Harbour Seal And Grey Seal - How To Tell Them Apart

True or Earless Seal

Spotting seals in the UK is not an unusual occurrence because they have a large population in the country. There are over 30 species of seals; however, only two types of species inhabit British waters – the harbour seal and the grey seal. While it’s possible for you to see other species such as ringed, harp and hooded species around the coasts, these vagrants seals are just visiting.

Both harbour and grey seals belong to the family of true seals (Phocidae). What distinguishes true seals from the other families is that they have no external ears. Hence, they’re also referred to as ‘earless seals’. The bodies of true seals are more streamlined than those from other families. There are 19 species of true seals, including harbour and grey seals.

Harbour or Common Seal

Harbour Seals

Also called common seal, harbour seals are the most widely distributed animals from the Pinniped (feather foot) group. Their habitat includes coastlines in artic and temperate waters in the north Atlantic and north Pacific Oceans. At times, they stay in fresh water like lakes and rivers for feeding purposes. Many of them also love to spend time on rocks to enjoy the sun as well as to become unreachable to predators.

Some of the locations where they can be spotted include Australia, China, North America, Ireland and UK. It is said that its population in the UK comprise five percent of the global population. The best places to see harbour seals in the UK are Portrack Marsh, Blakeney Point and Okney.

Common seals are non-migratory animals. This means that they stay in one location their entire life. Moreover, they never venture too far off their habitat, typically staying within 25 kilometres of shore. Harbour seals can dive deep into the waters – over 400 metres and can stay underwater for over 30 minutes. Male and female common seals tend to have the same size, making it difficult to tell them apart based on height or length.

Grey Seal

Grey Seals

The grey seals, just like harbour seals, are found in different locations. However, they are more common in colder regions. These seals, also referred to as horsehead seals, live on both sides of the Atlantic Ocean. They can be seen in Eastern Canada, Russia, Norway, Ireland and the UK. The British coasts serve as the home to half of the global population of grey seals. The recommended places to spot grey seals are Angel Bay, Lundy Island, Newquay Harbour and Land’s End, among others.

While they are called grey seals, not all of them are coloured grey; some have black or dark brown coats. Additionally, as compared to males, female grey seals typically have lighter coat colour.

Grey seals can stay submerged for quite a while – about thirty minutes. However, unlike common seals, they do not dive as deep as they only reach a maximum depth of seventy metres. This usually happens when they feed. Meanwhile, something noteworthy about their diet is that this species of seals can consume 5kg of food in one day.

What Are Differences Between Harbour And Grey Seals?

So, how do you know if you are looking at a harbour or a grey seal? Telling them apart can be challenging, especially if you are viewing them from a considerable distance. However, there are some features and behaviours which can help you easily identify them.

Body Size

Harbour seals are smaller in size compared to grey seals, with an average length of 1.3 metres to 1.7 metres. Meanwhile, grey seals are usually 1.8 metres to 2.1 metres long.

Head Features

Harbour seals tend to have a smaller head compared to grey seals. In terms of the head shape, harbour seals have round heads while grey seals have oval-shaped or elongated heads. Grey seals have what is called a ‘Roman nose’ which is flatter than those of common seals. Their nostrils do not meet at the bottom and their eyes are situated in the middle. Meanwhile, apart from having a concave forehead, harbour seals’ noses create a dog-like snout with V-shaped nostrils. Their eyes are closer to their nose, too. Lastly, grey seals have double chins while common seals do not.

Pelage Markings

Another characteristic you can use to distinguish harbour seals from grey seals is their pelage or coat markings. Harbour seals’ coat tend to be uniformly spotted. On the other hand, grey seals’ spots and blotches on their backs are bigger and irregularly shaped.

Hauling Behaviour

Harbour seals are solitary animals, but they congregate in small groups when they get off the water onto beaches or shores. However, when hauled out, they maintain individual space (even using aggressive behaviours like growling and headbutting to do so) and do not stay close to each other unlike grey seals. They are also often silent as compared to grey seals which usually make haunting howls.

Pupping Behaviour

If you see seals on beaches with pups in June and July, these are most likely harbour seals as they give birth during these months. Since they’ve moulted their white fur inside their mother’s uterus, these pups already bear spotted coats when they are born. Moreover, even just hours after birth, harbour seal pups swim and dive with their mothers.

Meanwhile, grey seals give birth between September and December. Their pups still have their white coats upon birth. Unlike common seal pups, grey seal pups cannot swim until their white fur is moulted.

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Earless Seal

Image Attribution: By Chmouel at en.wikipedia (Transferred from en.wikipedia) [GFDL, CC-BY-SA-3.0 or GFDL], from Wikimedia Commons

Image Resource: https://commons.wikimedia.org/wiki/File%3AEarless_seal_(Puerto_Madryn%2C_Argentina).jpg

Grey Seal

Image Attribution:By Boyd Amanda, U.S. Fish and Wildlife Service [Public domain], via Wikimedia Commons
Image Resource: https://commons.wikimedia.org/wiki/File%3AGrey_seal_animal_halichoerus_grypus.jpg