Responses in the abundance of generalist birds to environmental gradients: The rufous-collared sparrow (Zonotrichia capensis) in the southern Neotropics

Abstract

Bird species are adapted to certain ranges of physical conditions and will respond to environmental heterogeneity depending on their ability to exploit a broad range of resources and their tolerance to new environmental conditions. We used the rufous-collared sparrow as a model to explore how the abundance of generalist passerine birds may vary along environmental gradients in the southern Neotropics. We analyzed variations in the abundance along 6 gradients expressing variations in climate, productivity, the proportion of native forest in the landscape, the proportion of vegetation types through the transition between regions, and the intensity of human activities (agriculture, urbanization). The rufous-collared sparrow was most abundant in seasonal and semi-arid climates. Thermal amplitude was the best climatic predictor of the species abundance at the large scale. Within regions where climatic conditions are relatively homogeneous, land use better predicted abundance patterns. The species responded positively to increasing primary productivity, agricultural intensity, and native forest degradation and conversion and negatively to increasing urbanization. The rufous-collared sparrow adapts successfully to new environments created by human activities such as agriculture, ranching, forestry, and urbanization. Some native species may be tolerant to certain types and intensity of human activities, and knowledge of how they respond to both natural and human-created environments may help efforts to anticipate the impact of human activities on native birds in a changing world.

Temporal Beta Diversity of Bird Assemblages in Agricultural Landscapes: Land Cover Change vs. Stochastic Processes

“…Bird species can respond to environmental changes by moving from unsuitable to suitable sites, but they can also present phenotypic adaptation and behavioural changes which allow species to persist in situ [ 40 , 41 ]. Following changes in human activities, some species can thus adapt and persist in sub optimal habitats [ 42 , 43 ]. In this sense, a previous study based on the same data has revealed marked differences between both dates in species’ habitat selection [ 18 ].…”

Stay or Leave? Avian Behavioral Responses to Urbanization in Latin America

“…Although behavior adjustment has been recorded in relation to human disturbances (Salinas-Melgoza et al 2013), we did not find any study directly assessing avian behavioral adjustments to habitat loss and fragmentation in urban Latin America. Yet, we found studies that suggest that some native species take advantage of these urban conditions, such as the Rufoustailed Hummingbird Chilean (Ruiz et al 2002) and Argentinean urban centers (Bellocq et al 2011) have lower body weights, and several of their physiological blood parameters suggest they live in more stressful environments than their nonurban counterparts, as has been recorded in central Chile (e.g., Ruiz et al 2002). Accordingly, the Common Ground-Dove (Columbina passerina) was highly abundant in gardens and open areas from San Jose in Costa Rica up to the late 1990s, but nowadays has almost disappeared from urban areas from this region (Biamonte et al 2011).…”

Exploration and exploitation of foraging patches by desert sparrows: environmental indicators and local evaluation of spatially correlated costs and benefits

“…This decision‐making process does not seem the optimal strategy for efficient seed predation under the apparently predictable spatial seed dynamics in the algarrobal of Ñacuñán, and it is not obvious that birds are unable to perceive bold characteristics of the vegetation or to develop a patch‐searching rule based on them. Local evolutionary adjustment may not be feasible or convenient because Z. capensis occupies a wide spectrum of habitats across the Neotropics, from forests to semi‐deserts to suburban gardens and city parks (Bellocq et al ), and a fixed behavioral rule that maximizes foraging efficiency in this habitat may not hold as a good‐enough rule‐of‐thumb in other habitats. Similarly, a learned foraging rule may be unattainable because part of the local population of Z. capensis is nomadic or migratory.…”