DOCSLIB.ORG

Thalasseus Acuflavidus) in Brazil

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thalasseus Acuflavidus) in Brazil ISSN (impresso) 0103-5657 ISSN (on-line) 2178-7875 Revista Brasileira de Ornitologia Volume 19 Número 3 www.ararajuba.org.br/sbo/ararajuba/revbrasorn Setembro 2011 Publicada pela Sociedade Brasileira de Ornitologia São Paulo - SP Revista Brasileira de Ornitologia, 19(3), 358-363 ArtIGO Setembro de 2011 Evaluation of the status of conservation of the Cabot’s Tern (Thalasseus acuflavidus) in Brazil Márcio Amorim Efe1,2 and Sandro Luis Bonatto3 1. Setor de Biodiversidade e Ecologia, Instituto de Ciências Biológicas e da Saúde (ICBS), Universidade Federal de Alagoas. Avenida Lourival Melo Mota, s/n, Tabuleiro do Martins, CEP 57072‑970, Maceió, AL, Brasil. Corresponding author. E‑Mail: [email protected] 2. Seção de Ornitologia, Museu de História Natural, Universidade Federal de Alagoas. Avenida Lourival Melo Mota, s/n, Tabuleiro do Martins, CEP 57072‑970, Maceió, AL, Brasil. 3. Centro de Biologia Genômica e Molecular, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul. Avenida Ipiranga, 6.681, Partenon, CEP 90619‑900, Porto Alegre, RS, Brasil. E‑Mail: [email protected] Recebido em 13/03/2011. Aceito em 29/06/2011. RESUMO: Avaliação do estado de conservação do trinta-réis-de-bando (Thalasseus acuflavidus) no Brasil. O trinta‑réis‑de‑ bando, Thalasseus acuflavidus é considerado uma das mais vulneráveis espécies costeiras do Brasil. Sua distribuição está limitada ao Caribe, costa atlântica da América do Norte e América do Sul. No Brasil, seus ninhos em pequenas ilhas costeiras estão suscetíveis aos distúrbios humanos. Historicamente suas colônias tem sofrido intensiva coleta de ovos por parte de pescadores, o que contribui severamente com o decréscimo de seu sucesso reprodutivo. A população brasileira está confinada principalmente na costa do Espírito Santo. Este artigo avalia o estado de conservação da população de T. acuflavidus no Brasil e discute sua categorização. Nossa avaliação do estado de conservação desta espécie segue os critérios e categorias adotados pela IUCN. Aqui nós revisamos vários parâmetros incluindo o nível taxonômico, as principais ameaças, as áreas de extensão e ocorrência e o tamanho atual da população. Uma vez que o Trinta‑réis‑de‑bando vem perdendo áreas de reprodução em diversas áreas da costa brasileira, nós recomendamos que esta espécie seja considerada como “Vulnerável” no nível nacional. Ele também pode ser considerado “Em Perigo” em nível estadual. Finalmente, nós sugerimos que esforços de pesquisa e conservação sejam ampliados na costa do Espírito Santo e que ações de conservação semelhantes sejam implementadas ao longo da costa brasileira. PalaVRAS-CHAVE: Trinta‑réis‑de‑bando; Thalasseus acuflavidus; Estado de conservação; Brasil; Ave marinha; Critérios da IUCN. Abstract: Evaluation of the status of conservation of the Cabot’s Tern (Thalasseus acuflavidus) in Brazil. The Cabot’s Tern, Thalasseus acuflavidus is considered to be one of the most vulnerable coastal species in Brazil. Its range is limited to the Caribbean and Atlantic coasts of North and South America. In Brazil it nests on small coastal islands that are susceptible to human disturbance. Historically, its colonies have suffered extensive egg collection by fishermen, which has severely decreased its reproductive success. The Brazilian population is mainly confined to the coast of Espírito Santo state. This paper evaluates the population status of T. acuflavidus in Brazil and discusses its threat category. Our evaluation of the conservation status of this species follows the criteria