Arctic Mosquito Swarms May Threaten Caribou as the Climate Changes

In a new study, arctic researchers at Dartmouth’s John Sloan Dickey Center for worldwide Understanding used their field observations to model the effects of temperature changes on arctic mosquitoes. Scientists have found that climate change is leading to more, bigger mosquitoes in the Arctic, which may not be good news for caribou, or for humans.

The mosquitoes’ probability of surviving and emerging as adults will increase by more than 50 percent if Arctic temperatures rise 2 °C. Since they mature faster, they’re able to leave their childhood homes earlier, thereby eluding their natural predator, the diving beetle, and going on in greater numbers to adulthood to feed on the blood of people and animals like caribou. This would increase the total amount of adult mosquitoes.

Odd consequences were recorded; according to study author Lauren Culler, an ecologist at Dartmouth College’s Institute of Arctic Studies, the caribou have been observed to prefer the top of a windy ridge, even though they have less food of an inferior quality. Their models can be applied to other ecosystems that are sensitive to climate change, the researchers noted.

She says, “I have heard that mosquitoes can take enough blood from a calf to kill it. I have never seen this happen, fortunately”.

“It could be quite an important impact in terms of the amount of damage caused to a large mammal – one thing about the Arctic is there is a spectacular amount of biting flies there so they do have an impact on their prey”.

A number of lab experiments were conducted to measure the effects of temperature on mosquito development time during the course of research. The research reveals that warming temperatures cause the mosquitoes to hatch earlier and shortens their development time through the larval and pupal stages by about 10 percent – when they are vulnerable to aquatic predators such as diving beetles.

Average temperatures in the Arctic have risen at twice the global rate in the past 100 years, and this could change emergence patterns of mosquitoes that develop in shallow temporary ponds of springtime snowmelt.

Global warming is already underway, taking a toll on the Arctic sea ice and various wildlife populations such as the polar bears, but mosquitoes are thriving. Sadly, that uses up energy and feeding time as well as taking them away from their richest food source. And they’ve been rising so steadily, a new study says the region is in for a mosquito boom for which it is not prepared. “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”.