Vocal solicitation of heat as an integral component of the developing thermoregulatory system in young domestic chickens

Abstract

Young domestic chickens (Gullus gullus) were able to regulate their body temperature in a laboratory setting, where vocalizations triggered a period of rewarming (35°C) in an otherwise cold environment. Vocal solicitation of a rewarming period functioned in an analogous manner to the parental brooding response to a vocalizing chick. The number of vocally generated rewarming bouts increased if the cold-challenge temperature was decreased from 20 to 5°C. The body temperature and ambient temperature maintained during vocal regulation were not significantly affected by the cold-challenge temperature. Thermoregulatory reliance on vocally induced rewarming bouts decreased with age as endothermic capability and the ability to retain heat improved. This decreased reliance on vocally induced heat inputs matches the pattern of decline of parental brooding seen in chicks reared in a natural setting. Body temperature at both cold-challenge temperatures increased with age, while the preferred ambient temperature decreased with age. This pattern is also found in the young of many birds species tested in spatial thermal gradients. Vocal solicitation of heat thus appears to form an integral and finely tuned part of the overall thermoregulatory system of these young precocial birds.RCsumC : Des poussins domestiques (Gullus gullus) se sont avdrks capables de contrbler leur temperature interne dans des conditions de laboratoire oh leurs cris provoquaient une periode de rechauffement (35°C) dans un milieu gendralement froid. Le systkme de sollicitation vocale du rechauffement fonctionnait de la meme facon que la reponse parentale aux cris d'un poussin. Le nombre de periodes de rechauffement sollicitees par des cris augmentait si la temperature experimentale dtait baissee de 20 i 5°C. La temperature du corps et la tempkrature ambiante maintenues au cours de la periode de sollicitation vocale n'etaient pas significativement reliees h la temperature experimentale. Le recours aux periodes de rechauffement sollicitees par des cris diminuait avec I'ige. B mesure que I'endothermie et la capacite de retenir la chaleur augmentaient. Cette diminution du recours aux sollicitations vocales s'apparente au pattern de diminution des soins parentaux chez des poussins eleves dans des conditions normales. Avec I'ige, la temperature du corps aux deux temperatures froides augmentait et la tempdrature a~nbiante preferde diniinuait. Ce phenomitne est commun chez les oisillons de plusieurs espkces soumis B un gradient spatial thermique experimental. La sollicitation vocale de chaleur semble donc constituer une partie integrante et raffinde du systitme thermoregulateur global chez ces jeunes oiseaux precoces.[Traduit par la Redaction1

Thermogenic and vocalization responses to cold in the chicken hatchling during normoxia and hypoxia.

“…Several considerations lead to the expectation of some degree of reciprocity between autonomic thermogenesis and behavioral means of Tb control (Weiss& Laties, 1961; Myhre, 1978; Bugden and Evans, 1997; Schlader et al, 2009). For example, lower vertebrates with minimal endothermy rely heavily on behavioral means for Tb regulation.…”

Acoustic Cooperation: Acoustic Communication Regulates Conflict and Cooperation Within the Family

“…In a series of experiments in the 1990s, Evans showed that avian embryos do so using acoustic signals. In a number of precocial and altricial species, embryos increase calling rate when their temperature deviates from the optimal incubation temperature (Evans, 1990;Evans et al, 1995;Bugden and Evans, 1997) (Figure 1). Evans demonstrated that if parents respond to calls by resuming incubation, embryonic vocalisations can effectively maintain optimal incubation temperature (Evans, 1990;Evans et al, 1995).…”

Automatic Identification and Interpretation of Animal Sounds, Application to Livestock Production Optimisation

“…In relation to thermoregulation, chicken vocalisations have been shown to have specific patterns when chicks are exposed to cold stress [22]. Furthermore, vocal solicitation of heat, forms an integral part of the development of the thermoregulatory system of young chickens [23]. Finally, the thermal comfort of chicks has been shown to have links with the amplitude and frequency of calls [24].…”