Aromatic Herbs can Influence Parenting!
North Carolina: According to a new study, European starlings (Sturnus vulgaris) are influenced by the presence of aromatic herbs in the nest. The herbs lead to some improved parenting behaviors, the study proves. Specifically, birds whose nests incorporate herbs along with dried grasses were more likely to attend their nests, exhibited better incubation behavior for their eggs, and became active earlier in the day.
For the study, researchers replaced 36 natural starling nests in nest boxes with artificially made nests. Each nest retained the female's clutch of eggs. Half of the artificial nests included dry grass and a combination of herbs commonly found in starling nests. The other half of the nests had only dry grass.
The researchers also placed a "dummy" egg in each nest, which monitored temperature in the nest.
"Egg temperatures and nest attendance were higher in herb than nonherb nests - particularly early in the incubation period," says Caren Cooper, co-author of a paper on the work and a research associate professor in North Carolina State University's Department of Forestry and Environmental Resources.
"In addition, egg temperatures dropped less frequently below critical thresholds in nests that contained herbs, and those parents started their active day earlier," says Cooper, who is also the assistant head of the biodiversity research lab at the North Carolina Museum of Natural Sciences.
The percentage of eggs that hatched successfully was the same for both herb and nonherb nests. However, hatchlings in the herb nests showed signs of developing more rapidly in the egg than their nonherb peers, and nestlings in herb nests were more successful in gaining body mass after hatching.
"While the data indicate that these herbs influenced incubation behavior in a positive way, it's not entirely clear how that's happening," Cooper says.
"It's possible that one or more of the herbs have pharmacological effects on the parents," says Helga Gwinner of the Max-Planck Institute for Ornithology, who is a first author of the paper.
(Indebted to various sources)