1,78 
IOWA ACADEMY OF SCIENCE 
on a horizontal branch, in an upright fork, or pendant from some support. The 
first group is the simplest in form, the last most highly specialized. 
For the sake of illustration we may compare the nests of the birds breeding 
within our own state with those of British Honduras, so far as the latter are 
known, making the comparison in accordance with the above classification. Plac- 
ing it in tabular form, and letting the numbers express the per cent of the total 
number of species whose nests fall within each group, we have the following: 
Iowa 
British Honduras 
69 20 
54 28 
6 5 
7 11 
These per cents, it is true, are not exact, as the nesting habits of a consider- 
able number of British Honduras birds are totally unknown. It is doubtful, 
however, if a knowledge of the life history of all would materially affect the 
proportions given. 
If nov/ we leave out of account the nests of Raptorial, Gallinaceous and Anser- 
ine birds, the Herons and a few other large forms whose size, warlike disposi- 
tion or nidifugous habit place them largely out of danger of such enemies as 
smaller and weaker species must provide against, we obtain still more sug- 
gestive results: 
Location 
Nests open 
above, 
supported 
from below 
Nests in 
cavities 
Nests open 
above, 
pendant 
Nests with 
side 
entrance 
Iowa 
65 
21 
8 
6 
British Honduras 
43 
82 
10 
15 
It is evident that nests of the first type, though the mos|; numerous, are more 
exposed to danger from enemies than any of the others; therefore, the much 
smaller proportion of nests of this form in the tropics than in temperate regions 
doubtless indicates that the abundance of these enemies has brought about nu- 
merous instances of modification of what is plainly the most primitive type 
of nest. 
Protective adaptations in nests of the first class are numerous among British 
Honduras birds, as they are also among ours, and in many cases there is a 
strong similarity; this class, therefore, calls for little comment. The following 
may be noted: The nests of many Flycatchers and Hummingbirds are covered 
with lichens in imitation of the branches on which they rest; those of certain 
Tanagers are made to resemble masses of green moss; the curious Manikin 
Scotothorus veraepacis build's a nest that closely resembles a small mass of half- 
decayed leaves lodged in a tussock of sedge; the large Rail Aramides alMventris 
builds a loose nest of shreds of palmetto leaves and coarse sedges, and places 
it on a low branch over a stream, so that it can hardly be distinguished from a 
