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Variación Poblacional De Tres Especies De Piqueros (Suliformes: Sulidae) En Isla Gorgona, Pacífico Colombiano, Según La Temperatura Del Mar

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Variación Poblacional De Tres Especies De Piqueros (Suliformes: Sulidae) En Isla Gorgona, Pacífico Colombiano, Según La Temperatura Del Mar ISSN Impreso: 0034-7744 ISSN electrónico: 2215-2075 Variación poblacional de tres especies de piqueros (Suliformes: Sulidae) en isla Gorgona, Pacífico colombiano, según la temperatura del mar Alejandro Perlaza-Gamboa1*, Alan Giraldo1, Luis Fernando Payán2 & Felipe A. Estela3 1. Grupo Investigación Ecología Animal, Departamento de Biología, Facultad de Ciencias Naturales y Exactas, Universidad del Valle, Calle 13 Nº 100-00, Cali, Colombia; [email protected], [email protected] 2. Estación Científica Henry von Prahl, Parque Nacional Natural Gorgona, Parques Nacionales Naturales de Colombia, Calle 29 Norte Nº 6N- 43, Cali, Colombia; [email protected] 3. Departamento de Ciencias Naturales y Matemáticas, Pontificia Universidad Javeriana Cali, Calle 18 Nº 118-250, Cali, Colombia; [email protected] * Correspondencia Recibido 08-VII-2019. Corregido 06-II-2020. Aceptado 30-III-2020. ABSTRACT. Population variation of three boobies species (Suliformes:Sulidae) on Gorgona island, Colombian Pacific, linked to sea temperature. Introduction: Pelagic environment temperature variations may influence population variation of top predators, such as seabirds. Objective: A population response assess- ment of three species of boobies, in Gorgona Island (Colombian Pacific), in relation to sea surface temperature (SST) variations. Methods: We assessed the relationship between SST variability and monthly abundance of Brown Boobies, Blue-footed Boobies and Peruvian Boobies, in the influence area of Gorgona, the San José region (Peruvian coast) and the Niño 1+2 region. Results: The largest positive correlation was observed between Blue-footed Boobies and Peruvian Boobies with SST at the Niño 1+2 region, with a lag of four and five months, respectively. This delay may correspond to the migration duration from the Peruvian coast to Gorgona. In con- trast, Brown Booby abundance decreased as monthly SST in Gorgona increased. Conclusions: These trends may be related to less productivity and prey availability associated with warmer sea surface temperatures. We suggest that SST influences the abundance trend of these three species, and their continuous monitoring will improve our knowledge on the natural variation of these populations. Key words: distribution; trophic structure; foraging; time delay; climate variability. Perlaza-Gamboa, A., Giraldo, A., Payán, L.F., & Estela, F.A. (2020).Variación poblacional de tres especies de piqueros (Suliformes: Sulidae) en isla Gorgona, Pacífico colombiano, según la temperatura del mar. Revista de Biología Tropical, 68(2), 704-713. Las variaciones climáticas tienen efectos influyendo, por ejemplo, en la distribución importantes y diversos sobre los ecosistemas de especies, tamaño poblacional, superviven- marinos y terrestres (Stenseth et al., 2002; cia de adultos y la proporción de indivi- Champagnon, Lebreton, Drummond, & Ander- duos reproductivos (Jenouvrier, Barbraud, & son, 2018). Este es el caso de la temperatura Weimerskirch, 2005; Frederiksen, Edwardst, del ambiente pelágico, que ha sido utilizada Richardson, Halliday, & Wanless, 2006). Por para comprender algunos procesos biológicos, esto la variación en la temperatura del mar debido a que su variación puede influir en podría estar asociada con la abundancia de los la estructura trófica, al repercutir en la ener- consumidores tope del ambiente pelágico como gía producida por los productores primarios, las aves marinas. 704 Rev. Biol. Trop. (Int. J. Trop. Biol.) Vol. 68(2): 704-713, June 2020 El efecto de la variación en las condi- (Cadena-López & Naranjo, 2010; Payan, Orte- ciones de la temperatura del mar sobre la ga, & Cuéllar, 2017). dinámica de las poblaciones de aves marinas La isla Gorgona fue declarada en 2005 ha sido reportado frecuentemente en la litera- como Área de Importancia para la Conservación tura científica (Barbraud et al., 2011; Grémillet de las Aves (AICA Co120) (Franco, Devenish, & Boulinier, 2009; Sydeman, Thompson, & Barrero, & Romero, 2009; Zamudio, 2014). Kitaysky, 2012). Por ejemplo, bajo condiciones Además, forma parte del Complejo Marino- El Niño, se ha registrado una disminución en Costero Iscuandé-Sanquianga-Gorgona, que es el éxito reproductivo, aumento de mortalidad, el área más importante de Colombia para aves migraciones en busca de alimento y altera- playeras y marinas tanto migratorias como ciones en la diversidad de dieta y régimen locales (Ruiz-Guerra, 2011). Sin embargo, esta reproductivo de algunas poblaciones de aves región se encuentra recurrentemente bajo el marinas en el Pacífico Oriental Tropical (Wang efecto