and categories adopted by the IUCN. Here, we review several parameters, including taxonomic level, principal threats, area and extent of occurrence, and current population size. Because Cabot’s Terns have recently been extirpated from other areas of the Brazilian coast, we recommend that this species should be defined as Vulnerable at the national level. It may also qualify as Endangered at the state level. Finally, we suggest that research and conservation efforts should be increased on Espírito Santo coast, and that conservation actions should be implemented across the whole Brazilian coast. KEy-WORDS: Cabot’s Tern; Conservation status; Brazil; Seabird; IUCN criteria; Thalasseus acuflavidus. The ornithological literature contains scarce infor‑ the Caribbean. A recent mtDNA analysis of this species mation on Cabot’s Tern (Junge and Voous 1955). One complex (Efe et al. 2009) has helped to the phylogenetic of the remaining taxonomic uncertainties in the Sternini relationships of the group. was the classification of the species complex of the Sand‑ Cabot’s Tern (now Thalasseus acuflavidus; Efe et al. wich/Cabot’s/Cayenne tern (Efe et al. 2004). Within this 2009) breeds on the Caribbean and Atlantic coasts of North complex, there are three forms classified either as sub‑ and South America. Its range extends from the southern species or species: Sandwich tern (T. s. sandvicensis) that USA, Caribbean along the coasts of Colombia, Venezuela, breeds on the Atlantic and Mediterranean coasts of Eu‑ Surinam, Brazil, and Uruguay south to Argentina as far as rope, Cabot’s tern (T. s. acuflavidus) breeding on the At‑ Puerto Deseado (Escalante 1973, Shealer 1999). lantic coasts of North America and the Caribbean, and Antas (1991) identified the Cabot’s Tern as the most Cayenne tern (T. s. eurygnathus) that breeds on the At‑ vulnerable coastal species in Brazil, due to extensive egg lantic coast of South America from Argentina north to collection by fishermen. Since then, this species has been Evaluation of the status of conservation of the Cabot’s Tern (Thalasseus acuflavidus) in Brazil 359 Márcio Amorim Efe and Sandro Luis Bonatto the focus of studies and conservation initiatives. The An‑ Area of occupancy is the area inside the extent of oc‑ dorinhas do Mar Project curtailed egg collection in Es‑ currence which is occupied by a taxon, excluding cases of pírito Santo State, mainly through protection and edu‑ vagrancy. This category reflects the fact that a taxon will cation (Efe et al. 2000); however, the long‑term survival not usually occur throughout its extent of occurrence, of the Cabot’s Tern remains uncertain. In the nearshore which may contain unsuitable or unoccupied habitats. In zone of South Carolina it is subjected to anthropogenic some cases the area of occupancy is the smallest area essen‑ disturbances including development pressure and recre‑ tial at any stage to the survival of existing populations of ation, natural disturbances such as frequent hurricane a taxon (BirdLife International 2001). For the estimate of and other biotic factors such as predation, parasitism, or the area of occupancy in this analysis we used the follow‑ food availability may affect population dynamics as well ing reasoning: according to Shealer (1999) most breeding (Jodice et al. 2007, Emslie et al. 2009). birds forage at a maximum distance of 15‑25 km from Conservation strategies and coordinated manage‑ their breeding sites (mean value of 20 km). Bugoni and ment actions at the regional scale require knowledge Vooren (2005) showed that Common Tern on their win‑ of tern breeding distribution, the relationships among tering