Study is first to show whether nesting heat affects sea turtle hatchling ‘IQ’

While sand temperatures continue to increase, concerns about the future of sea turtles increase. The warmer nests do not only biahist sex-producing more women, but also reduce the survival of newborns, slow growth and increase the probability of physical deformations. However, an important and often neglected question remains: this heat also affects cognitive capacity-how many newborns can learn, adapt and respond to the rapidly evolving world with which they are confronted from their emergence?

A new study carried out by researchers from the Charles E. Schmidt College of Science from Florida Atlantic University offers a surprisingly of hope. They are the first to test if the incubation temperature affects cognitive capacity in newborns (Caretta Caretta) – how although they can learn, adapt and solve the problem. Although animal cognition has been widely studied in birds and mammals, there is still a lot to discover in reptiles.

Using a labyrinth y and a task of visual discrimination, the researchers trained newborns incubated at two temperatures producing women (88 F and a warmer 91 F), then tested their ability to “turn” when the rules of the task have changed. Eggs were collected during the 2019 and 2020 summers in nesting beaches from Palm Beach County.

In the initial acquisition formation phase, approximately four weeks after the hatching of turtles, they were trained to associate a food reward with a specific monochromatic motif such as scratches or a Bullseye, which were positioned at the ends of the labyrinth.

In the inversion phase, the reward model was switched, forcing turtles to abandon the original association and to learn that they should go to a different target for the reward. This inversion task has measured behavioral flexibility – the ability to adapt to new information, which can be essential to survival in dynamic environments such as the ocean.

Unexpectedly, the results of the study published in the journal Search for endangered species found no significant difference in the learning capacity between temperature groups. Over the two years, newborns in the two temperature treatments have successfully completed acquisition and reversal tasks. In 2020, they even worked much better during the inversion phase, learning faster than during the initial training.

“Not only were post -humanings capable of deleting the behavior previously learned to train new more advantageous associations, but they were able to do it at a remarkable speed – requiring less tests than the initial learning phase,” said Sarah L. Milton, PH.D., principal author and president and professor of the Faup Department of Biological Sciences.

“This surprising level of behavioral flexibility suggests that these young turtles can be better equipped to navigate and adapt to rapidly evolving environmental challenges that we have already understood. Such adaptability could be crucial for their survival in an increasingly unpredictable world.”

However, the results also revealed that higher incubation temperatures negatively affected several key physical traits. The newborns of the 91 nids of F had shorter incubation durations, a lower hatching success, slower post-human growth and more frequent scarcs anomalies-defects in the scales of their shell. They were also smaller – a result that could compromise swimming performance and the escape of predators.

“The concern remains very real,” said Ivana J. Lezcano, corresponding author and doctoral candidate in the FAU Biological Sciences Department. “High incubation temperatures are known to produce smaller and less resilient newborns and lead to a significant decrease in the overall success of hatching. Together, this may have serious risks to the survival of the population.

“However, our conclusion that cognitive capacity and learning can remain largely unchanged, at least in the short term, by these higher temperatures, these turtles can maintain the mental flexibility necessary to adapt to their changing environment. This resilience gives us a first of the efforts to understand the length of the temperature of the incubation can affect behavioral rounds, but on research outside the temperature outside, Behavioral temperatures, but on outside research, at the temperature temperature experience in full way, in search of temperature outside, to the experience of behavioral temperatures.

The researchers point out that, even if these results are encouraging, they come with warnings. The study only examined temperatures up to 91 F, and the nesting beaches in the south of Florida have already recorded sand temperatures above 93 F to almost 96 F – the levels known to seriously affect the success of the hatch and the performance of New New. More extreme temperatures could still present risks for brain development and cognition that were not obvious to the subletal range tested here.

In addition, while a nest in the field is generally considered to be “successful” if the majority of newborns emerge from it, the study suggests that survival models may need to go beyond emergence and take into account the quality of newborns-physical and behavioral.

“The newborns in our study were able to adapt quickly to new information despite the stressors of development,” said Milton. “This behavioral adaptability is not only a survival mechanism – it is an essential evolutionary advantage which can allow them to deal with the complex challenges posed by their changing habitats. Conservation efforts must prioritize not only the preservation of newborn populations, but also the environmental conditions which support their cognitive development and their current resilience.”

As sea turtle embryos are so strongly influenced by the thermal conditions of their nest, understand how the temperature affects not only who survives, but the way they are equipped for survival are essential.