RIOBAMBA (CTYS-UNLAM AGENCY ).-
Researchers from Argentina and Ecuador presented a new species of fossil owl that fed on various mammals and birds, particularly smaller owls. It was more than 70 centimeters height and a wingspan of over a meter and a half. It was found in the Ecuadorian Andes, at 2800 meters above sea level, being the first of its kind discovered in South America.
The discovery occurred in a small cave located in the Chimborazo province, in the geographic center of Ecuador. There, fossilized bones of micro-mammals, birds and, in particular, owls were found that had been the food of what appeared to be a great predator. To the paleontologists surprise, the great predator it was nothing more or less than a giant owl.
This new species exceeded 70 centimeters in height and was named Asio ecuadoriensis. Gastón Lo Coco, a researcher at the Laboratorio de Anatomía Comparada y Evolución de Vertebrados of the Museo Argentino de Ciencias Naturales (LACEV-MACN) and CONICET, described to the CTyS-UNLaM Agency that the legs of the giant owl were long and thin, effective in capturing prey that is difficult to subdue.
"One of its peculiarities is that, apparently, it had a predilection for consuming other smaller owls", said Dr. Federico Agnolin, co-author of the study published in the scientific journal Journal of Ornithology. And he added: "It is a biological rarity".
The field explorations in which these fossil remains were found were carried out by the Biology Department of the Escuela Politécnica Nacional in Quito, between 2009 and 2012, in one of the most important fossiliferous localities of Ecuador, known by the name of Quebrada Chalán.
The paleontologist José Luis Román Carrión of the Museo de Historia Natural de la Escuela Politécnica of Quito detailed: In this site, we were lucky to find ancient roosts of raptors, which were covered by sediments, among which were fossil remains of mice, shrews, rabbits and a lot of bird material.
"What is striking is that the remains of all these microfossils have a typical wear that causes the digestion of birds of prey on these bones", said Lo Coco. And he explained: Therefore, we proposed that all the remains of the other species would belong to the prey of this great owl.
"By finding the remains of the animals that had been the last meals of the Asio ecuadoriensis, we were able to know that, among mammals and birds, it consumed especially other types of owls, which shows us that this giant owl was practically what could be called a cannibal owl, weighed Agnolin, researcher at LACEV-MACN, CONICET and the Fundación Azara.
In the remains of that ancient cave, four species of owls were found. Three of them correspond to species that currently exist (Glaucidium sp., Tyto furcata and Athene cunicularia), while the fourth is the cannibal owl, which dominated to the other rest, but did not survive until today.
Román Carrión told the CTyS-UNLaM Agency that the Quebrada Chalán is part of one of the most prominent fossiliferous localities in Ecuador.
In these localities, there are fossil remains in hardened volcanic ash between 20 thousand and 42 thousand years old, in what corresponds to the Late Pleistocene. 40 thousand years ago, at 2,800 meters above sea level where that owl lived, there was a wasteland. "Currently, the páramos in Ecuador are more than 4,000 meters high, but back then they were at a much lower altitude, because it was the end of the Ice Age and the climate was much colder", Román Carrión analyzed.
The Ice Age and the giant animals
Until about 10,000 years before the present, throughout all of South America, huge mammals such as glyptodonts, giant sloths, mastodons and saber-toothed tigers lived.
In the case of birds, it is much more difficult for their fossil remains to be preserved, because their bones are hollow and brittle. t, it is rare to have been able to identify not only the giant owl, but also several species of birds that had been its food.
"Based on the remains that we have preserved, we calculate that it would be between 70 and 80 centimeters height", said the researcher Federico Agnolin (see illustration of the giant owl made by paleontologist Sebastián Rozadilla from LACEV-MACN).
When there are modifications in the environment, large birds of prey are more affected than small birds that have many offspring and do not need large extensions for their survival.
"We think that the climate change that occurred about 10,000 years ago, when the Ice Age ended, was partly responsible for the extinction of these large predatory birds of which they remain in currently very few species, such as the great eagles of the forests and the Andean condors", concluded Dr. Agnolin.