Sunday, December 29, 2013

A Persimmon in Every Pot - the Woodpeckers

Female hairy woodpecker showing a black back with a white blaze down the middle and white checkering on her black wing feathers.
The sapsuckers were the flashiest woodpeckers at the persimmon tree this fall. But there were several other woodpeckers that made appearances on the ripe glowing fruit and they challenged me to finally learn the difference between the hairy and downy woodpeckers. Well, at least the hairy part.

Male red-shafted woodpecker showing red malar stripe.
The red-shafted flickers visit the persimmon tree in the Dipper backyard at sunrise and stay just a few minutes. From the bedroom window, I spot their heavy bodies swinging on the dangling fruit but I never get up fast enough to photograph them there. Flickers are mostly insect-eating and primarily forage on the ground, so perhaps their quick stop is to add a sweet snack after the daily morning drink at the cattle trough.

Female red-shafted flicker foraging on the ground at a woodrat nest.
The flickers are year-round residents and easily recognized by their copper-tan color with black barring and the bold black brand on their chest. We mostly have the red-shafted race here, and those have a orange color to the shaft of their flight feathers. The males of the western states have a showy red malar stripe (=mustache). Occasionally, hybrids of the red-shafted and yellow-shafted flickers show up in the Santa Cruz Mountains. The yellow-shafted race of the flickers have a different shade to their flight feathers and the males have a black malar stripe.

Male red-shafted flicker catching the sunset at the top of a Douglas fir and showing the underside of its tail feathers with distinct orange color and black tip.
Red-shafted flicker feather on the forest floor.  
The acorn woodpeckers are also year-round residents and, unusual for woodpeckers, they are a colonial species. Every morning their clan flies in to drink at the cattle trough just after the noisy gang of stellar jays departs. In the fall, they stop for sun and socializing in the persimmon tree, but I don't see them foraging very much there. Mostly they seem to curiously check out the migrant woodpeckers and then go about their business elsewhere. Since persimmon season is the same time that acorns are dropping from the oak trees, the acorn woodpeckers are probably busy stashing their acorn granary which must be nearby but I haven't it found yet. Acorn woodpeckers are so unusual, they deserve a lot more attention than I will provide in this post. Just note that they have the woodpecker red head with white and even yellow on their head and a solid black back rather than a checkered back.

The wildlife camera catches an acorn woodpecker inspecting the trunk of the persimmon tree.
The smaller checkered woodpeckers do enjoy the ripe persimmons, at least when the bully red-breasted sapsucker gives them a chance. The persimmon fruit become ripe in the few weeks between Thanksgiving and Christmas. As the birds are spearing persimmons or lapping up orange goo, I squeeze the ripest persimmons into oatmeal or yogurt for breakfast, chop the medium ripe ones into salads for lunch, and eat the crunchy ones by the handful for snacks. It's a wonder my skin doesn't turn orange.

Sliced persimmons waiting to be dehydrated around the winter holidays.
Some people like to bake persimmons into breads but I think that is just a waste of their pure deliciousness so I dehydrate those I can't eat fast enough. Sliced persimmons have a beautiful star pattern like tangerine snowflakes and their sweet taste intensifies as they dry. Bags of dehydrated persimmon stars make good holiday gifts and I love watching people's faces when they first taste the old fashioned candy-like disks after they just said "I don't really like persimmons."

Male hairy woodpecker caught by wildlife camera in the persimmon tree.
Both the hairy and downy woodpeckers have black and white partially checkered wings, a white blaze on a black back, and the males have red hindcrowns. Everyone keeps telling me that the hairy woodpeckers are much bigger, but all the checkered woodpeckers look small to me and at the Dipper Ranch they're usually hyper-nervous and constantly on the move so it is hard to get a sense of size.

Female hairy woodpecker showing her stout bill.
The Woodchuk taught me to wait until the woody settles on a tree and then compare the bill to the front-to-back width of the head.  The hairy woodpecker has a stout spear of a bill which is almost as long as the width of the head. The bill is much smaller on the downy woodpecker. "Pitiful bill for a woodpecker," says the Woodchuk.

