Conservation Biology
Nathaniel T. WheelwrightEach February, when I return to Monteverde to study
the reproductive ecology of lauraceous trees, I stay
with friends in their farmhouse tucked on the edge of
the lower montane moist forest. On my first morning
back, I am always eager to listen to the dawn bird
chorus. During my most recent visit, I awoke to hear
a cacophony of Great-tailed Crackles, a noisy flock of
Brown Jays, an exuberant House Wren, and a gang of
Bronzed Cowbirds squabbling over spilled grain by
the cow barn. Back in 1978, during my first visit, there
were no Great-tailed Crackles in Monteverde. Brown
Jays had colonized the area, but their flocks were rela-
tively small and restricted to the lower parts of the
community. House Wrens, always familiar denizens
of Monteverde's yards and farms, are more abundant
today than ever. Once a rarity in Monteverde, Bronzed
Cowbirds are now common. Monteverde has changed,
and more changes are coming.
The rest of Monteverde's avifauna has undoubtedly
felt an impact from the explosive population growth
of these bird species. Crackles and jays prey on the
eggs, nestlings, and fledglings of other birds; wrens
also occasionally destroy other birds' eggs. Cowbirds
are brood parasites. All four species potentially com-
pete with other species for food. Without censuses
from earlier years, it is impossible to know how newly
colonizing species have affected the fauna and flora
of Monteverde. Contributors to this book have pro-
vided evidence that various species of animals and
plants, especially widespread species of Costa Rica's
lowlands and foothills, have expanded their ranges
and increased their population sizes in Monteverde.
At the same time, other species are rarer than they
used to be only a few decades ago. I used to marvel
at the frenzied breeding aggregations of Golden Toads,
hold multicolored Harlequin Frogs, and listen to
nightly serenades of glass frogs along the Rio Guacimal.
Most of them no longer exist in Monteverde.
In this chapter my goals are to (1) highlight aspects
of the biodiversity of Monteverde that are relevant to
conservation, (2) give a brief overview of general con-
cepts in conservation biology, (3) discuss conserva-
tion problems that are specific to Monteverde and
neotropical highland forests, and (4) consider how
principles of conservation biology might provide so-
lutions to those problems.12