One of our readers asked us:
What are the consequences of climate change in Mexico? I’d like to know what kind of animals, species, or plants have been going extinct in recent years in Mexico.
We asked the help of Tree Meinch, a YCC contributor based in La Paz, Mexico, to answer this question. Here’s what they found:
In the world of species conservation, “extinction” is a difficult term to pin down.
To start, how do you know when a particular species has officially disappeared from our planet? To say this with confidence, you have to look at a lot of things, both literally and figuratively.
In the most common scenario, where we know a species is in decline, a network of scientific disciplines must assess the contributing factors. Typically, there are many, including changes in our climate.
Coral has become one of the most iconic indicators of climate change in our oceans because of the close association between rapid ocean warming and major bleaching events that cause mass die-offs. And we’ve recently learned that our oceans are warming at twice the rate they were just 20 years ago.
This rapid change poses major obstacles for even the most adaptable plants and animals.
The climate is changing, and our journalists are here to help you understand what’s going on. Sign up for our newsletter and never miss a story!
“The problem with climate change and other human activities is that animals can’t change fast enough. They need hundreds and thousands of years to adapt to conditions,” said Gerardo Ceballos, a researcher at the Institute of Ecology at the National Autonomous University of Mexico.
In the case of the staghorn coral, it is now listed as critically endangered in Mexico. This is based on an inferred population decline of more than 80% in just 30 years, according to a comprehensive assessment in 2021.
The pace of environmental changes today as a result of human activity has brought about what many scientists are calling our planet’s Sixth Mass Extinction.
This sobering reality informed Ceballos’ latest co-written book, “Before They Disappear,” published by Johns Hopkins University this fall.
The threat of climate change has particularly high implications for Mexico, given its reputation as a “megadiverse country” that is home to nearly 10% of the world’s biodiversity, according to a 2019 study.
When we talk about species extinction and endangerment, the predominant global authority is the International Union for Conservation of Nature, commonly known as the IUCN. The organization maintains the Red List of threatened species, with categories such as “near threatened,” “critically endangered,” and “extinct in the wild” before “extinct.”
That final designation often comes at the end of a long chain of questions, research and escalating concern.
With that in mind, today nearly 50 species are officially designated as “probably extinct” in Mexico, according to a federal database. This includes the San Quintín kangaroo mouse, multiple species of warblers, the Caribbean monk seal and even grizzly bears.
Ultimately, focusing on complete extinction can be a distraction — and a costly one at that — in the field of conservation, according to Ceballos.
“If we focus only on species extinction, we’re missing the point,” Ceballos said. “What’s alarming now is the rate of disappearance of individuals and the rate of decline of populations.”
The Red List lists nearly 500 species in Mexico as “critically endangered” and fewer than 30 as extinct.
In 2020, a groundbreaking study that included the IUCN revealed that more than a third of Mexico’s freshwater fish species are threatened with extinction.
Ceballos can reel off a list of large megafauna that have completely or partially disappeared from Mexico at some point in the past 100 years. This includes the gray wolf, grizzly bears, bison, and elk, although some of these animals have been reintroduced to parts of Mexico from other global populations.
To be clear, many of the aforementioned population disappearances are linked to overhunting or poaching, deforestation, and in some cases mass poisoning—even strategically arranged by U.S. government officials in the case of the Mexican gray wolf. Factors like habitat loss often involve climate change or other human development and land modifications.
Still, climate has always been and remains a constant factor influencing species behaviors and success. We also know that regional temperature changes, droughts, unpredictable extreme weather events and habitat loss are on the rise.
Quantifying the impact of climate change on each case of species decline is a complicated matter that goes beyond surveying population counts. Specialists in the fields of biology, ecology and oceanography are dedicated to that quest, examining indicators such as sudden migration shifts and decreased species sightings.
Research expenses and the vast number of variables make progress slow and painful when it comes to connecting the dots between climate variables and impact on species.
Things get more challenging and expensive in ocean ecosystems, according to oceanographer Elva Escobar Briones, a deep-sea diversity and conservation specialist in Mexico.
“The effect of noise pollution, plastic pollution or dissolved compounds derived from anthropogenic activities is poorly documented,” Escobar Briones said.
The same goes for our understanding of beach erosion and its effect on turtles or the intricate consequences of ocean acidification and thermal stratification for marine life. We know that rising sea temperatures have an impact on many things, but the details are fuzzy and context-dependent.
The disappearance of the vaquita, a small, cartoonish-looking porpoise endemic to the Upper Gulf of California, has been one of the most widely recognized extinction events in real time. However, in this case, dangerous gillnets and illegal fishing practices have been the main threat to these creatures.
Beyond the fishing industry, Mexico’s biodiversity is also closely linked to a booming tourism industry, agricultural operations and other human forces that create a domino effect of change.
“If we continue down this path, we will lose many species,” Ceballos explained. “And it hasn’t yet affected animals and plants on a large scale.”
In a glimmer of hope, national officials reintroduced the American bison to parts of Mexico in recent years. Its return could help combat climate change, as it is considered a species that supports an entire chain of plants and animals within its ecosystem.
This reintroduction effort demonstrates the positive side of how a keystone species can quickly improve habitat diversity and life for the better, amidst many growing challenges in our rapidly changing world.
Source: yaleclimateconnections
