Habitat and space use of wintering Sprague's Pipits(Anthus spragueii) in northern Mexico

  • August 6, 2019
  • by Strasser, E. H., Ruvalcaba-Ortega, I., Peña-Peniche, A., Panjabi, A. O., Martínez-Guerrero, J. H., Canales-del-Castillo, R., & Correll, M. D.

Understanding home range size and habitat preferences is an important component of monitoring species in steep decline. Sprague’s Pipit (Anthus spragueii) is a declining grassland specialist with a substantial portion of its population wintering in the highly threatened grasslands of the Chihuahuan Desert. We radio-tagged and tracked 10 wintering pipits between 2014 and 2017 at 3 sites across northern Mexico to generate baseline home range estimates and habitat preferences on their wintering grounds. We found that mean home range and core-use area size with 95% and 50% kernel density estimators were 11.4 ha and 2.4 ha, respectively, almost twice as large as some other grassland specialist passerines. Two birds left the study area and one individual shifted its home range 1.3 km after 20 d of monitoring, indicating that some individuals are flexible in their space use strategies. Within their home ranges, pipits selected grasslands with more bare ground and less “other cover” (litter, duff, animal excrement, and rocks) than what was available on the landscape. We found no relationship at the microhabitat scale between pipits and grass height nor shrub cover and heights, which in previous studies have been shown to influence habitat selection at larger scales. These findings may reflect different habitat use, diet, and predator avoidance strategies than other grassland passerines that select for denser grass cover during winter in the Chihuahuan Desert and highlight the importance of structurally heterogeneous grasslands. For this reason, strategies to manage and conserve Chihuahuan Desert grasslands and its avifauna must consider the diverse habitat and area needs of grassland birds to be effective.

PUBLICATION AVAILABLE AT: https://birdconservancy.org/wp-content/uploads/2019/11/Strasser-et-al-2019-SPPI-HR-and-habitat-Wilson.pdf