Worrying results show an investigation carried out on bird populations in Amazonian forests that have not been intervened. The study indicates that although at the landscape level they have not had major changes or loss of coverage, What is evident is that a large number of species were no longer common.
There is a very specific group of birds that has been affected: they are those species that inhabit the lower strata of the understory, that is, they are closer to the ground. “We do not know the causes, but during the development of the research we were able to rule out factors that were promoting this phenomenon. We concluded that it was not due to invasive species, parasites or diseases, nor to the increase in populations of large mammals that could alter their habitat. species ”, indicated the researcher and biologist at the Humboldt Institute, Angélica Hernández Palma, who was part of the study.
The analysis that was carried out in the Brazilian Amazon and was led by scientists from Louisiana State University in the United States of America, indicates that of the 79 species of birds analyzed in the Amazonian primary forest in conservation status, located 80 kilometers north of Manaus in Brazil, about 50 percent are less common now than 35 years ago.
The results of the research carried out in the study area of the Biological Dynamics of Forest Fragments Project are not flattering. Hernández Palma says that due to the period of time it covers (35 years), this report has made it possible to monitor changes that are not evident, since if the forest has not suffered any disturbance, it is expected that the species will remain.
The research was carried out in three plots of 15,000 hectares in terra firme forest, in Manaus, in the north of Brazil.
Characteristics of missing birds
The truth is that the bird species that have been lost have a specific strategy of searching for food resources or foraging, which could indicate that the causes are due to changes in the availability of food. “It is possible that they are not finding their prey easily due to changes in the structure of their microhabitats, the soil and the forest. Everything points to the foraging strategy. Because the trees are growing more, leaves, branches, and bark fall very frequently to the ground, preventing them from easily accessing food, “said the researcher.
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The study points out that due to the change in climate characterized by higher temperatures and drier times, there are other species whose populations are increasing. “While we see strictly insectivorous birds disappear, others whose diet includes fruits demonstrate their adaptability to the new conditions of the system. Of the 79 species studied, five are on the rise,” said the researcher, who specified that the research was carried out in three plots of 15,000 hectares, in Manaus in the north of Brazil.
A total of 79 species of birds were analyzed over 35 years. Photo: Humboldt Institute
For the researcher, the challenges of conserving the largest tropical forest in the world are enormous. According to the new quarterly deforestation report from the Institute of Hydrology, Meteorology and Environmental Studies (Ideam), Between January and March 2020, around 64,000 hectares of forest were deforested in the Colombian Amazon region, especially in Caquetá, with 25,064 hectares; Meta, 24,288 hectares and Guaviare, 14,417 hectares.
“If this is happening in places on the planet where human interference is low, it is important to reflect on what may be happening in our Amazon, where the deforestation rate has increased considerably in recent years”, the researcher concluded.