Sapsucker, sucking sap

I spent part of this morning - a sunny, beautiful morning! - down at Green Lawn Cemetery on the south side of Columbus. This, Ohio's second largest cemetery at 360 acres, is a place that is near and dear to me, and one in which I have invested a considerable chunk of my life. Some of my first out-of-neighborhood birding forays as a tot were to Green Lawn, and I've made scores of trips since. About two years ago, I finished up a 12-year run as a member of the cemetery's board of trustees. Birders in Columbus take this cemetery seriously, and strive to see its habitats and venerable ancient trees protected. Bernie Master was the first birder representative on the board, followed by me, and I've been replaced by the extremely capable Randy Rogers. The place is looking good, and this morning it was birdy as usual.

The Scots Pine, Pinus sylvestris, in the above photo (taken in 2011) is a magnificent specimen. The tree is old and gnarled, and resembles a giant bonsai. I always like checking the tree out when I visit; partly just to admire it, and partly for the high probability of seeing Yellow-bellied Sapsuckers.

The sapsuckers did not disappoint. These interesting woodpeckers have been drilling sap well fields in this tree for as long as I can remember. They don't nest here - sapsuckers are birds of the boreal forest, by and large - and the Green Lawn sapsuckers are migrants and occasional winter residents. This is the only woodpecker in our range that might be considered a Neotropical migrant, at least part of the population. While some birds winter as far north as southern Canada, and the species can be fairly common in parts of Ohio in winter, some birds migrate as far south as Panama. I have seen them in southern Costa Rica on several occasions.

Anyway, when I approached the Scots Pine, a pair of sapsuckers were squabbling over its juice. The gorgeous male in these photos eventually ran the female off, and established primacy over the tree's numerous well fields.

The sapsucker, living up to its name. Pine sap can be seen glistening within the rectangular wells, and the bird was avidly lapping up this nectar (they don't actually "suck" sap; they lap it up with their tongue).

Yellow-bellied Sapsuckers use scores of tree and shrub species to "frack" sap, but certain individual plants become favorite feeding stations for some reason or another. The sapsuckers that visit this pine each year in migratory periods or winter either reopen existing well fields, or drill new ones nearby. As the weather warms, insects will increasingly be drawn to the flowing sap, which serves the woodpeckers well. They'll grab those too, dip them in the sap, and enjoy entomological caramel apples.

Sapsucker nests and Fomes fungi

A beautiful northern Michigan forest, filled with aspen, cherry, and other trees, and underlain with a dense growth of bracken fern. The forests here are typically mixed, with conifers: white spruce, balsam fir, white cedar, jack, red, and white pines, and depending upon the moisture regime, black spruce and tamarack.

It's a yellow-bellied sapsucker, Sphyrapicus varius, paradise, and this is probably the most common breeding woodpecker in Presque Isle County. Northern flickers certainly give the sapsuckers a run for the money in the abundance department, and downy, hairy, pileated, red-bellied, and red-headed woodpeckers can all be easily found as well.

An old paper birch log litters the forest floor. Note the prominent well fields drilled by sapsuckers long ago. There is ample evidence of sapsucker activity in these woodlands, especially in the form of the perfectly arranged rows of cavities created by feeding operations.

Sapsuckers drill and maintain extensive well fields in a variety of trees. Sap flows from the wells, giving the birds a ready source of sugary food. An entire food web is spawned by the sapsucker well fields. A great many insects come to feed at these excavations, and other vertebrates come in to feed on those insects, if not the sap itself.

The wells in this photo are drilled into the phloem tissues of the birch; round sapsucker holes tap the xylem layer. The rewards of such drilling and well field maintenance are great: paper birch, for instance, can have summer sap in the phloem of up to 16% sugar concentrate.

A female yellow-bellied sapsucker warily eyes your narrator. Those of us who live south of the sapsuckers' breeding range usually think of this as a rather shy and retiring species. And they are, usually, at least in winter and migration when compared to the other woodpecker species. But sapsuckers become much more extroverted on the breeding grounds, especially the males. The birds frequently give their highly distinctive drums: a short series of hammer blows that slows in speed, and sounds as if someone is tapping out a telegraph. The birds also frequently give soft mews, and even a loud raptorlike call.

This spring, while leading my annual NettieBay Lodge birding and nature forays, I found several active sapsucker nests. The entrance hole is a very neat affair. Nearly perfectly round in the center, the entrance is carefully sculpted with flanged openings on the top and bottom.

This year, we were fortunate indeed to have David Govatski on one of the trips. Dave is a forester from New Hampshire, and a wealth of natural history information. He taught me something about sapsucker nesting that I did not know. Sapsuckers often select aspen trees for nest sites, such as this quaking aspen, Populus tremuloides. That I knew, and always figured the birds chose aspen because it is a soft wood. Yes, but there's more to the story.

Note the fungus projecting from the tree below and slightly right of the cavity. That's the heartwood decay fungus, Fomes igniarius var. populinus. Sapsuckers are especially fond of aspen that have been colonized by this native fungus.

A stunning male yellow-bellied sapsucker nervously watches us inspect his nest cavity. We did not tarry. Note the animal's bright red throat, a feature that distinguishes it from the female.

This is the best shot I could manage of the interior of the sapsucker nest cavity. We can see the darker softer punky wood within - the effects of the Fomes fungus. Clever birds that they are, the sapsuckers know that it's easier excavating a deep nest hole in an aspen infected with this fungus, and seek out such trees.

Managers of "sugar bushes" - sugar maple groves managed for syrup production - also know about the sapsucker/Fomes fungus connection. They will often remove fungal-infected aspens from the sugar bush, in an attempt to keep the sapsuckers from inhabiting the area and drilling well fields into their sugar maples.

Learn something new every day.