ground in southern Brazil fed over water 10‑20 m populations, and of factors affecting them (Yorio and in depth, within 8 km of the coast. Therefore, we con‑ Efe 2008). This paper evaluates the conservation status sider the area of occupancy of the Cabot’s Tern in Brazil of T. acuflavidus in Brazil and discusses its current threat to be a circular area around the breeding sites 20 km in level. radius (e.g., area of 1,256 km2) and the feeding area a dis‑ tance of 8 km from the shore. Following the recommendations of Gärdenfors et al. METHODS (2001) for the evaluation Red List Criteria at the national and regional level, we analyzed: (1) contact of the national Our evaluation of the conservation status of the population with the neighboring populations, (2) disper‑ Cabot’s Tern follows the criteria and categories estab‑ sal capacity of the species, (3) abundance of and threats to lished by the IUCN (IUCN 2008). The IUCN catego‑ the species in the neighboring populations, (4) differenc‑ ries and criteria are defined for the global evaluation of a es in local adaptation between the national and neighbor‑ taxon. However, these definitions can also be appropriate ing populations, (5) the environmental conditions within for regional use (Gärdenfors et al. 2001). In this paper we each country or region and (6) environmental conditions review information on the conservation status, including necessary for the immigration and recolonization of the taxonomic level, main threats, area and extent of occur‑ species, within 100 years, should it be extirpated at the rence, and current population size in Brazil and follow country level. Gärdenfors et al. (2001) for the evaluation at the national and regional level. Likewise the Brazilian Ornithological Committee RESUlts AND DISCUSSION (CBRO 2010), we treat T. acuflavidus as a valid specie, following Efe et al. (2009), who showed, using a molecu‑ Using the above definition, the Cabot’s Tern is dis‑ lar phylogenetic analysis, that European and American tributed all along the Brazilian coast (~ 6.100 km). We T. “sandvicensis” are distinct species and proposed the estimate the extent of occurrence as the area contained treatment of the American acuflavidus/eurygnathus com‑ within the imaginary boundary of 6,100 km long and plex as Cabot’s Tern, Thalasseus acuflavidus. 25 km wide or approximately 125,500 km2. However, According to Birdlife International (2001), the ex‑ this area is not completely occupied by the Cabot’s Tern. tent of occurrence is defined as the area contained within A review of the historical nesting records indicates that the shortest continuous imaginary boundary which can Cabot’s Terns have bred in at least 16 different breeding be drawn to encompass all the known, inferred or pro‑ sites in Brazil (Table 1) and have been reported in four jected sites of present occurrence of a taxon, excluding foraging areas (Figure 1) during the non‑breeding period.
Load more

Recommended publications
  • REGUA Bird List July 2020.Xlsx
    Birds of REGUA/Aves da REGUA Updated July 2020. The taxonomy and nomenclature follows the Comitê Brasileiro de Registros Ornitológicos (CBRO), Annotated checklist of the birds of Brazil by the Brazilian Ornithological Records Committee, updated June 2015 - based on the checklist of the South American Classification Committee (SACC). Atualizado julho de 2020. A taxonomia e nomenclatura seguem o Comitê Brasileiro de Registros Ornitológicos (CBRO), Lista anotada das aves do Brasil pelo Comitê Brasileiro de Registros Ornitológicos, atualizada em junho de 2015 - fundamentada na lista do Comitê de Classificação da América do Sul (SACC).
