Most invertebrates reproduce by mating and this has led to a most curious result: scientists often find it easier to identify one species by looking at the male genitalia than by looking at the animal itself!
Hamadryas butterflies are camouflaged, or more appropriately, are cryptic on their backgrounds. This makes sense because many species of birds, lizards and mammals want to eat them. But when there is no appropriate background where they need to be for feeding or mating, they align on the closest match they can find. This is a collection of Hamadryas in nature that I did when studying them in the 1980's.
|Ears and sound producing organs in butterflies|
|Hamadryas butterflies emit loud sounds and have ears to hear them. A large eardrum allows them to hear each other as well as birds and other sounds that we, humans, can hear too. A second, smaller ear, probably lets them hear predatory bats. While strongly aggressive during the day, males sleep together at night. This behavior was photographed by Costa Rican scientist Francisco Hernández with captive butterflies. Nobody knows if it also happens in the field, but it probably does and may give them a better chance of escaping from bats. Actually, years ago I received a letter from a Cuban zoologist who wrote that he had found Hamadryas remains in the stomach of bats. Sadly none of this information has been formally published, as far as I know. How they produce sound is still debated, the only experiments available indicate that thickened veins produce them by percussion or sudden deformation.|
|Turrúcares, where the singing butterflies live|
|In the 1980's I studied Hamadryas, a group of extraordinary butterflies that emit loud sounds for defense, to fight for territories and to attract mates. I never published photographs of one of the places where I did most of my work: turrucares, a hot seasonal forest area (at the time under cattle production) in Alajuela, Costa Rica. This is the home of the singing butterflies (there is a note on National Geographic about them).|
|Crab Playa Flamingo, Guanacaste. Costa Rica. 2010|
|Mating Altica Coleoptera Costa Rican Highlands|