In his voyage to India, Sonnerat speaks of a Cape titmouse, the nest of which is made of cotton and is shaped like a bottle. While the female is hatching inside, the male, a most watchful sentinel, remains outside in a pouch or hammock, fixed to one side of the neck of the nest. When his mate moves off and he wishes to follow her, he beats the opening of the nest violently with his wing until he closes it, in order to protect the young from enemies.
Sagacity of a Bird.
In the museum of Brown University, Providence, R. I., is a curiosity in the shape of a bird's nest. Aside from its ingenious construction as a swinging nest, partly suspended by strings and cords carefully woven into it and around the slender branch which holds it, another evidence of the builder's sagacity is given. As the young birds grew, and the nest daily became heavier, the mother saw that the slender twig, about the thickness of a pipe-stem, to which it was attached, could not support it much longer, so she made it secure by fastening a stout cord about it and passing the end around a strong limb above, which steadied it and made it safe.
Change of Sight in Birds.
Birds destined to move in the medium of a very rare atmosphere and which has but little tendency to refract the rays of the sun, have a great quantity of aqueous humor, in order that the light, strongly refracted in entering their eyes, may bring distinct images. Thus birds at heights where they appear to us only as points, perceive the smallest reptile concealed in the grass. But, as presbyte birds do not distinguish objects when brought near, nature has provided for this difficulty, which occurs when they descend from the heights of the air to seize their prey. To provide for this emergency, they have a membrane, by means of which they remove the crystalline lens from the retina; and thus changing the power of the eye by changing the focal distance of objects, as we do with spectacles, they never lose sight of their prey, whether in the air or on the ground.
Nest of the Flamingo.
The flamingo arranges its nest in a peculiar way, as its long legs would not adapt themselves to the ordinary style of nest-building. The nests are placed upon the ground, are built solely of coarsely-tempered mud, and are very curiously shaped, being like narrow, lengthened cones. They are twenty inches in height, and their truncated summit presents a concavity, at the bottom of which the female deposits her eggs. In order to hatch them she places her abdomen over them, and allows her legs to hang down on both sides of the raised nest.
Barking of Dogs.
The Australian dog never barks; indeed, Gardiner, in his "Music of Nature," states "that dogs in a state of nature never bark; they simply whine, howl and growl; the explosive noise is only heard among those which are domesticated." Sonnini speaks of the shepherd dogs in the wilds of Egypt as not having this faculty; and Columbus found the dogs which he had previously carried to America to have lost their propensity for barking.