The nesting and some other habits of Alopochen, Nettapus, Plectropterus and Sarkidiornis Captain C. R. S. PITMAN

Summary African ‘geese’ are catholic in their choice of nest-sites. Most Egyptian and Spur-winged Geese nest on dry ground, but may use holes in trees, or old arboreal nests of other . Pygmy Geese occasionally nest on the ground but more often in trees or on buildings. The Knob-bill nests in trees and in Africa at least also on the ground. Clutch-sizes and parental behaviour are discussed. There is some evidence that Sarkidiornis may often be polygamous in Africa, though appa­ rently not in India. Alopochen and Plectropterus roost on water, the latter also sometimes on dry land. Sarkidiornis roosts chiefly in trees, though sometimes on mudbanks or floating islets. The roosting places of Nettapus are not known. Flocks of Alopochen and Plectropterus sometimes cause serious damage to crops, by trampling or nibbling maize, beans, and sweet potatoes and pulling up entire ground-nut plants.

Introduction nest site I was shown near Entebbe was Commonly known as ‘geese’ the members some 30 feet above the ground in the of the four tropical genera Alopochen, crown of a palm and was only discovered Nettapus, Plectropterus and Sarkidiornis when the goslets were seen falling from it. differ in many respects from those of Anser All these sites were close to water, but in and other closely allied genera. Delacour South Africa a nest three feet up in a (1954-64) and other authorities, treat the ‘mopane’ tree was 200 yards from water. Egyptian Alopochen aegyptiacus as a An unusual site was in the thatch of an member of the tribe Tadomini, which occupied African hut; the dry grass of the includes the sheld- and South thatch was pushed up to form a tunnel American sheldgeese, and puts the other about a foot long and the nest - there were three genera in the tribe Cairinini, along no eggs - was lined with down. Nests have with the wood ducks and the Muscovy been found in ant-heaps and in the tree- . But in its nesting, feeding and social nests of other birds, in particular, inside habits, with which this paper is concerned, the huge structures of the Hammerkop or Alopochen is much like the perching geese. Hammerhead Stork Scopus umbretta. In South Africa a nest - of grass but with no Nesting habits down in the lining - was found in a heavy Nettapus auritus - a f r i c a n p y g m y g o o s e clump of grass on a river bank; and one in OR DWARF GOOSE Northern Rhodesia, by a shallow 2 i acres This particularly lovely little goose - the pan in ‘mopane’ woodland, an untidy male with its exquisitely handsome head - grass structure under a log, on mud, and is found on lakes, lagoons, dams and back­ about 20 yards from the water’s edge. At waters. I knew it well in many parts of the same pan there was another Pygmy Uganda and, though widespread, less Goose nest - a rough structure of grass commonly in Northern Rhodesia. When I containing six eggs, but no mention of first went to Entebbe (on Lake Victoria), down - in fairly deep water. These last two Uganda, in 1925, I knew of four nests records are of particular interest as they which I did not disturb. One was in a hole indicate that the will nest on in an ironstone cliff and the others 30 to the ground even when there is woodland - 40 feet up in holes in large trees. These and the probability of suitable nest holes - were all in the same locality where Sir near at hand. There is an important factor, Frederick Jackson (a Governor of Uganda) however, which may have influenced these had previously found a nest at arm’s Pygmy Geese for in this locality there is a length in a hole, seven feet above the considerable population of large, deadly, ground in an ironstone cliff. This same predatory Black Mambas which freely hole and others near by in the low ironstone explore holes in trees. In the virtually cliff had been regularly tenanted by wild treeless vast open and swampy country of Grey Parrots Psittacus erithacus until Nigeria where the Pygmy Goose is com­ systematic robbing of their nearly fledged mon, it can only nest on the ground or in young eventually drove them away. Jack­ swamp. son found other Pygmy Goose nests in The nest is variously described as con­ trees at Entebbe respectively at 30 feet and structed of dry twigs, coarse grass and 60 feet above the ground - the latter in a leaves, etc., sometimes lined with down hole at the end of a dead branch. Another and (Jackson records) with a little green

