Begging and ectoparasite attraction

Abstract

Honesty of offspring begging behaviours is the keystone to understanding the evolution of parent-offspring communication. Three main begging costs have been traditionally advocated that ensure the reliability of offspring signalling: energy expenditure, loss of inclusive fitness and attraction of predators. Here, we propose that ectoparasites may eavesdrop on begging signals, especially acoustic signals, for host detection, a never considered but potentially generalized cost of begging that will constrain the evolution of exaggerated begging displays. Ectoparasitic insects possess a diversity of auditory systems for intraspecific communication that may be used to detect begging calls of host offspring. The use of auditory cues for host detection offers some advantages to ectoparasites, particularly in environments in which long-distance detection of hosts is necessary. There are well-known examples of interspecific eavesdropping on host auditory signals by parasites that include parasitoid flies attracted to calling crickets and cicadas, and frog-biting midges and mosquitoes attracted to frog calls. Eavesdropping on begging signals may have evolved in those parasites searching for hosts that display begging behaviours, which include not only birds but also mammals and some reptiles and insects with parental care of juveniles. Considering begging costs due to detection by ectoparasites may help us understand the reliability, and therefore the evolution, of signals of need and parent-offspring communication.

Smaller distance between nest contents and cavity entrance increases risk of ectoparasitism in cavity‐nesting birds

“…Effect size (partial eta-squared) and observed power (alpha = 0.05) are also shown. nestling physiological activity (Azcárate-García et al 2019), and/or auditory cues derived from begging behaviour (Tomás and Soler 2016). Nestlings in nests closer to the cavity entrance would be more easily located by ectoparasites.…”

“…Blood-sucking flying ectoparasites, or biting flies, are assumed to locate hosts mainly by means of visual and olfactory cues (Allan et al 1987, Bowen 1991, Gibson and Torr 1999, Lehane 2005. Recently, a potential role for acoustic cues has also been suggested in host detection by ectoparasites (Tomás and Soler 2016). A large nest can be more easily detected than a small one, either visually or because of the increased number of volatiles released by nest materials (Tomás et al 2008a).…”

Begging behavior as an honest signal of need and parent–offspring association during the postfledging dependency period

“…However, for this strategy to be evolutionarily stable, theory predicts that this behavior should be costly (Godfray, ). Costs of begging, which include energy expenditure (Godfray, , ; Ogawa et al, ), loss of inclusive fitness (Rodríguez‐Gironés, Cotton, & Kacelnik, ), and predator and possibly parasite attraction (Tomás & Soler, ), may limit this behavior and increase its reliability as an honest parent–offspring signaling mechanism (Levréro, Durand, Vignal, Blanc, & Mathevon, ). Alternatively, an evolutionarily stable strategy may still be achieved in the absence of high costs if there is little to be gained from displaying the behavior dishonestly (Royle, Hartley, & Parker, ).…”

“…Costs of begging, which include energy expenditure (Godfray, 1991(Godfray, , 1995Ogawa et al, 2015), loss of inclusive fitness (Rodríguez-Gironés, Cotton, & Kacelnik, 1996), and predator and possibly parasite attraction (Tomás & Soler, 2016), may limit this behavior and increase its reliability as an honest parent-offspring signaling mechanism (Levréro, Durand, Vignal, Blanc, & Mathevon, 2009).…”

Microclimate, CO2and CH4concentration on Blue tits (Cyanistes caeruleus) nests: effects of brood size, nestling age and on ectoparasites

“…CO 2 and 1-octen-3-ol) were secondary and occurred once host was located. Alternatively, Tomás and Soler (2016) also proposed that acoustic signals produced during nestling begging behaviour could attract blood-feeding insects to nests.…”