Mama never forgets her birds — Bird-Spider

Mama never forgets her birds, 1
Though in another tree-
She looks down just as often
And just as tenderly
As when her little mortal nest 5
With cunning care she wove-
If either of her "sparrows fall,"
She "notices," above.
(F.130/J.164)
[1] Mama:: a mother; a female bird-spider, a large hairy spider of tropical America, which kills small birds (OED bird 9). her birds:: the bird-spider's preys.
[2] in another tree:: a hint that the Mama isn't a bird.
[4] tenderly:: cautiously, with acute sensibility.
[5] nest:: the web woven by the spider. mortal nest:: deadly web for the birds.
[6] cunning:: skilful in compassing one's ends by covert means (OED 5a). wove:: a hint on spider.
[7] sparrows fall:: the doom fate of the birds; "a special Providence" from Hamlet.

the bag-bearing Spider; the water Spider; the bird Spider, and the Tarantula. ─ The System of Natural History, Volume 2 (1800)

One of the largest and most celebrated is the bird-spider. It forms the tube which it inhabits of a white silk like muslin, which it fixes amongst leaves, and in any cavities, and there watches its prey; it is accused by some of destroying even birds, whence its name, especially the humming-bird; but this rests upon questionable authority; ─ On the Power, Wisdom, and Goodness of God (1852)

Hamlet: "there's a special Providence in the fall of a sparrow. If it be now, it's not to come: if it be not to come, it will be now: if it be not now; yet it will come;" ─ The Tragedy of Hamlet