Development of playback census methods for Storm PetrelsHydrobates pelagicus

Efficiency of playback for assessing the occurrence of five bird species in Brazilian Atlantic Forest fragments

“…The annual period of greater playback effi ciency may be linked to the reproductive biology of the species. Many authors use the reproductive season to proceed with avifaunal surveys (Dawson 1981, Mayfi eld 1981, Greenwood et al 1995, Clergeau and Burel 1997, Ratcliffe et al 1998, Drapeau et al 2000, when individuals are reinforcing their dominance or establishing new territories and consequently are more active. For this reason, they may be more prone to confront intruders, increasing the chances of response to playback.…”

“…The playback-determined occurrence of the birds (dependent variable) was related with their abundance (IPA, independent variable) in a logistic regression (Ratcliffe et al 1998). A Pearson correlation analysis (Zar 1999) was done between the response rates to the playback in each fragment and the IPA.…”

“…Although playback techniques are widely used to survey birds, few studies have been conducted with the aim of standardizing it. According to Morrell et al (1991) and Ratcliffe et al (1998), the standardization of the technique can reduce the operation cost and increase the possibility of collecting a large data set in a short time. These factors become even more important when the objective is to sample a large number of fragments.…”

Evaluation of field and analytical methods for estimating the population size of burrow-nesting seabirds from playback surveys

“…However, despite the substantial effort and expense invested in developing the playback methodology, the response rates from petrels are usually low. For example, it has been found when surveying the European Storm Petrel that only around 31% of playbacks elicited a response from nests that were known to be occupied (Ratcliffe et al 1998). Similarly, Berrow et al (2000) reported that 10% of White-chinned Petrels Procellaria aequinoctialis did not respond at all to playback surveys carried out weekly over an entire breeding season on South Georgia.…”

“…James & Robertson (1985) first advocated the use of diurnal playback of conspecific song, to locate 'apparently occupied sites' (AOS). A standardized playback method (henceforth referred to as the 'Standard Method') was developed by Ratcliffe et al (1998), Fowler (2001) and Mitchell et al (2004) and was applied during the Seabird 2000 census, to provide the first systematic population estimates of the European Storm Petrel Hydrobates pelagicus, Leach's Storm Petrel Oceanodroma leucorhoa and Manx Shearwater Puffinus puffinus for Britain and Ireland (Mitchell et al 2004). This Standard Method has subsequently been widely applied to survey burrow-nesting Procelariiformes in a variety of species and circumstances (Ambagis 2004, Rayner et al 2008, Barbraud et al 2009, Ryan & Ronconi 2011.…”