Vol. XXII. 

 1923 



THOMSON, 77/r Tawny f, ■or/mouth 307 



Notes on the Tawny Frogmouth 

 (Podargus stngoides) 



By DONALD F. F. THOMSON, R.A.O.U., Canterbury (Vic.) 



Perhaps one of the best exami)les of protective coloration and 

 mimicry by Austrahan birds is afforded by the Tawny Froj^mouth 

 {Podargus strigoides). Though its characteristic pose and its 

 simulation of a broken limb are well known to all bird- lovers, 

 probably many people have never noticed the bird at all, except 

 for a glance, as it faded like a ghost through the shadows of the 

 night, passing it by with the slightest suggestion of a shiver, as 

 an "owl." The owl has always been regarded as ghostlike and 

 sinister — as a bird of ill-omen, but the Podargus is not an owl. 



No doubt, however, the strikingly protective coloration and 

 pose of this bird have had much to do with its survival in the 

 struggle for existence, and with the fact that of all our nocturnal 

 birds the various species of the Podargidac are the most num- 

 erous and widely distributed. 



One cannot but notice the wonderful provision of nature 

 in the adaption of this bird in a country where insect life is 

 extraordinarily abundant in species and numbers. Probably 

 there is no other bird so entirelx' useful, from the ])oint of view 

 of man, as the Podargus, nor one which does so much to preserve 

 the "balance of nature" of which we hear so often. Not only 

 is the Podargus thus one of the most economically valuable of 

 all our birds, but it is perfectly adapted for its "work" — the 

 capture of its insect prey — as well as for its own survival. 



A truly nocturnal bird, it is active just at the close of day, 

 W'hen myriads of insects come forth to disport themselves in 

 the evening air. Though quite large — about 24 inches over all — 

 the Podargus {Podargus strigoides) is v^ery light in weight, 

 and has the same facility for silent flight which characterises 

 Owls at night. The beak, from which the bird derives its 



name of "Frogmouth," is large, very broad and gaping when 

 open, and serves the double purpose of providing a big surface 

 for the capture of flying insects on the wing and also of in- 

 creasing the resemblance of the bird to a broken and jagged limb 

 when the creature is at rest. As if the bird were conscious 

 of this, when in repose it will often select the broken part of 

 a limb, and sitting upon it, thrust its head up at an acute angle. 

 In any case it is one of the most difficult birds to detect, and 

 very often is found only by tapping the tree, thus causing it 

 to fly. The bird which was photographed, though not so 

 well concealed as is often the case, was only discovered by 

 ■chance, being on a box tree at no great height from the ground. 



