Hábitos alimenticios y dieta invernal de Charadrius melodus (Charadriiformes: Charadriidae) en Boca Ciega, Tamaulipas, México / Food habits and winter diet of Charadrius melodus (Charadriiformes: Charadriidae) in Boca Ciega, Tamaulipas, Mexico

The Piping Plover (Charadrius melodus) is a migratory endangered species that arrives, along with a great number of other winter migratory birds, to Boca Ciega every year. In spite of the importance of this ecosystem, these species, are threatened by the current habitat change caused by the dredging activities in the area. With the aim to generate new information about the importance of this area during winter, we studied C. melodus activities during the winter season in Laguna Madre, from December 2009 to March 2010. Our objectives were: 1) determine the importance of the area during winter, 2) describe C. melodus ethology, feeding substrate preferences and food items, 3) to analyze and describe the sympatric diversity associated with C. melodus. A total of ninety nine individuals were observed during the monitoring. The Cochran and Kendall test showed a high significance of the species with the substrate and signs tests using a binomial distribution that indicated a high preference for algal type of substrate. The highest activity recorded for this species during this winter season was feeding. The principal food items found in sediments were larvae of Diptera: Chironomidae and Ephydridae. The sympatric species of C. melodus were two families of Charadriiforms: Scolopacidae (nine species) and Charadriidae (two species). We concluded that this is an important area for feeding, protection and rest sites for this species, and its protection and management is recommended.

Charadrius melodus es una especie migratoria en peligro de extinción. Cada año, la Laguna Madre recibe aves migratorias invernales, incluyendo a la especie antes mencionada, sin embargo su estabilidad se encuentra amenazada por el cambio de hábitat ocasionado por el dragado que se está realizando en la zona. La falta de estudios sobre C. melodus durante el invierno en la Laguna Madre, motivó la realización del trabajo (diciembre 2009-marzo 2010). Los objetivos fueron: 1) determinar la importancia del área invernal, 2) describir la etología y preferencias de sustrato en la alimentación, 3) analizar ítems alimenticios potenciales y describir la diversidad simpátrica asociadas a C. melodus. Se observaron 99 individuos durante el muestreo. Las pruebas de Cochran y Kendall presentaron una alta significancia de la especie con un tipo de sustrato y las pruebas de signos utilizando una distribución binomial indicaron que existe una alta preferencia hacia un tipo de sustrato. La mayor actividad registrada durante el periodo de muestreo fue la de alimentación. Los recursos alimenticios encontrados en las muestras de sedimentos fueron larvas de Dípteros. Las especies simpátricas a C. melodus pertenecen al orden Charadriiformes con dos familias: Charadriidae nueve especies y Scolopacidae dos especies. Por la importancia de la zona, se recomienda proteger Boca Ciega, pues representa sitios de alimentación, protección y descanso para el Chorlo melódico.

Flutuacoes mensais na abundancia dos Charadriidae e Scolopacidae da praia da Ilha Comprida, Sao Paulo, Brasil / Monthly fluctuation in the abundance of Scolopacidae and Charadriidae at Ilha Comprida beach, SP, Brazil

Foram registradas as freqüências de ocorrências e as flutuações mensais das famílias Charadriidae e Scolopacidae ao longo de um transecto de 70 km de praia entre o Boqueirão Sul e o Boqueirão Norte na Ilha Comprida, estado de São Paulo, durante o período de um ano (Janeiro a dezembro de 2010). Um total de 12.153 indivíduos de aves foram contados com a maior abundância ocorreu entre outubro e abril e a mais baixa entre maio a setembro. Das 20 espécies registradas as mais abundantes foram Charadrius semipalmatus, Charadrius colaris, Vanellus chilensis e Tringa flavipes. As menos abundantes foram Tryngites subruficolis, Limosa haemastica, Tringa melanoleuca e Actitis macularia. Dezesseis espécies eram migrantes do Hemisfério Norte, duas migrantes do Hemisfério Sul, e duas residentes. Sete espécies foram registradas regularmente, cinco esporadicamente e oito foram ocasionais. Quatro espécies neárticas foram registradas em Junho e julho, provavelmente indicando a presença de indivíduos imaturos não reprodutores. O número de espécies e o número de indivíduos provavelmente flutuaram devido a migração ou movimentos entre as praias vizinhas. A praia da Ilha Comprida é um importante sítio de parada durante a migração para muitas aves de praia na costa Sul do estado de São Paulo. Por esse motivo, devem ser feitos esforços de preservação, especialmente tendo em conta a crescente pressão de desenvolvimento que ameaça essa região.

We recorded the frequency of occurrence and monthly fluctuations of Charadriidae and Scolopacidae along a 70km transect of beach between Boqueirão Sul and Boqueirão Norte north of Comprida island, São Paulo State over a 1-year period (Jan - 2010 to Dec - 2010). A total of 12.153 shorebirds were recorded. The greatest abundance occurred between October and April and the lowest occurred between May and September. The most abundant of the 20 species recorded were Charadrius semipalmatus, Charadrius colaris, Vanellus chilensis and Tringa flavipes. The least abundant were Tryngites subruficolis, Limosa haemastica, Tringa melanoleuca and Actitis macularia. Sixteen species were migrants from the Northern Hemisphere, two were migrants from the Southern Hemisphere, and two were residents. Seven species were recorded regularly, five were recorded sporadically, and eight were recorded occasionally. Four Nearctic species were recorded in June and July most likely indicating the presence of non-breeding immature. The number of species and the number of individuals probably fluctuated due to migration or movements between neighbouring beaches. The Comprida Island beach is important migration stopover and wintering sites for many shorebirds in south São Paulo and should be a focus of conservation efforts, especially given the increasing development pressure that threatens these areas.