| Title: | Olfactory detection of trace amounts of plant volatiles is correlated with testosterone in a passerine bird |
| Author(s): | Graham JL; Charlier TD; Bonadonna F; Caro SP; |
| Address: | "CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France. Electronic address: Jessica.l.graham@ndsu.edu. Univ Rennes, Inserm, EHESP, Irset (Institut de Recherche en Sante, Environnement et Travail), UMR_S 1085, F-35000 Rennes, France. Electronic address: Thierry.charlier@univ-rennes1.fr. CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France. Electronic address: Francesco.bonadonna@cefe.cnrs.fr. CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France. Electronic address: Samuel.caro@cefe.cnrs.fr" |
| DOI: | 10.1016/j.yhbeh.2021.105045 |
| ISSN/ISBN: | 1095-6867 (Electronic) 0018-506X (Linking) |
| Abstract: | "In response to damage by insects, plants release herbivore-induced plant volatiles (HIPVs) into the air. Insectivorous birds exploit these cues and, consequently, reduce the damages inflicted to the plants. However, little is known about whether they solely use HIPVs as foraging cues, or if they also use them to modulate traits linked to reproduction. As caterpillars are the primary food source required for insectivorous birds to raise offspring, their ability to locate and predict future peaks in caterpillar biomass using olfaction is likely to be advantageous. Therefore, we tested whether an insectivorous songbird that naturally inhabits oak dominated forests can be trained to detect early spring infestation by hatchling caterpillars, at a time when oaks begin bursting, and birds prepare to breed. Tree buds were either infested with caterpillars or left as a control and visually obscured in a Y-Maze choice test. Additionally, we measured testosterone and 17beta-estradiol as they influence olfactory perception in mammals and are linked to reproduction in vertebrates. After being trained to associate the presence of HIPVs with that of food, blue tits spent more time with, were more active around, and more frequently chose to first visit the infested trees, showing that blue tits can smell caterpillar activity. Males with higher testosterone spent more time around infested trees, suggesting that foraging behavior during the pre-breeding season is linked with a major reproductive signal. There was no relationship between foraging and estradiol in females. These results are an important foundation for further investigation of the role of hormones in avian olfaction and how smell may be useful for making breeding decisions that could improve reproductive success" |
| Keywords: | Animals Estradiol Female Larva/physiology Male Mammals *Smell *Songbirds Testosterone Alarm HIPVs Olfaction Seasonal reproduction; |
| Notes: | "MedlineGraham, Jessica L Charlier, Thierry D Bonadonna, Francesco Caro, Samuel P eng Research Support, Non-U.S. Gov't 2021/09/20 Horm Behav. 2021 Nov; 136:105045. doi: 10.1016/j.yhbeh.2021.105045. Epub 2021 Sep 16" |
