How to Identify Seal in Connecticut

Harbor seals are the smaller of Connecticut's two resident seal species, typically 4 to 5 feet long and weighing 100 to 300 pounds. They have a rounded, dog-like head with large eyes positioned high on the skull. Their most distinctive feature is V-shaped nostrils that angle downward. Coloring ranges from brown to grey to spotted patterns, with lighter undersides. Their body shape is streamlined and compact, built for agility in water. When hauled out on rocks or sand, they rest in a caterpillar-like pose with their body curved rather than stretched out straight.

Grey seals are noticeably larger than harbor seals, typically 6 to 7 feet long and weighing 200 to 700 pounds. They have a longer, more pointed snout that gives them a distinct profile different from harbor seals. Their nostrils form a U-shape and are more widely spaced. Coloring is darker overall, ranging from charcoal to nearly black, though females and younger seals are often lighter brown. Grey seals have a larger frame and more robust appearance. On shore, they stretch out more horizontally than the hunched posture of harbor seals, making them easier to spot.

Head shape is the most reliable field mark for telling these two species apart. Harbor seals have a rounded, almost cat-like head with a gentle profile. Grey seals have a longer, more prominent snout and a head shape often compared to a horse's profile. The nostril shape is another quick check: harbor seals have V-shaped nostrils that point downward, while grey seals have U-shaped nostrils set farther apart. When you see a seal on the rocks, focus on the head profile first. A rounded, compact head with a small snout is nearly always a harbor seal. A longer, more prominent snout is a grey seal.

Harbor seals max out at about 5 to 5.5 feet long, while grey seals commonly reach 6 to 7 feet and can exceed 700 pounds. A grey seal hauled out on a rock will almost always look substantially larger and bulkier. However, size alone can be misleading when viewing a single animal without a reference. A large harbor seal and a smaller grey seal can overlap in length. Always pair size observation with head shape, snout length, and nostril configuration for a confident identification.

When seals haul out repeatedly on the same rocks or sand, they leave visible paths and wear marks. On sand, look for parallel drag marks from their body and flipper prints. Harbor seals leave narrower, more delicate track patterns. Grey seals leave deeper, wider trails due to their greater weight. On rocks and docks, greasy wear patches and scat deposits show where they regularly rest. If you find scat, harbor seal droppings are typically small and thread-like, while grey seal scat is larger and more robust. These habitat signs confirm which species are using a particular area.

Yes. Harbor seals are quieter hauled out but make barking and grunting vocalizations in water, especially during breeding season. They produce a distinctive series of bleats and growls underwater. Grey seals are louder and more vocal on shore, producing loud roaring and grunting sounds, particularly males defending territory during breeding season. If you hear sustained loud roaring or honking from a coastal area in late fall or winter, it is likely a grey seal. The generally quieter, calmer presence hauled out is more typical of harbor seals.

When viewing hauled-out seals, scan slowly from one end of the rock or beach to the other. Use binoculars or a spotting scope to avoid getting too close and disturbing them. Count each individual and note its head shape, size, and coloring. Record the time and location. Keep at least 150 feet away to prevent them from flushing into the water. If you are watching from a boat, maintain even greater distance. Document what you see with photos if possible, including close-up head shots showing the nostril and snout profile. These records help track population trends over seasons.

Rarely. Harp seals and bearded seals occasionally wander into Long Island Sound during harsh winters, but sightings are uncommon and unpredictable. These Arctic species move south when ice breaks up or food is scarce, but they do not haul out regularly like harbor and grey seals. If you see an unusual seal with distinctive long whiskers, pale coloring, or features you cannot match to harbor or grey seals, photograph it and report it to Connecticut DEEP Wildlife Division. Such sightings help document range shifts and population health.

Low tide exposes the most rocks and sandy areas where seals haul out to rest and warm up. Morning hours often see more seals ashore before human activity increases. Fall and winter, especially late September through March, are peak hauling-out seasons when seals spend more time on land to maintain body temperature. Spring and summer seals spend more time in water hunting fish, making them harder to see. Calm, clear weather reveals more detail through binoculars and makes photography easier. Overcast days are better than bright sun, which creates glare off water and rock surfaces.