Drones present a cheap, minimally invasive method for researchers to review threatened marsh deer populations and their habitat.
Marsh deer (Blastocerus dichotomus) are the most important cervid species within the Neotropics and occupy wetlands, savannas and grasslands in South America. Within the Pantanal wetland in Brazil, these deer face a lot of points, together with habitat discount and fragmentation on account of agriculture, cattle ranching and hydroelectric dams. Their populations have additionally been hit by unlawful searching, and so they have additionally traditionally been susceptible to ailments from livestock.
These challenges impressed Ismael Brack, a doctoral researcher on the Federal College of the Rio Grande do Sul in Brazil on the time, and his colleagues to make use of fixed-wing drones to estimate the deer’s abundance and their most well-liked habitat in a examine revealed in 2023.
Withdrawing within the wetland
The Pantanal Wetland is the world’s largest tropical floodplain. It has a seasonal wet local weather and receives periodic flooding from close by rivers. Brack and his crew’s examine space, the Sesc Pantanal Personal Reserve, covers 108,000 hectares and is characterised by a tropical savanna local weather and a mean rainfall of 1,200 millimeters.
The researchers performed the examine in the course of the wetland’s dry season in September and October, the place rainfall wouldn’t pose a problem. However the dense, moist tropical panorama nonetheless makes conventional wildlife counts tough, making drones the perfect software.
“I’ve been working with drones for some years,” Brack mentioned, including that he has used them to detect species earlier than. “That’s a pleasant factor with this examine. We’re actually making use of this method for an ecological downside.”
Whereas drones are pretty frequent, Brack mentioned that utilizing them for science could be considerably difficult, particularly when navigating correct licensure for drone flights.
“I believe it’s a software with nice potential to survey wildlife species,” he mentioned. “The challenges are implementing strategies that provide the most dependable info, and there are a lot of authorized restrictions which can be powerful to cope with.”
Every flight took the crew simply over an hour. The researchers performed the flights in the course of the coolest hours of the day when deer are most energetic, and so they made positive the drones prevented extremely forested areas marsh deer don’t have a tendency to make use of. In complete, the researchers operated 25 flights, gathering 25,000 photos.
Counting marsh deer
Researchers reviewed the hundreds of photos to make sure accuracy. They fastidiously examined the pictures whereas marking every marsh deer discovered with particular software program.
Over the course of two-month examine, the crew counted 66 marsh deer. Whereas this may occasionally not seem to be a big quantity, the flights and pictures offered worthwhile perception into the deer’s habitat. Figuring out these high-quality areas for marsh deer can enhance conservation planning actions, like designating protected areas or mapping firefighting priorities throughout wildfires.
The researchers discovered marsh deer most well-liked areas with vital inexperienced vegetation that had been nearer to our bodies of water. Nevertheless, the crew additionally found that this habitat overlaps with that of predators, particularly jaguars, in the course of the dry season. The chance of predation, although, didn’t deter the marsh deer from these areas.
Future analysis
In 2020, the Pantanal was severely impacted by wildfire. Because of this, Brack believes that utilizing drones will permit researchers to raised perceive the results of those fires on the Pantanal natural world.
“Understanding the elements that basically have an effect on the abundance of the species was step one,” Brack mentioned. “However now, we’ve been making an attempt to watch the species in the identical reserve with the identical strategies. We had these big megafires in 2020 that impacted greater than 90% of the reserve, so we are attempting to make use of the identical methodology to actually see the impacts.”
This article by Megan Radke was first revealed by The Wildlife Society on 7 October 2024. Lead Picture: Marsh deer (Blastocerus dichotomus) are a susceptible cervid species in South American wetlands, savannas and grasslands. Credit score: Ismael Brack.
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