Sunday, May 13, 2012

Bluebird Trail, Week 7 - Mom on Nest, First Fledging & Tree Swallow Eggs

Mama bluebird on her nest

While we were checking Trail 2 today,  a female stayed on her eggs when we opened one of the boxes. We have had a bird fly from a box as we've opened it before, but this was the first time one has stayed. It was quite a magical moment. We weren't able to ascertain how many eggs she's sitting on -- last week there were two eggs in this nest, so if she has the typical clutch of five, she's probably been incubating them for about four days and they'll hatch in another 8 to 10 days.

Trail 2 Box 4 nestlings at about 10-11 days

The nestlings are already quite advanced in the other Trail 2 box that has bluebirds in it (see photo above). We didn't know just when they hatched, but we estimate them to be at 10 or 11 days today, as shown in the photo above. This is the first photo we have that shows a nestling with an eye open. You can see they are becoming quite well covered with feathers.

Our very first nestlings, those in Box 9, have fledged. They were due to do so this past week, and on Saturday we found the box empty and the nest flattened out to accommodate the nestlings as they grew. You can see from the dark edges of the nest in the photo below that the nest was quite wet underneath. There was a lot of rain last week, and that box's opening faces south, exposing it to the prevailing direction of many of our rainstorms. Fortunately, as far as we can tell, the nestlings' health was not compromised. We cleaned out the box after taking this photo so that it is available for another nest. From what we've read, building the nest is an integral part of the reproductive urge, so it doesn't help to leave an old nest in place -- and starting fresh is more sanitary.

Flattened nest left after bluebird nestlings fledged

Nestlings are also very close to fledging in Box 16, if they have not already done so, and the Box 14 nestlings are due to fledge in the next few days.

Tree swallow nest with eggs in Box 15

We were very excited to find six eggs in our Box 15 tree swallow nest yesterday. We love seeing these feathery nests. We several times noticed tree swallows at Box 1 on our property today, as well -- one of the pair of boxes that have remained mainly empty but suffered the early chickadee loss to a house sparrow. And there is a bit of new moss in the other box, so we're hoping a chickadee is trying again. Still, we can sometimes hear a house sparrow nearby, so that threat remains.

Last week I did an abbreviated recap of our trail results. It's helpful to me to keep more detailed notes here, however, so those appear in the list below. Our Trail 1 totals so far: 25 nestlings5 fledged, 10 more are close to fledging, 5 more will probably fledge toward the end of this week, five more young nestlings, and only one nest still with bluebird eggs in it -- the worrying slow clutch of three pinkish eggs. This week they felt cold. The parents are always close by, but perhaps they just don't have the hang of this incubation business. We also have a nest of six tree swallow eggs. On Trail 2 we have four or five nestlings that should fledge in the week ahead, plus an unknown number of bluebird eggs being incubated in another nest, and one tree swallow egg so far in a third nest.

Trail 1:
  1. Tree swallows observed on the box; box remains empty.
  2. (Paired with #1) New moss this week, so we put the chickadee sleeve back on this box to reduce the entry hole size.
  3. House wren had started to put sticks into nestbox -- removed. 
  4. (Paired with #3) This is now clearly a tree swallow nest with large feathers; no eggs yet.
  5. Five nestlings, 11-12 days old.
  6. (Paired with #5) Tree swallow nest. No eggs.
  7. House wren nest with one egg.
  8. (Paired with #7) Now empty; previously contained a few strands of grass for several weeks. Wrens can clear nests.
  9. Our first clutch to fledge. Nestbox was empty; we cleaned it out.
  10. (Paired with #9) Complete nest, no eggs  - no change.
  11. Discontinued  
  12. Discontinued
  13. Five nestlings approx 5 days old.
  14. Nestlings close to fledging; parents still vigilant on wire when a tree swallow approach the box, so we suspect fledging has not occurred yet.
  15. Tree swallow nest with six eggs.
  16. Nestlings may have fledged or will do so shortly - we did not open the box. We did not open this box last week either, as parents were very protective.
  17. This box contained a substantial bed of moss for two weeks, but was suddenly empty last week -- a sign of possible house wren activity.
  18. (Paired with #17) Three pale pink bluebird eggs, cool. These eggs are past the age when they should have hatched with consistent incubation. Parents are always nearby and vigilant (swooping down at us protectively), but we fear incubation has not been successful.
  19. Tree swallow nest - no eggs.
  20. (Paired with #19) Partial nest.
Trail 2:
  1. Nest with several tiny dark downy feathers.
  2. Bluebird stayed on nest so we could not count eggs. Last week there were two cold eggs, so assuming a total clutch of five, probably four days into incubation.
  3. Tree swallow nest, one egg.
  4. Five nestlings approx. day 10-11.

1 comment:

Mary S. said...

It must have been really exciting to see a bluebird so close up!