About DNS Nestbox Program

The Delta Naturalists Society maintains about 100 nest boxes in five locations in South Delta:

  • Boundary Bay Regional Park
  • Earthwise Garden
  • Tsatsu Shores
  • North 40 Park
  • Kings Links Golf Course

Our primary intent is to provide nesting habitat for Tree Swallows, although other species have also used them.  Boxes were installed at various times between 2012 and the present, and more boxes will be added as funds and monitoring resources become available.

We maintain the boxes twice per year.  We open the boxes in the Fall to see which boxes were used for nesting, and by which species.  We clean out the boxes and leave them open or plug the openings so that rats and wasps do not occupy them during the winter.  We close and repair them as necessary in the Spring.

We are trying to encourage occupation and nesting by Tree Swallows, which, like other insect-eating birds, are declining world-wide.  This may be due to habitat loss, pesticide use, changes in insect populations and competition from non-native species like the European House Sparrow.  We have tried to discourage House Sparrows from occupying the boxes by adapting the opening sizes.  Some boxes are in wooded areas to encourage use by the native Black-capped Chickadees.

We record which species use each box, and the Reports page on this site shows details about the year-by-year nesting success of the boxes.  You can also find a link to an online map that shows year-by-year activity for each box.  The boxes at Kings Links Golf Course have been very successful for Tree Swallows, while we are still struggling to reduce the competition from European House Sparrows at the Boundary Bay Regional Park.  In 2016, Chris McVittie began a program of more frequent monitoring at Boundary Bay to get a better handle on the nesting activity.  Volunteer labour to monitor and maintain the boxes is a limiting factor to their deployment.  Most of the Tree Swallow boxes were built by Peter Ward and Peter Blair, and many Delta Nats help with the Spring and Fall maintenance.

In 2016, a group of Delta Nats expanded the program for Barn Owl boxes.  With government funding secured by Sofi Hindmarch and donations from farmers and other local businesses, Peter Ward, Jim Kneesch, Chris McVittie, and Jack MacDonald constructed about two dozen boxes large enough to house Barn Owls.  One of these boxes was installed at Kings Links Golf Course, and is being maintained by Delta Nats, while the other boxes are installed on various golf courses, parks, and in farmers fields and barns.  By encouraging nesting by Barn Owls, these boxes provide a more natural method of rodent control than using pesticides.  Video surveillance has shown that the boxes maintained by the Delta Nats have been successfully inhabited by Barn Owls, and that chicks have been fledged.  We will continue to install new boxes in local sites as funds, labour, and suitable habitat permit.

All photos below by Terry Carr

Tree Swallow nests are usually neat and thin, and made of grass and duck feathers.

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House Sparrow nests are thick and messy, and made of grass and duck feathers.

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Chickadee nests are made of moss and hair.

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Some boxes have more than one nest on top of each other.

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The Tree Swallow nesting box program has gathered considerable success since its inception in 2004.  In 2017 there are 17 boxes that have been occupied by Tree Swallows.  The average number of eggs is 5.  Some will not hatch but expectations are the boxes will produce in excess of 70 new Tree Swallows.

For more information about the DNS Nestbox Maintenance Program, click on the following links…

Maps – Map locations of Nestboxes in areas where Nestboxes are maintained by DNS

Reports – Reports of Nestbox observations, especially during maintenance:  cleaning (in Spring) and opening (in Winter)

History – Success of DNS Nestbox Maintenance Programs over the years, according to Nestbox Number and bird species

Tree Swallow nest boxes – Request for funding (May 2017)(downloadable PDF file) explains why we need to build and maintain Tree Swallow Nestboxes