Once near extinction, gray seals are a frequent sight in Delaware Bay

 

Nature: Once near extinction, gray seals are a frequent sight in Delaware Bay

In this column, I bring you a big chunk of mammalian exotica, at least by central Ohio standards. I spent six days in late January in Lewes, Delaware, a town of about 2,750 at the mouth of Delaware Bay. Lewes bills itself as “The First Town in the First State.” Delaware was admitted to the fledgling United States of America on Dec. 7, 1787, edging out the second state, Pennsylvania, by five days.

The founding of Lewes long predates that, its origins dating to 1631. There is much history in this seaside town, but I was mostly here to see and photograph birds and other animals. A friend, Jim Rapp, is an organizer of the Delmarva Birding Weekends, which include boat trips into Delaware Bay. He secured me space on the ship, and we set sail on Jan. 28.

Birds came fast and furious. We saw all three scoter species: black, surf and white-winged. Scoters are sea ducks that winter primarily on salt water and dive to great depths for clams and other marine animals. There were plenty of common loons and some red-throated loons, and massive northern gannets, the boobies of the north. Gannets have a 6-foot wingspan and dive for fish from great heights.

Many other species were seen, including the great cormorant, a maritime species that dwarfs the double-crested cormorant commonly seen in central Ohio. But as much as all these birds excited the 83 birders aboard the Thelma Dale IV, a mammalian plum awaited.

We eventually reached a large system of rocky breakwalls and started scanning the rocks. A small rocky pile known as an icebreaker – built long ago when the bay regularly froze – delivered the score. A dozen or so gray seals!

Seals need to “haul out” of the water regularly to rest, interact, birth pups, and get a break from icy waters. About a dozen seals loafed around on the rocks, lorded over by a massive bull. Gray seals inhabit both sides of the Atlantic Ocean, but animals on this side of the pond are bigger.

An alpha bull can weigh nearly 900 pounds and be almost 10 feet long. Females are comparatively svelte, growing to perhaps 7 feet and tipping the scales at 500 pounds. But “svelte” is probably not a good seal descriptor. When hauled out and completely visible, a seal looks like a lard-filled sleeping bag with a cute face and expressive flippers. They often elevate their head and hind end, creating the appearance of a big banana.

When in the water, a gray seal becomes the epitome of aquatic grace. They are swimming machines that specialize in capturing fish, and that takes speed and agility. Gray seals routinely hunt to depths of 250 feet but can go much deeper. They are known to descend to over 1,500 feet and can stay under for an hour.

It almost made me hypothermic just looking at the seals. The water was frigid, the air temperature was brisk, and they were lolling around on wet, wave-splashed rocks. Seals do have a coat of fur; it is a thick layer – up to several inches - of insulating blubber that keeps them warm. In times of lean food, the blubber serves as a food source.

Gray seals and many other seal species were once hunted to near extinction. Seal conservation via the Marine Mammal Protection Act of 1972 allowed populations to rebound. Now gray seals are a frequent and increasing sight in Delaware Bay, near the southern end of their range which spans northward to Newfoundland.

Harbor seals have increased as well, and lucky Delaware Bay seal-watchers might also see harp seals and, if truly fortunate, a hooded seal. Males of the latter species have a pinkish-red inflatable membrane that can be shot from the left nostril and inflated to the size of a balloon. The size of the nose sac helps establish dominance between males and is alluring to females. A male hooded seal with an inflated nose sac is high on my wish list.

For more about Delmarva Birding Weekends, visit: delmarvabirding.com.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.