JOHNSTON: CAYMAN ISLAND AVIFAUNA


FIGURE 17.-Typical roadside and house-site habitat, Cayman Brac.


uvifera, Bursera simaruba, Mangifera indica, Carica papaya, Psidium
guajava, and Manilkara zapoda. Included in this formation is the so-
called "roadside community" which contains powerlines, poles, and fence
lines. Because there is currently a small resident human population on
Little Cayman (about 20), this ecological formation is virtually absent
from that island.

 AVIFAUNAL DISTRIBUTION
 IN THE ECOLOGICAL FORMATIONS

 The impenetrability of most of the wooded formations on the Cayman
Islands, the exceedingly rough and uneven terrain, and the absence of
trails for accurately measuring distances made it possible to obtain
precise quantitative measures of the terrestrial avifauna, except in unusual
instances (see census data presented later). Thus, traditional techniques
for measuring bird population densities, such as a transect-count or the
territory-mapping technique, could not be employed in these investiga-
tions. A semi-quantitative method was devised, however, to provide rela-
tive indices of abundances of species populations. The method was used
on all three islands, although most of the censuses were taken on Grand
Cayman. Ten censuses, each of about two hours duration in early morn-
ing hours, were taken in representatives of each of the major ecological
formations during the months) indicated in the accompanying tables.


1975