Gan­nets

My first gan­net en­counter took my breath away such was the spec­ta­cle of both the mag­nif­i­cent sight and smell of a huge breed­ing colony. anyone with a pas­sion for wildlife should put this bird to the top of their must-see an­i­mals

World of Animals - - Contents - Words Michael Tay­lor

Where you can find Bri­tain’s largest seabird

The north­ern gan­net (Morus bas­sanus), nor­mally re­ferred to as sim­ply a gan­net, is the largest of the Sul­i­dae fam­ily, which also in­cludes birds such as the blue-footed booby. An im­pos­ing and el­e­gant seabird, it can be seen at a num­ber of coastal lo­ca­tions around Bri­tain. It is eas­ily recog­nis­able against other species in­hab­it­ing sim­i­lar ar­eas due to its sheer pres­ence, par­tic­u­larly when it’s air­borne.

Adults have a pre­dom­i­nantly white plumage and black wingtips with a light yel­low-buff colour­ing on the head and back of the neck, some­what rem­i­nis­cent of a French For­eign Le­gion­naire’s cap. Gan­nets have a large, grey and fear­some-look­ing dag­ger-like bill that is used to great ef­fect when de­fend­ing nest­ing ter­ri­tory. Their ap­pear­ance is com­ple­mented by sky-blue cir­cles of skin around pierc­ing eyes, a fea­ture as­so­ci­ated with the bird’s some­times al­ter­na­tive name of spec­ta­cled goose.

Fully grown adults weigh be­tween 2.5 and 3.6 kilo­grams (5.5 and 7.9 pounds), are around 92 to 110 cen­time­tres (36.2 to 43.3 inches) long and have a wing­span that can mea­sure from 1.7 to 1.8 me­tres (5.6 to 5.9 feet). While ju­ve­niles aged two to three years may ap­pear sim­i­lar in size to adults, they’re eas­ily dis­tin­guish­able as they don’t ac­quire the full dis­tinc­tive white plumage (es­pe­cially on their wings) un­til the com­ple­tion of suc­ces­sive moults usu­ally over a pe­riod of four years or so.

The be­havioural ac­tiv­ity of these birds is fas­ci­nat­ing, both in terms of their feed­ing

tech­nique and the rais­ing of young. Shoal­ing fish, such as mack­erel and her­ring, com­prise most of their diet, and in the an­i­mal world the gan­net has a dra­matic and some­what unique way of catch­ing them.

They of­ten go hunt­ing far out to sea in search of suit­able shoals of fish, and when one is found the sky above it soon be­comes con­gested with gan­nets all look­ing to get in on the act. es­sen­tially, they di­ve­bomb near ver­ti­cally into the wa­ter, of­ten from a height of around 30 me­tres (98.4 feet) or more, reach­ing tremen­dous speed as they near the sur­face. Just be­fore en­ter­ing the wa­ter, the head points down­ward and the wings are drawn closely back be­hind the body to form a stream­lined, al­most mis­sile-like shape. They dive up to a depth of some 20 me­tres (65.6 feet) to catch fish, of­ten tar­get­ing more than one in­di­vid­ual at a time when sub­merged by us­ing their large webbed feet to chase their in­tended prey.

The ques­tion of how they avoid in­jury in us­ing what seems to be a very risky fishing method comes to mind. The an­swer is that they have a few tricks up their sleeve, so to speak, which en­able them to dive rel­a­tively safely. For in­stance, un­like the vast ma­jor­ity of birds, gan­nets don’t have ex­ter­nal nos­trils (they breathe through their bill), thus help­ing to pre­vent wa­ter en­try. In ad­di­tion, prior to im­pact a strong, trans­par­ent mem­brane in­stinc­tively closes over the eyes to pro­tect them dur­ing a dive, which can last up to 40 sec­onds or more.

Fur­ther­more, gan­nets have a labyrinth of air pock­ets be­neath the skin sit­u­ated around the skull and neck re­gions. These pro­vide a cush­ion­ing ef­fect not too dis­sim­i­lar to the way bub­ble wrap works when the bird im­pacts with the wa­ter. how­ever, given the large num­ber of birds that may be fishing in a rather small area of the sea, and the high im­pact speeds in­volved, un­for­tu­nately col­li­sions be­tween div­ing birds do oc­cur, some­times re­sult­ing in their death.

on reach­ing full adult ma­tu­rity at five years of age, gan­nets pair up for life and will use the same nest each year within the gan­netry. Nest­ing colonies typ­i­cally ex­ist

“Gan­nets have a large, grey and fear­somelook­ing dag­ger-like bill that is used to great ef­fect when de­fend­ing nest­ing ter­ri­tory”

on cliff faces or small is­lands near the coast that are safe from preda­tors. Dur­ing early april, the es­tab­lished breed­ing males re­turn to the site first, with the fe­males ar­riv­ing later, which in­evitably leads to a greet­ing dis­play be­tween the pair to reaf­firm and strengthen their bond. The rit­ual be­gins with each bird stand­ing and fac­ing each other; the neck is then stretched with bills po­si­tioned near ver­ti­cal, af­ter which they turn their heads from side to side, gently al­low­ing their bills to cross and rub to­gether.

Nest re­fur­bish­ment be­gins in earnest shortly af­ter re­turn­ing to the site. The male gath­ers most of the ma­te­rial used, which can be a com­bi­na­tion of sea­weed and grass or other fo­liage, es­pe­cially so at coastal cliff lo­ca­tions. Space be­tween nests within the gan­netry is very much at a pre­mium and it’s de­fended vig­or­ously should a neigh­bour en­croach onto it. Such skir­mishes break out on a fre­quent ba­sis, and when they do the tres­passer is fended off by their re­spec­tive gen­der, males see­ing off other males while the fe­male rushes to con­front any in­trud­ing mem­bers of the same sex.

Be­tween late april and the mid­dle of June is when the fe­male lays a sin­gle egg. In­cu­ba­tion is shared by both par­ents and takes ap­prox­i­mately 44 days. When the chick emerges from its shell both par­ents are usu­ally present, one of them wast­ing no time to give their new-born off­spring a first meal of re­gur­gi­tated fish. af­ter three weeks the chick has grown con­sid­er­ably and has a thick white down.

at this ini­tial stage of its life a gan­net chick is not par­tic­u­larly at­trac­tive, as in the case of the swan’s ‘ugly duck­ling’ in the fa­mous chil­dren’s song, metaphor­i­cally speak­ing. how­ever, when it’s around 90 to 100 days old its ap­pear­ance will be very dif­fer­ent, for it will have trans­formed into a beau­ti­ful-look­ing ju­ve­nile gan­net ready to leave the nest, fend for it­self and face its first win­ter out in the North at­lantic.

Be­LowAny form of veg­e­ta­tion is used to line a gan­net’s re­fur­bished nest I’ve been pho­tograph­ing wildlife for 30 years. Be­ing en­tirely self-taught, in my opin­ion knowl­edge of your equip­ment, the sub­ject, per­se­ver­ance, prac­tice and above all pa­tience are key to cap­tur­ing a great im­age. My work has been pub­lished in var­i­ous na­tional and re­gional mag­a­zines and I’m also a con­trib­u­tor to stock agen­cies such as Alamy. Gan­net pairs use var­i­ous be­havioural dis­plays tostrengthen their bondPho­tog­ra­pher’s biomichaeltay­lor­photo.co.uk

Be­Low Nest­ing space is very lim­ited, and although they ap­pear to be spaced evenly, con­flicts be­tween neigh­bours are never far away

aBove The gan­net has a huge wing­span that it uses ef­fort­lessly to ride the ther­mal cur­rents

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