Wildlife diary

Felix Al­dred fol­lows a fam­ily of oys­ter­catch­ers

EADT Suffolk - - INSIDE -

Oys­ter­catch­ers are wad­ing birds found along coasts ev­ery­where, in­clud­ing Suf­folk. This unique species can be iden­ti­fied by its black and white plumage and its long orange bill, used to feed on in­ter­tidal prey such as shell­fish and worms.

The Eurasian Oys­ter­catcher ex­clu­sively lives in Europe, Asia and North Africa, typ­i­cally mi­grat­ing south dur­ing win­ter. They have a wide va­ri­ety of coastal habi­tats in­clud­ing salt marshes, coastal sand and shin­gle beaches, as well as river es­tu­ar­ies. Some pop­u­la­tions live more in­land in ar­eas such

as reser­voirs. Oys­ter­catch­ers sur­vive up to 35 years in the wild. They have a var­ied diet, which dif­fers de­pend­ing on its habi­tat. In rocky, coastal re­gions they feed on mol­luscs and crus­taceans, in river es­tu­ar­ies and reser­voirs they feed on worms and other in­ver­te­brates.

They also suc­cess­fully prey on mus­sels and other shell­fish, us­ing the hard tip of their bright orange bill – the heav­i­est of all the wad­ing birds – to force open the shells.

De­spite the name, oysters are not usu­ally part of the oys­ter­catcher’s diet. They also use their hard, bony bill to de­fend ter­ri­tory and fend off preda­tors.

Oys­ter­catch­ers have a dis­tinc­tive call, high pitched and loud. Adults are in con­stant com­mu­ni­ca­tion and the call be­tween the adults and young en­ables adults to feed their young and know where they are at all times. When dan­ger arises – a gull fly­ing over­head or some­one get­ting too close – they cre­ate a dis­tressed alarm.

I fol­lowed a new fam­ily of oys­ter­catch­ers along a river es­tu­ary in Suf­folk for six weeks, ob­serv­ing and pho­tograph­ing as the chicks grew from leav­ing the nest, to first flight. The nest was built on a dis­used wooden jetty along the river es­tu­ary. It was a safe nest­ing ground, but vul­ner­a­ble to pass­ing fish­ing boats and fish restau­rants. Three chicks hatched and the next day were on the river bank.

The next six weeks would de­ter­mine their sur­vival, at which point, they would be fully grown and able to fly. Along the jour­ney to adult­hood, chicks went up against gulls, other oys­ter­catch­ers and hu­man dis­tur­bance, as well as ob­sta­cles such as rope and rub­ble.

Af­ter just five days on the ground, three chicks be­came two. Al­though the chick’s death could’ve been from com­pe­ti­tion from its sib­lings, it is more likely

‘When worms were caught they were washed in the river, thought to re­move par­a­sites’

through pre­da­tion.

At such a young age, these chicks are smaller than a ten­nis ball, and easy pick­ings for a gull fly­ing over­head.

Oys­ter­catch­ers usu­ally pro­duce three or four eggs dur­ing the breed­ing sea­son but it’s rare that even two sur­vive.

Over the next few weeks, the re­main­ing two chicks lived along the muddy es­tu­ary, con­stantly fed with worms from their par­ents. The adult oys­ter­catch­ers took turns at feed­ing while the other watched over­head or de­fended the ter­ri­tory.

When worms were caught they were washed in the river be­fore feed­ing which is thought to re­move par­a­sites. With an abun­dance of food, these chicks changed ev­ery day. Af­ter four weeks, the chicks started to lose their fluffy coat and their full plumage came through.

Dur­ing this pe­riod a lot of time was spent preen­ing and re­mov­ing old feath­ers. Chicks bathed in the river and used their bills to shed those feath­ers.

Fly­ing is a ma­jor step in en­sur­ing sur­vival. With some fly­ing prac­tice along the bank, and with full plumage, the chicks were able to fly for the first time af­ter six weeks, al­though they may stay an ex­tra six months with the fam­ily be­fore leav­ing and find­ing a mate.

There are an es­ti­mated 284,000-350,000 pairs of Eurasian oys­ter­catch­ers in the wild, but this num­ber is de­creas­ing and, ac­cord­ing to the ICUN Red List, this is a near-threat­ened species, thanks to over­fish­ing of shell­fish and dis­ap­pear­ing mus­sel beds.

Other fac­tors in­clude habi­tat degra­da­tion, hu­man dis­tur­bance, coastal ero­sion and pol­lu­tion. Un­for­tu­nately, cur­rently there are no con­ser­va­tion ac­tions to pro­tect this unique species from be­com­ing en­dan­gered. N

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