HABITS OF AFRICAN WILDFOWL US moss. The usual complement of pale which contained the remains of their nests creamy-white eggs varies from 6 to 9, and which were said to be used year after though Delacour (1959) records up to 12; year. Various authorities on Indian birds and from the data available the African describe the nests as constructed of twigs, Pygmy Goose lays fewer eggs than either grass, dead leaves and feathers - but no the Cotton Teal or Green Goose-Teal. down - and at any height above the ground So few nests have been found, that as from water level to 30 feet up, though the yet little is known about the breeding majority are at about six to twelve feet; a behaviour of the African Pygmy Goose. nest sited as high as 68 feet has been found At Entebbe, a brood of eight newly hatched in a hole in a building at Rangoon, Burma goslets was caught by an African who had and another at 40 feet was in a niche in a trapped the parent; an attempt to keep factory chimney. A nest has also been them in captivity failed as the parent recorded in an ant hill at the base of a tree escaped and the brood died. The African and another - a nest of grass - on top of an Pygmy Goose is as agile as the Cotton ant hill. Nest holes usually have a wide Teal when entering its nest hole in a tree entrance, yet when they are as small as or cliff, vide Jackson’s graphic description four inches across these birds fly into them ‘shot in as nimbly as a Sand Martin or with the greatest accuracy, without pause Kingfisher’ ; he also recorded that the or hesitation. mother goose was accompanied to the In Burma, a Cotton Teal with five eggs cliff face by the drake. The female must was found nesting in the same tree-hole as be able to check itself in a remarkable way a Comb Duck, which had six eggs; all so as to enter a small aperture and its eleven eggs are in the National Collection restricted space seemingly at top speed. at the British Museum (Natural History). Watch as assiduously as I might, during Nests may also be placed in ruined houses, the breeding season, rarely did I see the temples and old chimneys, but Stuart- brooding female - she was not always Baker challenges the authenticity of two accompanied by the male in her flight - nests described as ‘a semi-floating nest on enter the elevated cliff-hole. The approach the water, among the rushes or lotus was not direct and when the two birds leaves, of weed, grass, etc., all together’. were together they flew several times to This is an observation of days long bygone, and fro at the correct level until one since when there has been no other such suddenly swerved into the hole. If one did Indian record. But this does not mean that not watch carefully one missed the split the record is valueless, for in Australia second entry on the realisation there was N.pulchellus, the Green Pygmy Goose, will only one visible instead of two ! nest on the ground and in swamp, as N.auritus, the Dwarf Goose, also does in Nettapus coromandelianus - COTTON TEAL Africa. or I n d i a n p y g m y g o o s e , and in Australia, For the size of the bird the complement where it is usually classified as N .c. of pale creamy-white eggs - usually varying albipennis, w h i t e - q u i l l e d p y g m y g o o s e from six to fourteen - is relatively large, Or WHITE-QUILLED GOOSE TEAL. and as many as 16, 18 and 22 have been When serving in the Indian Army, prior to recorded. A nest containing a total of 40 the First World War, I was familiar with eggs suggests competition for a nesting site the little Cotton Teal of south-east Asia, and more than one female responsible. The New Guinea and Australia in the course of male, though often accompanying the several shooting expeditions to the Central female to the nest hole, never enters. Provinces. As it breeds during the monsoon when the rains make the jungle impassable Sarkidiomis melanotos - k n o b - b i l l e d I had no opportunity of investigating its GOOSE, KNOB-BILL, COMB DUCK or NUKTA. breeding habits. In these jungles when I knew the Knob-Bill much better in there is no other permanent water the Africa than in India, where its nesting widely scattered villages are each sited habits have long been well known, whereas alongside a ‘tank’. A ‘tank’ may be either in Africa reliable records are almost as few quite small or of considerable size accord­ as those of the Dwarf Goose. In India, ing to the terrain and is an artificial expanse with rare exceptions, nests are in trees, of water created by an earth dam to retain usually in holes and hollows mostly within the rainy season’s surface flow. On these six to twelve feet of the ground, but ‘tanks’ were populations of Cotton Teal in occasionally even as high as 30 feet. pairs or groups, or in small concentrations Occasionally the Knob-Bill appropriates not large enough to be designated flocks. the nests of other birds, sometimes at Around them, in mango and other trees, I considerable heights, for its eggs have been was shown many hollows and holes, some found in a Vulture’s nest, in the nest of the eight to twelve feet above the ground, White-tailed or Pallas’ Fishing Eagle

