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Nest Box Monitoring

A house wren checks out ANS volunteers. Photo by Lisa Shannon.

April 2014

Revived nest box project begins its second year

We're on our second week of nest box monitoring; so far we have 11 boxes with nesting material in them. No eggs yet, but this morning chickadees were singing near several of the boxes, and we're keeping an eye on them now that we're into nesting season.

We've made a couple of innovations this year – first, Becky made up a brilliant long-handled mirror that enables you to look into the nest box without having to climb on something to see in. This will probably enable us to monitor the boxes without disturbing the birds as much, and it's also much more fun for short folks like me to walk around the grounds without having to carry around a stepstool or bucket to stand on. And here are some new documents for volunteers: an ANS grounds map showing nest box locations, and a printable nest box data entry form.

We're still looking for volunteers to monitor the nest boxes, so contact our Volunteer Coordinator if you're interested. We sent out a mass email to people on the volunteer list in March and will be following up this week to catch up with new folks (or in case the first mailing ended up in the spam folder). Let us know – it just takes an hour and is a lot of fun.


Lisa Shannon (Co-team lead with Becky Cromwell), 4/20/14

 July 2013

This year marks the reintroduction of ANS's nest box monitoring program, now led by Becky Cromwell. We currently have 16 active boxes, which have been on the property for many years, as is evidenced by their lovely lichen-covered roofs. The boxes are located along woodland and meadow edges in Woodend's 40 acres of grounds adjacent to Rock Creek Regional Park. With understory gone and meadow plant diversity reduced due to heavy white-tailed deer pressure, Woodend's habitat is degraded compared with what might have been there when the boxes were first installed. But despite that, we still have a number of Carolina Chickadees and House Wrens using the boxes.

Becky has done a great job assembling her nest box monitoring team. In addition to Becky, Chris Ley, and me, Nathan Villiger, an accomplished young birder who is working on his first Boy Scout badge, has been inventorying, numbering, cleaning, and repairing boxes along with his family members Erwin, Andrée, and Kate. And Ren Freeman, a high school junior, monitored nest boxes in early summer to earn student service hours; she'll be returning to volunteer again this fall.

So far this year's monitors have recorded 11 eggs and 7 fledged young for Carolina Chickadees, and 19 eggs and 5 fledged young for the House Wrens (unfortunately that one brood of young were confirmed as having died). House Wrens can continue with broods throughout the summer (according to the recent Maryland/DC Breeding Bird Atlas, House Wren nestlings have been recorded up to September 2nd), so we will continue monitoring them through the end of the summer in hope that they will have additional broods of young on the property.

In order to put this year's data into context, ANS Senior Naturalist Stephanie Mason gave me the notes from the last time the nest boxes were monitored (2003-2007) so that I could put the data into a spreadsheet and see if we could get an idea of how nesting birds did at ANS during that period and establish a baseline for upcoming years. So it turns out that during that 5-year period, ANS's chickadees averaged 17.4 eggs and 12.4 young per year, and the wrens produced an average of 46.8 eggs and 25.2 young per year. This unfortunately looks much better than the current year; we are hoping that at least the wrens may catch up with additional broods in August.

What we plan to do next is to refurbish the remaining missing or broken boxes and evaluate whether any boxes should be moved to more favorable locations; some are now in full sunlight, which in the heat of summer can cook the eggs inside. We also hope to collect more data per monitoring session, to monitor more frequently than once a week if possible, and to continue monitoring through the beginning of September.

Monitoring the nest boxes is fun: you can find some interesting surprises; the nestlings are adorable; and it's lovely walking the grounds, especially in the early morning. These are common birds, but we think keeping tabs on them is important in light of changing climate and habitat loss. So if you're interested in joining us to help out either for the end of this summer or next year, contact Volunteer Coordinator Pam Herrick at

 --Lisa Shannon, Nest Box Volunteer 7/12/2013