Colonial Nesters on and near Seabrook Island

On Friday, we asked which birds nest in “rookeries” here on Seabrook Island.  We got quite a few responses of Great Egret, which is correct!  Another person said Least Terns. They do nest in colonies, but in 2016 they didn’t nest on Seabrook as a result of predators.  And then of course there is the Blue Footed Booby – yes, they are colonial nesters but never seen on Seabrook!  LOL

So, what is colonial nesting?  This term describes bird species that nest and breed in close proximity as a group.  It can vary from just a few breeding pairs to hundreds or thousands of pairs!  A colony can be a single species or several bird species in a single colony.  As some of our residents can attest, these colonies can be quite loud and very active with courting adults, begging chicks and the comings and goings of birds.

It is estimated that 10% of the world’s bird species are considered colonial nesters.  There are several benefits for these birds:

• Safety in numbers
• Sharing of duties, including parental, gathering food, etc
• Easier to find a replacement mate
• Increased chance of chick survival

There are some downsides to colonial nesting as well:

• Availability of food sources
• More predators may be attracted to site
• Disease can spread quickly
• Natural disasters

Common colonial nesters found in South Carolina include herons, egrets, cormorants, swallows and several types of seabirds and shorebirds (these will be addressed in a future article).  Most of the egrets and herons form colonies with several species.  In most cases, the nests are built by both the male and female. In general, 3-5 eggs are laid with an incubation from 20-30 days depending on species.  The chicks are able to fly and leave the nests in as little as 4 weeks and some up to 7 weeks.

As most people know, the Great Egret and Snowy Egret colonies are the most obvious and can be seen easily on Jenkins Point and the pond off of the 4th hole of Ocean Winds. Great Egrets generally build their nests from 10-40′ above the water. Snowy Egrets build their nests 5-10′ above the water.

Green Herons can be found nesting in several locations, including around Palmetto Lake behind the Lake House, along Jenkins Point and on several of the canals and ponds throughout the island. They tend to nest as isolated pairs or in small groups, but not normally in large colonies.  Their nests are 5-30′ above water and the young are flying as early as 23 days.

The Black-crowned Night-heron and the Yellow-crowned Night-heron are both quite secretive and little is known about their breeding and rearing of young.  In fact, we are sure they do nest here on Seabrook Island as we have frequently seen their young, but the exact locations are not know.  They do nest in isolated pairs or small colonies.

Three additional colonial nesting herons raise their young here in SC, but we have not seen any of their colonies on Seabrook Island.  A great place to view their nests (along with many other species) is at Magnolia Plantation.  It is worth the drive to view the magnificent rookery they have which includes both egrets along with Anhingas and others!  The Great Blue Heron builds its nest 20-60′ above ground/water, the Little Blue Heron’s nest is 5-30′ above ground/water and the Tri-colored Heron is only 2-10′ above ground/water.

The White and Glossy Ibis are also colonial nesters and we’ve heard the Glossy nests in a secretive spot somewhere on Jenkins point.

The closely related Double-crested Cormorant and the Anhinga are also colonial nesters.  The first often nests near water on a cliff edge or in trees.  The latter near quiet sheltered water.  David Gardner reports that he frequently has an isolated pair of Anhinga nesting near the slough on St. Christopher.

Finally, two of the most unusual and spectacular wading birds, the Wood Stork and the Roseate Spoonbill, are also colonial nesters. Although we have no known colonies of these birds on Seabrook Island, a rookery with Wood Storks is only a 35 minute trip to Dungannon WMA.  It is rumored a pair of Roseate Spoonbills have nested in past seasons at Bear Island in the Ace Basin.

If you get a few minutes, take time to visit one of our rookeries to view the nesting birds and their young. It’s just another reason we love living here in paradise!

Article Submitted by:  Nancy Brown
Photographs by:  Ed Konrad