Signs of Spring: Phenology

The songs of the first red-winged blackbirds of the season were heard in north Maplewood on Thursday, March 8, six days earlier than the median date of March 14. At the same time the red wing blackbird call was heard, 14 inches of snow was on the ground and morning temperatures were around 10 degrees. The first western chorus frogs were heard during a warm late afternoon of April 23, just two days shy of the latest date in 2013. Warm conditions narrowed the delay of spring to just about a week for crabapple flowers and lilac blooming.

Phenology which is derived from the Greek word phaino meaning to show or appear, is the study of periodic plant and animal life cycle events that are influenced by environmental changes, especially seasonal variations in temperature and precipitation driven by weather and climate. The USA National Phenology Network (USA-NPN) collects phenological data from across the United States. Also track the progress of The Ruby-throated Hummingbirds as they migrate north.

Here is some recent spring phenology for a site in Maplewood just north of St. Paul.

First Red-winged Blackbirds Heard
----------------------
1999   March 22
2000   March 4
2001   March 28
2002   March 25
2003   March 19
2004   March 8
2005   March 12
2006   March 10
2007   March 13
2008   March 19
2009   March 15
2010   March 14
2011   March 17
2012   March 11
2013   March 29
2014   March 23
2015   March 13
2016   March 7
2017   March 5
2018   March 8
Frost Leaves the Ground
----------------------
2001   April 4
2002   April 12
2003   April 11
2004   March 28
2005   April 10
2006   April 2
2007   March 30
2008   April 18
2009   April 7
2010   March 16
2011   April 2
2012   March 15
2013   April 18
2014   April 12
2015   April 4
2016   March 8
2017   March 29
2018   April 24
First Western Chorus Frogs Heard
--------------------------------
1999   April 3
2000   April 13
2001   April 11
2002   April 12
2003   April 10
2004   April 5
2005   April 3
2006   April 10
2007   March 25
2008   April 14
2009   April 14
2010   March 30
2011   April 5
2012   March 16
2013   April 25
2014   April 9
2015   April 11
2016   March 12(just a few to start)
2017   March 27(just one at 10:45pm, then a few days later several)
2018   April 23
First Dandelions
-----------------
2003   April 29
2004   April 23
2005   April 8
2006   April 21
2007   April 15
2008   May 3
2009   April 27
2010   April 4
2011   April 22
2012   April 2
2013   May 6
2014   May 6
2015   April 25
2016   April 17
2017   April 21
Crabapples Blooming
----------------------
1999   May 2
2000   May 2
2001   May 9
2002   May 17
2003   May 7
2004   May 6
2005   May 3
2006   May 5
2007   April 30
2008   May 17
2009   May 8
2010   April 24
2011   May 18
2012   April 13
2013   May 19 (prolonged bloom. some varieties had full bloom through May 29) 
2014   May 25 (fast bloom, with petals falling by May 27)
2015   May 5  (first blooms opening May 2
2016   May 3
2017   May 7
2018   May 15 peak, petals falling at u of m on May 16
Lilacs Blooming
---------------------
1999   May 10
2000   May 4
2001   May 13
2002   May 25
2003   May 13
2004   May 9
2005   May 9
2006   May 6
2007   May 6
2008   May 24
2009   May 15
2010   May 1
2011   May 19
2012   April 14*
2013   May 25*
2014   May 27* (fast bloom, with some florets falling same day)
2015   May 7* (75% florets open on May 5)
2016   May 9
2017   May 13 (beginning to brown by May 16)Range of lilacs U of M to Maplewood May 12-15.
2018   May 16 U of M  
*from a variety of lilacs in the area.
Last modified: May 16, 2018
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