According to reports, bumblebees are dying at an increased rate and reason behind this is still not known. According to some, pesticides called neonicotinoids could have led to this in addition to bee habitat loss as a result of human development.

However, according to an extensive new study climate change is also a cause. It has been found in the study that rising temperatures are removing the pollinators from the south and at the same time pollinators are not appearing to move north to cooler areas.

According to Sheila Cola, one of the authors of the study and an assistant professor in the Faculty of Environmental Studies at York University, "We think part of the problem is they've evolved in cold weather. They're adapted to cold weather, and there are things about their ecological climates that are not keeping up with climate change. It seems that bumblebees are not moving north, with climate change".

However, she added that they're also getting extinct at the southern parts of their range, therefore their ranges are contracting in reality.

Cola said there could not be large enough fields of flowers for bumblebees in north and maybe because of that they aren't heading towards north. From early spring to the fall, bumblebees require large flowery fields in order to support the kind of populations required by them.

As per experts, bumblebees also require rodent burrows intended for nesting. Cola added that it is possible that the rodents are also not keeping pace with climate change. Cola said that bumblebees are going through a very tough time.