title: Multimodal communication in courting fiddler crabs reveals male performance capacities.
abstract: Courting males often perform different behavioural displays that demonstrate aspects of their quality. Male fiddler crabs,Ucasp., are well known for their repetitive claw-waving display during courtship. However, in some species, males produce an additional signal by rapidly stridulating their claw, creating a 'drumming' vibrational signal through the substrate as a female approaches, and even continue to drum once inside their burrow. Here, we show that the switch from waving to drumming might provide additional information to the female about the quality of a male, and the properties of his burrow (multiple message hypothesis). Across males there was, however, a strong positive relationship between aspects of their waving and drumming displays, suggesting that drumming adheres to some predictions of the redundant signal hypothesis for multimodal signalling. In field experiments, we show that recent courtship is associated with a significant reduction in male sprint speed, which is commensurate with an oxygen debt. Even so, males that wave and drum more vigorously than their counterparts have a higher sprint speed. Drumming appears to be an energetically costly multimodal display of quality that females should attend to when making their mate choice decisions.
authors.affiliation: Animal and Environment Research Group, Faculty of Science and Technology, Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK; Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.
authors.forename: Sophie L
authors.identifier: 0000-0002-2323-0509
authors.initials: SL
authors.lastname: Mowles
authors.affiliation: Evolution, Ecology and Genetics, Research School of Biology , The Australian National University , Canberra, Australian Capital Territory , Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Jennions
authors.affiliation: Evolution, Ecology and Genetics, Research School of Biology , The Australian National University , Canberra, Australian Capital Territory , Australia.
authors.forename: Patricia R Y
authors.initials: PR
authors.lastname: Backwell
keywords: biotremology; courtship; fiddler crab; multimodal signal; stamina; vibrational signal