In 1996, German herpetologist Gunther Köhler discovered a new species of anole lizard endemic to Honduras, the Anolis bicaorum, more commonly known as the Bay Islands anole. In 2012, the International Union for Conservation of Nature assessed and added the Bay Islands anole to its Red List of Threatened Species. Today, the small lizards are categorized as critically endangered, a fact that conservationists are trying to change.

The primary reason Bay Islands anoles have become so endangered is habitat loss. The lizards live in the lowlands of tropical forests where conditions are wet and shady. They sit and wait on branches, leaves, and vegetation for prey to pass by. As populations in Honduras increase, urbanization has led to the destruction of surrounding forest areas. As an ectotherm, a reptile with limited abilities to regulate its body temperature, the Bay Islands anole is dependent on its environmental climate for survival.

In July 2021, Emma Higgins, a lecturer in ecology at the University of South Wales, published her findings on how thermal temperatures, in particular, are vital in promoting healthy Bay Islands anole populations on the Honduran island of Utila. Following that study, Emma returned to Utila to further delve into how to gather data relevant to the Bay Islands anole conservation. Her research, published in April 2024, proved that drone technology is essential in monitoring environmental temperature conditions for Bay Islands anole conservation.

“Traditionally, measuring a lizard’s thermal environment has been a laborious and costly affair,” Emma explains. “It involves deploying 3D-printed lizard replicas which are equipped with special thermometers to log the nearby temperature of the forest.” She clarifies that while the 3D-printed lizards provide valuable data and still have a place in research, their cost—around $20 per unit—makes them too expensive for broad research areas. Emma and her team hypothesized that if the forest canopy determines the temperatures of the forest floor, they could gather data from the canopy instead.

To test this hypothesis, Emma used a DJI Phantom 4 drone equipped with “an integrated RGB (red, blue, green), 1-inch, 20-megapixel CMOS sensor mounted on a three-axis, gyro-stabilized gimbal,” as stated in her research paper titled Unoccupied Aerial Vehicles as a Tool to Map Lizard Operative Temperature in Tropical Environments. The team flew the drone at an altitude of 40-50 meters, approximately 1.5 times the height of the canopy. The flights were conducted during calm periods so that wind factors would not alter the temperature of the leaves in the canopy.

Hovering the drone over plots of canopy for a few moments, Emma and her team were able to capture high-resolution images revealing the greenness and texture of the canopy. These details provided information on canopy cover and structure. The drone data was then combined with the data collected by the 3D-printed lizards to create accurate predictive temperature models. “This method allows us to create continuous, high-resolution maps of temperatures across entire landscapes,” Emma states. “And this level of detail is far more relevant to the movement patterns of individual lizards compared to the limited data points collected with traditional methods.”

For Emma and her peers, research projects like this are vital in developing conservation methods. The continued decline of Bay Islands anoles can be indicative of further environmental consequences. These lizards play a vital role in ecology as prey animals controlling the overpopulation of the creatures they consume. Conversely, Bay Islands anoles are a food source for other larger predators. “Our drone-based approach allows us to map ecologically significant thermal data across vast landscapes, at resolutions relevant to individual animals and populations,” Emma goes on to say. “This level of detail far surpasses the limitations of traditional ground-based methods.”

As the Bay Islands anole faces an increasingly uncertain future, innovative approaches like those developed by Emma Higgins and her team offer a glimmer of hope. By harnessing the power of drone technology to monitor environmental conditions, researchers are gaining unprecedented insights into the needs of this critically endangered species. This advancement not only enhances our understanding of lizard ecology but also sets a precedent for future conservation efforts. With continued dedication and cutting-edge tools, there remains a chance to protect and preserve the Bay Islands anole, ensuring that this unique species continues to thrive in its natural habitat for generations to come.

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