This Christmas isn’t promising a snow-white winter. Across the United States, families will head out for warm, sunny strolls, and the fingerprints of climate change are warming the 2025 holiday season. We explored how the animals that shape our stories and traditions cope with rising temperatures.
From Santa’s reindeer to Hanukkah armadillos and mythical sea worms – our changing world is altering the lives of animals both big and small. And while some face challenges, others may offer clues for our adaptation to the future.
Reindeer: Can they withstand warming?
Reindeer have already endured abrupt warming during previous Arctic periods, but conditions are different now. Over the last three decades, the global population has declined by about 40%, and adaptations that once helped are no longer as effective.
Studies by researchers from the University of Adelaide and the University of Copenhagen indicate a possible decline in global populations of up to 58% by 2100, with declines potentially more pronounced in North America. Global warming is reducing available cold habitats for reindeer, complicating their reproduction and survival.
On the other hand, new data suggest that reindeer may mitigate the negative effects of warming if they continue grazing under forest canopy – the soil in doing so stores carbon even when snow is absent.
Christmas Tree Worm: A Small Indicator of Coral Health
Christmas worms are cone-shaped, brightly colored small worms that attach to coral reefs and lead a nearly immobile life, forming a symbiosis with corals.
Although they are not very active, they play an important role in water movement around the corals, helping the corals in feeding. Newborn coral polyps hide under the branches of “Christmas tree” worms, taking refuge from predators. Therefore, scientists view them as a potential early warning signal of coral health in the context of global warming.
For example, a 2022 study at the University of California, Berkeley found a correlation between healthy corals and a greater number of Christmas tree worms. In the future, these worms may become an early indicator of coral stress due to rising water temperatures.
Armadillos from Texas – New Frontiers and Iowa in Focus
Nine-banded armadillos were first recorded in Texas in 1849. As the climate changes, its range has expanded significantly northward and eastward from its historical home. In 2014, surveys showed that these animals may inhabit areas where January’s minimum temperature stays above roughly 18°F.
In 2025, researchers with the U.S. Geological Survey used public reports, trackers and other data sources to record more than 250 new armadillo sightings in Iowa. The data show that the animals are actively appearing in gardens and parks from Indiana to North Carolina, with the greatest prospects in Ohio, Virginia, and Michigan.
Narwhals: Genetic Risks in a Changing Climate
Narwhals – Arctic cetaceans with tusks, known for their distinctive appearance. Genetic diversity in this group remains low, which may limit their ability to adapt to the increasingly warm Arctic Ocean. A Danish study confirms that long-term low genetic diversity poses a threat to the continued stability of populations.
Red-legged Partridge and Its Vulnerability
The red-legged partridge has a long history of interaction with humans and environmental changes: overhunting, agricultural mechanization, pesticide use, and rural-to-urban migration. According to the International Union for Conservation of Nature, between 2010 and 2020 its numbers could have declined by 40–45%.
Although climate change is not the sole direct cause of the decline, environmental changes increase the species’ vulnerability to future climate shifts. In 2021, an international group of scientists from Sweden and Italy sequenced the genome of this partridge and found that the population did not recover after a deep decline about 140,000 years ago – unlike other species, such as narwhals. Such genetic vulnerability reduces the partridge’s chances of adapting to future climate changes.
The Contribution of Donkeys to Adaptation and Ecosystems
Donkeys play an important role in carrying water and food during droughts in various regions, particularly in Africa, supporting people and ecosystems during climate crises. Their ability to conserve moisture and distribute it across the landscape helps prevent soil drying and supports grass diversity.
Additionally, donkeys may help mitigate infection risks: ticks and tick-borne diseases rise with warming, but research from the University of Massachusetts Amherst suggests that donkey skin emits chemical compounds that ticks avoid, reducing bite rates.