Green iguanas taking over

A couple of years ago, if a green iguana crossed the road in front of your car, you might apply the brakes. It is possible people nearby might even stop and take a look at it.

If there was a camera on hand photographs might be taken.

Nowadays the Honduran green iguanas seem more common than ching chings (black bird). They are certainly more prevalent than land crabs, even in rainy season.

‘It’s hard to pinpoint exactly when they started showing up,’ said Fred Burton, the man behind the Blue Iguana Recovery Programme. ‘I recall it began in the 1980s. There were some Honduran fishermen selling some on the dock in George Town and two were kept in a chicken wire cage at the George Town Primary School. The iguanas at the school had a hatch of babies. I can clearly remember Ray (Ray’s Photo on Eastern Avenue) calling in 1991 saying there was a big green iguana in the ficus hedge outside his shop.’

The green iguanas are good swimmers and initially it was thought that the range of the Honduran iguana would be confined to the western side of Grand Cayman, which is wetter.

Mr. Burton explained that last year the green iguanas started breeding in Queen Elizabeth II Botanic Park, the area used as a release site for Blue Iguana hatchlings. The Blue Iguana is native to Grand Cayman and on the brink of extinction.

‘This is a problem at a couple of different levels. The park is intended to showcase native animals and plants. People will see the greens there and soon they will start to think they are native also. People will mistake blue-headed green iguana adults as blue iguanas, working against our efforts to teach people the differences and save the one that really belongs here. Other big dominant male greens may attack and harass young small blues and there may even be competition for nest sites and food, if the population of green iguanas in the park gets as dense as it is in some parts of the West Bay Peninsula.’

There are now reports that the green iguanas have made it up to the most easternmost point of the Island.

‘This year they turned up in Little Cayman for the first time,’ said Mr. Burton. ‘So far there are no reports from the wild on Cayman Brac, but they are very efficient swimmers and if they are allowed to stick on Little Cayman they will definitely make it over to the Brac. They are aggressive dispersers.’

There is no evidence that green and Blue Iguanas can inter-breed and create a hybrid species. It is considered very unlikely that this could occur. Scientific analysis has shown they are genetically quite different, so it is like a lion breeding with a tiger.

However the total population of green iguanas does not seem to have reached a peak yet; they are still expanding their range and numbers. ‘They are capable of very high population densities and they are definitely still increasing. East End is far from saturated,’ said Mr. Burton.

The Honduran iguanas are not believed to be present in the other major Blue Iguana hatchling release site, the Salinas Reserve. However, it is anticipated they will make it there very soon.

The Department of Environment, the National Trust for the Cayman Islands and the Department of Agriculture have met at length on the issue, but so far no decision has been made on the way forward.

‘The immediate problem is that until the National Conservation Law is passed it is technically illegal to do anything much about it all. Iguanas are protected, no matter what species, because when the original law was written it was assumed that iguanas referred to the Sister Isles’ Rock Iguana and the Blue Iguana. They did not anticipate there would be other kinds of iguanas here in the future.’

Some research has been done already to study the ecology of the green iguana to determine if they have any vulnerable points where control measures would work and be cost-effective.

Mr. Burton believes the country needs to become more pro-active about restricting and screening the creatures allowed to be imported as pets and ornamentals.

‘If we just let it happen, Cayman will end up like every other tropical island, biologically indistinguishable, because all the animals and plants will be the same pan-tropical tramp species, and most or all the uniquely Caymanian animals and plants will be gone. Grand Cayman, Key West, Hawaii – what will the difference be if our natural environment is homogenized like that?’

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