1 1 6 THE WILDFOWL TRUST Haliaëtus leucophyrys and once in a nest eggs found in Southern Rhodesia was in a of the Woolly-necked Stork Dissoura tree hollow, several feet deep, and quarter episcopus. Other sites include holes in o f a mile from water. As these little goslings ruined forts and amongst rocks, once a nest are skilful climbers and as a distance o f 440 was found in a hole in a bank and a deep yards is not beyond the bounds of possi­ grass nest has been recorded in a swamp bility of the brood having walked to the amongst thick growth. As a rule nesting water, it is a faulty premise ‘Undoubtedly trees are near water - though occasionally carried out of this cylindrical hollow by at a considerable distance - or even stand­ the male and female’. Another nest in a ing in water. The nests are of small sticks hollow tree in Southern Rhodesia was at a and grass lined with dead leaves and a few height of 50 feet and it was said that the feathers, but no down; at times there may young tumbled out of the nest. Some of be virtually no nest. Seven to twelve eggs the young were caught, but easily escaped is the usual complement. 40 and 47 eggs, by climbing out of an open, deep packing which have been recorded, are presumably case. Eleven eggs have also been taken attributable to more than one female. But from a hollow tree in a swamp in Nigeria. the most astonishing total of 54 was found Seven eggs recorded from nests in thick in a hole in a mango tree, with a nine inches reeds over fairly deep water in Nyasaland wide entrance, six feet above the ground are of dubious authenticity. In Nigeria a and nearly four feet deep. T h e eggs did not nest has been found in reeds. Only once hatch and were deserted. The finder did I find a nest in Uganda - in a deep suggested that it might be a communal nest hollow amongst the stone blocks of a and certainly one could reasonably claim disused pier - on Lake Victoria; it con­ that no less than four females must have tained two fresh eggs. The Knob-Bill, in produced so large a total. This suggests the small numbers, breeds regularly along the possibility of more than one female at­ northern Lake Victoria littoral - but as the tempting to brood at the same time, which local inhabitants are disinterested - I was would explain why some of the deserted unable ever to locate a nest, though I was eggs were cracked. The idea of a communal once told about one in a hole in a tree nest, apart from possible competition for which I was unable to visit. Every year nesting sites, raises the question of poly­ near Entebbe, in September, when out in a gamy, more especially as this record refers launch I used to come across broods, and I to one male with five females being was sometimes surprised to find how far observed nearby. The subject of polygamy out on the lake they would be. On one will be referred to below (p. 119). In occasion I spent the best part of a day, various parts of south-east Asia, according when engaged on fishery investigation on a to the local inhabitants whose reliability small lake in south-west Uganda, in can I think be accepted, communal nests searching the numerous hollow trees on containing multiple egg clutches are well tiny islets where these geese were said to known and two females have been seen to nest, although I was warned that it was enter the same nest-hole. the wrong season. It was not a particularly In Nyasaland, at the commencement of healthy pursuit for these islets were the rains, Knob-Bills arrive in hundreds infested with Puff Adders - on what they along the Lower Shire river and its fed I did not find out - and some were a adjacent swamps, and it may be that they few feet up in hollows in the trees. The are attracted to suitable nesting sites in the Puff Adder is a powerful swimmer and numerous Hyphaene and Borassus palms. buoyant as it partially inflates itself when This is a well-defined movement though I in the water. It was not an attractive doubt if it is a migration. A nest with eight lakelet for the only craft available were eggs was found in a hole 12 feet up in a bundles of reeds tied together and these dead Hyphaene, but it was one mile from soon became water logged, while at the water, and the finder realised too late that edge of a swamp the overhang of a huge had he made a thorough search o f the many sloping rock - above which in a small, dead palms he might have found more shrubby tree was a nest of the Goliath nests. In this connection the question arises Heron Ardea goliath - was covered with as to how the young got to the water one dozens of combs of vicious wild bees. mile distant. It is categorically stated, with The same nesting holes are said to be reference to South Africa ‘Young removed used year after year; this is well known in from nest on parent’s back’ but I am India. unaware of the evidence on which this is In Africa the usual complement of based. Nest sites in South Africa include creamy or pale yellowish eggs varies from holes in trees and boles, in long grass and six to eleven, which differs little from the among stones on a low hill. A nest of ten seven to twelve recorded in India.

