Improved foraging opportunities? A North Atlantic petrel associates with cyclones

 
From the publication

Francesco Ventura (Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA) and colleagues have published in the journal Current Biology on the Vulnerable Desertas Petrel Pterodroma deserta moving towards tropical cyclones during foraging trips.

The paper’s summary follows:

“In late summer and autumn, the passage of intense tropical cyclones can profoundly perturb oceanic and coastal ecosystems. Direct negative effects on individuals and marine communities can be dramatic, especially in the coastal zone, but cyclones can also enhance pelagic primary and secondary production. However, cyclone impacts on open ocean marine life remain poorly understood. Here, we investigate their effects on the foraging movements of a wide-ranging higher predator, the Desertas petrel (Pterodroma deserta), in the mid-latitude North Atlantic during hurricane season. Contrary to previously studied pelagic seabirds in tropical and mid-latitude regions, Desertas petrels did not avoid cyclones by altering course, nor did they seek calmer conditions within the cyclone eye. Approximately one-third of petrels tracked from their breeding colony interacted with approaching cyclones. Upon encountering strong winds, the birds reduced ground speed, likely by spending less time in flight. A quarter of birds followed cyclone wakes for days and over thousands of kilometers, a behavior documented here for the first time. Within these wakes, tailwind support was higher than along alternative routes. Furthermore, at the mesoscale (hours–weeks and hundreds of kilometers), sea surface temperature dropped and surface chlorophyll sharply increased, suggesting direct effects on ocean stratification, primary production, and therefore presumably prey abundance and accessibility for surface-feeding petrels. We therefore hypothesize that cyclone wakes provide both predictably favorable wind conditions and foraging opportunities. As such, cyclones may have positive net effects on the demography of many mid-latitude pelagic seabirds and, likely, other marine top-predators.”

Reference:

Ventura, F., Sander, N., Catry, P., Wakefield, E., De Pascalis, F., Richardson, P.L, Granadeiro, J.P., Silva, M.C. & Ummenhofer, C.C. 2024.  Oceanic seabirds chase tropical cyclones.  Current Biology doi.org/10.1016/j.cub.2024.06.022.

12 July 2024