Expert: Roger Lederer - 5/12/2010

Question
I have been feeding Rubies for 15 years. I live in the bush outside of Ottawa,Ontario,Canada. One or two males have ALWAYS showed up the week of May 4th.
May 4th has always been the day the first one has shown up. This year I haven't seen any hummers yet.
It has been cold, but I know they migrate with the day light time. Do you know of any thing that has happened to the hummers? It is now May 12,2010 and nothing yet.
thank you
Kim

Answer
Yes, they do migrate in tune with photoperiod, but there is always some variation. Photoperiod starts them on their journey, but weather and food supply in the form of blooming flowers affect their journey. Second, global warming has been throwing off migratory patterns of birds. Because the climate is warming, flowers are blooming earlier and the birds might be delayed by an abundant food supply south of you. Or the distribution of blooming flowers might have put them off course. I can't say for sure in your particular case as I have no information except what you told me, but I know this kinds of things are happening across the world.