Hairy woodpeckers have large black comma-like marks on their white shoulder. Downy woodpeckers might also have black marks at that location but they are a smaller and broken. I'm waiting to see a calm downy woodpecker to confirm that description myself. I did see a small woodpecker today that the Woodchuk firmly declared "downy" with barely a glance, but it moved too fast for me. "It's a dink," he said, "It's a downy."

Some field guides emphasize that downy woodpeckers have black bars across the outer white tail feathers whereas hairy woodpeckers don't, but ignore that advice here in the western states. Hairy woodpeckers in the Pacific might have black marks on their white outer tail feathers, and females of both don't, so that advice doesn't help us westerners much.

Female hairy woodpecker with plain white breast.
The sapsuckers are nearly silent while feasting on persimmons, but the hairy woodpeckers are constantly 'peek'-ing when they fly around the Dipper yard, so if I can untangle my feet fast enough, grab the binoculars, and get positioned well, I hope to have more practice identifying hairy woodpeckers and nailing the size difference between them and the downy woodpeckers.

Unlike the red-breasted, red-naped and yellow-bellied sapsuckers in their superspecies category, hairy and downy woodpeckers are not closely related, they've just separately evolved to look and behave in similar ways, so they don't hybridize as do the aforementioned sapsuckers. Why would these two birds look so much alike? Could it be convergent evolution or something else? A biologist and an economist at Yale University recently used game theory to propose that in the Hairy-Downy Game, "a subordinate species [the smaller downy woodpecker] evolves to mimic a dominant species [the larger hairy woodpecker], to deceive the dominant species into misidentifying the mimic as an individual of its own species, and thus to overestimate the mimic’s size and the costs of combat." With game theory on my side, I have absolutely no qualms about my struggles to distinguish hairy from downy woodpeckers.

Female hairy woodpecker sitting on a persimmon which is about fist sized.  She would fill a beer mug.*
Male downy woodpecker next to fist-size persimmons.  He would fill a coffee cup.*
Paul and Lola Ortega used to live here. Paul was adopted into the Silva family and became their caretaker on this ranch. As orchardists of the former Valley of Hearts Delight (now called Silicon Valley), the Silvas planted walnut and fruit trees in the Dipper farmyard, and the wildlife and I now harvest that bounty. The persimmon tree is so tall, I leave all the fruit on the top third of the tree - above safe ladder height - to the animals, and they delight me with their visits.

Perhaps all this birdwatching went to my head because I flipped the bird-persimmon paradigm around for Thanksgiving. I stuffed a turkey with persimmons and tomatillos and then grilled it outside in the crisp fall air. The turkey had a smoked citrus flavor, and when I added the persimmony stuffing to the crockpot with the carcass, it made a tart caramel broth for my winter soups. Yes, those woodpeckers-sapsuckers are onto something.

Guess what other animal "flies"into the Dipper Ranch tree for a feast of persimmons? Here's your clue until I get around to writing about them next:  a fantastic fossorial fellow according to Roald Dahl.

Red-shafted northern flicker, Colaptes auratus cafer
Acorn woodpeckers, Melanerpes formicivorus
Hairy woodpecker, Picoides villosus
Downy woodpecker, Picoides pubescens

Identification of downy versus hairy woodpeckers for the Great Backyard Bird Count

Identification of Woodpeckers with Red Heads for the Great Backyard Bird Count

The Hairy/Downy Game: A Model of Interspecific Social Dominance Mimicry, Richard Prum and Larry Samuelson, Yale University, Journal of Theoretical Biology, Volume 313, November 21, 2012, pages 42-60.

*The description of hairy woodpeckers filling a beer mug and downy woodpeckers filling a coffee cup  is from Pete Dunne's Essential Field Guide Companion: a Comprehensive Resource for Identifying North American Birds, Pete Dunne, Houghton Mifflin Harcourt, 2013.

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