Integrating survey and behavior data in the analysis of habitat use by birds in road borders of Argentine Pampas

MYRIAM MERMOZ; ALEJANDRA VALVERDE; PABLO PICCA; DANIELA DEPALMA

Chattanooga, Tennessee

Congreso; AFO/WOS meeting; 2018

Association of Field Ornithologists, Wilson Ornithological Society

Land transformation in the Pampas grasslands have led to habitat loss for birds. Roadsideborders provide remnant habitats, although species may use them differently. Here, we determinewhich characteristics of these roadsides and the surrounding habitat matrix influence their use bybirds and their behaviors. During the breeding season of 2016, we sampled birds, vegetation andfood resources in 87 roadside borders. We also estimated the amount of grassland, wetland,woodland, and modified land in the habitat matrix surrounding those borders. For the mostcommon species, we recorded their behavior and analyzed the associations between theirabundance and border characteristics, habitat matrix characteristics and food. We detected 3819individuals of 89 species using borders for feeding, roosting and nesting. According tobehavioral observations, wetland birds were the most selective regarding habitat use, whereasgrassland and woodland birds used a range of habitats such as grassland, woodland and wetland.Among 23 analyzed species (i.e., the most frequent), eight responded only to border variables,four responded to matrix variables, and five responded to both. The most relevant variables onspecies richness and species abundance were woodland and wetland cover of borders. Specieswere generally associated with their nesting sites. Species responded differently to thesurrounding matrix according to their habitat requirements and probably also to their sensitivityto habitat modification. Since birds respond to the size of habitat patches, the degree ofconservation in the Pampas do influence bird communities and characteristics of roadsideborders should be considered in management strategies.