Ecological crossovers of sexual signaling in a migratory bird

• Published in: Evolution
• Main Authors: Teerikorpi, Pauliina Elisabet, Sirkiä, Paivi Maria, Laaksonen, Toni
• Other Authors: Zoology, Finnish Museum of Natural History
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley/Blackwell 2021
• Subjects: Carry-over effect; climate change; fluctuating selection; mate choice; NAO index; seasonal interactions; NORTH-ATLANTIC OSCILLATION; PALEARCTIC MIGRANTS; MALE COMPETITION; CLIMATE-CHANGE; BADGE SIZE; SELECTION; COLORATION; FLYCATCHERS; PRECIPITATION; 1181 Ecology; evolutionary biology; 1172 Environmental sciences; North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10138/325591

Environmental shifts may induce sudden reversals in the relative quality or sexual attractiveness of mates (ecological crossovers) leading to non-directional sexual selection. Studies on such ecological crossovers induced by environmental shifts during the nonbreeding season are particularly rare. We studied the interactive effects between nonbreeding conditions and a male white wing patch on the breeding success of breeding pairs and the local survival of females in a migratory passerine population over a 32-year period. After dry winters, females paired with large-patched males were more likely to survive than those paired with small-patched males, and vice versa after moist winters. Moreover, after dry winters, large-patched males succeeded in attracting females that laid large clutches, while small-patched males bred with females that laid small clutches, and vice versa after moist winters. This phenomenon led to a difference in fledgling numbers only during years with dry winters and high precipitation during the breeding season. The selection on this male trait and its signaling value to females thus depended on a complex interaction between conditions both at the nonbreeding and breeding grounds. We show that it is important to consider conditions during the nonbreeding season when examining the effects of sexual ornaments on fitness. Peer reviewed