Tag Archives: evolution

Spring Migration Timing

Currently re-reading Scott Weidensaul’s Living on the Wind, a personal account of bird migration in the Americas, while studying how and why birds migrate, and what the future of migratory bird conversation looks like. In high school, it was one of my favorite books, as it combined both my scientific fascination of birds along with my more personal connection to birds and their environments. There’s a lot of really scientifically interesting stuff on the mechanisms of bird migration, but there’s also some really emotional stuff about the death of thousands of Swainson’s Hawks due to insecticides in Argentina, for instance.

Re-reading it now, it’s not quite as good as I remembered. The book doesn’t have a clear narrative arc, which I’m fine with, but it also doesn’t do the ‘sprawling New Yorker style’ that McPhee does so well, and that I’ve been reading so much of lately. Instead, there really doesn’t seem to be much of a structure at all, and feels like facts and stories haphazardly thrown together. There are probably better ways to structure this book.

Anyways, one small factoid caught my attention as I was reading the second chapter. It was mentioned that birds know when to migrate based primarily on two factors: genetic predisposition, and photoperiod (length of daylight). Continue reading

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