From 1960 to 2002 Kathleen Anderson recorded the first date each spring that migrating birds were seen on her property. For over 50 years Anderson has lived on a 100 acre farm just south of Boston and not far from the ocean. Everyday she was on her farm she recorded the birds, flowing plants, butterflies and amphibian choruses she encountered. Her observations were not systematic, but gathered as she enjoyed a walk or simply from the back porch.
Boston University biologists were able to extract her sightings from her vast journals, put them into a computer database and analyze them statistically. A nearby weather station showed that mean annual temperatures in the region climbed 3.6 F during the same time period. Could her records show species responding to the warming with earlier spring phenology?
There was enough data to look at 16 bird species, 3 plants, 3 amphibians and 2 butterflies. Five bird species showed significantly earlier arrival dates including, Wood Duck, Ruby-throated Hummingbird, House Wren, Ovenbird, and Chipping Sparrow. The strongest trend was for Wood Ducks, which arrived on average 32 days earlier than they did when Anderson first began recording her sightings. Hummingbirds arrived 18 days earlier. Overall, 22 of the 24 species they examined showed trends toward earlier spring activity, an overall average of 8 days earlier.
Kathleen Anderson had no idea that her records might be a piece in the climate change puzzle when she started to record her observations over 30 years ago. Perhaps your observations will help scientists learn more about the changing world too.
Source: Ledneva, A., A.J. Miller-Rushing, R.B. Primack and C. Imbres. 2004. Climate change as reflected in a naturalist’s diary, Middleborough, Massachusetts. Wilson Bulletin 116(3): 224-231.