April 19, 2011

Another Kind of “March Madness”

By Senior Naturalist Dave Erler

Every year for the past 30 years, I have taken a day in March to do the annual inspection of the nearly four dozen bird nesting boxes scattered around the Science Center’s fields. March is good time as it’s just before the coming nesting season, I have the time, and as I am allergic to wasp and hornet stings (they also like bird nesting boxes) there’s little threat of getting stung. On March 22 I completed this year’s bird box inventory. It was a bright sunny day and cold enough that I could walk on top of the frozen snow pack without the use of snowshoes. Armed with a bucket containing a clipboard, data sheet, pencil, three-inch putty knife, hammer, cordless power drill, and an assortment of nails and screws I head out.

Upon arriving at the first nesting box, I quickly back out the screw to the access panel using the cordless power drill. I slide the putty knife under the nest and carefully pull out the contents. A quick inspection of the nesting material helps me to identify the user. A thin one-inch layer of grasses with a few duck or poultry feathers indicates a Tree Swallow. A box full of woody twigs with a two-inch cup lined with pine needles points to a House Wren. An inch to inch and half of moss points to a Black-capped Chickadee. An accumulation of fecal sacs provides evidence that the nest was probably successful, since the fledgling birds’ fecal sacs are no longer removed by the parents prior to heading out on their own. I record what I find on the data sheet, finish cleaning out the box, replace the screw, tap any loose nails back down with the hammer, and go off to the next box.

It can be a dirty somewhat tiring job by the time I’m finished, but it’s also a little like Christmas morning with the anticipation of what I will find in each box. Some boxes are empty and unused. Most have evidence of some use, hopefully by the Tree Swallows, House Wrens, Bluebirds, and Chickadees that the boxes are intended for. Some show use by multiple tenants with a Tree Swallow nest (early nesters) buried by a House Wren nest, which is in turn buried beneath the winter nest of a white-footed or deer mouse. Two or three boxes might have a paper wasp or bald-faced hornet nest and a few contain food caches from red squirrels or mice. The latter can be exciting when a surprised mouse jumps into your open coat or a red squirrel leaps on to your face in a panic to escape the intrusion.

When I’m done, the boxes are ready for another season of use by those cavity-nesting birds that depend on our help to give them a chance to raise another generation. So, if you are so inclined I encourage you put up a nest box or clean out the ones you have before the mad rush of the nesting season begins. Good luck and have fun!

2010 SLNSC Bird House Use


8 Successful Tree Swallow nests

2 Successful House Wren nests

1 Successful Black-capped Chickadee nest

1 House Sparrow nest

3 Peromyscus mouse nests

2 Peromyscus mouse food caches

4 Red Squirrel nests or food caches

4 Dummy House Wren nests

2 House Wren nests with one un-hatched egg

1 Tree Swallow nest with 2 dead nestlings

2 Boxes with Paper Wasp nests

1 Bald-faced Hornet nest

6 Boxes unused

Individual House Use

1. Mouse and Red Squirrel use

2. Tree Swallow nest successful

3. Tree Swallow nest successful

4. Tree Swallow successful but with two un-hatched eggs

5. Red Squirrel nest

6. Tree Swallow nest successful

7. Mouse nest

8. Tree Swallow partial nest/abandoned

9. Mouse cache acorns and black cherry pits

10. Mouse cache of black cherry pits

11. Tree Swallow nest abandoned, red squirrel cache of mushrooms

12. No use; small pine trees growing up around it

13. Red Squirrel cache of acorns

14. No use

15. Paper Wasp nest

16. House Wren dummy nest

17. Tree Swallow nest abandoned

18. Red Squirrel use only

19. House taken down in 2007 because of confusion with bat house interpretation

20. House Wren dummy nest

21. Empty, screw missing and access panel partially open

22. Tree Swallow nest beneath House Wren nest containing one undeveloped egg

23. Tree Swallow nest successful

24. Mouse nest made of milkweed fluff

25. Tree Swallow successful

26. Black-capped Chickadee nest successful

27. Tree Swallow successful

28. House Wren dummy nest

29. House Wren dummy nest

30. No use

31. No use

32. Tree Swallow partially successful (signs for fledged young along with two partially developed eggs)

33. No use, house pulled out of the ground

34. House Wren nest successful

35. Tree Swallow nest successful, but with 2 dead nestlings

36. No use

37. Mouse nest made only of cattail fluff

38. No sign of use, nest box was pulled up and laying on the ground

39. No use

40. Black-capped Chickadee nest beneath a House Wren nest with one un-hatched egg

41. House Sparrow nest, success? (no sign of fecal sacs)

42. Paper Wasp nest

KG1. No use

KG2. Red Squirrel cache of acorns and rose hips

KG3. Red Squirrel use (acorn shells, etc.)

KG4. Small Bald-faced Hornet nest

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