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VOL. XI 
SOME RARE BIRDS AND SETS OF EGGS FROM THE CAPE REGION 
OF LOWER CALIFORNIA 
By JOHN E. THAYER 
M R. Wilmot W. Brown has been collecting for me in the vicinity of La Paz, 
Lower California, for nearly a year. Among the rare sets of eggs he has 
sent me I think one of the most interesting is a set of Mangrove Warblers 
( Dendroica bryanti castaneiceps) . Unfortunately he was unable to collect but 
one set, containing three eggs. He found two other nests, one with eggs so far 
advanced that he could only save one, and the other containing young. The nest 
with three eggs I have in my collection, also the other two nests. 
These nests, especially on the outside, look much more like Vireos’ than they 
do like Yellow Warblers’ ( Dendroica (estiva). The nest with eggs is made (and 
the others resemble it very much) of light green fern down, cobwebs and light-col- 
ored dried grasses, with a few white feathers plastered on the outside. It is beau- 
tifully lined with feathers. It is not so perfectly shaped or so well made as the 
Yellow Warbler's nest. It would seem that three eggs are the complete set. Mr. 
Brown found this nest at Pichalinque Bay, near La Paz, Lower California, June 2, 
1908, in a mangrove tree, ten feet from the ground. Incubation was advanced. 
The eggs measure .68X.53, .67X.52, .68X.53, and look very much like the 
Yellow Warbler’s, but are not marked so heavily. 
The second set he found at San Jose, near La Paz. The nest was on the edge 
of a very muddy lagoon in a mangrove tree, about five feet from the ground. In- 
cubation was very far advanced, so only one egg out of the three could be saved. 
On June 16, at San Jose, Mr. Brown found another nest which contained three 
young; by June 25 they had left the nest except one, which was dead. This nest 
was placed on a mangrove bush on an island in a lagoon. 
Mr. Brown collected a very large series of these birds as he knew their song 
and could imitate it; otherwise, he said it would have been a most difficult task as 
they are very shy. Mr. Frazar, in Mr. Brewster’s interesting book on “The Birds 
of the Cape Region of Lower California”, says he took only eight in all and did 
not shoot more than a pair in any one day. He notes the bird as “rare”. That 
was in 1887; since that time they must have increased. 
Mr. Brown says, “I found the Mangrove Warbler a rare bird, but my previous 
experience with this species in Panama, the Pearl Islands, and in Yucatan is what 
made me successful. I learned its song and alarm note in 1893. The first morning 
I went into the mangrove swamps of La Paz I whistled the song of the Yucatan 
species and the birds answered me; this is the secret of my success, for the species 
is very secretive in its habits. I found it so difficult to get that I offered fifty cents 
apiece to the duck hunters and others, including the local taxidermist, but they 
all failed to get it! By covering eight miles of territory I generally managed to get 
four or five. Sometimes when I shot one it would fall in the mangroves, -with a 
tide running fast. Under such conditions it generally took a long time to find it, 
and a great deal of cutting with the machete.” 
Brown found one nest of the St. Lucas Swallow ( Tachycineta thalassina 
brachyptera ) at Pichalinque, near La Paz. It was situated in a depression on the 
face of a cliff among the rocks. It contained two eggs. The nest was made of 
dried grasses and lined with hair. The eggs are pure white and measure .65X.51 
and .66X.50. 
Altho he collected a large series of the PYazar Green Heron ( Butorides vires- 