    [Show full text]
  • Successful Conservation Measures and New Breeding Records for Damara Terns Sterna Balaenarum in Namibia
    Braby et al.: Breeding of Damara Terns Sterna balaenarum in Namibia 81 SUCCESSFUL CONSERVATION MEASURES AND NEW BREEDING RECORDS FOR DAMARA TERNS STERNA BALAENARUM IN NAMIBIA R.J. BRABY1, ANAT SHAPIRA2 & R.E. SIMMONS3 1Resource Management, Ministry of Environment & Tourism, P/Bag 5018, Swakopmund, Namibia 2Ben Gurion University, Beer-Sheva, Israel 3National Biodiversity Programme, Directorate of Environmental Affairs, Ministry of Environment & Tourism, P/Bag 13306, Windhoek, Namibia ([email protected]) Received 19 February 2001, accepted 23 July 2001 SUMMARY BRABY, R.J., SHAPIRA, A. & SIMMONS, R.E. 2001. Successful conservation measures and new breeding records for Damara Terns Sterna balaenarum in Namibia. Marine Ornithology 28: 81–84. Damara Terns Sterna balaenarum nest at high densities on the central Namibian coast and overlap in both space and time with vacationing fishermen and quad bikers. This results in high non-hatching rates of up to 50% and reduced breeding success for the densest known colony of terns. In November 2000, information boards and a barrier preventing off-road vehicles from entering a Damara Tern breeding site near Swakopmund were erected. Comparisons between nesting density, hatching success and vehicles passes before and after these measures showed that nesting density increased slightly (12 to 15 nests/km2/month), hatching success increased from 56% to 80% and vehicle passes dropped from 870 per month to zero. The overall result was a doubling of the number of chicks hatched in the study area. The success of this approach augurs well for similar approaches to other conflicts between semi-colonial coastal-breeding birds and visitors. New breeding records from southern Namibia and a nesting record from 11.5 km inland are also detailed in our attempt to elucidate the ecology and conser- vation of this rare seabird.
    [Show full text]
  • Sandwich Terns to Isla Rasa, Gulf of California, Mexico, with Our Observations of Single Individuals in 1986 and Again in 2008
    NOTES SANDWICH TERNS ON ISLA RASA, GULF OF CALIFORNIA, MEXICO ENRIQUETA VELARDE, Instituto de Ciencias Marinas y Pesquerías, Universidad Veracruzana, Hidalgo 617, Col. Río Jamapa, Boca del Río, Veracruz, México, C.P. 94290; [email protected] MARISOL TORDESILLAS, Álvaro Obregón 549, Col. Poblado Alfredo V. Bonfi l, Cancún, Quintana Roo, México, C.P. 77560; [email protected] In North America the Sandwich Tern (Thalasseus sandvicensis) breeds locally along marine coasts and offshore islands primarily of the southeastern United States and Caribbean (AOU 1998). In these areas it commonly nests in dense colonies of the Royal Tern (T. maximus) and Laughing Gull (Leucophaeus atricilla; Shealer 1999). It winters along the coasts of the Atlantic Ocean and Gulf of Mexico from Florida to the West Indies, more rarely as far south as southern Brazil and Uruguay. It also winters on the Pacifi c coast, mainly from Oaxaca, Mexico, south to Panama (Howell and Webb 1995), occasionally to Colombia, Ecuador, and Peru (AOU 1998). As there are no breeding colonies on the Pacifi c coast, all birds wintering there are believed to represent migrants from Atlantic and Caribbean colonies (Collins 1997, Hilty and Brown 1986, Ridgely 1981, Ridgely and Greenfi eld 2001). Sandwich Terns have occasionally wandered as far north as eastern Canada (New Brunswick, Nova Scotia, and Newfoundland) and inland to Minnesota, Michigan, and Illinois (AOU 1998, Clapp et al. 1983). In the Pacifi c vagrants are known from California and the Hawaiian Islands (Hamilton et al. 2007, AOU 1998). Here we report vagrancy of Sandwich Terns to Isla Rasa, Gulf of California, Mexico, with our observations of single individuals in 1986 and again in 2008.
