Colony Size and Breeding Success of Red-billed Tropicbird (Phaethon aethereus) on Peña Blanca Island, Colima, México

• DOI: 10.1675/063.041.0203
• Publication Date: 2018-06-20T10:21:25Z
• Authors: Salvador Hernánde...; José Alfredo Cast...; Eric Mellink; Ana María Almague...
• Keywords: 0106 biological sciences; 14. Life underwater; 01 natural sciences

The Red-billed Tropicbird (Phaethon aetehreus) is a seabird that breeds on islands in tropical seas. Mexican government has listed it as threatened; however, the International Union for Conservation of Nature considers least concern, although recognizes its global population decreasing. Its breeding ecology was studied at Peña Blanca island, Colima, México, through monthly visits from 15 January 2008 to 10 December 2009. By extrapolating density 4,227-m2 survey area, 1,390 (2008) and 1,225 (2009) nests were estimated entire colony. In both years, earliest eggs laid September, last active recorded during 14 May–19 June, with peak activity 7 March 25 February Egg volume not different between years (57.4 cm3 ± 5.1 vs. 56.8 3.3), but nest success higher (77% 57% 2009). Highest densities occurred May, coincident regional upwelling processes (colder water high concentration nitrites, nitrates chlorophyll-a). colony largest one two colonies world.