Media Releases

Fears of a decline in bee pollination confirmed: may be due to climate change

September 7, 2010

TORONTO, ON – Wide­spread reports of a decline in the pop­u­la­tion of bees and oth­er flower-vis­it­ing ani­mals have aroused fear and spec­u­la­tion that pol­li­na­tion is also like­ly on the decline.  A recent Uni­ver­si­ty of Toron­to study pro­vides the first long-term evi­dence of a down­ward trend in pol­li­na­tion, while also point­ing to cli­mate change as a pos­si­ble con­trib­u­tor.

“Bee num­bers may have declined at our research site, but we sus­pect that a cli­mate-dri­ven mis­match between the times when flow­ers open and when bees emerge from hiber­na­tion is a more impor­tant fac­tor,” says James Thom­son, a sci­en­tist with U of T’s Depart­ment of Ecol­o­gy and Evo­lu­tion­ary Biol­o­gy.

Thomson’s 17-year exam­i­na­tion of the wild lily in the Rocky Moun­tains of Col­orado is one of the longest-term stud­ies of pol­li­na­tion ever done.  It reveals a pro­gres­sive decline in pol­li­na­tion over the years, with par­tic­u­lar­ly note­wor­thy pol­li­na­tion deficits ear­ly in the sea­son.  The study appears this week in Philo­soph­i­cal Trans­ac­tions of the Roy­al Soci­ety B: Bio­log­i­cal Sci­ences.

Three times each year, Thom­son com­pared the fruit­ing rate of unma­nip­u­lat­ed flow­ers to that of flow­ers that are sup­ple­men­tal­ly pol­li­nat­ed by hand.  “Ear­ly in the year, when bum­ble bee queens are still hiber­nat­ing, the fruit­ing rates are espe­cial­ly low,” he says.  “This is sober­ing because it sug­gests that pol­li­na­tion is vul­ner­a­ble even in a rel­a­tive­ly pris­tine envi­ron­ment that is free of pes­ti­cides and human dis­tur­bance but still sub­ject to cli­mate change.”

Thom­son began his long-term stud­ies in the late 1980s after pur­chas­ing a remote plot of land and build­ing a log cab­in in the mid­dle of a mead­ow full of glac­i­er lilies.  His work has been sup­port­ed by the U.S. Nation­al Sci­ence Foun­da­tion and the Nat­ur­al Sci­ences and Engi­neer­ing Research Coun­cil of Cana­da.

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For more infor­ma­tion, please con­tact:

James D. Thom­son
Depart­ment of Ecol­o­gy and Evo­lu­tion­ary Biol­o­gy
Uni­ver­si­ty of Toron­to

Sean Bet­tam
Com­mu­ni­ca­tions Offi­cer
Fac­ul­ty of Arts & Sci­ence
Uni­ver­si­ty of Toron­to