Courting females affects the feeding effort of male fiddler crabs

Abstract

In animals, both monotasking and multitasking behaviours are observed. Multitasking behaviour helps to increase output quantity, but one activity may distract attention from another, and activities may interact negatively as they compete for the same amount of time available. To test this, we video recorded 23 Austruca bengali (Crane, 1975) males who were ‘feeding only’ (monotasking) and 24 males who were ‘feeding and courting (waving major claws) females’ simultaneously (multitasking). We measured the feeding and waving rates for ‘feeding and waving’ males, and the feeding rate for ‘feeding only’ males. We found that the feeding rate of ‘feeding only’ males was higher, but they reduced their feeding rate when they shared the time for feeding and courting. Moreover, feeding rate was negatively correlated with waving rate for ‘feeding and waving’ males. Our results indicate that courting activity distracted attention from feeding activity, and that activities interacted negatively with each other.