Persistence and habitat associations of Purple Martin roosts quantified via weather surveillance radar
- 393 Downloads
Weather surveillance radars (WSR) have been used to locate roost sites used by Purple Martins (Progne subis) for decades. Improvements in radar data processing and accessibility now make it possible to monitor roosts over a broad spatial scale.
We sought to locate all of the Purple Martin roosts in North America and to use the data to evaluate (1) the land cover types associated with roosts (2) relationships among roost persistence, land cover type, and regional population trends.
We used mosaicked images of radar reflectivity based on the NEXRAD WSR network to locate 234 Purple Martin roosts that were active between 2009 and 2014. Of these roosts, we ground-truthed a subset of 57 with site visits and reports from citizen scientists. We assigned roosts to different classes based on local land cover, and used a variety of statistical and spatial analyses to address the objectives listed above.
Roosts were mainly associated with forest, cropland, urban, and water land cover types, with cropland being the most common. There was an apparent preference for urban sites, and urban roosts were associated with the high year-to-year persistence. We found no correlation between roost persistence and regional population trends in data from the North American Breeding Bird Survey (BBS).
Although they use a diverse array of roosting habitats, urban roosting areas appear to be increasingly important for Purple Martins. Persistence of urban roosts was high, which aligns with the species’ unique natural history and its association with human societies.
KeywordsAerial insectivores Aeroecology Purple Martin Radar Remote sensing Roost behavior
This study was funded by NSF-EAGER Grant 143210. We thank the Purple Martin Conservation Association for sharing their database of martin roost locations, and we thank Jacob van der Ploeg for ground-truthing martin roosts locations in Texas, Oklahoma, Arkansas, Missouri, and Kansas during the summer of 2012.
- Burney CW (2002) A study of swallow roosts found in the Eastern United States. Cornell University, IthacaGoogle Scholar
- Drummond MA, Auch R (2014) Land-cover change in the United States Great Plains. Available via http://landcovertrends.usgs.gov/gp/regionalSummary.html. Accessed 23 Mar 2015
- Loveland TR, Acevedo W (2014) Land cover change in the Eastern United States. Available via http://landcovertrends.usgs.gov/east/regionalSummary.html. Accessed 23 Mar 2015
- Natural Resources Canada, The Canada Centre for Mapping and Earth Observation, United States Geological Survey, Insituto Nacional de Estadística y Geografía (INEGI), Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, Comisión Nacional Forestal (2010) North American land cover at 250 m spatial resolutionGoogle Scholar
- R Core Team (2014) A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/. Accessed 15 Nov 2014
- Ray JD (1995) Purple Martins in northwest Texas. Purple Martin Update 6(3):10–12Google Scholar
- Russell KR, Gauthreaux SA (1998) Use of weather radar to characterize movements of roosting purple martins. Wildl Soc Bull 26:5–16Google Scholar
- Russell KR, Gauthreaux SA (1999) Spatial and temporal dynamics of a Purple Martin pre-migratory roost. Wilson Bull 111:354–362Google Scholar
- Russell KR, Mizrahi DS, Gauthreaux SA (1998) Large-scale mapping of Purple Martin pre-migratory roosts using WSR-88D weather surveillance radar. J Field Ornithol 69(3):509–509Google Scholar
- Sauer JR, Hines JE, Fallon JE, Pardieck KL, Ziolkowski DJ Jr, Link WA (2014) The North American breeding bird survey, results and analysis 1966–2013. USGS Patuxent Wildlife Research Center, Laurel, MDGoogle Scholar
- Tarof S, Brown CR (2013) Purple Martin (Progne subis). In: Poole A (ed) The birds of North America Online. Cornell Lab of Ornithology, IthacaGoogle Scholar
- Tautin J, Cousens B, Kostka K, Kotska S, Airola DA (2009) Addressing regional declines in Purple Martin populations. In: Rich T. D., Arizmendi C., Demarest D., Thompson C. (eds), Tundra to tropics: connecting birds, habitats and people. In: Proceedings of the fourth international partners in flight conference. Partners in Flight, McAllen, TX, pp 82–87Google Scholar
- Tøttrup AP, Klaassen RH, Strandberg R, Thorup K, Kristensen MW, Jørgensen PS, Fox J, Afanasyev V, Rahbek C, Alerstam T (2012) The annual cycle of a trans-equatorial Eurasian–African passerine migrant: different spatio-temporal strategies for autumn and spring migration. Proc R Soc 279(1730):1008–1016CrossRefGoogle Scholar
- Wilson A, Bonaparte CL, Jameson R, Ord G, Hetherington WM (1831) American ornithology; or the natural history of the birds of the United States. Constable and co., EdinburghGoogle Scholar
- Winkler DW (2006) Roosts and migrations of swallows. Hornero 21:85–97Google Scholar