CORVALLIS, Ore. (KOIN) — As songbirds learn from other birds that food is low, they change their physiology and behavior to prepare, Oregon State University College of Science research shows.
According to OSU, the red crossbills in the study raised their pace of consumption, increased their gut mass and maintained the size of the muscle responsible for flight after receiving social information from food-restricted birds for three days.
The songbirds’ own eating opportunities were later limited to two short feeding periods per day.
Jamie Cornelius’ findings – an assistant professor of integrative biology at the university – suggest that birds can use social information about food shortages to impact an adaptive advantage for survival. The findings were published in the journal Proceedings of the Royal Society B.
“This is an entirely new form of physiological plasticity in birds and builds on prior work showing that social cues during stress can actually change how the brain processes stressors,” said Cornelius.
The assistant professor, who is also an ecophysiologist, looks at the process that wild animals – specifically songbirds – use as they manage with uncertain and extreme events in their environment, including a shift in food availability.
According to the university, her research combines natural history, endocrinology and biotelemetry to look for a better understanding of what limitations an animal’s fitness under tough circumstances.
“Animals have all kinds of strategies for dealing with challenging environments, ranging from seasonal avoidance strategies like hibernation or migration to behaviors like caching or altered foraging activity,” she said. “Physiological adjustments in metabolic rate, digestive capacity and energy reserves can sometimes accompany behavioral changes, but those things can take time to execute. That means unpredictable environmental conditions are particularly challenging for many animals.”
A red crossbill with a food-restricted neighbor will produce higher than usual levels of a stress hormone during its own food-stress periods, Cornelius’ research showed.
The birds also go through brain activity changes that prepare the bird to respond more strongly to the challenge.
The university describes the bird as a “nomadic species” that migrates based on food availability and integrates other birds’ calls or behavior into its decision-making on how to respond to food deprivation.
Found throughout Europe and North America, the crossbill is a member of the finch family.
According to OSU, it’s known for upper and lower beak tips that cross, a feature that helps the bird pull seeds from conifer cones and other fruits.
“Crossbills are an interesting study system because of their dependence on conifer seeds,” Cornelius said. “Conifer seed crops are somewhat unpredictable both in where seed crops develop each year and in how long a seed crop might support birds. We use crossbills as a study system to try to understand what strategies birds might have available when food suddenly declines because crossbills may have to cope with this more often than other species.”
The research involved crossbills in captivity. This means some of the birds received three days of social information from food-deprived birds prior to their own food limitations.
OSU added that other birds received three days of social information from food-deprived birds at the same time as their own food deprivation.
Cornelius describes the former collection of birds as the “social predictive focal group” and the latter as the “social parallel focal group.”
“The birds did better at maintaining body mass during food restriction if the social information was predictive of the decline in food resources,” she said. “Social information is important to animals in many different contexts, and this study demonstrates a novel benefit: Advance warning about declining food can lead to better outcomes during times of scarcity.”