In the last few days swallows returned to nests under the bridge on the bike path. A friend at Mammoth Mountain CA, heard the long eerie call of the common loon and the drumming of a Williamson sapsucker on April 12th. A cousin in Chippewa Falls, WI heard a loon call 2 weeks ago, before it continued north. Plum, apple, cherry, and lilacs all are blooming and spreading their sweet, full aromas. Irises are abloom. Blackbirds and meadow larks have been back for several weeks. But there was still good snow last week up by the continental divide for cross country skiing. Ospreys mate and nest by Longmont, Colorado.
My grandfather, who lived by a lake in Wisconsin, wrote the dates on the wall when the ice would form in the fall and when it would break up in the spring. In Wisconsin, we would listen in the spring when the whippoorwill called as it stopped in the wetland on its way north. Here in Boulder, I get excited when the poorwills return to the foothills. Also, the crossbills are neat as they pass thru.
Phenology is observing and recording the changes in nature. Birds and animals migrate and mate, plants bloom There are groups you can share you observations with.