A Swinhoe's storm petrel sits near its nest on Dagong Island. Cheng Yachang (left) from Sun Yat-sen University in Shenzhen, Guangdong province, fixes a tracking device on a storm petrel on the island. [Photo provided to China Daily]

The researchers also found that some of the birds were flexible in their foraging strategies. For example, those with longer wings were more inclined to take longer foraging trips.

"Other physical attributes such as body weight, bill length, and wing width showed no correlation with foraging strategies," Liu said. "It was a surprise for us."

The findings emphasize the influence of environmental factors and individual characteristics on the foraging decisions of Swinhoe's storm petrels in a productive oceanic ecosystem.

"The foraging strategies observed among the storm-petrels breeding on Dagong Island show the species' adaptation to the environmental conditions of the Yellow Sea, aligning with the region's high marine productivity," Liu said.

Contrary to initial expectations, the study did not find any significant effects from offshore wind conditions or marine primary productivity, which is measured by using the chlorophyll-a concentration observed by remote sensing satellites, a well-used indicator for evaluating nutrition levels in the open sea.

Instead, it hints at the presence of specific but as yet unidentified resources in the open sea, such as particular fauna within the Yellow Sea Cold Water Mass, which may play a crucial role in attracting foraging seabirds.

"The study's findings not only enhance our understanding of the bird's behaviors," Liu said. "It also underscores the importance of continued research and efforts to protect these enigmatic seabirds and the delicate ecosystems they inhabit."