IOWA ACADEMY OP SCIENCE 
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interwoven with those fringing the sheathes, so that one might easily mistake 
the whole structure for a mere tangled tuft of loosened fibres. The small hole 
at the side by which the cavity is entered is turned directly away from the 
trunk and would not be likely to attract the notice of any reptile climbing it. 
Many other instances might be cited of similar adaptations in nests of this 
class, as in the case of the Wood Wrens, Pheugopedius, the Passerine genus Ar- 
remon, the Cotingine genus PacJiyramphus, a small Rail, Creciscus ruter, etc., 
but further illustrations are unnecessary. 
Most of the protective adaptations thus far considered are characteristic of 
species inhabiting forests or dense thickets, where the principal enemies to be 
guarded against are reptiles or small mammals. In the more open sections 
of British Honduras, known as pine ridges — flat, grassy tracts with a scant sprink- 
ling of low pines — the case is quite different. Here the chief enemies are Jays, 
especially Psilorhinus, Hawks, and probably Vultures. Several of the common 
species inhabiting these localities have adopted a means of protection eminently 
suited to their circumstances. In studying the nesting habits of the bird fauna 
of the pine ridges, one of the first phenomena noticed is the tendency of several 
species to nest in close proximity to each other. The colonies thus established 
are composed of widely separated forms, mostly Tanagers and Flycatchers, which 
may be found nesting peacefully within a few yards of each other. If a number 
of the colonies are examined it will invariably be found that the nests of the 
other species are grouped about that of the splendid Derby Flycatcher, Pitangus. 
This bird is one of the most powerful and warlike, as it is one of the handsomest 
of the great Tyrannine group. It is never known, however, to molest weaker 
species, permitting them to make their nests undisturbed within a few yards 
of its own. Doubtless the courage and “magnanimity” of this species have caused 
it to become the unconscious protector of its weaker neighbors. The most com- 
mon of these are the two Tanagers, Tanagra abhas and T. cana, and the Fly- 
catchers, Myiozetetes similis, Legatus albicollis, Elaenia martiniea subpagana, and 
even the large but weak and sluggish MegaryncJius. It is worthy of note that 
those forms that gather about Pitangus to nest are such as would be most likely 
to become the victims of Hawks, Jays, etc., both on account of their weakness 
and the exposure and conspicuousness of their nests. Many of the common pine 
ridge forms, for example, Tyrannus melancholicus and species of Myrarchus, do 
not regularly associate themselves with these little communities, for the obvious 
reason that a strong and pugnacious species like T. melancholicus is amply able 
to defend its own, while those that nest in cavities of trees, like Myiarchus, are 
beyond the reach of most of the common enemies. Whenever the location of 
one of these colonies permits of such a choice, Myiozetetes and Legatus invariably 
and even Pitangus occasionally build their nests in one of the small Acacias with 
hollow thorns inhabited by stinging ants; it is, therefore, not unusual to see 
the nests of two or three species of Flycatchers in a single small tree. 
A few words may be added here regarding the relation of ants to the nesting 
habits of British Honduras birds. In several instances referred to their pres- 
ence is employed by the birds as a means of defence from larger enemies, 
but they are by no means always beneficial. The writer once found a nest of 
Myiarchus mexicanus containing a newly hatched bird just breathing its last 
and covered with small red stinging ants that had evidently attacked it as their 
prey. Such cases are doubtless common. The fierce Driver Ants, of the genus 
Eciton, which move in vast hosts through the forests, destroying every living 