HABITS OF AFRICAN WILDFOWL I I 7 Plectropterus gambensis - SPUR-WINGED attract attention it is possible that un­ GOOSE deserved prominence has been given to its tree-nesting proclivities. I am inclined to The nests of Spur-winged Geese though believe that only a relatively small pro­ occasionally in trees or on cliffs are mostly portion of Egyptian Geese nest in trees and on the ground, sometimes a considerable that the majority of nests are on the ground distance from water. I used to know of a where they are rarely found. Nests are of number of tree-nests, none higher than 20 grass and similar material, profusely lined feet, in old raptor nests in the woodland at with the parents’ down which is used to the southern end of Lake Nakuru, in cover the eggs when the bird is away from Kenya. Like the Egyptian Goose, the the nest. Nests on the ground or at ground Spur-wing will lay on top of the Hammer- level may be in a reed bed, in grass or kop’s massive structure, from which I rashes, on floating water plants, on low, imagine the young are called down. The Spur-wing, too, nests in rather arid condi­ flat grass-covered islands, in matted vegetation near water, amongst rocks on tions on elevations of nearly 6,000 feet islets, in a rocky cleft on a river bank, above the 3,000 feet high western scarp among boulders in a rock cleft in a cave, of the great Rift Valley, at Uganda’s frequently on a river bank, amongst the extreme north-east comer. Goslings are broken stonework of a lake pier, on an ant- seasonally seen there on some of the numerous pools, many of them saline. heap, in the disused burrows of porcupines and ant-bears, and in an old boat-house. Ground nests are usually well hidden in The Egyptian Goose is thoroughly at dense, long grass, not far from water, or home in the trees and is equally adept at in reed beds, but the Spur-wing seems to perching on the tops of flat-topped thorny prefer to nest on dry ground rather than acacias as on solid boughs. It frequently on the water - where standing space on a appropriates the old nests of other species. nest is extremely limited. Nests vary from Nests of my own finding include : in a Fish large, bulky grass structures, when in Eagle’s nest at the top of a flat-topped swamp, to shallow hollows scantily lined acacia 80 feet above the ground and a with grass; there is no down. Nests have Goliath Heron’s nest at the top of an been found on termite hills; another was Albizzia about 60 feet up - in both these under a low bush 15 yards from a river cases the goose nests which are usually well bank. shaded were very exposed to a fierce sun, The usual complement of large, ivory- but I also found another goose nest on the white eggs is hard to judge as records vary flat top of a lofty rock which must have from six to twelve, but sets of six and seven fresh eggs do seem to suggest incomplete been excessively hot for the brooding bird except when it was dull or raining. On a sets. Unusually large sets of 15 and 16 eggs ledge a few feet below this goose nest was are known, but as a rule I think sets consist the occupied nest of a Lanner Palco of eight to twelve eggs. This goose and its biarmicus, but its young flew before the young are much preyed on by crocodiles. The Spur-wing will lead its brood to goslings hatched. Others were in a hollow of a cliff face some 12 feet above water water from a considerable distance; both level on an islet; on top of Hammerkop parents look after the brood. At the Whip- nests (several) ; in the broken stonework of snade Zoological Park, in Bedfordshire, one of these geese hatched her brood of ten a pier; on a tiny islet, in scrub, amongst some half-a-mile distant from the nearest several nesting crocodiles - all about 11 feet; and on another islet which harboured water and when the parents and their many sluggish, massive Puff Adders and goslings, on the move, were set upon by a large (6 feet to 8 feet) Black-lipped Cobras pair of aggressive Saras Cranes Grus antigone the geese successfully saw off the - how the eggs successfully hatched and the brood survived, as it did, was quite attackers. astonishing. But at certain seasons ample food was available for the snakes from a Alopochen aegyptiacus — E G Y PT IA N g o o s e large nesting colony of Grey-headed Gulls The nesting habits of this well-known, Larus cirrocephalus and ground-nesting noisy, quarrelsome species are bewildering colonies of Sacred Ibis Threskiornis in their diversity for it may nest on the aethiopicus. Crocodiles are accustomed to ground or as high as 80 feet in trees or in a lie above their buried eggs (incubation variety of other sites, and at altitudes from period c. 90 days) to protect them from sea level to nearly 13,000 feet, though the predators such as the voracious Monitor latter occurrence (Hachisuka, Bull. B.O.C., Lizard Varanus niloticus and Hyenas. 52: 18-19,1931) is quite exceptional. Tree- These crocodiles always return to the nesting is a characteristic of this goose, but water by the same runway. The goose nest as nests above the ground are likely to found on the Crocodile breeding islet was

