Climate change threatens 9 lizard species in Mexico

The Laguna region of Coahuila and Durango in Mexico holds nine unique species of lizards . However, they are currently in danger of extinction due to an increase in temperature, mineral extraction, and light regulations for farming activity and land use changes in the region, specialists warned.

Héctor Gadsden, PhD in Biological Sciences

and researcher at the Institute of Ecology , commented that specialists have discovered evidence showing that local lizards are at a critical point and are likely to become extinct by 2050 .

Gadsden commented that, according to comparative studies on lizard communities in northern Mexico and the southern region of the United States , the Laguna region –located in the desert of Chihuahua- is the richest in terms of reptile endemism.

The endemic species are: Xantusia extorris (located in the Jimulco mountain range, the Canyon of Fernandez, and Pedriceña), Xantusia bolsonae (found in the Sarnoso mountain range), Sceloporus gadsdeni and Crotaphytus antiqus (located in the Texas, Solís, and San Lorenzo mountain ranges), Sceloporus lineolateralis and Sceloporus maculosus (Peñón Rock and Jimulco), Uma exsul (Viesca dunes), Uma paraphygas (Mapimí dunes), and Sceloporus ornatus (Mayrán).

Climate change threatens 9 lizard species in Mexico

The endangered Sceloporus gadsdeni species - Photo: File photo/EL UNIVERSAL

These reptiles live in rocky hills surrounded by plains where they are relatively isolated and unable to travel long distances. Because of this, according to Gamaliel Castañeda Gaytán , a research professor from the Sciences Faculty at the Juárez University in the State of Durango (UJED) , lizards are considered to be micro-endemic species since they are not only unique in the region, but they also live in very specific areas where they are exposed to several threats and various degrees of vulnerability.

According to some research models, the distribution of these species does not exceed 30 square kilometers (11.58 square miles) within a habitat of 600 kilometers (231.6 square miles) . “The reality is that these animals live in small patches and any mishap, as small as it may be, may constitute a threat to the species,” claimed Gamaliel Castañeda.

Global warming: A critical factor

The researcher Héctor Gadsden assured that, for at least two decades, an accelerated warming of 1.5°C has been detected in the region, affecting these endangered organisms. “We are talking about exponential changes, subtle transformations that lead to a modification of phenology and the species’ reproduction,” he explained.

This change in temperature, he stressed, is the main factor threatening lizard species in Mexico’s northern region

. Since these animals have very small distribution areas, they are confined in small ecological islands, which impedes them from migrating.

Due to high temperatures, lizards tend to limit their daily activities and spend more time hidden among rocks and small caverns. “They don’t come out because it’s too hot and this has affected their ecological relations: They have stopped reproducing and they don’t eat as much as they used to,” said Gadsden.

Climate change threatens 9 lizard species in Mexico

This species lives in rocky hills surrounded by plains - Photo: File photo/EL UNIVERSAL

These reptiles rely on the temperature of their environment to keep warm or cool down. The fact that they are so dependent on temperature hampers their capacity to move and colonize other areas.

Gamaliel Castañeda mentioned that, should temperatures surpass their current limit, the species will have to search for cooler areas. Otherwise, the species will begin to disappear.

The importance of the species

In the opinion of Gamaliel Castañeda, these lizards are important because they are part of the region’s identity. Secondly, lizards represent a crucial link in the food chain, considering that natural resources and biomass are scare in arid zones .

“They represent an important source of food for many species and thus generate more biodiversity in their environment,” Castañeda commented.

He claimed that lizards can act as regulators of other species, promoting the diversity of arachnids and controlling some species of arthropods .

Climate change threatens 9 lizard species in Mexico

The 

Sceloporus maculosus species is confined to small areas in the desert - Photo: File photo/EL UNIVERSAL

According to Héctor Gadsden, the ecosystem works similarly to a brick wall. If one were to remove some bricks, there will come a point when the wall will fall down. “The ecosystem’s biotic relationships can become disrupted, which would lead to an ecological collapse,” he stressed.

The investigator considers that lizards can serve as living thermometers of nature. “They allow us to assess temperature changes at a biological level. If we could gather information from several habitats, we may learn more about their environmental degradation.”

However, these living thermometers are in danger of becoming extinct.

Hasty, unprecedented change needed to reverse global warming

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