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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Insect Control and Cotton Disease Research » Research » Publications at this Location » Publication #304878
Title: An integrative study of weather-driven dynamics in a dual-migrant system

Author
item KRAUEL, JENNIFER J. - University Of Tennessee
item Westbrook, John
item MCCRACKEN, GARY - University Of Tennessee

Submitted to: Journal of Animal Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/29/2014
Publication Date: 1/10/2015
Citation: Krauel, J., Westbrook, J.K., McCracken, G.F. 2015. An integrative study of weather-driven dynamics in a dual-migrant system. Journal of Animal Ecology. 84:604-614.

Interpretive Summary: Migrations of many species of agricultural pests are linked to continental-scale weather patterns, which may impact the role of ecosystem services provided by predators such as bats. We tracked migrations of five species of crop pest moths during the fall seasons of 2010-2012 as they flew near a large colony of migratory Brazilian free-tailed bats at Frio Cave in Uvalde County, Texas. Fluctuations in moth abundance, mass of bats, and duration of bat activity at the cave were significantly correlated with passage of cold fronts and resulting increases in northerly wind. Moth responses to weather patterns varied among species and seasons, but overall abundances were low in late summer and spiked after one or more cold front passages in September and October. Changes in bat mass and behavior were not directly linked to passage of migratory moths, but may be evidence of bat migration as cave use transitioned from summer maternity roost to fall migratory stopover. Weather-driven migration is at considerable risk from climate change, and bat and moth responses to that change may have significant impacts on ecosystem services and agricultural systems.

Technical Abstract: Animal migrations generate large fluctuations of resources and are likely to drive many interactions over time and space. These interactions are often driven by continent-scale weather patterns and are difficult to study. We tracked migrations of five species of agricultural pest noctuid moths over the 2010-2012 fall seasons as they traveled past a large colony of migratory Brazilian free-tailed bats (Tadarida brasiliensis) at Frio Cave in Uvalde Co., TX. Fluctuations in moth abundance, mass of bats, and duration of bat activity at the cave were significantly correlated with passage of cold fronts over the study area and resulting increases in northerly wind. Moth responses to weather patterns varied among species and seasons, but overall abundances were low in late summer and spiked after one or more cold front passages in September and October. Changes in bat mass and behavior were not directly linked to passage of migratory moths. Instead, those changes may be evidence of bat migration, as cave use transitioned from summer maternity roost to fall migratory stopover. Weather-driven migration is at considerable risk from climate change, and bat and moth responses to that change may have significant impacts on ecosystem services and agricultural systems.