The lower region of the Paraná Delta and Islands occupies an area of more than 3,200 square kilometers in the provinces of Buenos Aires and Entre Ríos. This area, which Argentines call “El Delta”, is one of the most human-encroached areas, mainly due to land use changes (livestock, forestry and urban projects) affecting ecosystems.
Its rivers, streams, and wetlands are home to at least 36 species with some degree of threat. Among all this fauna, there is an animal that is of particular interest, being the most emblematic species of the area and a natural monument of the province of Buenos Aires: the marsh deer. It is the largest native deer in South America, classified as “Vulnerable” throughout the area and is a key species for conservation.
The Swamp Deer Scientific-Technical Committee was formed with the idea of working to restore the species, rescuing injured animals, and raising awareness among the population. It is a program promoted by the Temaikèn Foundation together with national, regional and municipal organizations, members of various public and private institutions committed to the conservation of the species.
Marsh Deer Scientific-Technical Committee staff work with a sedated deer Image courtesy (Temaiken Foundation)
According to calculations by the Temaikèn Foundation, the current population is around 800 individuals. Over the past ten years of work, 21 specimens have been rescued, 13 of which, due to their serious condition, were transferred to the facility’s veterinary hospital. Half of those cases were orphaned puppies; six have been successfully returned to nature and two remain in human care as ambassadors at Temaikèn Biopark due to consequences that would not allow them to survive in their natural habitat.
“The swamp deer is a herbivorous animal and one of the few amphibian deer in the world. One of its ecological roles is to disperse the seeds of its food throughout the delta ecosystem. They are threatened by the degradation of the environment, mainly the floodable grasslands in which they live. Hunting and attacks by wild dogs are also a threat,” says Lina Zabala, biologist and operational coordinator of the Temaikèn Foundation’s Species Recovery Center.
A deer among the leaves of a wetland Courtesy (Temaiken Foundation)
In many cases, the committee’s work begins with notifying local residents and islanders of an injured animal that needs veterinary attention. An adult specimen can weigh 150 kilos and be 130 centimeters tall. A team task begins, which must be stealthy to avoid the escape of an elusive animal, which some residents call “ghost” because of this characteristic of the species, which lives only 40 kilometers from the city of Buenos Aires.
“We entered difficult terrain, which in many cases is wetlands with wild vegetation where we walked and were buried. Sometimes we have to cross the river in rafts because they are in the heart of the delta. The team quickly calculates the animal’s weight and the necessary anesthetic dose to shoot an arrow and put it to sleep,” says the biologist.
As soon as the animal is asleep, a group of animal keepers, biologists and veterinarians check vital parameters and take blood and hair samples. The most common injuries in summer are myiasis and being run over by vehicles; In some cases, orphaned puppies emerge, small fifteen-day-old puppies that need to be bottle-fed.
A service calf being cared for by committee members Courtesy (Temaiken Foundation)
“It is much better if the help can be solved locally, but on many occasions they are taken to the Temaikèn Species Recovery Center. There we have enclosures in total human seclusion, with lush vegetation. We can only reinstate an animal if it has a health and behavioral discharge. They shouldn’t have any trouble getting around either,” says Zabala.
When released, the deer return to their natural habitat with radio collars that allow valuable data to be obtained with satellite tracking. “As a result, we know more about its biology, behavior and movement through GPS signals. After a while, it’s programmed to come loose,” he explains.
The recovery and conservation efforts of the swamp deer and other animals would not be possible without the collaborative work of the community. In addition to active participation with other actors in the Swamp Deer Scientific-Technical Committee, the Temaikèn Foundation implements the Delta program with the idea of restoring other species and actions such as the restoration of riparian forests through the planting of “mini-forests”.
A captive swamp deer Courtesy (Temaiken Foundation)
“If you don’t engage the community, every action you take will have continuity issues over time. We work with schools to create ‘biocorridors’; They are mini-forests on the banks of rivers and streams to help restore the site and provide shelter for wildlife that needs to be more connected,” said Germán Hansen, environmental information specialist and Delta Program member of the Department of Conservation Temaiken Foundation.
This planting work is carried out with schools in the area. Students ages 3 to 5 participate in a program called Environmental Multipliers, with this and other projects related to the Delta environment. The Olga Cossettini Garden, in the Escobar district, is one of those that work with the children and the Foundation to raise awareness among students and their families. The choice of this institution, like the other seven participating schools, is crucial as it is located in the case of the conservation of the delta. With small actions, they begin to impart knowledge about the native flora and fauna, with the support and training of professionals.
“Many children and families were unaware that the swamp deer existed or that it was endangered despite living so close. The people of the Temaikèn Foundation provide us with material and knowledge. They also invited us to release two foxes near our house,” said Paola García, director of the garden, where 52 students are enrolled.
A girl draws a swamp deer Courtesy (Temaiken Foundation)
With educational activities, the boys learn what the marsh deer and other species are like, what their characteristics are and why we should take care of them. “The guys ask the Temaikèn speakers direct questions when they have doubts. It’s a nice job, with a lot of connection and communication. Children not only learn a lot, but are the basic link to the family. They become multipliers of the message and those who get their families interested.”
The swamp deer is just one species that needs to be preserved. The river otter received the Vulnerable label, along with the mountain guan and others. Hansen warns of the dangers of soil improvement. “Productive activities from the pampas are transferred to wetland ecosystems. The habitat is being altered and this is having a global impact on all species in the delta.”