Corticosterone-implanted chicks transmit stress to parents and neighbors in a colonial seabird

In animals living in groups, stress-induced changes in behavior can be a source of social information, and stressed individuals can potentially become stressors for other social partners, with important consequences for social and population dynamics. Here, we studied stress transmission from experimentally stressed chicks to both their parents and neighbors in the yellow-legged gull (Larus michahellis), a seabird that forms large breeding colonies. To do this, we experimentally increased the level of a stress hormone by corticosterone implant in the first-hatched chicks of the brood and observed its effects on their parents and both adults and chicks in the neighboring nests. Two days after the implant, corticosterone-implanted chicks showed reduced basal corticosterone levels, probably due to a physiological feedback response. Exogenous corticosterone promoted behavioral changes in the corticosterone-implanted chicks, showing faster responses to a potential predator attack than the pl..., , # **Corticosterone-implanted chicks transmit stress to parents and neighbors in a colonial seabird**

#### Journal: Behavioral Ecology

#### Susana Cortés-Manzaneque, Sin-Yeon Kim, and Alberto Velando
Corresponding author: [[e-mail]](mailto:[e-mail])

#### About the Study

In this study, we experimentally increased corticosterone levels in gull chicks and observed physiological and behavioral changes not only in the focal individuals but also in their parents, and neighboring adults, and chicks.

**before_implant.csv**

This data was used to test for any possible difference before implantation.

**Description of variables used for data analysis:**

* `broodID`: brood identifier
* `dyadID`: nest dyad identifier
* `dyad_treat`: nest dyad treatment (cort or placebo)
* `brood_manipu`: brood type (implanted or neighbor)
* `cort0`: plasma corticosterone level at implantation
* `sex`: sex of the chick (F = female, M = male)
* `eggvol`: egg volume (cm³)

**2dpi.csv**

This...,