If you see a bald eagle with a stick in its beak, let Massachusetts officials know.

That’s the message from the state’s Division of Fisheries and Wildlife, which notified the public this week that its staff needs help tracking the birds of prey.

State ornithologist Andrew Vitz told GBH News that December to February is known as “stick season” for bald eagles, and the state agency hopes residents will let them know if they spot one of the iconic birds flying with nesting material.

“We know there are a bunch more nests out there that we just haven't been alerted to,” Vitz said. “That's why we are trying to engage the public to increase our knowledge.”

Bald eagles, the largest nesting bird of prey in Massachusetts, were once considered endangered under the Massachusetts Endangered Species Act. They are now considered a bird of “special concern” following decades of recovery, leaving their signature white heads visible in areas across the Commonwealth.

Since the 1980s, the state has worked to increase the eagle population, including bringing young eaglets to the area and breeding pairs. Many historic threats to eagles, like the presence of the chemical DDT and polluted waterways, are also now less of an issue.

Vitz said that nesting is most common during the morning hours and encourages residents to take photos of eagle activity, as well as note the location and direction the eagle is flying. If the birds fly with sticks or come to the ground to collect grass or mud material, it’s usually a sign a nest is nearby, he said. “Once they have the material in their talons or in their beak, they're going make a direct flight to that nest.”

Residents can email mass.wildlife@mass.gov with the location and time of their observation.