Abstract
Proximity to humans can influence behaviors that are essential in birds’ life, such as breeding, foraging and flight. In urban parks, which are important natural shelters to birds, human activity varies broadly in time such that attentiveness and escaping behavior of birds may be intensified as humans’ density increases. In this study, we tested this hypothesis in six urban parks at Curitiba, southern Brazil, using three common bird species as models, the Rufous Hornero (Furnarius rufus), the Southern Lapwing (Vanellus chilensis) and the Rufous-bellied Thrush (Turdus rufiventris). Specifically, we tested if foraging rate, alert distance (AD), flight initiation distance (FID) and flight distance (FD) were related to human density at birds’ surroundings. We found no influence of humans on birds foraging rate, whereas AD, FID and FD decreased with human density in the area. We also found differences in birds escaping strategy; “flying” strategy was associated with higher AD, FID and FD than “walking”. Results also indicate that humans’ presence temporally affected birds’ vigilance and flight responses, evident through their constant foraging rate irrespective of human density, i. e. increased tolerance to human proximity. Our study provides evidence of behavioral plasticity of the model species to the intensity of human use of their living area, which also highlights the importance of further efforts in creating refuges within urban parks to minimize negative anthropic impacts on urban species.
Highlights
Many bird species are sensitive to environmental change, but several can cope with anthropic activities
We found no influence of humans on birds foraging rate, whereas alert distance (AD), flight initiation distance (FID) and flight distance (FD) decreased with human density in the area
PC1 was positively related to human density (E ± SE = 0.04 ± 0.01, n = 131, t = 4.09, P < 0.0001, Fig. 3), and indicated that AD, FID and FD reduced as human density increased
Summary
Many bird species are sensitive to environmental change, but several can cope with anthropic activities. Parks and other green areas become important shelter especially to birds in human-altered environments (FernándezJuricic et al 2001), because ecological and environmental conditions may match with the natural contexts where these species have evolved. Even though selection has favored agile escape behaviors in birds to overcome potential threats (e.g. predators, Ydenberg & Dill 1986), individual habituation to human co-occurrence can be decisive for survival and may represent an important filter selecting individuals and species less sensitive to urbanization. Individual responses involve an optimal decision-making that maximizes foraging and daily general activities (e.g. mating and nesting) while reducing any potential threat (Blumstein et al 2003, Piratelli et al 2015). The second indicates the distance in relation to a potential threat at which the individual begins to escape by walking or flying away The second indicates the distance in relation to a potential threat at which the individual begins to escape by walking or flying away (Cooper-Jr. & Pérez-Mellado 2011), and the third represents the actual distance travelled for escaping
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
