O uso de praias arenosas com diferentes concentrações humanas por espécies de aves limícolas (Charadriidae e Scolopacidae) neárticas no sudeste do Brasil

Abstract

were recorded. Only Red Knot were restricted to the low human concentration area. The average number of humans and domestic dogs differed between areas with different levels of disturbance, whereas no difference on the average number of birds was detected. There were no correlation between number of humans and birds, nor between domestic dogs and birds. Additionally, the frequency of flocks and average number of birds per flock did not vary significantly between the areas. These results highlighted the sensibility of Red Knot in the high human concentration area as well as the need to find out, in future investigations, the maximum concentration of people and domestic dogs that birds can tolerate in human occupied areas to employ conservation efforts in preserving Nearctic shorebirds. Keywords: human disturbance, sandy beaches, Scolopacidae, shorebirds. CESTARI, C. O uso de praias arenosas com diferentes concentrações humanas por espécies de aves limícolas(Charadriidae e Scolopacidae) neárticas no sudeste do Brasil. Biota Neotrop. 8(4): http://www.biotaneotropica. org.br/v8n4/pt/abstract?article+bn01308042008Resumo: As aves migratórias podem reconhecer humanos e animais domésticos como possíveis predadores, alterando seus padrões de abundância e comportamento de formação de bandos. O objetivo do presente estudo foi comparar a abundância de aves migratórias neárticas, a freqüência de bandos e o número médio de aves por bando em áreas com alta e baixa concentração humana em uma região costeira de praia arenosa no sudeste do Brasil. As aves, pessoas e cães foram contados mensalmente entre novembro de 2006 a abril de 2007. Foram registradas seis espécies de aves (Arenaria interpres, Calidris alba, Calidris canutus, Calidris pusilla, Charadrius semipalmatus, Pluvialis dominica) nas duas áreas, no entanto somente C. canutus foi registrado exclusivamente na área com baixa concentração humana. Houve diferença significativa no número médio de pessoas e cães entre as áreas, mas não no número médio de aves. Não houve correlação entre o número de humanos e aves, e entre cães e aves. Adicionalmente, não houve diferença significativa na freqüência de bandos e número de indivíduos por bando entre as áreas. Os resultados deste estudo destacaram a sensibilidade de C. canutus na área com alta concentração humana e a necessidade de futuras investigações que determinem os limites máximos de concentração de pessoas e cães domésticos que as aves migratórias neárticas podem tolerar para a tomada de ações de proteção em áreas costeiras com ocupação humana. Palavras-chave: aves costeiras, perturbação humana, praias arenosas, Scolopacidae.

Do artisanal fishers perceive declining migratory shorebird populations?

“…This finding is consistent with the survey data from the study area, which show that the populations of certain bird species have been declining since the 1990s [ 19 ]. These fluctuations in bird populations have also been observed on Coroa do Avião Island [ 45 ] and the coast of southeastern Brazil [ 44 ]. This variation may be related to the greater or lesser capacity of different migratory shorebird species to adapt to new conditions or changes in the quality of their overwintering sites [ 47 , 48 ].…”

“…Although a limited number of studies [ 44 – 46 ] have focused on the LEK of artisanal fishermen in relation to migratory shorebirds, most of the research has focused on the coastal areas of North America [ 47 – 49 ]. Studies of the perceptions of artisanal fishermen with regard to the abundance of these birds [ 50 – 52 ] and the effects of human activities on their populations [ 53 ] are of considerable interest for the development of effective conservation and management plans for overwintering sites [ 54 ] as well as the maintenance of viable populations.…”

Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: Implications for management

“…At increasing distance from human settlement, small wading birds became slightly more abundant. Cestari (2008) found no difference in small wading birds abundance between areas with contrasting levels of human disturbance in the Southeastern Brazilian coast. However, recent evidence suggests that human activities may induce stress in these birds (Borneman et al, 2014;Pagel et al, 2014), with negative consequences on site occupancy due to correlations between environmental features and space (Gianuca et al, 2013).…”

Behavioral aspects of waterbirds

“…Changes in behavioural patterns may act as an indicator of environmental quality (Blanco, 1999). Factors that influence habitat selection, such as density, distribution, probability of detection, prey capture and competition (Maccarone and Parsons, 1994;Arengo and Baldassarre, 1999;Gawlik, 2002), as well as the disturbance generated by human presence, can interfere in the frequency and abundance of birds in coastal regions (Burger and Gochfeld, 1991;Barbieri et al, 2003;Barbieri and Pinna, 2005;Cestari, 2008). The observation of daily activity patterns of waterbird can be a tool to delineate their habitat use, types of behaviors and feeding sites (Ntiamoa-Baidu et al, 1998;Kasoma, 2000;Shimada, 2002;Yang et al, 2007;Pimenta et al, 2007;Branco et al, 2009;Zhou et al, 2010).…”

“…This locality is also considered one of the top tourist destinations of Santa Catarina (Brasil, 2004), making the habitats in its region susceptible to anthropogenic activities. Assuming that the variation of the richness, abundance and behavior of the waterbird community are associated to differences in time of day, environmental variables and habitat use by different species (Gawlik, 2002;Barbieri et al, 2003;Barbieri and Pinna, 2005;Cestari, 2008), this study aimed to evaluate the importance of these areas for the maintenance of the aquatic avifauna diversity, considering the different microhabitats found. For this, behavioral data of the local aquatic avifauna and its relation with the environmental variables, tidal height, temperature and wind velocity were analyzed.…”