- By Katrin Powell and Greg Ross (Posted May 2024)
In the spring of 2024, the Cavity Nesting Group (CNG) had four outings where we cleaned out existing boxes and erected five new boxes. It's been very exciting going out with the various Rocky Mountain Naturalist volunteers as we excitedly ‘unbox’ a nest to see what we would find inside. We take turns looking, observing and giving deductions as to what used the box based on what we see, and with monitor notes from the previous season.
The CNG group now has 22 volunteers who come out and help with the opening of the boxes once a year, to decipher what has used them and to clean them out. The monitors, by putting everything together, determine the species use and the outcomes, having learned a lot over the past two years.
Monitors also ‘adopt’ a box for the nesting season and take some time each week to observe it from a distance, approximately once a week for 30-60min (or to whatever degree the monitor is able), noting any use of the box as well as any cavity nesting species in the area.
Out of the 16 boxes we monitored in 2023 located at Elizabeth Lake, Community Forest and Irrigation Fields, seven had successful fledglings of ducks, most of which were Barrows Goldeneye. There was also a Goldeneye species (unconfirmed which one), and one wood duck, or WODU, at Elizabeth Lake. Notable mention also goes to the Bufflehead that used a box at the Irrigation Fields, but something must have happened to the female, as the chicks were partially developed in the eggs and did not come to a fledgling state.
We are overjoyed that the monitors have been so keen! We have heard such remarkable experiences from everyone, just by sitting quietly in nature once a week and being able to share those experiences with the group. The CNG is growing to become something quite remarkable, leading people to ‘slow life down a little’ and ‘experience nature’ as well as learning about our feathered duck friends and other appreciated species that use cavities - owls included!
2023 marked the second year that we’ve had a dedicated Cavity Nesting Group. Thank you so much to the monitors, past and present! If you would like to learn more about the CNG or get involved, please contact via the webforms here on the website or email [email protected]
Below are photos from this spring’s ‘unboxing’ events.
Irrigation Fields and Rampart
The CNG group now has 22 volunteers who come out and help with the opening of the boxes once a year, to decipher what has used them and to clean them out. The monitors, by putting everything together, determine the species use and the outcomes, having learned a lot over the past two years.
Monitors also ‘adopt’ a box for the nesting season and take some time each week to observe it from a distance, approximately once a week for 30-60min (or to whatever degree the monitor is able), noting any use of the box as well as any cavity nesting species in the area.
Out of the 16 boxes we monitored in 2023 located at Elizabeth Lake, Community Forest and Irrigation Fields, seven had successful fledglings of ducks, most of which were Barrows Goldeneye. There was also a Goldeneye species (unconfirmed which one), and one wood duck, or WODU, at Elizabeth Lake. Notable mention also goes to the Bufflehead that used a box at the Irrigation Fields, but something must have happened to the female, as the chicks were partially developed in the eggs and did not come to a fledgling state.
We are overjoyed that the monitors have been so keen! We have heard such remarkable experiences from everyone, just by sitting quietly in nature once a week and being able to share those experiences with the group. The CNG is growing to become something quite remarkable, leading people to ‘slow life down a little’ and ‘experience nature’ as well as learning about our feathered duck friends and other appreciated species that use cavities - owls included!
2023 marked the second year that we’ve had a dedicated Cavity Nesting Group. Thank you so much to the monitors, past and present! If you would like to learn more about the CNG or get involved, please contact via the webforms here on the website or email [email protected]
Below are photos from this spring’s ‘unboxing’ events.
Irrigation Fields and Rampart
 Bufflehead eggs in box at Irrigation Fields |  Nest used by a ‘biggish bird’ at Irrigation Fields (please let us know if you have ideas to identify) |
 Feather in nesting box of ‘biggish bird’ - very technical! |  Enlarged photo of ‘poop’ in nesting box of ‘biggish bird’ |
 Possible beginnings of a house wren nest in small box from alternate school at the installation of new box at Rampart Irrigation fields. It even had feathers with hearts!  Ft Steele - Westport and Community Forest  Installation of 2 boxes at Westport, by Ft Steele |  <3 |
 A happy group of monitors!  Egg membranes when whole, make it easier to count success! Egg fragments always mean success! |  Deciphering eggs in the Community Forest  |
Elizabeth Lake
 Lots going on here - a nesting box swung upside down and was still used! |  Many hands make light work |
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We’re learning more about identifying WODU eggs versus Bufflehead eggs, which we used to not be able to tell apart. Thanks to Gretchen’s donation of a ‘Birds of the World’ account from Cornell, we now have better information than we would have had just by googling. WODU eggs can vary from elliptical to sub elliptical. Bufflehead eggs are elliptical to oval. The egg on the left is sub elliptical, and the one on the right is elliptical. The one on the left is too short to be a BUFF egg, and the one on the right is too wide to be a BUFF, based on minimum and maximum sizes from Cornell data, but they both meet the specs for a WODU. Strange, as they are so different. One cannot be too quick to make assumptions! But we are open to discussion as we are learning too!
McGinty Lake – Cavity Nesting Box Project
- By Theckla Sawicki
- By Theckla Sawicki
Thursday, April 4th, McGinty Lake was the focus of the Cavity Nesting Group, with the permission of the Executive from the Meadowbrook Community Association – the Stewards of the McGinty Lake Recreation Area. 12 participants took part in placing two cavity nesting boxes close to the lake. One box is highly visible from the main picnic area, which will make for ease of monitoring as well as offer up an opportunity for instruction of school groups that make good use of the area. The second box was placed at the south end of the lake close to a known nesting area for Common Goldeneye.
 Installation of Box #1, easily visible from the main picnic area Cavity nesters that we were able to observe while installing the boxes: Bufflehead – a successful fledging of 5 ducklings in June, 2022, 2 families in June 2023! Common Goldeneye – the largest number was 19 in June 2022; a cavity nest can be spotted in a poplar tree along the south trail. Barrows Goldeneye – successful fledging of 10 ducklings in June 2022 |  Installation of Box #2, south end of the lake.  Barrows Goldeneye Male |
Barrows Goldeneye Males showing off for the ladies
Other cavity nesters seen at McGinty Lake in the past include:
Hooded Merganser - last seen in April 2023.
Wood Duck – no reports from 2021-2024.
Hooded Merganser - last seen in April 2023.
Wood Duck – no reports from 2021-2024.
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