Anuran malformations are rarely reported to occur with high frequencies in natural populations. However, there is consensus that they can be caused by several factors. Herein, we report malformations in Rhinella ornata toads from land-bridge islands and compare their frequency with those of mainland populations from Rio de Janeiro. All islands showed levels of malformation significantly higher than the threshold of 5%, and one of the islands, Ilha Grande—which is the largest, farthest from the coast, and has been isolated for the longest time—had the highest frequency of morphological defects. Although it is possible that factors such as chemical contamination and parasite infection cause these defects, we also propose populational bottlenecks as contributing to the high frequency of malformations. Further studies are needed to understand the causes and consequences of malformations in these insular populations.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.