de variaciones oceanográficas regionales & Fiedler, 2006; Ancona, Calixto-Albarrán, como El Niño, que puede ocasionar alteraciones & Drummond, 2012; Quillfeldt & Masello, en la estructura trófica del ecosistema pelágico 2013). Estos eventos podrían relacionarse con circundante (Crick, 2004; Santisteban, Benk- man, Fetz, & Smith, 2012), generando proba- el aumento en la temperatura del mar, y conse- blemente efectos indirectos sobre el número de cuentemente con el reclutamiento de algunos individuos o éxito reproductivo de la colonia peces, como Engraulis ringens (Jenyns, 1842) reproductiva de S. leucogaster etesiaca, subes- (Barber & Chávez, 1986; Sánchez, Calie- pecie endémica y vulnerable del Pacífico tropi- nes, & Zuta, 2000; Wang & Fiedler, 2006; cal húmedo americano (Ospina-Álvarez, 2004; Bakun et al., 2015), la principal presa de Renjifo, Amaya-Villarreal, Burbano-Girón, & Sula nebouxii (Milne-Edwards, 1882) y Sula Velásquez-Tibatá, 2016). En este contexto, esta variegata (von Tschudi, 1843) en la costa investigación pretende describir la dinámica peruana (Zavalaga, Benvenuti, Dall’antonia, & temporal de la abundancia de las poblaciones Emslie, 2008; Zavalaga, Halls, Mori, Taylor, & de S. leucogaster, S nebouxii y S. variegata Dell’omo, 2010). en isla Gorgona y evaluar su posible relación Isla Gorgona es una localidad importante con la variabilidad temporal de la temperatura para las aves marinas del Pacifico colombiano, superficial del mar (TSM), en la isla, la región por tener colonias permanentes de anidación y Niño 1+2 y San José en la costa peruana. descanso de cuatro especies (Fregata magni- ficens Mathews, 1914, Pelecanus occidentalis Linnaeus, 1766, Sula leucogaster etesiaca Tha- MATERIALES Y MÉTODOS yer & Bangs, 1905 y S. nebouxii), cuyas pobla- Isla Gorgona y el islote de Gorgonilla ciones han sido monitoreadas mensualmente (2˚55’45”-3˚00’55” N & 78˚09’00’’-78˚14’30” desde el año 2002. Este monitoreo representa la W) se ubican a 30 km del continente, y confor- mayor serie de abundancias mensuales de aves man el área insular emergida más extensa de la marinas registradas en Colombia. También se plataforma continental del Pacífico colombiano ha registrado la presencia de S. variegata, que con una extensión de 13.7 km2 (Giraldo, Diaz- al igual que S. nebouxii, es considerada como Granados, & Gutiérez-Landázuri, 2014). En la especie migratoria proveniente de la costa isla se encuentran playas coralinas, arenosas y peruana. Gracias a este monitoreo se tiene un rocosas, acantilados y promontorios rocosos conocimiento preliminar de la variación pobla- emergidos de origen volcánico, en los cuales cional de estas especies y que la isla puede predomina la roca desnuda, aunque puede haber actuar como refugio temporal para S. nebouxii presencia de arbustos y herbáceas. Estas forma- y S. variegata cuando la disponibilidad de ciones rocosas se encuentran representadas en alimento en las costas peruanas disminuye el sur por las rocas alrededor de Gorgonilla, y Rev. Biol. Trop. (Int. J. Trop. Biol.) Vol. 68(2): 704-713, June 2020 705 en el norte y noroccidente de Gorgona (Giraldo (Sula leucogaster y S. nebouxii), también se ha & Valencia, 2012; Zamudio, 2014). registrado la presencia de S. variegata en algu- La Zona de Convergencia Intertropi- nas temporadas. En cada registro se incluye la cal condiciona el régimen climático de la actividad de los individuos (vuelo o descanso), isla, caracterizado por una alta pluviosidad y en caso de vuelo, solo aquellos que se des- (4 164-8 176 mm anuales). La temperatura plazan en dirección contraria al recorrido de la media anual del aire es 26 °C y la humedad embarcación. El muestreo de las tres especies relativa promedio es superior al 90 %. La época de piqueros en isla Gorgona abarca un recorri- lluviosa transcurre entre mayo y octubre, y do de 24.04 km, distribuidos en tres trayectos es seguida por otra de menos precipitaciones lineales (Poblado-Horno, Horno-Palmasola y entre diciembre y febrero (Diaz, Pinzón, Perdo- Palmasola-Palmeras) y uno circular (Horno) en mo, Barrios, & López-Victoria, 2001; Blanco, la zona norte de la isla, además de un trayecto 2009). En esta localidad han sido descritos dos lineal (Poblado-Tasca) y dos circulares (Gorgo- periodos oceanográficos opuestos, uno cálido nilla y El Viudo) en la zona sur (Payan, 2016). de baja salinidad superficial y con una profun- Los datos fueron estandarizados dividien- didad promedio de la termoclina (profundidad do la abundancia (sumatoria de registros en los de la isoterma de 22 °C) de 47 m, entre mayo dos días) por la distancia recorrida, ya que no y diciembre, y uno frío de alta salinidad y con siempre se visitaron todos los sectores de la isla una profundidad promedio de la termoclina de debido a condiciones climáticas adversas. Los 7.5 m, entre enero y abril (Giraldo, Rodríguez- datos recolectados en esfuerzos equivalentes a Rubio,
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