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I've been asked by several folks if woodcocks in Vermont are less 
abundant this year than usual.  Were the early warm spells and then the 
return to winter cold and Nor'easter snows the cause of seemingly low 
abundances?  What can we learn from eBird data?

So I've gathered some eBird numbers from 2008 through 2017 from the 
first observation of the year through the first half of April (which 
includes the peak frequencies).  In this case frequency of encountering 
woodcocks is a better measure than the number of woodcocks found at one 
time, since the average number of birds per checklist doesn't vary much.

This overview is for the entire state, so it doesn't explore data at a 
county or backyard level.

*First reports* --- This year was the first year to have the first 
Vermont reports in February.  Among the last ten years, the latest first 
report was in 2015 in the last week of March.  With the exception of 
anomalous 2015 all the first reports from 2012 to 2016 were in the first 
week of March, whereas the first reports in 2010 and 2011 were in the 
second week of March, and those of 2009 and 2008 were in the third week 
of March.

Thus, there is clearly a trend toward earlier first reports of Woodcocks 
in recent years.

*Peak report frequencies* --- Here are the peak weekly frequencies for 
this year back to 2008. This year is one of the three lowest frequencies 
during the period.  The average frequencies for the last three years is 
5.7; for the preceding three years is 5.7; and for the remaining four 
years (2008-2011) is 7.5.  So the frequency of observations in the last 
six years is notably lower than in the preceding four years.  And this 
year is one of the lowest frequency years in the 10 year period.  But 
this might not be as significant as it appears because it only looks at 
one two-week period (see the next topic).

2017    4.9
2016    6.1
2015    6.1
2014    5.6
2013    4.0
2012    7.4
2011    5.0
2010    6.1
2009    10.9
2008    7.8

*Frequencies for first two weeks of April* --- This is the period that 
typically has the highest frequencies of observation. The average of 
these frequencies is 4.8.  So this year's peak period for woodcock 
observations actually is not low or high, but right at the long-term 
average.  Moreover it is notably higher than last year, which had the 
lowest frequency during peak observations for the 10 years.

2017    4.7
2016    3.7
2015    5.3
2014    5.4
2013    3.9
2012    4.3
2011    4.4
2010    5.1
2009    6.4
2008    4.9

*Average bird counts during peak frequencies* --- The average count of 
birds during woodcock encounters during peak frequencies is 2.0.  This 
year is right in the middle and quite typical.

2017    1.9
2016    1.8
2015    1.7
2014    1.7
2013    2.0
2012    2.0
2011    2.1
2010    2.3
2009    3.1
2008    1.8

*Peak report dates* --- Peak report dates have a different meaning than 
do first arrivals.  Here are the weeks with the highest observation 
rates.  The latest was the 3rd week of April in 2008, and the earliest 
are three scattered years with peaks in the last half of March.  All but 
one are between the 3rd week of March and the 2nd week of April, with no 
trend showing.

2017    2nd week of April
2016    4th week of March
2015    2nd week of April
2014    2nd week of April
2013    2nd week of April
2012    3rd week of March
2011    1st week of April
2010    1st week of April
2009    4th week of March
2008    3rd week of April

*Time between first reports and peak frequencies* --- Long periods 
between first reports and peak reports might indicate that weather and 
ground conditions might have been too cold, snowy, and frozen for 
survival after the first birds arrived.  Here are the lengths of time:

2017    6 weeks
2016    2 weeks
2015    2 weeks
2014    5 weeks
2013    5 weeks
2012    2 weeks
2011    3 weeks
2010    3 weeks
2009    1 week
2008    4 weeks
*
**Relationship between period of time between first arrivals and peak 
time vs. the frequency of woodcocks at peak* --- There is none 
observable.  So what happens to the very early arrivals doesn't seem to 
have much effect on the overall population.

*So what's up with woodcocks this year ??* ---- Not much. It is a pretty 
average year except for having the earliest arrivals in the eBird 
record, which helps to create the longest period of time between the 
first arrival and peak frequency.  If compared with last year, there are 
more woodcocks being reported this year than last by 27%.

Here at my location on the southern end of Snake Mountain in Cornwall, I 
do morning and evening observations for woodcocks beginning in early 
February.  After a couple of remarkably early birds in February, there 
was a long, long wait until they began to show up in late March.  For 
the past three weeks they have been continuously present as normal, 
though from my observation location it is difficult to monitor numbers.

Best spring wishes,

Ian