Global warming is changing everything. This is not hype or exaggeration, but rather a simple statement of fact.
Further proof of this basic truth comes from a new study showing that mosquito populations are increasing dramatically in the Arctic due to higher temperatures. Moreover, the rapidly increasing mosquito populations are having a negative impact on other Arctic wildlife, in particular threatening the already decimated northern caribou herds.
The new study from researchers at Dartmouth College shows that the likelihood of mosquitoes surviving and emerging as adults is boosted by more than 50% if Arctic temperatures increase by a mere 2°C. The new data about mosquitoes is important because changes in the timing and number of mosquitoes has a major impact on the life cycles of plants and animal wildlife, including caribou and Arctic and migratory birds.
The new global warming research was published in the journal Proceedings of the Royal Society B: Biological Sciences earlier this week.
“Increased mosquito abundance, in addition to northward range expansions of additional pest species, will have negative consequences for the health and reproduction of caribou,” notes the lead author of the study Lauren Culler, a postdoc student at Dartmouth’s Dickey Center’s Institute of Arctic Studies. “Warming in the Arctic can thus challenge the sustainability of wild caribou and managed reindeer in Fennoscandia (Norway, Sweden, Finland and parts of northwest Russia), which are an important subsistence resource for local communities.”
More on global warming and increasing Arctic mosquito populations
Global warming is leading to climate change, which can have a huge impact on insect physiology and growth rates, and of course also impacts potential predators. Keep in mind that average temperatures in the Arctic have moved up at more than twice the rate of the rest of the planet over the last century, and the low biodiversity of Arctic ecosystems provided a simple predator-prey interaction for this study.
The study authors note that Arctic mosquitoes reproduce in the numerous ponds of springtime snowmelt formed on the tundra, and their main predators are diving beetles.
With both field and lab studies, the Dartmouth researchers measured the impacts of temperatures on the development and death rates of immature mosquitoes in western Greenland. Using the data, they developed a model to evaluate how temperature affects Arctic mosquito survival from the immature stage to adult stage across a range of temperatures in various climate change scenarios.
The research makes it clear that that warmer spring temperatures caused the mosquitoes to emerge two weeks earlier and shortened their development time through the larval and pupal stages by close to 10% for every 1°C boost in temperature. While the warming did lead to more mosquitoes being eaten by diving beetles, the mosquitoes’ accelerated growth in the most vulnerable juvenile stages led to less time in thew water with aquatic predators, which meant more mosquitoes survived to adulthood. Under a 2°C arctic warming scenario, the model projects the mosquitoes’ probability of survival will increase by 53%, leading to a massive surge in mosquito populations.
Of note, Arctic mosquitoes can only reproduce if females find enough blood to drink. The researchers note that they are likely to have better access to caribou for pre-reproduction snacking because global warming / arctic warming makes the mosquitoes life cycle more closely match caribou calving season. The calving season gives mosquitoes a larger, less mobile caribou herd to feed on, especially calves with less hair and thinner skin..