io6 



THE NIDIOLOGIST 



The Hammerkop. 



{ScoJ>us umbrctta?) 



BY DR. E.MIL HOLUB. 



THE Hammerkop, so named by the Dutch 

 settlers, or N jaka (Rain Doctor), as it 

 is called by the natives, is one of the 

 most remarkable birds of the Gralhe in South 

 Africa. 



Every settler and every traveler who visits 

 South Africa is well acquainted with this great 

 philosopher among the South African l)irds. 

 Hardly the traveler has come to the South Af- 

 rican shores when he will meet the Hammer- 

 kop, and he will have an opportunity to observe 

 it on every large river, and even on the banks 

 of such large pools as show water the whole 

 year through. Its name, N'jaka, or Rain Doc- 

 tor, is received from the natives from its pecul- 

 iarity of screaming loudly before a rain sets in; 

 the name of a ])hilosopher, because you can ob- 

 serve it walking up and down for hours on a 

 small woody place on the bank of the river. 

 During such a "meditation " the bird shakes its 

 head \ery often and will not utter a single sound. 

 'J'his quiet, noiseless walk will turn suddenly 

 into a wild dance. The cause of this sudden 

 change in behavior of our philosopher was the 

 arrival of its mate, which, a female, came from 

 adding the finishing touch to the big nest on 

 which the pair have been working for several 

 weeks. 



The Hammerkop is, on the whole, a useful 

 bird. It feeds on small fish, but without being 

 thus of any damage to mankind, as fish are still 

 plentiful in South African rivers. It is sin- 

 gularly useful also, as the bird, by passing 

 sometimes undigested fish eggs into another 

 pool of water, where fish have not been before 

 found, transplants the fish from one pool to an- 

 other. 



The Hammerkop belongs to the Stork fami- 

 ly, but being one of the smaller Storks, is about 

 fifteen inches in height. It is a uniform coffee- 

 brown in color, with black feet and bill. It 

 carries its body more on a horizontal plane than 

 upright. 



The flight of this bird is graceful and very 

 interesting. It flies noiselessly close to the 

 ground, or it sails up to three hundred feet in 

 height, just as noiselessly, above the marshes. 

 During this flight the bird will very often sud- 

 denly turn its head to the right and left, by 

 whi( h peculiarity a person can identify it in the 

 dusk. It covers long distances in the interior 

 when it migrates on account of the drying ujj oi 

 the water pools. But on the ever-flowing rivers 

 it becomes a constant resident, and makes use of 

 the same nest year after year. 



A most wonderful structure is the nest of the 

 Hammerkop. We find it in two different shapes, 

 according to the situation in which it is placed. 

 It is commonly a large structure, several hun- 

 dred pounds in weight, built of mud, in which 

 are found imbedded large quantities of small 

 driftwood, but more often rags and bones. When 

 built in the forks of a large tree it is cone-shaped, 

 with the apex turned downward, as in the ac- 

 companying illustration ; when built on a pro- 

 jecting rock of a steep river bank the apex is 

 more flattened, looking upward — just the reverse 

 of the former position. In this shape the nest 

 is never so carefully made as when built on a 

 tree. The nests in this position are up to three 

 feet in height, while those in trees are twenty to 

 twenty-four inches high, and measure from eight 

 to nine feet in circumference in their broadest 

 part. 



The nest is really a rainproof hut. The en- 

 trance is six to eight inches square. The walls 

 of the nest are from five up to seven inches thick, 

 and the nest is generally built in a lonely spot, 

 but often, when the birds are not disturbed, in 

 proximity to dwellings. In such locations, and 

 where are found everlasting marshes, several 

 pairs of birds will settle down in close proximi- 

 ty ; so I found, during my eleven years in South 

 Africa and the southern portions of Central Af- 

 rica, from two to five pairs in the same locality. 

 A larger number, say six to ten pairs, is not 

 often met with at one spot; but in some favor- 

 able localities we find up to ten pairs, or even 

 more. 



The nest is such an extraordinary structure 

 that it is at once conspicuous to the stranger 

 when he enters the locality. It is also such a 

 solid structure that 1 have found some of the 

 deserted ones — as I could guess, deserted about 

 two years previously by the Scopus — in quite a 

 good condition. In my South African Ex- 

 positions (Vienna, 1891, and Prague, 1892) I 

 have exhibited to the public eight specimens of 

 this bird, with two nests. These nests were my 

 own close imitations of the real nests, made ac- 

 cording to exact measurements, sketches, and a 

 minute examination of their structure, as I have 

 not been able to transport the originals to Eu- 

 rope, of which one was about two hundred and 

 fifty and the other over six hundred pounds in 

 weight. These two imitations of the nests, 

 with the birds sitting around them, created gen- 

 eral admiration of the bird's ability as an archi- 

 tect. 



The eggs of the Hammerkop — commonly 

 three or liveware, according to Layaid, white, 

 with the long diameter of 1.90 inches and the 

 short diameter 1.40 inches. 



During my last journey I had opjjortunity to 

 witness other sjjecies of large birds breeding in 



