In this April 20, 2014, file photo, a loon swims on Lake Winnipesaukee in Wolfeboro, New Hampshire. Credit: Jim Cole / AP

CONCORD, New Hampshire — Annual counts of loons are up slightly in New Hampshire and Vermont, wildlife authorities and advocates said Tuesday.

In New Hampshire, the number of territorial loon pairs rose from 321 to 326 this year, according to the Moultonborough-based Loon Preservation Committee. Those are pairs that stay together for at least a month and have a potential to breed, said Harry Vogel, senior biologist with the committee.

Vermont’s Fish and Wildlife Department said loons in that state are also thriving. A record of 109 nesting pairs were recorded in 2021 — the highest since loon monitoring began in 1978, the department said Tuesday.

Maine is home to the largest population of loons in the eastern United States. Maine Audubon said Monday the count of adult loons increased this year, but the count of loon chicks fell.

Loon counters in Maine found 3,446 adult loons this year, up from 2,974 last year, however the number of chicks was down to 224 from 414, Maine Audubon said.

Wildlife advocates in the states attributed the increase in loon counts to management measures such as protection of nesting areas. Bans on the use of lead fishing tackle have also played a role, they said. Ingestion of lead can kill the birds.