Submitted by Sonjia Shelly, YAS Board

In early 2020, the Yolo Audubon Society board was approached by two local organizations (Friends of North Davis Channel and Woodland Regional Preserve) to fund and install song bird nest boxes in their respective areas. The YAS board provided the funding for needed materials, and a group of volunteers made the boxes, installed them and then monitored them for activity and nesting success. The following is a synopsis of the activity from spring through mid-summer 2021.

North Davis Channel Nest Boxes

-In early February 2021, 14 song-bird nest boxes were installed on poles along the North Davis Channel (NDC). Eleven boxes were new and 3 had been installed along the channel in previous years.

-Weekly monitoring began 02/25/21 and ended 07/30/21. At the first monitoring we found a banded male WEBL and an unbanded female showing interest in one of the boxes. These birds were seen later but never committed to a full pairing/nest.

-On 3/19 a pair of TRES were noted near one of the boxes and a partial nest was found. Over the next two weeks this nest grew and was completed. At two of the visits a bird was in the box so we did not open it for fear of scaring off the pair. This nest was complete by 4/15. Another box had loosely arranged nest material plus a few feathers.

-By 4/22 two additional boxes showed nest building activity, and were thought to be WEBL. At the end of April (4/29) the TRES had 2 eggs, the male WEBL was on a box and the female was near, but no progress had been made on the nest. A third box was attended by TRES with the nest enlarged compared to the previous week.

-The first week of May showed two boxes (TRES), each with 5 eggs; and no activity in the third box. On 5/20 we had 5 newly hatched chicks in one box and 3 chicks and one egg in the second box. On 5/27 there were 9 nestlings (2 boxes) and a new nest in a different box.

-On 6/3 the new nest had 2 eggs and the female present in the box; and another box showed new nest building activity. On 6/10, 7 of 9 hatchlings fledged and 2 stayed in the box. Another box contained 4 eggs with adult nearby and 1 unattended egg in a nest in yet a different box.

-On 6/24 a second clutch was underway in the first box of activity and contained 4 eggs; 1 box had an abandoned egg and the third box still had eggs but these were suspected to have been abandoned.

-The second clutch had hatched by 7/9 and fledged by 7/30. The box with the suspected abandonment contained fragile cold eggs that broke when one was picked up (and smelled really bad). The remaining eggs were discarded and were equally stinky!

In summary we had one box with 2 successful clutches, another box with one successful clutch, and one box that was abandoned (all of the above were TRES). The box with the WEBL interest/activity did not progress to a final nest/eggs. We believe this is due to the youth of the male (name TETON, hatched near community park in 2020). We are hoping he will be back next year.

Many thanks to:

Advisor: Dr. Melanie Truan
Box builders and installers: Drs. Joe Zinkl, and Ron Ringen plus John Mott-Smith, Eric Newman and others
Dedicated crew of monitors: Zane Pickus, John Hansen, Ina Rommeck, Sonjia Shelly

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Woodland Regional Preserve Nest Boxes

In February 2021, 14 song-bird nest boxes were installed on conduit poles at Woodland Regional Preserve (WRP). These nest boxes were monitored weekly beginning 2/27/21 and ending 7/25/21.

The first week (2/27) many of the boxes had attracted wasps, but not birds. By the week of 3/7 adult tree swallows (TRES) were showing interest in 3 of the boxes. Interest in the boxes fluctuated through March. By April 11 TRES were seen on, near or in 7 different boxes and by 4/24, 4 boxes showed evidence of nest building with 3 eggs in another box. Eggs were present in 3 boxes and a nearly completed nest in another box on May 1.

By May 15 we found 3 boxes with eggs and 2 boxes with nestlings (4 each). The following week nestlings were present in 3 boxes and eggs present in 2 boxes. Also this week (5/22) we were excited to find 3 Ash-throated flycatcher (ATFL) eggs in one box.

The following week, TRES nestlings were present in all boxes including one box with 3 newly hatched and 2 warm eggs remaining. The ATFL box now had 4 eggs.

By the week of June 6 nestlings had fledged from 2 boxes (9 birds), with nestlings (7 or 8) [don’t judge us, they’re hard to count] present in 2, and 5 ATFC eggs in one box. By the next week (6/13) we found 7 or 8 nestlings. Sadly, in one box we found a perished, cachexic adult female with an egg; and it appeared that the ATFC nest had been abandoned.

On 6/19 the above nestlings had fledged, one egg failed to hatch and a second clutch had begun in one box (4 eggs). Three of these eggs hatched on or about 7/4, 3 fledged by 7/25 and one egg failed to hatch.

All boxes have been cleaned and lowered on the poles to protect against the winter winds, but will be checked and readied to go again in the spring.

In all 24 birds fledged from the boxes, 8 eggs failed to hatch and 2 broods were raised in one box.

Many thanks to:

Advisor: Dr. Melanie Truan
Monitors: Zane Pickus (data recorder and enterer), John Hansen, Ina Rombeck, Ryan Janke and Kirk Ehnsen.
Box builders and/or installers: Joe Zinkl, Ron Ringen and others.