The bark of the striped squirrel is a first sure sign of decided spring weather.

March 9. 

Wednesday. Rain, dissolving the snow and raising the river.

I do not perceive that the early elm or the white maple buds have swollen yet.

So the relaxed and loosened (?) alder catkins and the extended willow catkins and poplar catkins are the first signs of reviving vegetation which I have witnessed.

Minott thinks, and quotes some old worthy as authority for saying, that the bark of the striped squirrel is the, or a, first sure sign of decided spring weather.

H. D. Thoreau, Journal, March 9, 1853

I do not perceive that the early elm or the white maple buds have swollen yet.  See March 23, 1853 (“The white maple may perhaps be said to begin to blossom to-day, — the male, — for the stamens, both anthers and filament, are conspicuous on some buds. It has opened unexpectedly, and a rich sight it is, looking up through the expanded buds to the sky.”); March 29,  1853 ("The female flowers of the white maple , crimson stig mas from the same rounded masses of buds with the male , are now quite abundant. I think they have not come out more than a day or two.") See also A Book of the Seasons, by Henry Thoreau, White Maple Buds and Flowers

The relaxed and loosened (?) alder catkins and the extended willow catkins and poplar catkins are the first signs of reviving vegetation. See March 7, 1853 ("The dark chocolate-colored alder catkins — what I have called A. incana — are not only relaxed, but there is an obvious looseness and space between the scales. ");March 10, 1853 (".Methinks the first obvious evidence of spring is the pushing out of the swamp willow catkins, then the relaxing of the earlier alder catkins, then the pushing up of skunk-cabbage spathes (and pads at the bottom of water). This is the order I am inclined to, though perhaps any of these may take precedence of all the rest in any particular case . . . The early poplars are pushing forward their catkins , though they make not so much display as the willows . . . ");  March 29, 1853 ("The catkins of the Populus tremuloides  are just beginning to open, — to curl over and downward like caterpillars. Yesterday proved too cold, undoubtedly, for the willow to open, and unless I learn better, I shall give the poplar the precedence, dating both, however, from to-day.") See also A Book of the Seasons, by Henry Thoreau, The Alders

The bark of the striped squirrel is the, or a, first sure sign of decided spring weather. See  March 4, 1855 ("May not this season of springlike weather between the first decidedly springlike day and the first blue bird, already fourteen days long, be called the striped squirrel spring?"); March 7, 1855 ("In a sheltered and warmer place, we heard a rustling amid the dry leaves on the hillside and saw a striped squirrel eying us from its resting-place on the bare ground. It sat still till we were within a rod, then suddenly dived into its hole, which was at its feet, and disappeared. The first pleasant days of spring come out like a squirrel and go in again."); March 17, 1859 ("I hear rustling amid the oak leaves above that new water-line, and, there being no wind, I know it to be a striped squirrel, and soon see its long-unseen striped sides flirting about the instep of an oak. Its lateral stripes, alternate black and yellowish, are a type which I have not seen for a long time, or rather a punctuation-mark, the character to indicate where a new paragraph commences in the revolution of the seasons. ").See also Walden ("I am on the alert for the first signs of spring, to hear the chance note of some arriving bird, or the striped squirrel's chirp, for his stores must be now nearly exhausted, or see the woodchuck venture out of his winter quarters."); A Book of the Seasons, by Henry Thoreau, Signs of the Spring, the striped squirrel comes out