Breeding biology and population increase of the Endangered Bermuda Petrel Pterodroma cahow

Abstract

SummaryThe Bermuda Petrel Pterodroma cahow was thought to have become extinct early in the 17 th century due to a combination of hunting by human colonists and predation by introduced rats, cats, dogs and pigs. However, single individuals were found on four occasions during the first half of the 20 th century, and in 1951 a small population was discovered breeding on several rocky islets in north-east Bermuda. Recovery actions began in 1962 when the population numbered just 18 pairs, dispersed among five small islets. Although rats extirpated one of these five colonies in 1967, the population has grown steadily to 56 breeding pairs in 2000. We investigated the breeding phenology, productivity and population size of the Bermuda Petrel between

Are artificial burrows efficient conservation tools for seabirds? A case study of two sympatric shearwaters on neighbouring islands and guidelines for improvement

“…Occupancy rates of artificial burrows generally increase over time and high rates (N20%) have been reported for many seabird species either from the first breeding season after artificial burrow installation (Wilson, 1986(Wilson, , 1993Bolton, 1995;Ramos et al, 1997;Lalas et al, 1999;Sullivan et al, 2000;Bried et al, 2009), or from 2 to 4 breeding seasons after installation, as occupancy rates can take years to build up (Priddel and Carlile, 1995;Gaston, 1996;De León and Mínguez, 2003;Bolton et al, 2004;Libois et al, 2012). Several studies have thus shown an increase in the breeding population following the provision of artificial burrows (De León and Mínguez, 2003;Bried et al, 2009;Libois et al, 2012;Madeiros et al, 2012). However, artificial burrow occupancy rates have remained low (b6%) in some petrel species, even after 3 or more years of artificial burrow provision (Podolsky and Kress, 1989;Cruz and Cruz, 1996;Miskelly and Taylor, 2004).…”

“…They can be used to supplement available suitable breeding habitat (Priddel and Carlile, 1995;Lalas et al, 1999;De León and Mínguez, 2003;Bried et al, 2009;Madeiros et al, 2012;Sherley et al, 2012), increase breeding success and adult survival (Byrd et al, 1983;Priddel and Carlile, 1995;De León and Mínguez, 2003;Bolton et al, 2004;Libois et al, 2012;Sherley et al, 2012), decrease inter-specific competition for nesting habitat (Wingate, 1977;Ramos et al, 1997;Sullivan and Wilson, 2001;Bolton et al, 2004;Gummer et al, 2015), establish new breeding sites when coupled with chick translocation and/or vocal attraction (Podolsky and Kress, 1989;Bell et al, 2005;Miskelly and Taylor, 2004;Priddel et al, 2006;Miskelly et al, 2009;Carlile et al, 2012;Gummer et al, 2015), and make the study of breeding biology and habits easier and less disturbing (Wilson, 1986(Wilson, , 1993Bolton, 1995;Gaston, 1996;Gummer et al, 2015). Occupancy rates of artificial burrows generally increase over time and high rates (N20%) have been reported for many seabird species either from the first breeding season after artificial burrow installation (Wilson, 1986(Wilson, , 1993Bolton, 1995;Ramos et al, 1997;Lalas et al, 1999;Sullivan et al, 2000;Bried et al, 2009), or from 2 to 4 breeding seasons after installation, as occupancy rates can take years to build up …”

Using miniaturized radiotelemetry to discover the breeding grounds of the endangered New Zealand Storm Petrel Fregetta maoriana

“…, Madeiros et al . ). Impacts of introduced predators have been particularly acute for petrels and shearwaters (Procellariidae) and storm petrels (Hydrobatidae).…”

“…Cahow Pterodroma cahow (Madeiros et al . ), Gould's Petrel Pterodorma leucoptera leucoptera (Priddel & Carlile ) and Chatham Island Taiko Pterodroma magenta (Imber et al . , Taylor et al .…”

Managing the Effects of Introduced Predators on Hawaiian Endangered Seabirds

“…Examples of the effect of rats include direct depredation of seabird eggs (Jones et al 2005), chicks (Thibault 1995, Igual et al 2006, Caut et al 2008), and in smaller species, even adults (Moors and Atkinson 1984, Bertram 1995, Martin et al 2000). Lastly feral pigs have been identified as the primary predator responsible for the near extinction of multiple seabird species including the Bermuda cahow ( Pterodroma cahow ; Carlile et al 2012, Madeiros et al 2012) and the rapid decline of others (Harris 1970, Cuthbert et al 2001, Cuthbert and Davis 2002).…”