Catastrophic storms, forest disturbance, and the natural history of Swainson’s warbler

The core breeding range of Swainson's warbler (Limnothlypis swainsonii) overlaps a zone of exceptionally high tornado frequency in southeastern North America. The importance of tornadoes in creating breeding habitat for this globally rare warbler and other disturbance-dependent species has been largely overlooked. This paper estimates tornado frequency (1950–2021) and forest disturbance in the 240 counties and parishes in which breeding was documented from 1988 to 2014. The frequency of destructive tornadoes (EF1-EF5) varied 6-fold across the breeding range with a peak in the Gulf Coast states. Counties from east Texas to Alabama experienced the lowest median return interval of 5.4 years per 1000 km2, resulting in approximately 2477 ha of forest damage per 1000 km2 per century, based on current forestland cover. Tornadoes were significantly less frequent north and east of the core breeding range, with return intervals increasing to 9.1 years per 1000 km2 for breeding counties on the Atl..., Geolocation of territorial Swainson's warblers. From 1988 to 2014, I surveyed breeding populations in 15 states as part of a comprehensive study of the warbler’s natural history. These surveys targeted Swainson’s warbler and were not incidental components of broader community censuses. Territorial males were documented in 240 counties and parishes documented by song recordings. Surveys were conducted during the breeding period, which began on 22 April in the Gulf Coast states and ended on 30 June in the Appalachian Mountains. I surveyed a wide spectrum of forestland and shrubland habitats, broadly classified as “forest land” by the USDA on public and private land and along waterways. Most breeding territories of this monogamous species were located using playback of songs, utilizing a protocol that was field-tested and fine-tuned in the late 1980s on the breeding and wintering ranges. Territorial males respond to playback by approaching the song source and delivering agitated “chip” not..., , # Catastrophic storms, forest disturbance, and the natural history of Swainson’s warbler

[https://doi.org/10.5061/dryad.gmsbcc2w8](https://doi.org/10.5061/dryad.gmsbcc2w8)

## Description of the data and file structure

The spreadsheet presents the song recording field number, location (state and county or parish), date, and geographic coordinates of 1717 territorial Swainson's warblers (*Limnothlypis swainsonii*) documented from 1986 to 2014 in the southeastern United States. Records are ordered by state, county or parish, date, and song recording field number. All recordings were made by the author.