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Senses
Whiskers
Seals search for food with their coarse , continuously growing whiskers.
The seal sweeps its upper lip to and fro, using these sensitive
whiskers to detect fish in murky waters.
Vision
Seals have very good vision in water. The eye must focus in both
air and water so is very large and round.
Smell
Seals have a keen sense of smell in air, which allows them to detect
predators. Females also use smell to recognise their pups on crowded
breeding beaches. While swimming the nostrils are kept tightly shut
Hearing
Seals hear very well in both water and in air. Females and pups
often call to each other. Seals also make growls and grunts underwater
especially during the breeding season
Feeding
Seals are opportunistic feeders – they feed on a number of
different prey depending on which is available, diving to around
120 metres or even 300m deep. Their diet consists mainly of fish
such as sand eels, herring, saithe and whiting as well as bottom-dwelling
fish like plaice and flounder. Squid and octupus are also frequently
eaten.
Breeding
UK seals breed in colonies where
animals congregate on beaches, sandflats and in caves. Male seals
often fight for access to females.
Pupping
Grey seals give birth to a single pup on beaches or in hidden sea
caves from July to November. Common Seals pup on beaches and tidal
sandflats within tidal reach, from May to July. In both species
conception to birth takes around 11 months and implantation of the
embryo is delayed by around 3 months.
Grey seal pups are born with silky
white coat or lunugo, which is moulted at around 9-18 days old and
are quite helpless. Common seal pups are dark and motted, having
shed their lanugo before birth, and can swim within 5 minutes.
Grey seal pups are nursed for only
around 17 days so they must grow very rapidly consuming 3.2kg of
fat- rich milk per day! The female does not eat during this time.
After weaning, the pup moults and must fast, living on its stored
fat for up to 4 weeks before it learns to forage and catch its own
fish. The common seal pup learns to forage much earlier as it accompanies
its mother on short trips during the 3-5 weeks after she nurses
it. They spend much more time playing in the water from a very early
stage.
Mating
Seals mate at the end of lactation. Grey seal females can breed
at around 4 years old whereas female common seals must be 3-7 years
old to breed and males must be 3-8 years old. Both species can mate
in water. Moulting: During the moult seals spend much of their time
hauled out of land as they need to conserve energy. Grey seals moult
from December-March ( females) and March-May ( males ) in the UK
and the republic of Ireland and common seals, from mid July to mid
September
Threats
The main threats to the UK and Irish seals are: Interactions with
fisheries Disease e.g. the phocine distemper virus (PDV) Epidemic
of 1988 which killed 18,000 seals Pollution – plastic debris
and toxic chemicals. Seals could be a threat from repeated calls
for a cull in Scotland
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