RFID Correlates Birds’ Adventurous Feeding with Social Activity

Published: July 1, 2024
  • Research found a cohort of songbirds that display more social behavior are more adventurous in food source choices as well.
  • The study used RFID to track which birds accessed unfamiliar foods in feeders and linked that activity with their sociability.

Tracking the behavior of small songbirds in the UK’s Wytham Woods has been a multi-decade process for Oxford University. While the ornithology research began in 1947, RFID technology was introduced in 2007 to identify individual birds and thereby track behaviors for a wide variety of research.

Most recently, a study used RFID on great tit birds (GTBs), to understand—over the course of 19 days— how they feed and if there is a social aspect to their food source choices.

In fact, the study, led by researcher Keith McMahon, Oxford’s biology department doctorate, found that more social birds tend to be more likely to use novel sources of food.

Based on RFID technology, researchers were able to track the relationship between social and feeding behavior of 105 wild, GTBs while they foraged in flocks during the last winter. With RFID rings (or bands) on birds and readers at feeders, the team tracked which birds approached specific feeders as well as socialized amongst other tagged birds.

Uniquely Identifying a Small Bird

The GTB is a woodland bird, common in the UK, as well as being one of the most widespread species within the tit (Parus) genus. It’s small— 16 to 22 grams, about the size of a house sparrow —with notable yellow breast, black head and white cheeks. And these birds are being actively studied near the university.

Over the years, researchers have applied Passive Integrated Transponder (PIT) bands with built in EM4102, 125 kHz LF tags around one leg of each member of the entire breeding population of great tits that reside in the research area.

“Each spring we ring and tag approximately 8,000 birds,” McMahon said. By doing so, he said, “we end up with around 80 to 90 percent of the winter population of (the birds) already ringed and tagged.”

Throughout the winter, researchers continue to tag any individuals that migrate into the woods from the surrounding areas.

75 Years of Data

According to Oxford University, this specific species of birds is a good study for ecological research as they readily take to nest boxes, breed in high densities, do not travel far from where they are born, and cope well with being monitored by scientists. The ongoing Wytham project was set up by David Lack, then director of the Edward Grey Institute for Field Ornithology, (EGI) who had visited a research site in the Netherlands related to GTB. He subsequently decided to set up a similar system in Wytham Woods in Oxford.

Today there are more than 1,200 nest boxes used by GTB blue, coal, and marsh species as well as the Eurasian nuthatch. The EGI concentrates mainly on the breeding population of the birds that use the nest boxes.

“To this day, we still monitor this breeding population and their behavior throughout the winter,” said McMahon.

Use of RFID

Researchers at the EGI began using RFID technology in 2007. An RFID antenna was attached to the entrance of nest boxes so that the visitation rates of the birds could be recorded. Cameras mounted inside the nest box also provided data on what the parents were feeding their nestlings.

Research at this early stage of RFID technology use mainly focused on the breeding biology of the birds. But in 2011, the European Research Council provided funding to investigate how the social lives of these birds influence other aspects of their behavior. This area of research would be the focus for the subsequent decade or more.

2024 Findings Related to Social Behavior and Feeding

McMahon explained that as part of the most recent project, birds were given a choice between familiar foods such as ground peanuts in one feeder or more novel looking food consisting of ground peanuts dyed red or green in a second feeder.

The researchers tracked the birds that entered the feeders for 19 days using RFID to identify which birds were willing to try the unfamiliar food. A total of 105 individual birds were identified.

Additionally, the technology enabled study of the social connections to other birds. By correlating the data, the team found that the most sociable birds ate twice the proportion of novel food compared to their least sociable peers.

Further Research Will investigate Causes

Data about bird behavior based on RFID reads is stored in a central database managed by the EGI.

Based on the relatively short winter study, “Our findings that birds showing the highest degree of dietary conservatism (those eating least novel food) held the least central network positions may suggest that these individuals generally experience a reduced level of competition compared to those willing to eat the novel food,” said McMahon.

In future research the team intends to explore any reasons that might explain why social birds are more likely to be adventurous around new foods.

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