30 December 2023 Over the past week my husband and I traveled to Virginia to visit family, the same trip we made a year ago just as a massive cold front swept across the eastern US. Last year temperatures...
Yellow-rumped warbler in myrtle at the coast (photo from Wikimedia Commons)
30 December 2023
Over the past week my husband and I traveled to Virginia to visit family, the same trip we made a year ago just as a massive cold front swept across the eastern US. Last year temperatures dipped to 13 degrees F in Virginia. This year the weather was mild in the upper 40s to low 60s. The temperature made a difference in how many birds I saw on the trip. Believe it or not there were fewer birds in mild weather!
For instance, on both trips I visited Back Bay National Wildlife Refuge. In 2022 it was well below freezing yet I saw 29 species including thousands of waterfowl: Canada geese, 250-300 tundra swans, gadwall, wigeons, black ducks, ring-necked ducks, scaup, ruddy ducks, and coots (see checklist here).
This year I saw only 18 species and the water birds were reduced to literally a handful each of Canada geese (heard), tundra swans (heard), gadwall and pied-billed grebes (checklist here). Meanwhile the most abundant species was 40-50+ yellow-rumped warblers feasting on myrtle berries.
Abundant myrtle berries attracted yellow-rumped warblers at Back Bay NWR (photo by Kate St. John)
This year�s El Ni�o is has certainly affected the birds. On the East Coast it is warm enough that many don�t have to come south to find food.
Seasonal temperature and precipitation outlooks for the U.S., Dec 2023-Feb 2024 (maps from NOAA)
Will temperature make a difference during today�s Pittsburgh Christmas Bird Count? I suspect precipitation will have a larger affect. There�s a 90% chance of snow showers and then rain. 