    [Show full text]
  • Patterns of Prey Provisioning in Relation to Chick Age in the South American Tern (Sterna Hirundinacea)
    ORNITOLOGIA NEOTROPICAL 22: 361–368, 2011 © The Neotropical Ornithological Society PATTERNS OF PREY PROVISIONING IN RELATION TO CHICK AGE IN THE SOUTH AMERICAN TERN (STERNA HIRUNDINACEA) Alejandro A. Fernández Ajó1, Alejandro Gatto2, & Pablo Yorio2,3 1Univ. Nacional de la Patagonia “San Juan Bosco”, Puerto Madryn, Chubut, Argentina. 2Centro Nacional Patagónico (CONICET), Boulevard Brown 2915, U9120ACV Puerto Madryn, Chubut, Argentina. E-mail: [email protected] 3Wildlife Conservation Society, Amenabar 1595 – Piso 2 – Oficina 19, C1426AKC Ciudad de Buenos Aires, Argentina. Resumen. – Patrones de abastecimiento de presas en relación con la edad de pollos en el Gavi- otín Sudamericano (Sterna hirundinacea). – El estudio de los patrones temporales en la composición de la dieta es clave para interpretar ciertos aspectos de la ecología e historia de vida de las aves mari- nas. La variación en la composición y tamaño de presas en relación con la edad de los pollos fue evalu- ado en una colonia de Gaviotín Sudamericano (Sterna hirundinacea) en Punta Loma, Argentina, durante la temporada reproductiva del 2006. La dieta de los pollos de Gaviotín Sudamericano incluyó al menos 12 especies de presa. El pescado, mayormente anchoíta (Engraulis anchoita) y pejerrey (Odontesthes argentinensis) fue la principal presa entregada (91%) a los pollos. La proporción relativa de tipos de presa varió entre las clases de edad de los pollos, y la proporción de Anchoíta en la dieta se incrementó con la edad de los mismos, alcanzando el 58% en las crías mayores. El tamaño de las presas aumentó con la edad de los pollos. Las presas robadas por otros gaviotines adultos fueron significativamente más grandes que aquellas consumidas por los pollos.
    [Show full text]
  • Nest Spacing in Elegant Terns: Hexagonal Packing Revisited Charles T
    WESTERN BIRDS Volume 39, Number 2, 2008 NEST SPACING IN ELEGANT TERNS: HEXAGONAL PACKING REVISITED CHARLES T. COLLINS and MICHAEL D. TAYLOR, Department of Biological Sci- ences, California State University, Long Beach, California 90840 (current address of Taylor: Santiago Canyon College, 8045 East Chapman Ave., Orange, California 92869); [email protected] ABSTRACT: Within an important breeding colony in southern California, Elegant Terns (Thalasseus elegans) nest in one to several tightly packed clusters. Inter-nest distances within these clusters average 31.2 cm. This value is less than that reported for the larger-bodied Royal Tern (T. maximus) and Great Crested Tern (T. bergii). For Elegant Terns, the modal number of adjacent nests was six (range 5–7). This type of nest arrangement has been previously described as hexagonal packing and now appears to be typical of all Thalasseus terns for which data are available. Many seabirds nest in large, often traditional, colonies (Coulson 2002, Schreiber and Burger 2002). The ontogeny of annual colony formation has been reviewed by Kharitonov and Siegel-Causey (1988), and the evolution- ary processes which have led to coloniality have been considered by a number of authors (Lack 1968, Fischer and Lockley 1974, Wittenburger and Hunt 1985, Siegel-Causey and Kharitonov 1990, Coulson 2002). Seabird colonies may be rather loosely organized aggregations of breeding pairs of one to several species at a single site. At the other extreme, they may be dense, tightly packed, largely monospecific clusters where distances between nests are minimal. A graphic example of the latter is the dense clustering of nests recorded for several species of crested terns (Buckley and Buckley 1972, 2002, Hulsman 1977, Veen 1977, Symens and Evans 1993, Burness et al.
