There are few natural spectacles more impressive than the massive arrival of sea turtles. At night, turtles will gather near the coast in preparation for their departure from the water to come ashore in an extraordinary effort to lay their eggs and thus ensure the next generation. They return to the same beach where they nested before, guided through the vast ocean by instincts and skills difficult to understand. These arrivals detonate other natural cycles that cascade through the ecosystem, taking advantage of this majestic natural happening. Predators, from rodents, raccoons and coatis, as well as coyotes, jaguars and even humans come to the nesting beaches for their part of the bounty. The turtles themselves dig up eggs of neighboring nests from lack of space. Despite the feast, thousands of hatchlings are born to refresh the populations of these species.
Similarly, events such as the first storms of the rainy season ignite large concerts of frogs and toads, frantically looking for their partners to take advantage of each pool, each wetland and every puddle to deposit the next generation. Some wear bright, elegant colors for courtship, while others take advantage of the great reproductive distraction to catch a meal or two. As with turtles, the survival strategy is the massive event. Hundreds of thousands of eggs or tadpoles can feed a variety of animals, snakes, fish, and even peccaries and birds, still leaving many more to ensure the success of the species.
Even crocodiles show a preference of reproducing in groups, using seasonal rains and flooded areas for the offspring to develop without as much danger. Despite being relatively primitive reptiles in regards of evolution, her motherly care is exemplary, defending her nest and even keeping the newly born safe from potential predators. In this case, the more numerous they are, the better their chances of survival.
Unlike sea turtles and amphibians, squirrel monkeys are not as abundant as to create a massive presence. However, they have a strategy of synchronized reproduction that has not been observed in other primates that exist in the country. Squirrel monkeys mate seasonally, taking advantage of natural resources in the forest, such as fruits and seeds that feed the mothers and provide nourishment to the newborn. Squirrel monkeys at Manuel Antonio have their own birth schedule which differs from the subspecies in Corcovado and thus each ecosystem provides us with its own timing, waiting to be explored.
Natural events respond to signals provided by the weather, rainfall, temperature, or the presence of other animals. These cycles create a truly wonderful tangle of relationships, forming a complex food web where reproduction of a species supports the survival of many others.
If we flew over Costa Rica’s beaches at dawn, we would see tracks in the sand left by thousands of turtles. With a little experience, we can learn to identify which species of turtle made each trail after covering its nest. In Costa Rica, sea turtles’ nesting rituals are fantastic natural events that can be seen throughout the year on both the Pacific and the Caribbean coasts. Turtle nesting is mainly a nighttime spectacle, although there are always some individuals that are late returning to the water and are caught in the act by the sunrise.
Turtle tracks appear every morning, especially on beaches where ocean currents make turtles’ access to the coast easier. Five out of the seven existing sea turtle species in the world lay their eggs in Costa Rica’s beaches. The Olive Ridley sea turtle is the only species which arrives by the thousands along the Pacific. The Leatherback, Hawksbill and the Loggerhead come out of the ocean one by one to lay eggs. The Pacific Green turtle is a sub-species of the Green sea turtle. Separated from its Caribbean relatives, Pacific Green turtles adopted the habit of laying eggs alone. The Green turtles of the Caribbean, in contrast, emerge from the ocean by the hundreds. Because individuals spread out over a large geographical area, the Green turtle’s nesting pattern is not considered a massive arrival.
Some species of sea turtles undergo long journeys as part of their drive to reproduce. Others mate near the coast, as multiple males fertilize the eggs and females await the proper signals and the moment for which they’ve been genetically programmed. Then they go ashore to lay eggs. The turtles are so sensitive that a strong light, obstacles on the beach, or inadequate temperature of the sand can make them turn back to the ocean without accomplishing their mission.
anuary and February is Leatherback season on the Pacific. Since they are solitary and egg laying has greatly declined, it is difficult to predict when and where it will be possible to observe them. Instead, we recommend going to the Caribbean, where more Leatherbacks nest and thus you have a higher probability of seeing them. January and February are also the best months to observe Pacific Green sea turtles, which come out along many beaches in Guanacaste and along the Nicoya peninsula. In the southern Pacific region they are less numerous.
Leatherbacks begin arriving on the Caribbean coast in March. The nesting season extends into June and takes place mainly in three areas: Pacuare, Moín and Gandoca, near the border with Panamá. In July, also on the Caribbean coast of Costa Rica, Green sea turtles begin arriving on the stretch of coastline between Tortuguero and Parismina. This abundance of female turtles attracts jaguars that roam the intricate system of canals and protected areas where rainforest remains.
Starting in May, we have Olive Ridley and Loggerhead turtles along both coasts. The Loggerhead, also known as Cahuama, is another difficult species to observe because their arrivals are unpredictable and widely dispersed. Olive Ridleys lay eggs all year long, but if we want the experience of seeing thousands of them coming out of the water under the light of the moon, then we must visit Ostional, on the pacific coast of Costa Rica, between July and November. In October, Leatherback and Green turtle season on the Pacific starts again, offering us the opportunity to see on the beach turtle shells and tracks that indigenous peoples of Costa Rica once considered a sign of abundance.
Amphibians’ reproductive calendars are tied to the rainy season. Without rain, there would be no natural concerts or enchanted forests filled with the sound of tiny bells ringing in the night. Precipitation makes these animals active, creating an unforgettable sensory experience. In Liverpool, Limón, researchers at the University of Costa Rica (UCR) have identified up to six species of frogs singing at the same time and in the same place. While some males call to attract females, others quarrel with each other to the point of physical fighting. Some increase the pitch of their singing to mark their territory.
The pitch of the frogs’ song determines how attractive a male is to females. Females usually seek out larger males, which tend to have larger vocal sacs. During mating, the male embraces the female until she releases the eggs and he fertilizes them. Although they may share a pond, different species are distributed throughout it. Some sing near the edge of the water, others in the middle and others from the vegetation above. If several species sing at the same level, then they will vocalize at different frequencies. The vocalizations of glass frogs tend to be of a higher frequency to avoid intermingling with the sound of the creek. In addition to using their songs for courtship, frogs also vocalize to confuse predators and in this case, the bullfrog is a master of mimicry. His singing simulates the cry of a baby caiman and thus wards off predators.
Egg laying is the whole point of this symphony of sounds of insects and amphibians. Frogs lay eggs on leaves and then wait for the rain to complete their life cycle.