The use of the point count method for bird survey in the Atlantic forest

Abstract

The point count method has been widely used in tropical forest for sampling bird communities. In the present study, we investigated if data on richness and abundance acquired using the point count method are different comparing spring/summer (breeding season) and fall/winter (non-breeding season) in three types of the Brazilian Atlantic forest. Twelve sites were sampled seasonally during one year. In general we recorded more species and individuals during the breeding seasons. However, bird communities vary seasonally among the forest types and functional groups. We demonstrate that the use of point counts in tropical forest should be adjusted considering the differences in forest types and feeding guilds

Recommendations for monitoring avian populations with point counts: a case study in southeastern Brazil

“…Thus, neither time of day (in contrast to the northern hemisphere) nor month of the year should be given priority. Along with month, seasonality was also unimportant, as in a subtropical setting in southern Brazil (Volpato et al, 2009) and other studies in São Paulo (Antunes, 2008;Cavarzere, 2013). In contrast, rainforests may tend towards more species and individuals being counted during the wet season (Volpato et al, 2009).…”

“…In contrast, rainforests may tend towards more species and individuals being counted during the wet season (Volpato et al, 2009). Although one must consider that Volpato et al (2009) may have failed in defining two six-month seasons (see Madeira & Fernandes, 1999), which could incur in statistical error, these results do suggest that there is a certain liberty in deciding when counts should be carried out to monitor long-term trends.…”

“…These monitoring programs (except for CBC) use point counts (Blondel et al, 1970;Bibby et al, 2000) and have been refined and well-studied in temperate latitudes (Shields, 1977;Ralph & Scott, 1981;Skirvin, 1981;Verner & Ritter, 1986;Ralph et al, 1995). Recently, point counts have been used in Neotropical regions to improve the results obtained while using such method (Esquivel & Peris, 2008;Volpato et al, 2009). However, few studies have addressed the issue that point counts, being stationary for limited time, tend to miss non-vocal, rare or canopy species, or provide biased estimates of abundance and can be influenced by environmental features (Verner, 1985;Terborgh et al, 1990).…”

Does the reproductive season account for more records of birds in a marked seasonal climate landscape in the state of São Paulo, Brazil?

“…Neotropical habitats, however, have not been the scope of these evaluations (e.g., Hutto et al, 1986;Blake, 1992;Lynch, 1995;Esquivel & Peris, 2008). It has been proposed that counts of birds can vary seasonally according to forest type and functional groups, whereas a trend in decreasing detections can be observed throughout the day (Herzog et al, 2003;Blendinger, 2005;Isacch et al, 2006;Brandolin et al, 2007;Antunes, 2008;Volpato et al, 2009). Although there is increasing literature on variations of bird detections, a clear consensus on when and how to survey Neotropical birds is still far from being achieved.…”

“…This typical approach has been poorly demonstrated in Neotropical habitats (Blendinger, 2005;Brandolin et al, 2007;Antunes, 2008;Volpato et al, 2009); in the Cerrado, for example, a tropical savanna with seasonal rainfall, only hourly counts of birds have been examined (Cavarzere & Moraes, 2010). Determining successful protocols for surveying birds is a priority as many studies use counting techniques with no a priori tests regarding method efficiency or habitat type.…”