I left the baby here somewhere…

Posted on December 9, 2010

In the evolution of species that provide parental care to developing young, it’s likely that selection has tended to favour traits that allow parents to distinguish their own offspring from unrelated individuals.  Amphibians are known to be capable of kin recognition, but until a study was carried out in Costa Ricawith poison frogs  (Oophaga pumilio), no one had examined whether this mechanism allows amphibian parents to recognise their own tadpoles.  The study species lays its eggs in leaf litter and when the tadpoles develop, the mother transports them individually to water-holding axils of nearby bromeliads and then provisions them by returning regularly with food (unfertilised eggs) over the next few days.  Experiments were carried out by using plastic beakers as tadpole-rearing cups.  Pairs of cups containing water were tied to trees and mother frogs were allowed to deposit their tadpoles in one of them.  Later in the experiment, tadpoles in some cups were replaced by unrelated young, but provisioning mothers continued to visit the cups as before, regardless of the identity of the young inside.  In another treatment, mothers didn’t switch cups even when their own tadpoles were transferred only 20 cm, to the other cup in a pair.  These results suggest that, in this species at least, parents recognise their young indirectly by identifying their location, rather than by recognising the tadpoles themselves.  It also shows that amphibians have impressive powers of spatial memory. 

Reference:  Stynoski, J.L.  2009.  Discrimination of offspring by indirect recognition in an egg-feeding dendrobatid frog, Oophaga pumilioAnimal Behaviour 78, 1351–1356.

Posted in: amphibians, behaviour