Survival of the Most Adaptable: Animal Strategies for Handling Climate Change

By Jen Obrigewitch, Biology, 2017

As global warming has been heating up legislation rooms around the human world, it has been chilling spines across the animal world. How the current climate changes might affect economically useful resources is a large source of concern and discussion, but the effect on the animal kingdom is less widely known. Recently, researchers across the globe have been exploring these effects with upsetting results. In the 71 percent of the earth’s surface that is covered by water, parasites and disease-causing organisms are abundant. According to research conducted in both freshwater and marine ecosystems, the distribution, transmission rates, and virulence of these organisms has begun to (and will continue to) increase as temperature rises. With this, animal deaths will also skyrocket due to the difficult task of having to defend against stronger parasites, not to mention the challenges of adjusting to the changes themselves. So, what are animals doing to fight back?

One of the first strategies noticed by researchers was the change in the migration patterns of flying animals. Birds are flying higher north earlier in the spring season, staying longer into the fall, and breeding earlier in the spring. Butterflies, like the brown argus butterfly (Aricia agestis) have been able to expand their habitat by 50 miles over the past 20 years by learning to lay their eggs on a new plant, the dovesfoot geranium(Geranium molle). Bird species like the long-tailed tits (Aegithalos caudatus) are taking advantage of the longer, warmer, and drier summer season by breeding more. The warmer climate increases the chance of baby bird survival. The large albatross (Diomedea exulans) has been using the increase in the wind intensity over the Southern Ocean to fly faster and widen its search area for food, increasing both body mass and breeding success.

Flightless animals have been adjusting to the temperature changes by migrating to more northern and higher altitude habitats, but their populations have also been adjusting in other ways. For example, the brown anoles (Anolis sagrei), a Cuban lizard species, have learned that moving faster and more actively during the day has enabled them to catch more food than their slower counterparts; in other words, those with speedy genes are better equipped to handle the heat. Genes are also helping an important model organism, the zebrafish, (Danio rerio) survive: those with a certain variation of muscle composition are able to swim faster through warmer waters and have a higher chance of survival.

Coral reefs are an extremely important and sensitive part of the aquatic ecosystem. Warmer waters have resulted in significant and detrimental bleaching of these areas, but last year, researchers found that corals capable of storing fat in the form of algae were better able to survive bleaching. Individuals had an even better chance of survival if they were able to alternate between consuming different types of algae based on what was available to them.

The story is there in the coral’s fat storage and in the long-tailed tit’s breeding habits: adaptability is the key to animals’ success as the climate changes all around them. Some species are moving north and spreading out while others are making use of more of the materials found in the habitats they already claim. Still others are experiencing changes in their population dynamics based on traits that happen to given certain organisms a leading edge. For all of these animals, their temporary survival feels like safety. The question remains, however, what if the temperature keeps on rising? Where will the animals move to once they’ve migrated all the way to the North Pole?

Europe PubMed Central (2008). PMIC: 18819673.