12 THR COlqDOR Vol. XI like tree grows commonly close to water and is used by several other birds in common with the Derbys; among them the Hooded Cactus Wren (Heleodytes capistratus capistratus), the Sclater and Lichtenstein Orioles (lcterus sclateri and Icterus gularis gularis), Giraud Flycatcher, and Gray Becard (Platypsar,s aglaiae latirostris). These trees almost without exception were swarming with fire ants which lived in the greatly enlarged and swollen thorns and whose sting is very sharp and irritating. They seemed to cause the birds no inconvenience, even though the tearing apart of a nest would sometimes show the insects present in considerable numbers. Wasps' nests were encountered all too frequently for comfort and the above mentioned species sometimes built near them, un- doubtedly for the added protection. One Derby's nest was built over and par- tially supported by a wasps' nest as big as a foot-ball. That of a Hooded Cactus Wren was also observed in a like situation. It may be noted here that the country Derbys seem to be much more peaceably inclined than are their city kin, often nesting in close association with one or more pairs of other species. In one case four nests were found in one small tree, a Derby's, a Giraud Flycatcher's, a Les- son's and a Lichtenstein's Oriole. Three other nests may be recorded as being in rather unusual locations; one in a dead tree sticking out of a mud flat about two hundred yards from shore at Lake Ilopango, another in a tangle .of vines hanging over a bank, and the third thirty feet up in a great creeper-hung tree and almost hidden in a cluster of purple orchids. Remarkable similarity in construction, material and shape of nests was noticeable. The body, including the roof, made up of fine dead grass stems with the addition of much soft stuff, such as feathers, plant down and small rags (when available), was rather loosely put together. The cup (or more properly saucer, in this case) consisted of slightly coarser grass stems well packed and smoothed down and placed well toward the back of the nest; entrance on the side and pointing slightly downward, thus making a more effective water-shed. Measurements: outside, eighteen inches long by ten wide by eight high; inside, (nest cavity) seven inches long by five wide by five high, the saucer taking up the whole floor. These measurements were taken from the first nest collected and may be a little larger than the average. By the time the young are ready to lea[e, the formerly purse-shaped nest has been flattened out and blackened by the tropical rains and sun, and the young birds have so enlarged the entrance that the entire cavity can be plainly seen. Fresh eggs were found from March 28 to the first of June, so two broods at least are raised each year. In every instance a new nest was built for the reception of the second set, whether the birds succeeded in raising a first brood or not; but in neither case was material ever taken from the first nest to be used in the second. Number of eggs ran from four usually, three occasionally, to two once. In the city of San Salvador are a great many birds which are without doubt non-breeders (as only two nests were found in the city proper), even though they are mostly in pairs. These individuals, having nothing better to do, contrive to keep things lively by scrapping not only with each other but with anything that happens to attract their attention, such as a stray house-cat or a wandering hawk. A favorite lookout is a tall flag pole or similar point o.f vantage, and this is taken possession of to the exclusion of all other birds, most especially of their own kind; in fact, the advent of another pair onto their preserve is the signal for a battle royal which generally ends as it should--in favor of the home team. From dawn till an hour or so after sunrise, and in the cool of the late afternoon
