Long-distance migrating species of birds travel in larger groups

Abstract

How individuals migrate over long distances is an enduring mystery of animal migration. Strong selection pressure for travelling in groups has been suggested in long-distance migrating species. Travelling in groups can reduce the energetic demands of long migration, increase navigational accuracy and favour group foraging at migratory halts. Nevertheless, this hypothesis has received scant attention. I examined evolutionary transitions in migration distance in all North American breeding species of birds. I documented 72 evolutionary shifts in migration distance in the pool of 409 species. In contrasting clades, long-distance migration, as opposed to short-distance migration, was associated with a larger travelling group size. No other transitions occurred alongside in other traits such as group size in the non-breeding season or body mass. The results suggest that larger group sizes have been beneficial in the evolution of long-distance migration in a large clade of birds.

Observation of Daytime Sleep-like Behavior in a Migratory Songbird during Stopover

“…Longdistance migrants, for example, may be under stronger selection to minimize migration time than short-distance migrants Lindström 1990, Alerstam 2003), thus we could expect that incentive for timely refueling would increase tolerance of risk and use of potentially less accurate social information (Metcalfe and Furness 1984, Moore 1994. Consistent with this prediction is the finding that long-distance migrants tend to travel in larger groups than shorter-distance migrants (Beauchamp 2011). Because migration speed seems to increase with migration distance (Ellegren 1993, Alerstam 2003, speed may be a good predictor of social information use: The faster the migration (either at the species, Specialists will prefer conspecific SI, while generalists will also value heterospecific SI.…”

A High Diversity of Eurasian Lineage Low Pathogenicity Avian Influenza A Viruses Circulate among Wild Birds Sampled in Egypt

“…Thus, the identification and significance of possible reassortment among these viruses were difficult to establish [54]. Migratory birds carrying influenza viruses travel long distances in large groups and could intermingle with local bird populations transmitting influenza viruses to local wild birds and free range poultry [55]. Our data support these findings with genes sequences that evolved independently and grouped with viruses of diverse origins and lacking a defined association by subtype, origin or date of collection.…”

A collective navigation hypothesis for homeward migration in anadromous salmonids

“…Theo retical work predicts that collective migratory strategies might evolve under a wide range of eco logical scenarios (Torney et al 2009(Torney et al , 2010Guttal and Couzin 2010;Shaw and Couzin 2013), and it may be no coincidence that migrations and other navigational feats are often undertaken by large groups (Beauchamp 2011;Milner Gulland et al 2011). Homing pigeons return more efficiently when released as groups than they do as individu als (Biro et al 2006;Dell'Ariccia et al 2008), and birds with less information can benefit from fol lowing others (Flack et al 2012).…”