    [Show full text]
  • Environmental Contaminants in Arctic Tern Eggs from Petit Manan Island
    U.S. FISH AND WILDLIFE SERVICE MAINE FIELD OFFICE SPECIAL PROJECT REPORT: FY96-MEFO-6-EC ENVIRONMENTAL CONTAMINANTS IN ARCTIC TERN EGGS FROM PETIT MANAN ISLAND Petit Manan National Wildlife Refuge Milbridge, Maine May 2001 Mission Statement U.S. Fish and Wildlife Service “Our mission is working with others to conserve, protect, and enhance the nation’s fish and wildlife and their habitats for the continuing benefit of the American people.” Suggested citation: Mierzykowski S.E., J.L. Megyesi and K.C. Carr. 2001. Environmental contaminants in Arctic tern eggs from Petit Manan Island. USFWS. Spec. Proj. Rep. FY96-MEFO-6-EC. Maine Field Office. Old Town, ME. 40 pp. Report reformatted 1/2009 U.S. FISH AND WILDLIFE SERVICE MAINE FIELD OFFICE SPECIAL PROJECT REPORT: FY96-MEFO-6-EC ENVIRONMENTAL CONTAMINANTS IN ARCTIC TERN EGGS FROM PETIT MANAN ISLAND Petit Manan National Wildlife Refuge Milbridge, Maine Prepared by: Steven E. Mierzykowski1, Jennifer L. Megyesi2, and Kenneth C. Carr3 1 U.S. Fish and Wildlife Service Maine Field Office 1033 South Main Street Old Town, Maine 04468 2 U.S. Fish and Wildlife Service Petit Manan National Wildlife Refuge Main Street, P.O. Box 279 Milbridge, Maine 04658 3 U.S. Fish and Wildlife Service New England Field Office 70 Commercial Street, Suite 300 Concord, New Hampshire 03301-5087 May 2001 EXECUTIVE SUMMARY Petit Manan Island is a 3.5-hectare (~ 9 acre) island that lies approximately 4-kilometers (2.5-miles) from the coastline of Petit Manan Point, Steuben, Washington County, Maine. It is one of nearly 40 coastal islands within the Petit Manan National Wildlife Refuge.
    [Show full text]
  • INFORME July 2014
    Chapter 3: Baseline EIA Espejo de Tarapacá Region of Tarapacá, Chile INFORME July 2014 Prepared by: Environmental management Consultants S. A Father Mariano 103 Of. 307 7500499, Providencia, Chile Phone: + 56 2 719 5600 Fax: + 56 2 235 1100 www.gac.cl Capítulo 3: Línea de Base EIA Proyecto Espejo de Tarapacá Index 3. BASELINE ......................................................................................................................................... 3-1 3.1. Introduction ................................................................................................................................. 3-1 3.2. Physical environment ................................................................................................................. 3-2 3.2.1 Atmosphere ........................................................................................................................ 3-2 3.2.1.1 Meteorology .................................................................................................................... 3-2 3.2.1.2 Air quality ........................................................................................................................ 3-5 3.2.1.3 Noise and vibration ......................................................................................................... 3-9 3.2.1.4 Electromagnetic fields .................................................................................................. 3-29 3.2.1.5 Luminosity ....................................................................................................................
    [Show full text]
  • Annual Survival and Breeding Dispersal of a Seabird Adapted to a Stable Environment: Implications for Conservation
    J Ornithol DOI 10.1007/s10336-011-0798-7 ORIGINAL ARTICLE Annual survival and breeding dispersal of a seabird adapted to a stable environment: implications for conservation Justine Braby • Sigrid J. Braby • Rodney J. Braby • Res Altwegg Received: 9 December 2010 / Revised: 6 December 2011 / Accepted: 9 December 2011 Ó Dt. Ornithologen-Gesellschaft e.V. 2012 Abstract Understanding the spatial dynamics of popu- based on AICc favoured a model that suggests local annual lations is essential for conservation of species at the survival of Damara Terns for the dataset was 0.88 (95% CI, landscape level. Species that have adapted to stable 0.73–0.96) and the annual dispersal probability was 0.06 environments may not move from their breeding areas even (0.03–0.12). High survival and low dispersal probabilities if these have become sub-optimal due to anthropogenic are consistent with other seabirds adapted to stable envi- disturbances. Instead, they may breed unsuccessfully or ronments. These estimates contribute to the first baseline choose not to breed at all. Damara Terns Sternula balae- demographic information for the Damara Tern. Low dis- narum feed off the highly productive Benguela Upwelling persal probabilities indicate that current protection of System. They breed on the coastal desert mainland of breeding sites is an important management approach for Namibia where development and off-road driving is protecting the species. threatening breeding areas. We report annual survival and breeding dispersal probabilities of 214 breeding adult Keywords Breeding dispersal Á Fidelity Á Survival Á Damara Terns through capture–mark–recapture at two col- Conservation Á Sternula balaenarum Á Damara Tern onies for 9 years (2001–2009) in central Namibia.
