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Status and Conservation of
Treeboas on the Grenada Bank

The Grenada Bank Treeboa (Corallus grenadensis) exhibits one of the most variable color patterns in any species of snake,
and that variation has been shown to be correlated with elevation and associated meteorological conditions (temper-

ature, rainfall, amount of possible sunshine). The species is known to occur on ten islands on the Grenada Bank. The largest
island on the bank is Grenada, with an area of 311 km2. The other nine islands are part of the Grenadines (with political
affiliations to St. Vincent or Grenada), have areas ranging from 0.7 km2 (Petit Martinique) to 32 km2 (Carriacou), an aver-
age size of 8.5 km2, and a total area of 77 km2. The total potential range of Corallus grenadensis is under 400 km2. Over the
past 200–300 years, however, deforestation has reduced that area by at least 50%.

Over the past 500+ years, treeboas on Grenada have had to adapt to new prey species (introduced rodents), large-scale
elimination of native trees and the introduction of orchard trees (nutmeg, mango, breadfruit, citrus, cacao), and the intro-
duction of alien predators (opossums, mongooses, monkeys).

Since 1989, projects focused on treeboa biology (primarily on Grenada) have monitored numbers of snakes at several
localities in disparate habitats and weather regimes across the island. In the late 1990s, researchers from the Milwaukee Public
Museum (MPM) began to witness declines in treeboa encounter rates. Those declines have continued to the present — and
are of grave concern.

Of equal concern is a lack of information about what may be happening on those Grenadines that harbor treeboas.
These small, picturesque islands are rapidly being developed for a burgeoning tourist industry, and several have been sold to
private entities. MPM would like to initiate population assessments of treeboas on several of the smaller Grenadines, and
anyone interested in contributing to the treeboa assessment program is encouraged to send tax-deductible contributions to:

Milwaukee Public Museum
Attn: Bob Henderson
800 W. Wells Street

Milwaukee, WI 53233-1478

F O C U S  O N  C O N S E R V A T I O N

Grenada Bank Treeboa
Corallus grenadensis

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