118 THE WILDFOWL TRUST in an old runway, with runways in use on Hammerkop was seen to emerge from a either side of it. How did it know where it nest on which an Egyptian Goose was would be safe ? An unusual site in South perched. The goose and Hammerkop were Africa was on a small islet in the centre of a never observed to come into contact on the breeding colony of some 300 pairs of the top of the nest. According to Turner, the Greater Flamingo Phoenicopterus ruber. Egyptian Goose seems to breed all the year Even stranger is a 1963 record from South round in the Seronera region of the Africa of an Egyptian Goose unmolested Western Serengeti, in Tanganyika. sitting on ten eggs on a small island where The usual complement of creamy-white a female Cape Otter Aonyx capensis and eggs varies from six to ten, but sets of 11, three young were living. The island was 12 and 15 (two were infertile) are known. strewn with hundreds of duck eggs which Nests of my own finding varied from seven the otters had collected for food from to nine eggs. Records I have of several nearby islands. Layard (1875-84) records dozen nests include more than two dozen finding a nest in South Africa on a ledge of sets of nine and over a dozen of eight, rock amongst a breeding group of eight figures which may indicate the normal Cape Vultures or Kclbe’s Griffons Gyps clutch size; sets of six and seven, too, are coprotheres from which it possibly derived numerous. a measure of protection, as the Vultures Early wastage amongst the broods seems were friendly disposed towards it. common, for though 7 to 11 goslings may Other nests have been recorded in the hatch and reach the water and are con­ fronds of a palm tree about 15 feet above stantly guarded by both parents, they are the ground; 10 feet from the ground in a subject to attacks by four-footed, feathered stunted thorn tree on a kopje overlooking a and aquatic predators, and are soon perennial stream; in hollow trees; on reduced. In the water coarse fish such as flood debris in a bush; at various heights on Cat-fish (Silurids) and Eels, Nile Perch cliffs ; and on precipices sometimes as much {Lates), (which in the past annually took as 200 feet above water. It is unusual for the whole gosling broods which hatched in nests to be far from water; occasionally the Giza Zoological Gardens at Cairo), they may be a quarter of a mile distant and Monitor Lizards ( Varanus), Water Tor­ rarely as much as a mile; all the nests I toises Pelomedusa subrufa, which cause found were close to water. Egyptian Geese much loss to goslings in parts of South nest very commonly on the top of the Africa, and Crocodiles (where they occur) enormous structures built by the Hammer­ are all responsible for considerable 'wastage. kop. Van Ee (1963) records finding three Crocodiles too have been seen to take adult Hammerkop nests occupied inside by Egyptian Geese and at Entebbe, on Lake Egyptian Geese which contained 6, 10 Victoria a 5 A foot, enormous Lungfish and 15 eggs, all of which hatched with Protopterus aethiopicus choked itself to the exception of two infertile eggs in the death trying to swallow a full-grown last. He records ‘In watching the approach Egyptian Goose. of the geese to the nests I noticed that one flew straight in to the somewhat bigger Polygamous behaviour of Sarkidiornis opening while the other two clung to the Many dams were created all over Uganda, nest before entering’. Ten goslings in one from 1945 onwards. Most of these attracted nest 25 feet above the ground, in the small populations of Knob-Bills, but I Zoological Gardens at Bloemfontein, were never came across any nests, though not carried down by the parents but fell, seasonally broods would be seen on them. after the two parents were observed calling The most interesting feature of these from the ground. Even when goose nests populations was their composition, which are as high as 60 and 80 feet there is a definitely suggested polygamy, for the possibility that the goslings may be ‘called’ Knob-Bills were always in groups - rarely