Image credit: Danielle Haulsee
Emily DeMarco of Inside Science reports that researchers from the the University of Delaware are fitting Delaware Bay tiger sharks with devices to track them during their southward migration. These researchers are interested in, not just where they go, but how the sharks interact with each other and other animals during their long swim.
The team implanted acoustics transceivers into 350 adult tiger sharks staring in 2012. They found that when the sharks migrate south, they become extremely dispersed into small male-dominated groups. However, when the sharks migrate back north to the Bay of Delaware, the network of sharks “fuses” back together with both male and female sharks mixing together again.
This data illustrates the social networks of sharks. The dispersion-fusion behavior they display is typically associated with higher-order mammalian species like dolphins and elephants. Evidence of this pattern in the Delaware population suggests that sharks could have more complex social networks than perviously conceived.