Edible bird's nest

Definition and stakes

Portrait of William Henry Giles Kingston William Henry Giles Kingston,  Mark Seaworth

“ The chief articles exported by my captors were bees’ wax and camphor, honey, vegetable tallow, areca-nuts, trepang dawma, sharks’ fins, tortoise-shell, edible birds’ nests, and pearls. These are only a very small portion of the articles they might export under other circumstances.
The edible bird’s nests are formed by a species of swallow, which builds them in the caves on the coast. They adhere in numbers to the rocks, very like watch-pockets to the head of a bed. They are either white, or red, or black, and are formed chiefly of agal-agal a marine cellular plant.
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Source: Gutenberg

Austin Loomer Rand,  Stray Feathers From a Bird Man's Desk

“ But some of the edible-nest swifts go further and make their nest entirely of this secretion from their enormously enlarged salivary glands. This material, as it comes from the mouth of the bird, resembles a saturated solution of gum arabic and is very viscid. If one draws out a strand from the mouth of the bird and sticks it on a rod, by rotating the rod and winding up on it the thread of saliva one can empty the salivary glands of the bird. This material dries quickly, and is the material of which the nest is made. ”
Source: Gutenberg

Portrait of Spencer Fullerton Baird Spencer Fullerton Baird,  A History of North American Birds…

“ He keeps ever in the vicinity of the nest, calls her from time to time to come to the mouth of the hole to take her food, or else to receive his endearments and caresses, and at the approach of danger fearlessly intervenes to warn her of it. When feeding together, the male bird keeps up his peculiar nasal cry of hŏnk-hŏnk, repeating it from time to time, as he moves around the trunk or over the branches.
Their favorite food is insects, in every condition. With this, when abundant, they seem content, and rarely wander from their accustomed woods in summer.
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Source: Gutenberg

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