Rock Iguanas dwindling on LC

More than 200 iguanas a year being killed on Little Cayman’s roads


Fred Burton, who has been
instrumental in preventing the extinction of Grand Cayman’s blue iguanas, says
the Sister Islands Rock Iguana population is being decimated by drivers, dogs
and cats.

Mr. Burton said 10 per cent of
Little Cayman’s estimated 2,000 iguanas were being killed each year and unless
steps are taken immediately, those iguanas could face the same fate as the blue

“If we don’t find some way to
improve this in the next couple of years, then basically the Sister Islands
Rock Iguana will go the same way as the blue iguana and we’ll have to launch a
recovery programme. It costs so much more to bring a species back from the
brink of extinction than to prevent it happening in the first place,” Mr.
Burton said.


his recent three-day trip to Little
Cayman, one pregnant iguana was killed by a free-roaming dog, and two adult female
iguanas were run over by cars or trucks. He also saw feral cats, which he said
kill baby iguanas.

“That pregnant animal was probably
going to lay 20-something eggs. Those would have hatched, and then she would
have laid the same next year and the year after that… possibly for up to 40
or 50 more years. The potential reproductive loss from that one kill is just
immense,” he said.

According to Mike Vallee at
Pirate’s Point Resort on Little Cayman, who has been keeping track of iguana
road kills, four iguanas are killed by vehicles every week.

“It’s not yet possible to come up
with precise numbers, but my rough estimations from Mike’s records leave me
thinking at least 200 iguanas are killed on Little Cayman’s roads each year.
Add to that the adult iguanas that are killed by the island’s few free-roaming
dogs, and the baby iguanas, which are killed by cats. We are looking at a truly
horrific burden of unnatural mortality,” Mr. Burton said.

In an article that appeared in the
Department of Environment’s Flicker online magazine, Mr. Burton said the last
population estimate of the Sister Islands Rock Iguana suggested there were
about 2,000 iguanas, nearly all on Little Cayman, as the Brac population has
almost entirely disappeared.

“If 200 of these are road-killed
every year, then we have 10 per cent of the entire population being killed by
vehicles every year. If, on top of that startling number, the survival of their
young is being extinguished by cat predation, then it is easy to see how a
population which seemed to be thriving as recently as my own first visit to
Little Cayman in 1980, may now be in catastrophic decline,” he said.

And while visitors and residents of
Little Cayman may argue that they see plenty of iguanas, Mr. Burton said this
was due to a quirk of iguanas’ behaviour in that they compete for the most
preferred territories, which are usually around the places where people have

“This is because people put food
out for the iguanas and because warm road surfaces are very effective basking
spots and because the coastal sites where iguanas like to nest in are also the
preferred places for humans to settle. In other words, the iguanas are drawn to
the places where they are most likely to be run over, killed by a dog and/or
lose their young to a semi-domestic cat.

“As each of these iguanas is
killed, another iguana that was living in a less desirable territory will spot
his or her opportunity and take over the vacated space. The effect over time is
that iguanas are lured from the interior of the island to the coastal hot spots
around resorts and roadsides.

“As fast as they are killed there,
others move out from the interior to take their place. From the perspective of
people living in Little Cayman, it seems superficially that all is well, because
the numbers of iguanas around the places where people live and work seems to
stay about the same,” he said in the article.

Mr. Burton said he and others are
trying to organise a strategic meeting involving the Durrell Wildlife
Conservation Trust, the Department of Environment, the National Trust in Little
Cayman and other interested parties early next year to develop a strategic plan
to tackle the declining iguana population.

Matt Goetz from the Durrell
Wildlife Conservation Trust – an international charity that aims to save
species from extinction – and a team of volunteers recently completed a project
to map where iguanas nest on Little Cayman so they can identify key sites where
the Trust can focus efforts to stem the growing mortality rate of the iguanas.

They found clusters of iguana nests
in specific locations along the coast, with one site having 60 nests.

This information, along with
statistics on how many iguanas are being killed and where, will be among the
data examined at the meeting. “We’re going to put all the information together
and figure out what is the best thing to do,” he said.

One option might be introducing
speed bumps along areas where iguanas are known to nest, but Mr. Burton said
that enforcing the existing 25-mile-per-hour speed limit on the island would
also cut down on the number of iguanas killed on the roads.

Less than five years ago, the blue
iguana was considered extinct in the wild, but due to the work done by Mr.
Burton and colleagues in the recovery programme at the National Trust’s Blue
Iguana conservation facility in the Queen Elizabeth II Botanic Park on Grand
Cayman, there are now hundreds of the endangered iguanas roaming in the wild.

“History need not be repeated,”
said Mr. Burton. “We should remember the lesson of the Blues on Grand Cayman.
For the Sister Isles Rock iguana now is time to act. For them, this is indeed a
time of crisis.”


Rock iguanas are in danger of being wiped out on Little Cayman.
Photo: File