    [Show full text]
  • 90 FIRST RECORD of ELEGANT TERN in FLORIDA 3803 Cloverhill Court, Brandon, FL 33511 E-Mail:[email protected] on 3 October 1999
    90 Florida Field Naturalist 29(3):90-94, 2001. FIRST RECORD OF ELEGANT TERN IN FLORIDA ED KWATER 3803 Cloverhill Court, Brandon, FL 33511 E-mail:[email protected] On 3 October 1999, Greg Butcher and I led a field trip to Honeymoon Island State Recreational Area, Pinellas County, Florida, as part of the second annual Florida Bird- ing Festival. At 09:15 we located a large flock of terns (Sterna spp.) at the “Pet Beach,” a long, sandy beach at the southwestern corner of the island. There were at least 4,000 Common Terns (S. hirundo), 500 Forster’s Terns (S. forsteri), and 400 Sandwich Terns (S. sandvicensis), but very few Royal Terns (S. maxima). During our scrutiny of the tern flocks an Elegant Tern (S. elegans) landed directly in front of us. This constitutes the first record of this Pacific Coast species for Florida. The Elegant Tern was present for 45 minutes, allowing approach to within 40 m. De- tailed field notes and photographs were taken. The bird was seen almost daily at the Pet Beach until its final appearance in Pelican Cove at the north end of the island on 22 No- vember 1999 (Pranty 2000). A number of photographs were taken of the bird during its stay and three of these, by Lee Snyder, are reproduced here (Figs. 1-3). Identification of the Elegant Tern was relatively straightforward, and was based on the following characters. In size the bird was noticeably smaller than a Royal Tern but slightly larger than a Sandwich Tern in direct comparison with both species.
    [Show full text]
  • Elegant Terns Breeding in Orange County, California
    SCIENCE expansionof the Elegant Tern's breedingrange might be expected (Garrett and Dunn 1981:192). We report herethe establishmentof a ELEGANTTERNS breedingpopulation in Orange County,California, approximately 73 kilometersnorthwest of theonly BREEDINGINORANGE otherUnited States breeding colony locatedin SanDiego Bay. In the latespring and summer of •986, a flockof 200-250__Elegant COUNTY,CALIFORNIA •ernswas present atthe Bolsa Chica EcologicalReserve, Orange County. The 530-acre reserve is a saltmarsh environment managed by the CaliforniaDepartment of Fishand Game.During June the ternsoften spenttime on the groundin dense aggregationson both North and byCharles T. Collins, South Islands, two sand-fill islands thatwere created in 1978as nesting William A. Schew,and EstherBurkett sitesfor the endangeredCalifornia Least Tern (Sterna antillarum THEELEGANT TERN (STERNA ELEGANS) Pacific coast of Baja California browre).The two islandsare located occurscommonly to abundantlyon (Bancroft 1927), have not been in a part of the reservewhich has a the southern and central California activebreeding sites in recentyears mutedtidal regime. These aggrega- coast, particularly from July to (Wilbur 1987, Schaffner1986). tions closely resemblednesting October,when it rangesnorth as far assemblages,and ground courtship asMonterey Bay, San Francisco Bay, displayswere frequently observed and Point Reyes (Small 1974, throughoutthis period. Although Harrison 1983, A.O.U. 1983, the terns made numerous shallow Shufordet al. 1989). It alsooccurs, scrapesin thesand, we could find no lesscommonly, still farther north in eggsor other .evidenceof actual Oregon(Fix andHeinl 1990), and breeding.InlnI•8•, weobserved simi- rarelyin Washingtonand British lar aggregations,particularly on Columbia (Godfrey 1986). The North Island,and t•hi•y_-one p•trs ElegantTern's winter range extends laid eggsin a singlecluster on the southalong the Pacific coast as far as edgeof, and slightly intermixed with, Ecuador,Peru, and Chile (Harrison a groupof nestingCaspian Terns (S.
