NATURE NOTES

Evening Post, Volume CXXVI, Issue 50, 27 August 1938, Page 17

NATURE NOTES

THE BITTERN

INTERESTING SWAMP BIRD

{By K. H. D. Stidolph.)

The fcdttern, a fairly large bird whicht leads a skulking life among swampy vegetati on, may still be seen in various pant of the Wellington district. Although it is conspicuous enough when it js seen in flight, it is extremely hard [to locate when at rest among, the rush, fes, as if it is alarmed it stands motionle. ci»s, with the head extended upwards amd in this attitude it is easy to pass ii t over as a stump. Often the presence of a bittern is not suspected until thai, bird takes flight, when its' appearance and size. are comparable to the harrier's, though its pointed bill and gene pally -lighter plumage serve to distingl fcish it. Moreover, it seldom flies at ai ly height and usually settles again after flying a short distance, in which res pect its habits are quite dif» ferent fra tn those of the hawk. Therw is no cxc ose for shooting the bitten* in mistakifc for the harrier, and it is as well to remember that the forme* bird is strictly protected, and anyonf destroying it is liable to a substantial, penalty it a conviction is secured under the SAnimals Protection Act. . f . . NOT Ti WHOLLY NOCTURNAL. The bittc pi found in New Zealand does not differ in any marked, degree from manj' of the bitterns inhabiting* various otl ier countries. It is not unlike . the b i rd that was formerly common in England, but, largely as the result of p fersecution. and drainage of swamp laru Is, was later lost for a period as a breeding species. In more recent yeai S, however, under protection, a f evi pairs; have again bred in the Fens c'fistrict. Some authorities claim that i he bittern is almost wholly nocturnal 13 1 habits, but this appears hardly to b*-v the case, as this bird may be seen at any time during the day, if a careftil! approach is made, feeding on the '^'borders of lagoons and on the marshy banks of rivers. Only the other day, fq r instance, when the writer visited the .borders of a large lake, two bitterns were seen .stalking about in the shall p»\V water amid rushes. The bittern is bfltlb. diurnal and nocturnal. There is no question that it sometimes makes extcfl ided flights during the night, wheui. its peculiar notes may also be heai"?9. In the course of its nocturnal flights it sometimes comes, to grief, as r ttore than one bittern hai been picked .\ up dead after it has flown into js>p>wer lines and becoma electrocuted.- :>. •. .■. ■ • !. .' • ' • .'-.». PE^tJLIAR NOTES. The pecul pair booming notes of tha bittern, con 9 parable to the distant roaring of aj Ibull, have given rise to many fables •*& to how the bird makes this noise. Ai!; one. time, it was said that it inserted', its bill into a reed or plunged it into the ground and in that manner caused... the booming sound! In. any case, as f8 ir as the New Zealand bird is conceri led, this booming may be heard both : during the day and the night, though . it appears ta be most frequently utti jred in the breeding season. Someti imes, when in flight, it utters a totallj r different note, something like "gj low," a harsh, weirdsounding cry. v Hardly anything that is alive comes amiss to the bittern as food. The irhtJ :oduction .of frogs into New Zealand* 3 has added considerably to its bill of, lare, and in the quieter parts of tkjeT "countryside, where a colony of '£. fog} - may be heard croaking to their parts' <iontent, the bittera is often to.bje.jseen awaiting its oppor* tunity to msti&e a sudden thrust, with its bill and M.akea capture. When that happens. th^oja is an ominous silence for a few mon tents and then the croaking commer (cejg again. The bittern also eats bisects, Jfi^Ji, lizards, rats, mice, and Crustacea. •' "1 • . • _._. • .. •.■ •' ■ • . • ITS MOVEMENTS DESCRIBED. The late I Sir Walter Buller ably described thjKs bird's habits. "It i» interesting tj^ steal up, under cover, and watch this? bittern alternately feeding and reposij lg in its sedgy haunts, 1* he wrote. ""WB iien in a quiescent posture the body j is nearly erect, the head thrown back " and nesting' on the shoulders, wit.ll the beak" pointed upwards and the contracted neck forming a broad cul rye with the closed ruff depending, the attitude altogether being rather gi otesque. The instant, however, any «* iund causes it alarm the whole charactei • of the bird is changed; the neck is str« ;tclied to its full length and every movement betokens caution and vigilance; \ unless immediately reassured, it -sprei ads its broad wings and raises itself ill the air in a rather awkward manner, .with the legs dangling dowa , but gradually raised to a level withj the tail; the flight then assumes a sfieejdy course, often in a broad semi-afircle, and is maintained by slow and jicepular flappings. If unmolested, it *Wa;y be observed stalking knee-deep mi t^ie water in search of food, with its' neck inclined forward, raising its f pot •at --every step, as it deliberately f measuring the ground." Sir Walter "fjulliir's description of the bird's moveuD«tnf s shows that he was well acquainted*; with its habits. THE 813 TERN'S NEST. Very few nejslts cf: the bittern have • been found in j Tew Zealand. Mr. H. Guthrie-Smith, v ., of Tutira, Hawke's Bay, many year's ago investigated the swamps and m iaqrshes of the Petone district and was fortunate enough, after an extensive i ' and long-continued search, in flm Jing three nests of this bird. In his ' Bird Life on Island and Shore," he describes his adventures with the bitter n. One nest was located on an islet su; Grounded by black ooze, in the centre oi' a meagre rush plant. It contained fiv% young ones, which in appearance hei compared with golliwogs rather "than bird?. Another bittern's nest v ras found within twenty yards of a roacfr over which there was a considerable 'volume of traffic. The site of this nctiit was quite dry, although well hidlden. It contained five eggs, pale olivaiyjous blue in colour. The third nest was built on dry rush land, close to an extfepsive area of swampline. Within tWenty yards of it was the nest of a rtairrier! Mr. GuthrieSmith succeedect 1 in securing some excellent photographs of the bittern's nest, showing t »th the eggs and the young. There itfc still plenty.of opportunity for recording further observations of the bit fcern's habits in New Zealand. \

W,!L. Suwi