News Update: April 9 , 2009        Name _____________________ 

Ruby-throated Hummingbird Map Questions
(Teachers: Map is hotlinked for larger projection on smartboard or screen.)
Some observers have noticed an interesting pattern on the rubythroat migration map. Look closely at both maps.

Ruby-throated Hummingbird Migration

Relief Map of the Eastern United States
Describe the pattern you think they noticed.
How would you explain why the region circled on the map seems to have fewer hummingbird sightings than areas around it? Write your answer, then read below.

In general, spring comes later to higher elevations, in this case, the Appalachian mountains. Temperatures are colder the higher up you go. A hummingbird's food sources, flowers and insects, are less likely to be available at cold temperatures. That's one explanation, but it's important to always ask, "What else could explain the data?" For instance, there may simply be fewer people — and so fewer observers — in those regions!