Scents of Adolescence: The Maturation of the Olfactory Phenotype in a Free-Ranging Mammal

Olfaction is an important sensory modality for mate recognition in many mammal species. Odorants provide information about the health status, genotype, dominance status and/or reproductive status. How and when odor profiles change during sexual maturation is, however often unclear, particularly in free-ranging mammals. Here, we investigated whether the wing sac odorant of male greater sac-winged bats (Saccopteryx bilineata, Emballonuridae) differs between young and adults, and thus offers information about sexual maturity to potential mating partners. Using gas chromatography – mass spectrometry, we found differences in the odorants of young and adult males prior and during, but not after the mating period. The wing sac odorant of adult males consists of several substances, such as Pyrocoll, 2,6,10-trimethyl-3-oxo-6,10-dodecadienolide, and a so far unidentified substance; all being absent in the odor profiles of juveniles prior to the mating season. During the mating season, these substances are present in most of the juvenile odorants, but still at lower quantities compared to the wing sac odorants of adults. These results suggest that the wing sac odorant of males encodes information about age and/or sexual maturity. Although female S. bilineata start to reproduce at the age of half a year, most males of the same age postpone the sexual maturation of their olfactory phenotype until after the first mating season

Parental care and external sexual characters in the Warbling Doradito (Pseudocolopteryx flaviventris)

Biparental care is the dominant (81 %) form of parental care in birds. The degree of sexual selection and the resulting mating system and parental care type have been determined, in many cases, by inference from external characters of sexual dimorphism. The lack of information and the biological attributes of the tyrant flycatchers (e.g., low sexual dimorphism) make it difficult to determinate the parental care roles in most species. Tyrant flycatchers comprise a diverse bird family, but information on the reproductive behavior of many Tyrannid species is lacking. Our aim was to describe external sexual characters (morphology and coloration) and determine the parental care behavior at the nest in the Warbling Doradito (Pseudocolopteryx flaviventris), especially considering the potential role of sexual differences in relation to parental roles at nest. We studied the parental care behavior during two breeding seasons. Parents were captured to take morphological measurements and a blood sample for molecular sex determination. We found that parental care in the Warbling Doradito was biparental biased toward females, where the incubation was performed exclusively by females and the 74 % of activities of nestling brooding and feeding was performed by females. We also found sexual differences, slight in size and plumage, but more conspicuous in bill color. Despite the relatively slight sexual dichromatism of the Warbling Doradito, the parental care behavior in the nest was biased towards females, and the assistance of males to nestlings was highly variable and was not correlated with either clutch size or increasing nestling mass. Therefore, the evidence presented here suggest that Pseudocolopteryx genus may have an unusual social system, otherwise uncommon in tyrannids.Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pretelli, Matías Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Madrid, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Baladron Felix, Alejandro Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Chiaradia, Nicolas Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin