Discovered in the wetlands area of Argentine Mesopotamia during 2016, the Capuchin Iberá has just become a paradigmatic case study for science around the world. The bird, which feeds on seeds and can weigh about eight grams, caught the attention of researchers from Argentina, the United States and Brazil because it offers clues to understanding how new species emerge in the animal kingdom.
The Iberá Capuchin, whose scientific name is Sporophila iberaensis, is a close relative of the Capuchin Canela bird, another native species of wetlands. However, despite the fact that they share territory, the individuals of both species of birds “know” to distinguish themselves when looking for a mate, through song and plumage. According to a study published in the journal Science and signed by Sheela Turbek, from the Department of Ecology and Evolutionary Biology at the University of Colorado; Despite the fact that both species have similar genomes and the ability to form viable hybrids, they remain isolated in terms of mating with each other.
The study carried out in the Esteros del Iberá made it possible to demonstrate “the important role of behavior in the origin of a new species”. The males of the species Capuchino Iberá and Capuchino Canela differ in coloration and song. Females are indistinguishable by coloration. However, even though they have nearby breeding grounds, they reproduce in a synchronized way and feed together on the same grasslands; The scientists found that the genotype of each female always matched the genotype of her partner.
Usually, new species are formed because some members of a population are isolated by a river or mountains. Over time, the two groups diverge genetically, and in their traits and behaviors. If the isolation is maintained long enough, the groups will no longer be able to produce fertile offspring together. However, although sometimes these physical barriers do not exist, two species still emerge. The rare process is called parallel or “sympatric” speciation. In this sense, the study on capuchin birds in Iberá National Park is one of the few that documents this type of speciation in vertebrates.