Of Nests, Frass, and Climbing Groundhogs

Nesting and fledging continues around campus, with the early season breeders already feeding young while the mid-season nesters are still working on construction. A pair of Cedar Waxwings was recently observed building their nest out of oak catkins (the oaks' "flowers") in a Plane Tree between Hallowell and BP:



Both of the pair work constantly to gather the materials and weave them into the walls of the nest, finally settling in and "shimmying" to shape the cup before heading out for another batch of catkins.

Down at the boathouse, two pairs of Barn Swallows have finished their mud nests after the first attempts failed. The dry weather may have prevented the mud mixture from adhering well to the concrete, but the second round of nests appear to be sticking well.

The wide gape of this perched swallow demonstrates how well-suited it is to snatch (and, ahem, swallow) flying insects on the wing.  In this case, though, the bird was just yawning.

In other news, the trees in Estabrook are being hit hard by several species of insects this spring, primarily the introduced, invasive Winter Moth, whose small, green caterpillars have effectively defoliated acres of the woodland.  After a late hatching due to the prolonged winter, the caterpillars emerged several weeks ago with a vengeance.

Usually, trees can recover from defoliation, sprouting a new set of leaves after caterpillar populations drop off in June and July.  The long term effects of defoliation are unclear, but if this becomes an annual event, it could result in increased tree mortality.  In the meantime, there are some side benefits for other species; birds now have a bumper crop of inchworms to feed their young, the plants of the forest floor have ample sunlight penetrating through the thinned leaves, and the organic material synthesized by the trees and passed through the digestive tracts of the caterpillars is falling down from the canopy and fertilizing the forest soil.  That's right, it's raining caterpillar poo.  The technical term for it is "frass," and if you stand quietly in the forest, you can hear it striking the leaves around you.  It builds up in other places besides the soil, of course, as seen here on the East Fields bridge:

And finally, if you're still reading, you may be interested to know, as I discovered on a recent jog through Estabrook, that Groundhogs (aka Woodchucks or Whistlepigs) can, in a pinch, climb trees.  After emitting an explosive, piercing alarm call, this one dashed out from under me and skittered up a nearby tree, stopping about 20 feet up the trunk, where it clung to a thick Poison Ivy vine and stared at me.  I was thrown for a loop at first, because not only are Groundhogs seldom found far from open fields (this was pretty deep in the woods), I had not known them to climb anything higher than a stump or a stone wall.  But here is photographic evidence, snapped with my phone:

While the Groundhog was a mammalian highlight of that day, I also kept track of which birds I heard on my run through Estabrook: 46 species, a new "running list" record.  Here's the list, in case you're interested:

Estabrook Woods, Middlesex, Massachusetts, US
May 28, 2015 9:00 AM - 10:30 AM
Protocol: Traveling
7.0 mile(s)
Comments:    Jogging, birding by ear, pausing occasionally.  Circuit through northern Estabrook, starting from MX school, through Carlisle portion, down Two-rod Rd., across to old Estabrook Rd. <br />Submitted from BirdLog NA for iOS, version 1.8
46 species

Cooper's Hawk  1
Red-shouldered Hawk  1
Broad-winged Hawk  1
Mourning Dove  1
Red-bellied Woodpecker  1
Downy Woodpecker  4
Hairy Woodpecker  3
Northern Flicker (Yellow-shafted)  1
Pileated Woodpecker  2
Eastern Wood-Pewee  5
Great Crested Flycatcher  1
Red-eyed Vireo  12
Blue Jay  3
Black-capped Chickadee  5
Tufted Titmouse  4
White-breasted Nuthatch  1
Brown Creeper  2
House Wren  1
Carolina Wren  1
Blue-gray Gnatcatcher  2
Veery  3
Hermit Thrush  1
Wood Thrush  5
American Robin  3
Gray Catbird  5
Ovenbird  10
Northern Waterthrush  3
Common Yellowthroat  5
American Redstart  1
Yellow Warbler  1
Pine Warbler  3
Black-throated Green Warbler  1
Canada Warbler  2
Chipping Sparrow  3
Song Sparrow  2
Swamp Sparrow  1
Scarlet Tanager  4
Northern Cardinal  3
Rose-breasted Grosbeak  2
Indigo Bunting  2
Red-winged Blackbird  1
Common Grackle  2
Brown-headed Cowbird  2
Baltimore Oriole  3
House Finch  1
American Goldfinch  2

Thanks for reading, and enjoy the wilds of Middlesex!