cypressgrove. Northern Flicker(Colaptes auratus [cafergroupl). Fairly common in the cypressgrove; we foundseveral active nests and collectedtwo birds.A male (CNAV 24795) had enlargedtestes and a female(CNAV 24794) had yolking eggs.The endemicform, C. a. rufipileus,has not beencollected since 1906 and has been considered extinct. We believe the birds we saw and collected were mainland Red-shaftedFlickers and that Isla Guadalupehas been successfullyrecolonized by flickersfollowing the extirpationof the endemic subspecies(see below). RockWren ($alpinctesobsoletus). Abundant from the beachesup to the cypressforest. Swainson's Thrush (Catharus ustulatus). We collected a male with moderatelyenlarged testes (CNAV 24746) in the cypressgrove; no other individualswere seenor heard.This is the firstrecord of thisspecies on Isla Guadalupe.Presumably it representsa vagrant;Swainson's Thrush occurs throughoutBaja Californiaas a migrant(Howell and Webb 1995) and has been recordedand presumedto be migratingin the mountainsof Baja Californiaas late as early June (Wilbur1987). Escalante-Pliegocompared the specimento seriesat CNAV and tentativelyidentified it as nominateC. u. ustulatus,common in migrationon the nearbymainland. Northern Mockingbird(/•/im us polyglottos).We saw two togetherin an openarea near the cypressgrove but could not determineif theywere a pair. Bryant (1887) observedtwo birdsin 1886, and subsequentlyindividuals were seennear the airstripin January1988
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