Osprey nests signal a rebounding population in Delaware

The boat is very loud when it comes, and then it leaves and comes back but at night it leaves and it’s gone again until morning.

The cars go on and off and rumble by and once they’re on the Cape May-Lewes Ferry, people come up to the deck and if they know where to look, they can spot an osprey’s nest on a power boom at the terminal. If a crew member has good eyesight, and is up by the pilot’s house, they might be able to spot one of the three, rumored to possibly be four, eggs in the nest.

The pair of ospreys have returned to that spot, surrounded by machinery and the constant movement of people, for another year.

Ospreys nest in the area from March through April, often in the same spot, and it has become increasingly common for them to pick manmade objects to nest on, according to Delaware Department of Natural Resources and Environmental Control Wildlife Biologist Kate Fleming.

As the ferry comes in one afternoon around 4 p.m., one of the ospreys is returning to the nest to sit over the eggs. The other is gone, but crew members said he’ll return, often resting on the boom a bit closer to the boat.

The birds are remarkable for their ability to stay in a spot so influenced by man, but also because 40 years ago osprey populations in Delaware and other places were decimated by the use of DDT in pesticides. Now the population is flourishing.

After that crash, DNREC was aware of 25 osprey nests in the state that were producing young. Last year, they were aware of close to 200 active nests throughout the state, Fleming said.

“We’re seeing more and more osprey in Delaware every year,” she said.

One way DNREC keeps track of the ospreys is through its citizen osprey monitoring program, where volunteers monitor nest sites during the breeding season at least once every few weeks to record milestones, such as when the ospreys return, when they witness nest building, when eggs are laid and when chicks have hatched.

Adults hunkering down on top of the nest is a good sign eggs have been laid, and when chicks hatch, people can see ospreys bringing fish back to the nest as well as the adult shading the young birds with their wings. DNREC is looking out for which nests are successful and which ones have failed.

Ospreys are an interesting species to DNREC because, apart from being important to the ecosystem, the birds are sensitive to changes in the environment, so contamination in an area or a water quality problem will often be reflected in the osprey population.

Additionally, many residents are interested in ospreys because they create big nests in open areas near the water where they are highly visible.

“The more osprey we see, the more interest from the public,” Fleming said.

It is also becoming more common to see ospreys nesting on man made structures, such as the boom at the Lewes terminal. It’s an interesting situation, considering concerns DNREC has considering osprey’s interactions with humans.

The Cape May-Lewes Ferry’s Twitter page occasionally posts updates about the ospreys. Chicks are usually able to fly by August, and in October osprey migrate south in October to Florida, South America or even the Caribbean.

rpacella@dmg.gannett.com

302-537-1881, ext. 207

On Twitter @rachaelpacella