[EBB Sightings] Black-headed Grosbeaks and Phenology at Tilden Nature Area

Friends: Phenology is the correlation of animal and plant world events. The 
famous example is the late sportswriter Red Barber saying, "The watermelon 
is ripe when the crepe myrtle blooms."
Working at the Tilden Nature Area, I noticed that  "The Black-headed 
Grosbeaks return when the box-elder blooms." Box-elders are the maples (Acer 
negundo) that line the Boardwalk to Jewel Lake (there are a few near the 
entrance to the Nature Area as well). I have not been up there recently (it 
is March 20 as I write- Happy Spring!) but will be curious to see if in this 
new age of "climate change" the phenologic clue still holds- look for the 
box-elder blooming (male and female trees are separate) and then listen for 
that Black-headed Grosbeak song (or the reverse, hear the song and look for 
the flowers).

Best of birds to you! (and thanks for the notice of the Oakland Bird Club 
meeting last night- a great program on the Breeding Bird Atlas of Santa 
Clara County).
Alan Kaplan