to jump down, for I noticed there was more than one or two groups unless a dam always an abundance of secondary growth, was of considerable extent - which con­ to break the fall of the youngsters, beneath sisted of one male and three or four females. such heights - but this is just a conjecture. Much of the day was spent by a group In the western region of the Serengeti perched in one dead tree. There is no National Park in Tanganyika Myles Turner evidence of polygamy in South Africa, but (in litt.) has twice seen an Egyptian Goose this may be due to the sexes being equally and a Hammerkop using the same nest. T h e represented, for where the females pre­ Hammerkop on arrival perched on a low ponderate - as has been recorded in West branch below the nest, which was about Africa - polygamy is likely. It has been nine feet above the ground and then dived recorded that to keep Knob-Bills success­ into the nesthole. The sitting goose fussed fully in captivity there must be a consider­ a bit, but not unduly. Another time a able preponderance of females to males,

HABITS OF AFRICAN WILDFOWL II9 otherwise a male will constantly pursue and Plectropterus were widespread, abundant exhaust a female during the breeding and tame, but the introduction of firearms season. This behaviour seems to indicate quickly put an end to such a happy state and a natural tendency towards polygamy. The numbers all too rapidly dwindled. Only male is more than twice the size of the fifteen years ago I still knew of utterly wild female. places in Uganda where in the early morning Major Ian Grimwood, Chief Game dozens, mainly in pairs, of confiding, fearless Warden of Kenya, has kindly sent me the Alopochen grazed right up to one’s tent and following comments. ‘I have no evidence would scarcely move out of the way to let one pointing to Knob-bill being polygamous pass. This is a wonderful recollection of and the only three nests I have found have something which will never happen again all been solitary in position. Even in the for ‘progress’ long ago decreed the dis­ breeding season these birds seem most appearance of these refuges. In East Africa frequently to be found in parties but sex- I have exceptionally come across flocks (or ratios seem to be completely flexible, e.g. concentrations) respectively of Alopochen three males in “full knob” with five females and Plectropterus of several hundreds, or I male and three females which were on though as a rule they are a good deal my dam at various times last rains. smaller. These flocks mostly consist of a ‘Curiously enough a professional hunter number of family parties and are usually was yesterday, 27 February (1964), talking seen either in shallows, on sandbanks, on of a small pan on which he had just been land close to water or when feeding. It has camping in Tanganyika which was occu­ been recorded that Alopochen by night rests pied by two males, four females and two on the water - it would be safe from broods of Knob-bill ducklings compared crocodiles where the water is about 20 feet with one male, three females and two deep and over - and that Plectropterus broods last year.’ roosts on a convenient bank or similar safe Despite Major Grimwood’s opening site. M y comment is that I have often come remarks, these records do seem to suggest across Alopochen far out on a lake late at a degree of polygamy, more particularly night, and have occasionally in the darkness the occurrence of a male with three females disturbed Plectropterus roosting on land, and two broods. but I hesitate to say more than that m y own Polygamy by Sarkidiornis in India does experience would sometimes appear to not seem to have been suggested. This support the record. Before leaving the divergent behaviour may not be so strange subject of flocking it can be mentioned that as might at first seem for in India the where the three larger species are common curious Painted Snipe Rostratida bengha- one will sometimes see - especially Alopo­ lensis is polyandrous which my own chen and Plectropterus - several broods observations certainly indicate, yet in East together in the water particularly when the Africa where I, and others, have had juveniles are fairly large. Parents may be considerable experience of this species absent, but there is usually an adult or a there is no evidence to suggest that it is sub-adult with them. Associated with other than monogamous. flocking is flighting and where Alopochen and/or Plectropterus are numerous there Roosting and flighting will be evening and morning flights to the Sarkidiornis feeding grounds