This wild and un­tamed mav­er­ick div­ing species is like no other duck you’ve seen be­fore – both in terms of how they feed and their breed­ing be­hav­iour

Bird Watching (UK) - - Con­tents -

DO YOU RE­MEM­BER the day when you first learnt about ducks? The chances are that you were a child, it was at a park lake, and you threw bread to them as they quacked con­ver­sa­tion­ally and bick­ered over each of­fer­ing. You would have con­cluded that ducks were tame and greedy and prob­a­bly a lit­tle fat, too. Later on, you might have picked up more facts about ducks from your ex­pe­ri­ence, such as their ten­dency to nest in strange places and be­come very ragged in the early au­tumn.

What­ever you have learnt about ducks prob­a­bly isn’t true about the Goosander. This is a very dif­fer­ent an­i­mal from your quack­ing park sta­ples, and al­most ev­ery­thing they do, it doesn’t do. If you take a list of un­usual duck facts, many of them will be true of Goosanders. The Goosander is a duck apart, a thor­ough­bred and a mav­er­ick. Far from be­ing a portly, bread-iv­o­rous con­sumer of ben­e­fit hand­outs, the Goosander is a big-game fish­ing duck. In­stead of oc­cu­py­ing slummy wa­ters in the ur­ban sprawl, this bird is at home in fast-flow­ing, highly oxy­genated, su­per­charged wild rivers and deep pools. It lives, in many parts of its range, among forests full of bears and wolves. It is the an­tithe­sis of the duck that is, if not do­mes­ti­cated, then domi­ciled. It is wild and un­tamed. My first ex­pe­ri­ences with these char­ac­ters al­ways led me to as­sume that peo­ple, in the view of Goosanders, were to be avoided. From deep reser­voirs in win­ter to streams in sum­mer, you tended to see the back end be­fore you saw the front, the big, tor­pedo-shaped bodies whistling off and away, not a thought for pleas­antries. There is no break­ing bread with a Goosander. Their diet, too, is the op­po­site of a handout. Many species of ducks,

through­out the world, take an ex­tremely leisurely ap­proach to feed­ing. Mal­lards, for all their adapt­abil­ity, give the im­pres­sion that they are never mak­ing any more ef­fort than we would to dig up car­rots. Shov­el­ers bull­doze the wa­ter sur­face, Teals pick seeds from the mud; Pochards graze un­der­wa­ter and sleep for much of the rest of the time; even Eiders in the sea only dive down to yank im­motile cock­les from the sea bed. Goosanders, though, are birds that chase, and their prey is both fast and re­luc­tant to be caught. They are among the very few ducks that catch fish for a liv­ing, along with their ‘saw­bill’ rel­a­tives, the Red-breasted Mer­ganser and Smew. These ducks need pace un­der­wa­ter, and they need un­ob­structed space in which to spot and snatch their prey. Al­most any fish species less than 20cm in girth may be con­sumed, any­thing from a stick­le­back to a salmon. They catch what is most abun­dant; in ex­treme cases they can swal­low a fish 36cm long. They will search among the sed­i­ment and among stones, in a sub­ma­rine world it is hard for us to imag­ine. They have ex­cel­lent vi­sion and will hunt well into dusk, or even af­ter dark. The ser­rated edges of their mandibles al­low them to hold slip­pery prey.

