Birds and Birding's Guide to:

Watching THE PENGUINS

Anatomy of an Auk

The bones of the wing, as might be expected from the altered function of this organ, show very great modifications. The shoulder-blade (scapula) is of enormous size and affords attachment for the powerful muscles of the shoulder joint. The coracoid bone is also of great strength. The other bones of the wing are much compressed laterally and are more or less fused or anchylosed until there is relatively little freedom of motion between them.

The shoulder joint is as perfect in Penguins as in other birds, but the remaining portions of the wing are so arranged as to”almost entirely exclude those movements of flexion and extension which are essential to an organ of flight,”and it is moved as hard as his legs will carry him at the least show of anger from a larger and stronger one. By imitating their cry — the deep rasping one being the most successful — I have always had the clear, shrill one in response.

If in the close neighborhood, I would then send in the dog, and it would always turn out to be the male. With this bird the ordinary relationship between the sexes appears to be reversed; for instance, it is the female that undertakes the defense of the house and home, for the male gives in after a very slight struggle; but the male is the faster runner of the two.

After the young is big enough to follow its parents the male (not the female) seems to take special charge of it. The male has a high, shrill cry; the female utters a low, hoarse note — between a cry and a hiss. Although a nocturnal bird, its sight is weak even at night, for I have seen them running against objects that could easily be avoided; but their hearing and sense of smell are very acute. By going against the wind I have got to within ten feet of them and seen them feeding.

They do not confine themselves to worms, but will also take any kind of vegetable matter available; for example, the young shoots of a very common alpine orchid. I have found three different kinds of seed and a small white berry in the stomachs of those I have opened.”as an almost rigid body. However, most of the muscles which are present in the wing of a flying bird are represented in the wing of a Penguin by tendons, showing beyond question that the present flightless condition has been produced by degeneration from an ancestor which enjoyed the power of flight.

 

 

 

 

  

 

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