Monitored by the Sea Mammal Research Unit annually, the islands of Lingay and Groay have been managed for conservation over the last decade and are recognised breeding sites for both Atlantic Grey and Common (or Harbour) Seals.

Haul out sites exist around both islands, with the main concentration of seals being in the sheltered areas on both islands and on the tidal island in-between.

It is known that the seals return to the same breeding sites generation after generation.

The female grey seals give birth mainly during October and November.  At birth the pups weigh about 13Kg and are protected by a creamy white coat.  The pups are weaned after losing their cream coat approximately 3-4 weeks after birth.  They will have gained about three times their birth weight, which they use to survive on whilst they learn to feed which may take several weeks.

The female common seal gives birth in Spring.  The pups are well formed (weighing up to 16Kg) and are capable of swimming and diving within hours of birth.  They suckle for 3-4 weeks, putting weight on quickly on their mothers rich milk diet.  By the time they are weaned they can have doubled their weight.