Hunt­ing and homes

Where fish­ing is good, Goosanders will gather. In con­trast to the quar­relling Mal­lards spit­ting over bread, these sleek hunters will hunt co­op­er­a­tively, and with deadly ef­fec­tive­ness. Some­times they dive as one to star­tle fish into rash de­ci­sions, and some­times they will form a line to drive shoals of prey into shal­low wa­ter. There is no jostling in this classy species. Goosanders don’t fol­low the duck trail in much of their breed­ing be­hav­iour, ei­ther. De­spite be­ing large, they nest in holes in trees, or some­times rocks or strange sites, such as hol­low logs on the ground, or in build­ings. These holes may be any­thing from 1m above ground to an im­pres­sive, de­cid­edly lofty 30m. True, that epit­ome of duck-hood, the Mal­lard, will some­times nest in tree-holes as well, but among duck species as a whole it re­mains un­usual. Most types, from Tufted Ducks to Gad­walls, nest among veg­e­ta­tion on the ground. One might im­me­di­ately sense a prob­lem for Goosanders, when look­ing for nest-sites: where can they find any­where big enough? You could fit a Man­darin or a Smew into a small space, but not a Goosander. The pent­house suite must be spa­cious. For­tu­nately, in most parts of their range, Goosanders can call in large wood­peck­ers to pro­vide hous­ing. In Europe, it is Black Wood­peck­ers and in North Amer­ica, Pileated Wood­peck­ers, both of which are im­pres­sively bulky, and the wood­peck­ers’ habit of con­tin­u­ously ex­ca­vat­ing holes means that the ducks can keep their num­bers up. In Bri­tain, where Black Wood­peck­ers are ab­sent, Goosanders can use other holes and hol­lows, per­haps where branches have bro­ken off. They will also use nest-boxes. Al­most all duck species’ prog­eny are quickly led to wa­ter al­most as soon as they hatch. Nestling Goosanders spend their first day or two in the hole and then con­form to type. Of course, this ar­range­ment comes with a snag, if you are 30m above ground. The chicks might be lightweights, phys­i­cally, but they cer­tainly aren’t in courage; ne­ces­sity urges them to make the jump to ground, and then the mother urges them on, dur­ing the walk to wa­ter, how­ever far that might be – 1.5km has been recorded. It is quite a jolt­ing start in life. In their early days, the mother may treat the

chicks to a parental quirk which is un­usual among wild­fowl, a ride on her back. Pre­sum­ably this has some sur­vival value, but she isn’t al­ways able to ac­com­mo­date the whole brood, which can num­ber 12, and oc­ca­sion­ally as much as 17.

Goosander mys­tery solved

Look­ing at the Goosander’s over­all be­hav­iour, it seems to fol­low al­most every un­usual lead in the world of wild­fowl, from hole nest­ing to fer­ry­ing young to chivvy­ing fish. Yet an­other strange be­hav­iour that it ex­hibits might qual­ify as the strangest of all, and it is tak­ing place at about the time you are read­ing this ar­ti­cle, or just af­ter. You are prob­a­bly aware that some birds per­form spe­cial mi­gra­tory move­ments for the pur­poses of moult. The most fa­mous of these birds is the Shel­duck, which flies from Bri­tain to Ger­many in the sum­mer, while Bar­na­cle Geese some­times fly north of the breed­ing grounds to moult. They go for no other rea­son than to change their feath­ers in a safe en­vi­ron­ment. It has been dis­cov­ered quite re­cently that Goosanders also have a moult mi­gra­tion, yet ex­traor­di­nar­ily, it is con­fined to the males. For many years, it had been noted that the drakes were ab­sent from their Scot­tish rivers from June to Oc­to­ber or so, even where the moth­ers and broods were feed­ing, and for many years their where­abouts was a mys­tery. It has now been shown that these drakes un­der­take a re­mark­able jour­ney, trav­el­ling all the way to the North Cape of Nor­way. Here they min­gle with 35,000 other males from other parts of west­ern Europe and loaf about, moult­ing their plumage. It is well known that ducks com­monly show dif­fer­en­tial mi­gra­tion, with each gen­der ex­hibit­ing a dif­fer­ent mi­gra­tory strat­egy – for ex­am­ple male Smews re­main close to the breed­ing grounds in win­ter, while in Bri­tain, fur­ther away, we see more fe­males and im­ma­ture males. How­ever, for the male Goosanders to mi­grate such a sig­nif­i­cant dis­tance, leav­ing the fe­males be­hind, is of a dif­fer­ent or­der of mag­ni­tude. On the other hand, for such a re­mark­able, un­con­ven­tional duck, it is just an­other ex­am­ple of do­ing ev­ery­thing in its own way.

BOT­TLE GREEN HEAD Males are eas­ily picked out when in full plumage, by their pale bodies and black­ish to bot­tle green heads

ê GRASP­ING BILL The long, thin, hooked-tipped bill is beau­ti­fully de­signed for snatch­ing even quite size­able fish

ÉDIVER STRUC­TURE The feet are set well back, and the body is long and stream­lined. This is the clas­sic struc­ture of a div­ing spe­cial­ist

ê ALL ABOARD Goosander moth­ers may take some fluffy pas­sen­gers , grebe-style, from time to time

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