whether they be natural The Knob-bill is not so nocturnal as most grazing, cultivated grassland or stubble. In ducks, though resting a lot by day. In the Chad region of Northern Nigeria it has India where its habitat is normally associ­ been recorded that in these evening and ated with trees it has been described as morning flights Alopochen invariably pre­ ‘strictly tree-loving’ and it is probable that ceded Sarkidiornis and Plectropterus. Some there it always roosts in trees; but in the forty years ago near Lake Nakuru in Kenya tree-less swamp regions of Africa it rests I was able for several weeks to witness the on mud-banks and floating islets. In the flights of Alopochen and Plectropterus to the well-treed parts of Africa where I was maize stubbles and I can confirm that it familiar with this species it certainly spent was the former which first flighted on to much of the day perched on trees, parti­ the feeding grounds; the regularity of their cularly dead trees standing in the water of timing was remarkable. The flight, varying recently created dams. A check with a torch considerably in intensity according to the revealed that the Knob-bills roosted on weather, usually lasted from twenty to these trees for much of the night. thirty minutes, and inevitably in the middle of the flight there was an overlap of the two Plectropterus and Alopochen. species. Skeins varied in size from about When the white man first penetrated South­ a dozen to a few score birds, some of which ern and Eastern Africa Alopochen and were calling as they flew. Although these

120 THE WILDFOWL TRUST geese regularly were shot at they did not just before dawn, but though easily scared become unduly wild, and seemed reluctant from cultivation, I have frequently seen to change their normal lines of flight. One them unconcernedly raiding a particularly authority has recorded how wary is Plec­ tempting crop in broad daylight. Geese and tropterus when flighting to a feeding ground ducks are incredibly destructive to ground­ which it will circle more than once before nut plots, for to get at the nuts they coming down. This was not my experience destroy the plant. The birds do not dig for at Nakuru where both Plectropterus and the nuts but pull out the plant, with the Alopochen despite much shooting habitu­ nuts attached to the roots. I imagine that ally flew straight to their goal and when the nuts were originally found by chance unmolested settled immediately. when a goose accidentally pulled up a plant. It is a simple matter for the powerful Feeding and damage to crops goose to jerk the plant out of the ground, The Egyptian Goose is usually found in but not so easy for a duck. N ot being strong pairs or groups of pairs or in small flocks enough to uproot the plant directly, the of sub-adults but in parts of South Africa duck, having firmly seized the plant in its it joins up seasonally into vast flocks to raid bill, gyrates around it, meanwhile pulling the wheatlands where it becomes a real hard, until achieving the desired result. pest and causes tremendous damage. Spur- This is an example of the type of curious wings can also cause severe damage, by complaint so often received by a Game trampling, when feeding in flocks in Warden in Africa - havoc caused by ducks growing crops. Like Egyptian Geese, they to numerous ground-nut plots. It sounds are very partial to ground-nuts and to highly improbable, but investigation con­ sweet potatoes. The tops of the sweet firmed its truth; and the culprit, the potatoes are eaten and the tubers are Fulvous Tree-Duck or Whistling Teal ruined by nibbling. Dendrocygna bicolor was not only caught Spur-wings are mainly nocturnal feeders, in the act, but had a crop stuffed with though by day they are sometimes found ground-nuts; every plot examined had on grasslands far from water. These big really been devastated and around each birds can create havoc amongst growing uprooted and discarded plant were the crops of beans and ground-nuts which they unmistakable signs of the modus operandi are accustomed to visit as dusk falls and of the marauder.

White-headed Ducks in West Pakistan t - CHRISTOPHER SAVAGE

Sum m ary An influx of White-headed Ducks Oxyura leucocephala was observed in West Pakistan in December, 1964. Five specimens were caught and sent to Slimbridge. Some notes are given on their behaviour and measurements. The White-headed Duck Oxyura leucocep- less than thirty published records over the hala is known in India and Pakistan from last hundred years, from which it is classi-

HABITS OF AFRICAN WILDFOWL 1 2 1