Colonial Beach's osprey season was 'a disaster'

Colonial Beach residents celebrated the number of osprey nests in the Potomac River town this spring and summer — as volunteers banded four times more chicks this year than 2023 — then their delight turned to despair.

From late July to early September, the majority of osprey chicks died. Their feathered carcasses were seen by drones that hovered over the nests, built on pilings and platforms in and around the town. Or the birds fluttered to the ground, too weak to fly. They were quickly shuttled to rehabilitators in the Tidewater area but couldn't be helped.

"It's a sad state, I have never seen anything like this," said Joanie Millward, president of the Virginia Osprey Foundation based in Colonial Beach. "I can't say what happened, I'm not a scientist, I'm not a researcher, but what we do know is they starved to death."

What caused the starvation is the bigger question. Speculation ranges from the lack of menhaden — an oily fish full of nutrients found in Chesapeake Bay waters — to the impact of climate change. Warmer water may be causing fish to go deeper, making it harder for surface fishers like osprey to catch them with their talons.

But for Colonial Beach residents, who've watched nearby nests from back porches and docks, the events have been devastating. The osprey has become as iconic to the town as golf carts, and one display along the boardwalk combines both. Visitors can hop into the front seat of a golf cart that has the word LOVE spelled out in wooden letters behind them.

An image of an osprey sits in a platform nest atop the letter "L."

Mary Wenz, who in recent years formed the Colonial Beach Wildlife Facebook group to rescue animals in distress, watched as osprey parents seemed to abandon the nests before teaching the young to fly or fish on their own.

She couldn't intervene, saying it's against the Migratory Bird Treaty Act to interfere with an active nest.

"We had to just watch," Wenz said. "We felt helpless, it was such an awful, awful summer. It was like which baby was going to be the next one down."

'It's been a disaster'

There are 58 monitored osprey nests within the 2.5 mile limits of the Town of Colonial Beach. Last year, the Virginia Osprey Foundation reported that 55 chicks fledged, meaning their wings were developed enough for flying but they were still dependent on their parents for care.

This year, of the 44 chicks volunteers spotted in nests, maybe six to eight made it out alive, Millward said. She doesn't have a precise number because the nest height and location sometimes make it difficult to know exactly what happened.

Often, volunteers would see one or two chicks in the stick-filled nest one day, then several days later, no activity.

Predators may have gotten some; younger birds that died in the nest might have been carried away by their parents, Millward said. The bottom line is the skies that were filled with adults and successfully fledged offspring last year showed little evidence of the raptors late this summer.

"It's been a disaster," she said.

When there's not enough for parents and offspring to eat, adult birds abandon the nests and feed themselves so the species can go on. It's a harsh reminder of nature's survival-of-the-fittest rule, Millward said.

Colonial Beach osprey chicks aren't the only ones starving. The Center for Conservation Biology at William & Mary released a report on Sept. 13 that said osprey young aren't surviving at rates to sustain the population. They're dying from lack of food, particularly in areas of the bay where the birds rely on menhaden fish.

The study followed 571 osprey pairs at 12 study areas in Maryland and Virginia. The results prompted Chris Moore, executive director of the Chesapeake Bay Foundation, to call once more for a study on the industrial fishing of menhaden as the fish are a food source for striped bass, osprey and whales.

"This year's osprey data adds to the growing concerns about the number of menhaden in the bay and the importance of a robust menhaden population for species that depend on them for food and Virginia's economy," Moore said.

Last month, the Atlantic States Marine Fisheries Commission voted to form a workgroup to consider additional restrictions on the menhaden harvest in light of the problems with osprey young. Virginia did not approve funding for a similar study earlier this year.

'Emaciated' chicks

Colonial Beach was not among the sites studied in the William & Mary report, but Millward sent the researcher, Dr. Bryan Watts, information about the town birds.

"Based on what the rehabbers have had to say, it does not sound like there is any doubt that the young starved," Watts said in an email to The Free Lance–Star.

But because the center hasn't done a diet study at Colonial Beach, he couldn't say if the chicks starved from a lack of menhaden or another species or from poor fishing conditions. "I just don't know," he said.

The waters of the Potomac certainly were warmer during key times in osprey development, which might have caused surface fish to go deeper for cooler climes. Millward is also a volunteer with the Potomac Riverkeeper Network, and she said water samples showed temperatures were 6.2 degrees to 8.1 degrees warmer from May to July than for the same period in 2023.

Virginia's Department of Wildlife Resources did necropsies on three dead chicks from Colonial Beach and found no evidence of disease such as avian flu or West Nile virus. "They were in poor body condition with very little in their GI tracts," according to the DWR report.

Wenz and her volunteer rescuers saw the same.

"These babies were emaciated and we could tell that by feeling that their crop was not full," she said. "Some had mites and ... they can be prevalent when the birds are under stress."

Part of a pattern?

It's difficult to determine if what happened with Colonial Beach osprey chicks this season is part of the ongoing pattern of decline in the Chesapeake Bay, which has been happening at least since the mid-2000s — or a one and done.

"It is not uncommon to have wide swings in osprey breeding performance one year to the next," Watts said.

Predators play a part as do heat waves and hail storms, droughts and rainy seasons, but the year-to-year fluctuations aren't the concern, he said.

"Repeated poor production is a much greater reason for concern for the population," he said.

Craig Koppie, a raptor biologist who's retired from the U.S. Fish and Wildlife Service, said osprey declines, along with those of peregrine falcons, are being reported across the nation and world.

"It's amazing how many of the populations that were so robust are decreasing, some are down 60%," he said. "There's literally something going on with raptors, not so much bald eagles yet, but I think it's just a matter of time. It's kind of scary."

Millward would say the same about Colonial Beach osprey although she hopes adult birds will have the kind of successful breeding season next year that they've had in the past.

One thing is for sure, many eyes will be upon them. Even if similar issues are happening with ospreys around the Chesapeake Bay and beyond, they're not likely to draw the kind of attention the birds received in Colonial Beach, said Ken Smith, a federally licensed raptor bander from Prince George's County, Maryland.

Colonial Beach is "pretty unique," both in the number of ospreys and the people watching and monitoring their nests.

"The community involvement with the osprey and conservation in that town is just wonderful," he said. "At the same time, one of the reasons you're hearing so much about (chicks) that died is because there are so many people involved and so many nests in a concentrated area, more people are able to see what's going on."

Cathy Dyson:

Health, King George, features and is a local columnist