A new study links the rapid decline of bumble bees to climate change.
The study was published this week in the journal Science.
It used 110 years worth of scientific data.
It's authors say the bees are not migrating north like some other species as the climate warms, but are losing habitat in the south due to the heat.
The study suggests bumble bees are losing none kilometers of their southern ranges per year.
It says the trend is the same across continents in the northern hemisphere.
Biologist Laurence Packer of York University says bumble bees are key pollinators because they're active from spring to fall collecting pollens from a wide range of plant species.
They are one of more than 800 bee species in Canada.
The study took into the account the impact of pesticides - such as neonicotinoids.
However, it found the declining bee populations pre-date the use of the insecticide while tracking closely with changes in climate.
