Cull of the threatened Mauritius fruit bats: disregarding science can bring one more species to be as dead as the dodo

There is no lack of news on major environmental problems. In the recent decades, they mushroomed strong by the day. Fortunately, there are some stories of success. A few of such stories come from a tiny island in the Indian Ocean that many call ‘paradise’ for its idyllic mountain landscape and sea views. Such stories are surely blockbusters – bringing back to life species surely destined to oblivion. Biology students learn about them in their textbooks – the kestrel, the pink pigeon, the echo parakeet, etc. These stories from Mauritius spark light for a nation that gave the planet the symbol of human caused extinction, the dodo.

The ‘paradise’ Mauritius was one of the last places to be colonised by humans but it is today one of most ecologically devastated. The main causes are the fast and massive deforestation (most of the forest was cut in less than 100 years, with < 5% remaining today). Invasive alien species were introduced by the thousands, even before human settlement (e.g. rats via shipwrecks). So not surprisingly, Mauritius holds both the highest percentage of extinction and of threatened species per landmass. The rarest species on Earth lives alone on Mauritius since over 73 years.

The only remaining seed disperser of large fruited Mauritian trees is the flying fox Pteropus niger. This is the last of the three species of Pteropus that once lived on the island. The species used to occur in the nearby islands of Rodrigues and Reunion but disappeared from these around 200 years ago because of overhunting (luckily some dozen bats were recorded in Reunion in mid-2000s).

Bat-pic

Mauritius fruit bat having a nap

Pteropus diet causes tension with fruit growers in many other countries including Australia. It is no different in Mauritius. The Government of Mauritius planned to cull the species since 2006, but this did not materialise as it was legally protected. Introduction of adequate cultural practices (e.g. tree pruning and netting) and the lack of scientific data to back a culling programme were also reasons to hold this type of radical action.

The population of Pteropus niger has, over the last decade, increased slowly to an estimated < 50,000 bats in 2013. This was one reason for the IUCN reducing the species threat category from Endangered to Vulnerable (https://www.iucnredlist.org/details/18743/0).

In 2014-2015, a study made on litchis and mangoes orchards showed that fruits were lost mostly to wind or becoming overripe (up to 30%), and that bats did damage fruits but to an extent barely higher than caused by alien invasive birds. Further, over the years farmers who pruned and netted their trees sucefully increased their yield.

So, facts indeed show little support for the need to cull the bats. In addition, elsewhere the cull of other Pteropus species failed to reduce fruit damage or disease transmission.

However, against this background and scientific facts, the Mauritius Government took a top-down decision to cull 18,000 bats on 06 October 2015, in the hope of increase profits of its small fruit export industry. This seems to be an unparalleled cull of a native species.

The cull was  made legal by the enacting a new biodiversity law a couple of weeks later. The new law, which aims at improving indigenous biodiversity conservation, made its debut by enabling the killing of thousand of animals of a native species alredy threatened with extinction and which  has a small population on a reduced land area, and is severely affected by cyclones. Cyclones can decrease the population of flying foxes up to 80-90%.

Non-lethal solutions to the conflict abound. There are a number of win-win solutions such as improviment  of cultural practices or restoration of native forests that are highly invaded by alien plants; but these are being done at very slow pace. Even better, bats can generate funds through ecotourism (wildlife watching). Surprisingly, politicians of the country resorted to an old-fashion and ineffective control measure. The international media and international organisations are standing against the cull).

Mauritius fruit bats are mostly exported to Europe, where there is a growing movement calling for a boycott of both the fruits and also of the destination.

Thousands of bats have already been killed. I hope that there is still time to stop this barbaric and ignorant action – please sign this petition.