Tornadic Storm Avoidance Behavior in Breeding Songbirds

Abstract

Migration is a common behavior used by animals of many taxa to occupy different habitats during different periods. Migrant birds are categorized as either facultative (i.e., those that are forced to migrate by some proximal cue, often weather) or obligate (i.e., those that migrate on a regular cycle). During migration, obligate migrants can curtail or delay flights in response to inclement weather or until favorable winds prevail, and they can temporarily reorient or reverse direction when ecological or meteorological obstacles are encountered. However, it is not known whether obligate migrants undertake facultative migrations and make large-scale movements in response to proximal cues outside of their regular migration periods. Here, we present the first documentation of obligate long-distance migrant birds undertaking a facultative migration, wherein breeding golden-winged warblers (Vermivora chrysoptera) carrying light-level geolocators performed a >1,500 km 5-day circumvention of a severe tornadic storm. The birds evacuated their breeding territories >24 hr before the arrival of the storm and atmospheric variation associated with it. The probable cue, radiating >1,000 km from tornadic storms, perceived by birds and influencing bird behavior and movements, is infrasound (i.e., sound below the range of human hearing). With the predicted increase in severity and frequency of similar storms as anthropogenic climate change progresses, understanding large-scale behavioral responses of animals to such events will be an important objective of future research.

Combining direct and indirect tracking techniques to assess the impact of sub-Saharan conditions on cross-continental songbird migration

“…The majority of work using geolocator technology has so far been focused on describing migration patterns in songbirds. However, the accumulation of sufficient data has sparked an interest in studies considering the ecological context of movement patterns (Bridge et al 2015;Emmenegger et al 2014;Fraser et al 2012Streby et al 2014;Tøttrup et al 2012b). Despite this progress, tracking devices are still limited by the need for recapturing individuals to retrieve the data (Bridge et al 2011).…”

“…The Red-backed Shrike (Lanius collurio) is a long-distance Palearctic-Afrotropical migratory songbird, breeding in most of Europe and western Asia and wintering in southern Africa (Snow and Perrins 1998;Tøttrup et al 2012a). Like many other long-distance migrants this species has been declining, mainly in the western part of its breeding range (BirdLife International 2004).…”

Snoozing through the storm: torpor use during a natural disaster

“…Unfortunately, few studies have focused on how animals respond to such challenges. Although there are reports of sharks escaping to the open sea prior to hurricanes3, elephants fleeing coastal regions during a tsunami4, or birds circumventing a tornadic storm5, the behaviour and physiology of animals during storms has never been quantified.…”

Pallid bands in feathers and associated stable isotope signatures reveal effects of severe weather stressors on fledgling sparrows

“…Severe weather is a prime example, as it can cause widespread mortality and is known to necessitate specific local adaptations within biological communities (Wingfield, 1988; Newton, 2007). Severe weather impacts on birds have generally been studied in association with large, widespread, and relatively long-lasting events such as cold snaps, hurricanes, blizzards, and regional storm fronts (Whitmore, Mosher & Frost, 1977; Wiley & Wunderle, 1993; Brown & Brown, 1998; Newton, 2007; Frederiksen et al, 2008; Rittenhouse et al, 2010; Streby et al, 2015). However, intense but relatively localized perturbations, such as large hail or tornadoes associated with severe thunderstorms, have primarily received attention only after the most obvious and widespread destruction (e.g., Gates, 1933; McClure, 1945; Smith & Webster, 1955; Narwade et al, 2014).…”

“…During extremely heavy storms adult birds may flee (Streby et al, 2015) and abandon their nests to the weather (Hanford, 1913; Hume, 1986; Kirkpatrick, Conway & Ali, 2009). Young that survive ‘riding the storm out’ may be traumatized by the event itself or because of reduced provisioning by adults.…”