The Condor/1 (1)/Spring Migration of 1896 in the San Gabriel Valley
Spring Migration of 1896 in the San Gabriel Valley.
[Read before the Southern Division of the Cooper Orn. Club, Jan. 8, 1898.]
OWING to the mild winter of 1895-96, the spring migration was somewhat earlier in than usual. Beginning in the latter part of February with the arrival of flocks of Violet-green Swallows, the migration promised to be at its height before the middle of April. But on March 2 and 3 it was suddenly checked by severe snow storms in the mountains and cold weather in the valley.
The cold weather not only proved be a check to the northward migration, but it cut off the food supply of birds, which had not been seen or only recorded in small numbers during the winter, and compelled them to move southward out of the mountains into the warmer valleys nearer the coast. The most noticeable example of this was the Band-tailed Pigeon. This species had not been seen in the valley during the winter, but immediately after the storm large flocks of them were noticed in the grain-fields and oaks of the valley. The mountain Bluebird had before March 3 been noticed once or twice during the winter; but in the two weeks following March 3 it was common. Among other species whose numbers in the valley were considerably increased by the effects of the storm were the Californian Woodpecker, and Golden-crowned Sparrow, Lincoln's Sparrow, Thurber's Junco, Cedar Waxwing, and Western Robin.
The Swallows which had so early ventured upon their northward journey were caught in rough weather. A number were seen on March 3 flying wildly in the pouring rain. However, the quick return of warm and pleasant weather cleared the valley of a large number of winter visitants and by March 10 the swallows had again taken up their course through the valley from southeast to northwest, breaking the wind, as it were, for the great multitude which was to follow.
Before the end of March the northward migration was well under way; Band-tailed Pigeons, Sharp-shinned of Hawks, Red-naped and Red-breasted Sapsuckers, Lewis' Woodpeckers and American Pipits had disappeared on their northward journey; while Say's Phœbes and Vermilion Flycatchers had left the valleys of the coast for their breeding homes on the east side of the mountains. But to fill the vacancies made by these departures there had arrived from the south Texan Nighthawks, Costa's and Rufous Hummers, to Arkansas Kingbirds, Bullock's and Arizona Hooded Orioles, Cliff Swallows, and others.
The number of arrivals and departures each day was increasing, and by the last two weeks in April the northward movement was at its height. Most of the migrants were moving northwest, parallel to the mountain ranges.
About April 4 the last Cassin's Kingbirds were seen; on the same date the Ash-throated Flycatcher was first noted in Eaton's Arroyo. The Black-chinned Hummingbird, Western and Hammond's Flycatchers, Black-chinned Sparrow, Green-tailed Towhee, Black-headed Grosbeak, Lazuli Bunting, Warbling and Cassin's Vireos, Calaveras, Yellow, Black-throated Gray, Macgillivray's and Pileolated Warblers, Russet-backed Thrush were present in numbers before April 15. Before this date Lutescent Warblers and Western Yellowthroats had increased their numbers over winter residents to a large extent. California Purple Finches and Ruby-crowned Kinglets had left the valley.
The migration was fast reaching its height; still, a number of summer residents and transients had not arrived. April 25 showed the presence of more species than had hitherto been noticed; over sixty different species were recorded within the radius of 1½ miles from the mouth of Arroyo Seco outside the mountains. Warblers, sparrows and flycatchers were especially abundant. The new arrivals were the Belted Kingfisher, Olive-sided Flycatcher, Western Wood Pewee, Western Blue Grosbeak, Phainopepla, Townsend's and Hermit Warblers, and the Long-tailed Chat. The Thurber's Junco and the Dwarf Hermit Thrush were the only species which had left since April 15.
Soon after the 25th, however, the great wave of birds began to show signs of decreasing, and by May 5 there had been considerable lessening in the numbers of a good many species. The Belted Kingfisher, the Intermediate, Golden-crowned, Black-chinned, and Lincoln's Sparrows, Green-tailed Towhee, Western Blue Grosbeak, Cassin's Vireo, Calaveras, Lutescent, Audubon's and Black-throated Gray Warblers, had entirely disappeared. There was yet to appear an important factor of the season's migration, and its magnitude was possibly more noticeable because it showed itself in its full strength after the greater part of the general migration had passed. Filling the entire valley with one of the most beautiful forms of bird-life, it was a pleasant sight to everyone but the orchardists. The first individuals of this migration-wave of Louisiana Tanagers appeared during the last few days in April. The birds were common by May 3, and from May 6 to 20 they were abundant everywhere in the valley. Two of the greatest centers of attraction for the mass of migrants were the blossoming grevilia trees and unfortunately, the cherry orchards, whose fruit was then in its prime. Never before had a spring migration filled the valley with such a number of brilliantly-colored birds of the same species. Even uninterested persons remarked the abundance of Tanagers. Happily this was only a migration, and by May 25 the greater part of them had gone, and May 29 saw the last one in the valley.
While so much attention was directed toward this remarkable migration of Tanagers, most of the other migrants had passed on, and all our summer residents had arrived. However, large numbers of Phainopeplas were still in the valley; and had it not been for the presence of so many Tanagers their numbers would have seemed very remarkable. The pepper trees and oaks were the feeding places of hundreds of these birds, which stayed in the valley until June 10, after which all but the breeding birds had left.
Since the last of February 1 had been busy watching the ever-changing representation of bird-life, and now could rest and wonder at the great transformation which had taken place. An avifauna only represented by residents and winter visitants had been gradually replaced by summerers. No date could be fixed when the summer visitants appeared and the winter birds departed; no definite line drawn between migratory and sedentary birds; but from the time when the first Violet-green Swallow obeyed the natural law which told it to return to its summer abode, until the last Phainopepla had reached its breeding home in our fields, there had been an ever-changing avifauna in the San Gabriel Valley.
John M. Welch of Copperopolis, Calaveras Co., writes of the Phainopepla as a common summer resident at that place. They were first observed in May, their single bell-like note acting as an index to their location. He says: "While the notes of these birds are heard all through the hills, each pair have their own foraging grounds which are not intruded upon. I endeavored to locate some of the nests but the female was probably on the nest and the male would not approach it while I was near and I could never detect him taking food. I watched for their broods but could never observe them. The birds have been gradually disappearing since the first of September but I have heard occasional notes up to the first of November."
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