Bad news for Green toads (Bufo viridis balearicus) on Ibiza
Recently whilst researching my summer trip to the Balearics, I came across a very interesting publication, ”el libro rojo de los vertebrados de las baleares” which gives specific information of the conservation status of all vertebrates on these Spanish islands, especially the largest three: Majorca, Menorca and Ibiza. Although it is considered as vulnerable on the first two islands, on Ibiza is now regarded as being in danger of extinction. In the 1960s a study of the toads on this Mediterranean island showed quite a healthy green toad population, and between 1970 and 1980 over 50% of the toad populations on Ibiza were wiped out. During a more recent evaluation in 1992 only four water sources with tadpoles of the species were found on the island. More recently one additional breeding site has been located far away from the previously known sites, but it appears the species presence on Ibiza may soon be a thing of the past. In Spain the Green toad is only found on these islands and is absent from all of the mainland, and they are currently classified under the subspecies Bufo viridis balearicus, despite the fact that these toads were believed to have been introduced in ancient times they are now considered part of the fauna of the islands. It is believed the decline of the toad in Ibiza since the 1960s has been due to the continued urbanisation of the island for the tourist industry, destroying what few water sources were present on the island to begin with. I visited Ibiza in May 2008 and I could not find any appropiate water source which could maintain a population of this beautiful toad species.