[Tweeters] Chickadee abundance

[Bob Boekelheide via Tweeters]

Hi Dennis & Tweets,

Your chickadee question inspired me to look at some data.  At Railroad Bridge Park in Sequim, where we have a weekly Wednesday bird survey, both chickadees and nuthatches seem to be doing quite well this fall.  We conduct the survey along the same 0.75 mi section of trail every week, during the same morning time period.  

Here are some comparisons of mean numbers of chickadees and nuthatches just for September/October surveys for the last ten years.  For the ten years, Sep/Oct 2024 scores the second-highest year for Black-capped Chickadees, the third-highest year for Chestnut-backed Chickadees, and the second-highest year for Red-breasted Nuthatches.  The standard deviations are fairly large for some of these years, so there are likely not many statistically significant differences — I’m just looking at general trends.  Hope these format okay.       
 
2015 (N=9 surveys):   BCCH mean=4.3, SD=3.4;    CBBH mean=8.5, SD=6.5;     RBNU mean=3.8, SD=1.9

2016 (N=8 surveys):   BCCH mean=5.6, SD=1.6;    CBCH mean=7.8, SD=5.4;     RBNU mean=2.9, SD=1.1

2017 (N=8 surveys):   BCCH mean=5.6, SD=3.0;    CBCH mean=11.9, SD=8.5;   RBNU mean=3.9, SD=1.0

2018 (N=9 surveys):   BCCH mean=7.4, SD=2.4;    CBCH mean=14.2, SD=8.4;    RBNU mean=8.2, SD=3.8

2019 (N=9 surveys):   BCCH mean=8.3, SD=2.9;    CBCH mean=15.0, SD=10.5;  RBNU mean=4.8, SD=1.6

2020 (N=9 surveys):  BCCH mean=12.0, SD=5.4;   CBCH mean=13.1, SD=9.0;    RBNU mean=8.2, SD=3.5 

2021 (N=9 surveys):  BCCH mean=8.6, SD=3.1;     CBCH mean=9.3, SD=7.8;      RBNU mean=4.5, SD=2.2

2022 (N=8 surveys):  BCCH mean=9.1, SD=5.8;     CBCH mean=11.9, SD=5.9;    RBNU mean=10.6, SD=2.8

2023 (N=8 surveys):  BCCH mean=9.8, SD=4.1;    CBCH mean=8.0, SD=2.7;	 RBNU mean=7.1, SD=2.9

2024 (N=8 surveys, so far):  BCCH mean=11.1, SD=4.4;   CBCH mean=13.4, SD=4.4;   RBNU mean=10.3, SD=4.8


To compare this fall with last summer, it looks like the average counts for all three species are higher during Sep/Oct 2024 compared with July/August 2024.  Here are the Jul/Aug numbers: 

2024 Jul/Aug (N=9)   BCCH mean=4.9, SD=1.5;    CBCH mean=11.2, SD=5.5;    RBNU mean=7.9, SD=3.5

From these data, this local population of Chestnut-backed Chickadees seems to be holding its own or slightly increasing this fall compared with summer.  It’s not declining, anyway, particularly compared with other years.  Hope this helps. 

Best,
Bob Boekelheide
Dungeness

 

From: Dennis Paulson via Tweeters <tweeters at u.washington.edu <mailto:tweeters at u.washington.edu>>
Subject: [Tweeters] chickadee abundance
Date: October 28, 2024 at 5:36:08 PM PDT
To: TWEETERS tweeters <tweeters at u.washington.edu <mailto:tweeters at u.washington.edu>>
Reply-To: Dennis Paulson <dennispaulson at comcast.net <mailto:dennispaulson at comcast.net>>


Hello tweets,

Two of us, living several miles apart in Seattle, have noticed a substantial decline in Chestnut-backed Chickadees in our yards from their abundance this summer. Black-capped are still in the same numbers. Has anyone else seen this?

Dennis Paulson
Seattle

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