NA­TURE

See the seals on our coast

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It’s the sea­son of the seal. The grey seal, or Hali­choerus gry­pus, which trans­lates un­flat­ter­ingly as ‘hook nosed sea pig’ if you pre­fer.

It is now that these sea mam­mals will be vis­it­ing our largely un­mo­lested beaches to haul out and breed. Dur­ing Novem­ber to Jan­uary in­creas­ing num­bers of these large an­i­mals – some bulls reach nearly three me­tres in length and weigh in at more than 300kg – use our shores to raise their young.

The cows which are smaller and lighter ar­rive first, al­ready heav­ily preg­nant from last year’s mat­ing; they will give birth within a day or two of beach­ing. The bulls ar­rive shortly af­ter­wards and set about es­tab­lish­ing a loose ter­ri­tory within which a harem of fe­males will be birthing. Most ter­ri­to­rial skir­mishes be­tween ri­val males are some­what half-hearted, du­els be­ing no more vi­o­lent than clumsy chases across the beach or grumpy snarling and pos­tur­ing, much like the an­tics adopted by pro­fes­sional foot­ballers. How­ever, oc­ca­sion­ally a fierce con­test does take place with the testos­terone fu­elled crea­tures squar­ing up and tak­ing chunks out of one an­other in an ef­fort to as­sert dom­i­nance. This all gen­er­ally leads to just a small num­ber of males mo­nop­o­lis­ing the mat­ing process.

Nearly 50% of the world pop­u­la­tion of grey seals is found in the UK, with the East Anglian coast­line rep­re­sent­ing a sig­nif­i­cant breed­ing re­source. The colony at Horsey and the sur­round­ing area on the east Nor­folk coast is per­haps the best known and most eas­ily ac­ces­si­ble rook­ery. Here, friendly vol­un­teer war­dens are on hand to pro­vide in­for­ma­tion about the seals’ life-cy­cle and breed­ing be­hav­iour.

The beach is sub­ject to a vol­un­tary clo­sure dur­ing the win­ter months to al­low the seals to breed with­out in­ter­fer­ence; the cows are very sen­si­tive to dis­tur­bance, par­tic­u­larly by dogs, so pro­vid­ing a safe zone for them to nurse their young is es­sen­tial to breed­ing suc­cess. Should the cow be dis­turbed, it ex­poses the pup to the risk of mov­ing into a bull’s ter­ri­tory or the ter­ri­tory of an­other cow re­sult­ing in an at­tack lead­ing to in­jury or death. De­spite the beach be­ing roped off, there are still ex­cel­lent op­por­tu­ni­ties for ob­serv­ing and pho­tograph­ing the

“It is a tremen­dous ex­pe­ri­ence – es­pe­cially so for chil­dren – and an op­por­tu­nity to get close to some re­mark­able wildlife”

seals up close, with some suck­ling their at­trac­tive, dark liq­uid-eyed pups within a few me­tres of the ador­ing pub­lic. These pups, which only weigh around 14kg at birth, are cov­ered with a thick white fur but soon grow fat on the rich milk sup­plied by their moth­ers. This milk is so fat rich that the pups in­crease their weight by two kilo­grams a day. Un­like com­mon seal pups which can swim within a few hours of birth, it takes three weeks of in­tense feed­ing and a few more to grow a wa­ter­proof coat be­fore grey seal pups reach suf­fi­cient size and weight to take on the rigours of the North Sea. The cows do not them­selves feed dur­ing the wean­ing process and will lose a sig­nif­i­cant per­cent­age of body weight. They aban­don their off­spring once they judge them ca­pa­ble of an in­de­pen­dent life, will mate with the dom­i­nant bull and then hun­grily re­turn to the cold depths that is their home.

Grey seals are quite ex­traor­di­nar­ily adept swim­mers and hun­ters. They hunt singly, div­ing to a depth of up to 70 me­tres to catch their favourite food, fish, squid and sand eels. Their abil­ity to slow their heart rate while un­der­wa­ter al­lows them to stay sub­merged for sev­eral min­utes at a time. They are al­most ex­clu­sively sea dwellers, but I’ve watched in­di­vid­u­als ac­tively hunt­ing along the tidal rivers of Nor­folk, tear­ing into a hap­less flat­fish with rel­ish. They hunt by sound as well as sight, which would seem to be in­valu­able in the murky wa­ters sur­round­ing our coast­line. They are long lived an­i­mals, typ­i­cally at­tain­ing an age of 25 to 30 years al­though first year mor­tal­ity is very high with only 50% of pups mak­ing it be­yond their first birth­day.

If you get a chance over the next few weeks I can thor­oughly rec­om­mend a visit to a grey seal breed­ing colony. It is a tremen­dous ex­pe­ri­ence – es­pe­cially so for chil­dren – and an op­por­tu­nity to get close to some re­mark­able wildlife. At Horsey visi­tors are mon­i­tored and paths well marked and po­liced; at other sites it is es­sen­tial you en­joy the seals while ex­er­cis­ing cau­tion.

There are a few sim­ple rules to fol­low (Friends of Horsey Seals web­site – friend­sofhorsey­seals.co.uk):

• Stay at least 10 me­tres from the seals

• Look out for seals in the dunes and give them a wide berth

• Be care­ful – seals have a nasty bite

• Keep dogs on a lead

• Keep to marked view­ing ar­eas and re­spect the fenc­ing

• Re­mem­ber grey seals are wild an­i­mals and should not be ap­proached

• Re­spect other visi­tors For more of Barry Mad­den’s bril­liant na­ture mus­ings and art­work, take a look on­line at: www.east­ern­bushchat.blogspot.co.uk

The grey seal colony spread across a large part of the beach at Horsey, on the Nor­folk coast.

Peep­ing out from among the dunes at Horsey.

The grey seal colony on the beach at Horsey, Nor­folk.

A baby seal pup with its mother on the beach at Horsey.

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