    [Show full text]
  • Short Communication Cape Anchovy in Swift Tern Diets and Fishery Landings in the Benguela Upwelling Region
    S. Afr. J. Wildl. Res. 1987,17(4) Short Communication introduction of small-mesh nets, Cape anchovy has become the most important component of the purse- seine catches in Satdanha Bay (Butterworth 1983). Schaffner (1986) has demonstrated extensive overlap in the size and age compositions of northern anchovy E. mordax fed to elegant tern Sterna elegans chicks and Cape anchovy in swift tern diets and samples from the pelagic fishery off the coast of fishery landings in the Benguela California. We examine here the degree of overlap upwelling region between the diet of the swift tern and the purse-seine catches in Saldanha Bay. We determined the relative abundances and sizes of Claudia B. Walter*, D. C. Duffy**, J. Cooper Cape anchovy in swift tern diets and fishery landings, at and W. Suter*** weeks, months and years, in relation to the 'fishing Percy F tzPatrlc6 nst~tLteof Ahcan Ornltno ogy, Unlversfty of behaviour' of both swift terns and the fishery. We Cape Town, Rondeoosch, 7700 Rep~bllcof South Afr~ca confined our investigation to the Cape anchovy because it is the main target species of both the fishery and swift Received 3 April 1987; accepted 22 July 1987 terns (Walter etal. 1987). The same data set collected by Walter et a/. (1987) from nestling swift terns on islands in Swift or crested terns Sterna bergii capture smaller Cape Saldanha Bay (33"03'S 1 17"56'E), south-western anchovy Engrauiis japonicus closer to the mainland than do Cape, South Africa, was used for this study. We boats of a commercial purse-seine fishery in the Saldanha compared size of fish (fork length) and relative Bay area of the Benguela upwelling region off South Africa.
    [Show full text]
  • Monitoring of Damara Terns at Mile 4 Salt Works, Summer 2014/2015
    Social and Environmental Impact Assessment for Rössing Uranium's Proposed Desalination Plant near Swakopmund BASELINE REPORT Bird assessment Additional study: Monitoring of Damara Terns at Mile 4 Salt Works, summer 2014/2015 Prepared by: Prepared for: African Conservation Services cc SLR Environmental Consulting (Namibia) (Pty) Ltd June 2015 1. Introduction The Damara Tern Sternula balaenarum is Near Threatened in Namibia (Simmons, Brown & Kemper in press 2015) and also globally Near Threatened (IUCN 2015). The species is little known and faces several conservation issues (Braby 2011). A recent review of all accessible information of breeding populations in Angola, Namibia and South Africa identified 70 breeding colonies globally for the species (Braby 2011). Most of the population (98%) breeds in Namibia, where overall breeding success (measured as the probability of fledging one chick per pair, per season) is estimated at only 0.36. A bird assessment study was completed for the Social and Environmental Impact Assessment for Rössing Uranium's Proposed Desalination Plant near Swakopmund, Namibia in August 2014. Although a literature search and local sources indicated that Damara Terns have been recorded and have bred regularly at this site (Braby 2011; Boorman M pers. comm.), more detailed and updated information was required on the present distribution, numbers and breeding success at this site, which according to the bird assessment study should be categorised as sensitive, together with a buffer zone. This study was therefore initiated to investigate and update the above aspects for the summer 2014- 2015 season. 2. Methods Figure 1. The site used historically for breeding by Damara Terns (red marker) and the present main study site at Mile 4 Salt Works; a roosting area was subsequently confirmed and investigated (yellow marker).
    [Show full text]