Human threats outweigh the natural factors in the design of deer population in the Atlantic rainforest

A group of Brazilian researchers first estimated the density of five types of deer in the entire Atlantic rainforest. This allowed them to measure the main factors that affect the number of deer per square kilometers (km²) in forest areas.

Results suggest a strong connection between low animal density and human pressures such as hunting, predator Homemade dogsdiseases that are transmitted by livestock and competition with wild pigs, an invasive species that consumes the same resources as deer.

The study was published in Magazine for applied ecology.

“Jelena living in the forests is the hardest to spot and therefore evaluate their population density. This is an essential metric for preservation And the one who has just been able to get after more than a decade of effort, “says Mácio Leite de Oliveira, a professor at the University of Araraquar (Uniara) and the first author of the article.

Oliveira conducted some of her studies during her postdoctoral research at the Center for Research and Preservation of Jelena (Nupecce) by the State University of São Paulo (UNESP), JaboticaBal.

Estimates are based on samples collected in 31 points in 21 conservation units representing the Atlantic rainforest, from northeast to south of Brazil. Jelena feces were located specially trained dogs. Researchers then used a fecal DNA analysis to identify the species.

The method of assessing the density developed by the group and previously used in other studies also includes statistics that take into account the rate of defecation of each kind.

Due to the robustness of the data, they are included as indicators in the national action plan to preserve Ungulates, public policy of the Brazilian Ministry of Environment and Climate Change (MMA) for this group of animals.

In the now published study, researchers have also recorded environmental information such as the type of vegetation, altitude and inclination. Finally, a survey was conducted at each place to identify human threats, which were assigned an index of 0, 1 or 2, and zero represented the total absence and two representing a high prevalence.

“Although a direct relationship between deer derivative deer and threats was expected, this has never been proven as strong as now. The work therefore provides strong evidence that supports the management of protected areas and the preservation of the species,” Oliveira explains.

The lowest density listed was 0.14 individuals per km² For Roe Deer (Mazama Rufa) at Araucárias National Park, Santa Catarin. The highest was found at the Sooreta biological reserve, in the state of ESPírito Santo, with 18.17 red deer (Passaliti Non -Norivagus) per km².

The case of red deer was an exception. In sampled areas, the average density ranged from 1.47 to 3.42 individuals on km².

Anthropogenic influence (stems from human activity) had the greatest effect on deer density, extinguishing natural factors such as altitude, slope and latitude. In addition to correlation with Environmental monitoring And the rates of the exploitation of plants in the places studied, the presence of hunters, domestic dogs (which can capture deer), cattle (which can convey diseases) and wild pigs (competing for resources and can convey diseases).

In one case, however, the human presence favored the animals: the number of parked retainors. “The density of professionals working in conservation units influenced the density Jelena. The more it parks, the more deer could be revealed in an area, “Oliveii says.

Another group of group has already shown the importance of protected areas for Jelena. At that time, researchers pointed out that protection only 2% more Atlantic rainforest would bring benefits to preserve at least three types of deer.

“The published work provides a parameter of Cervid’s current situation in the Atlantic rainforest. The ideal would be to repeat these estimates every five or ten years and see where it remained the same, where it increased and where it was reduced. In this way, the preservation could be guided by the evidence,” the researcher concludes.

In addition to Barbanti, the study supervisors include Fernando de Camargo Passos, the coordinator of the Laboratory for the Biological Diversity, Preservation and Ecology of Wildlife (Labceas) at the Federal University of Paraná (UFPR).