Natur & Miljø i Mexico: Månedsrapport
Conservation in Mexico - Monthly Update: June-September 2016
Sea turtle conservation
Patrolling the beaches was one of the most important activities over the last few months. Driving into the dark with mist rolling in from the marine breeze is a thrilling experience. We searched for the adult female turtles and collected their eggs so we could protect them from predators and poachers in a secure and controlled hatchery. The eggs will be incubated until they hatch. During this time the volunteers had the opportunity to see hatchlings come out of the nest and be released into the ocean.
At the beginning of the season (May to August) the eggs are planted in ice coolers and kept in a storage room. This is a common method in sea turtle conservation, and helps control the temperature and increase the survival rate.
Another method is to plant the eggs in holes directly on the beach, another kind of nursery, a more natural one. During the month of July the construction of this area began, activity in which the volunteers participated with dedication.
During both methods a cylindrical hole, 45 cm deep, needs to be dug. It is then hollowed out at the bottom to create a pot where the eggs are deposited which recreates the holes that turtles make as much as possible. If built on a beach, out in the open, the construction requires more effort.
Once the hatchlings come out of the nests the volunteers have to take out all the remnants such as empty eggshells, eggs that hadn't developed and trapped hatchlings. One can appreciate the danger this species faces, even inside the nest where flies can dig and deposit their eggs. The cleaning of the nest is a gnarly experience but it is extremely important. Volunteers save the hatchlings that are trapped who would otherwise have been eaten alive by maggots, and they clean it for statistical purposes to quantify the effectiveness of a particular nest. Volunteers have expressed that it is very rewarding to rescue turtle hatchlings from the maggots, a process that happens a lot in a natural nest. This complete cycle (patrolling, getting the eggs, planting them, seeing the hatchlings come out, and cleaning the nest) can be better appreciated during September when the number of turtles increases. We currently have 975 nests and counting, with 27 149 hatchlings released.
Most of them have been olive ridley sea turtles (Lepidochelys olivacea), with only a couple (10 nests) of green/black turtles (Chelonya mydas) and a few nests of leatherback turtles (Dermochelys choriacea) which only one volunteer was lucky enough to see. Unfortunately poaching is still constant on these coasts, and since everything is about timing and efficiency while collecting the eggs, the contribution from volunteers is welcomed. Teamwork is essential in all the activities especially while collecting the eggs. One volunteer can take out the eggs swiftly and without error while the other counts the eggs.
An activity that requires a lot of help from volunteers is the maintenance of the Tortugario. The Tortugario is the main facility in which Projects Abroad collaborates. It has the space for the turtle hatcheries and also accommodates 12 adult marine turtles in tanks for community awareness and research projects. They also keep juveniles of green/black turtles for research, as well as other conservation projects such as the iguana breeding project, mangrove nursery house, and the crocodiles breeding project. They are also involved in the protection of the Palo Verde Estuary, which encompasses a mangrove ecosystem that contains a high biodiversity of reptiles, birds, insects, mammals and plants. This facility is well regulated by the government environment agency.
It's a big place with few staff and requires a lot of effort to keep it well maintained. The facility depends mostly on their income of visitors and donations. The volunteers have made quite a difference and help is well appreciated. Most of their activities revolve around the Tortugario such as keeping the animals and their habitats clean and healthy.
The iguana is an endangered species in Mexico as it is hunted for its meat. The breeding project in the Tortugario helps to reintroduce this species in areas where they have disappeared. So far 100 hatchlings have been obtained and 47 juveniles have been released to the Palo Verde Estuary. The main involvement for volunteers would be to maintain the facilities but the volunteers enjoy working with the animals and observing their behaviours, especially the iguanas as they already know when breakfast is going to be served so they come really close to behaving like little reptile ‘dogs’.
Tortugario has a nursery house in which they grow red and white mangroves (Rhizphora mangle and Laguncularia racemosa) and they have approximately 5 000 sprouts that are being kept and cared for. The volunteers keep them happy with fresh water. We hope that in the future volunteers can get involved and plant them in the estuary.
The crocodile farm is located approximately 30 minutes from the camp in the Alcuzahue lagoon which is dedicated to the breeding and reintroduction of native species to the area. In this project the volunteers are involved in activities like the collection of eggs that crocodiles lay around the lagoon.
Chuy, a veteran in the protection of the crocodiles in the area, is in charge of the farm, and guides and coordinates the activities. Collecting eggs is actually a very thrilling activity especially because the team has to keep an eye out for the female. It sounds high-risk but Chuy knows the perfect time to do it, like when the female is out looking for food. The activity consists of digging up the eggs from the nest, measuring them and if you are lucky help the hatchlings come out of the egg.
One particular nest had 42 eggs and 40 viable hatchlings. Since there are not always eggs to collect, the volunteers also help with the maintenance of the place. Like the Tortugario, the farm only receives income from visitors and there are only two staff members to run the entire place. Volunteers help clean out the crocodile tanks and ensure the vegetation, that can overgrow very quickly, is kept in line. Some volunteers don’t have experience using tools to cut a tree, and the classic style around this area is using a machete so the staff demonstrated and explained the safe use of the tool.
Projects Abroad have been doing a great job in monitoring birds in the Chupadero Lagoon in the past. In the estuary of Palo Verde, the Tortugario already had a checklist of the birds in the area, which is very close in abundance to the one monitored in the Chupadero Lagoon. The species vary slightly although you can find subtle differences in both places. It was proposed by Projects Abroad that maybe another systematic approach could be taken with the volunteers in the estuary of Palo Verde.
Species distribution models are tools that have been used more and more in this decade due their ability to predict and show data in a map, and different information can be extracted from this. The areas more susceptible to impact, areas where a particular species is more likely to be observed, places that species use more than others, and habitats that have a higher diversity, number of species or more abundance. It's a useful tool for conservation purposes. The method is similar to what Projects Abroad was doing in the Chupadero Lagoon, a point census, which works by choosing a random point in the lagoon and counting the birds observed in a radius of 300 meters for duration of time, in this case 10 minutes. Species distribution models need more data to be feed to the mathematical models. In this case we are taking humidity, temperature, type of vegetation, type of habitat and the location of each point. The volunteers are pre-trained in identification and ways to estimate and count the most conspicuous birds and are also involved in recording the data.
We haven’t acquired enough data to start running the statistical models, so we need to gather more to make the spatial projections. We expect to collect data that can show the areas that the aquatic birds use more in the lagoon, and pinpoint the locations that are more susceptible to human disturbance as well as the ones that have a significant importance for the birds in the Lagoon.