NWA 8/7/15

A Northwoods Almanac for 8/7 – 20, 2015 

Sightings: Northern Mockingbird, Three-toed Woodpecker, Evening Grosbeaks

7/20 – David Foster sent me two photos of a juvenile evening grosbeak – one of them showing the fledgling being fed by an adult – taken by Kay Lynch from her deck in Natural Lakes. Kay reports seeing evening grosbeaks regularly at her feeders. David noted, “I think it's interesting that a breeding pair of a declining species is available for photo-ops!” They are indeed continuing to decline in number, so any local breeding activity is good news! We’re at the southernmost edge of the evening grosbeaks’ breeding range, so that has something to do with their status as an uncommon breeding bird in our area. But the species is also quite secretive during the breeding season, unlike its noisy presence at our winter feeders, and its courtship occurs without elaborate song or display. This secretiveness, together with a flimsy nest placed high in a tree, has made it difficult to observe and study. Kay’s observations are thus all the more interesting.

7/21 – A northern mockingbird appeared in our yard in Manitowish, sitting on a post right outside Callie’s office. This wouldn’t be a big deal if you lived in Illinois or Indiana, but northern mockingbirds typically nest only as far north as the Wisconsin/Illinois border. The Atlas of the Breeding Birds of Wisconsin reported only seven confirmed nests in Wisconsin during the five-year Atlas census, which took place from 1995 – 2000. So, we certainly feel blessed to have had one suddenly show up on our land and start eating Juneberries from trees we’ve planted.

Unfortunately, we never heard the mockingbird sing, because their repertoire contains more than 150 distinct song types! Actually both male and female mockingbirds sing, acquiring their songs through imitating the calls and songs of other birds, as well as imitating the vocalizations of non-bird species (frogs, dogs, cats, etc.), and occasionally even copying mechanical sounds like motors, gate squeaks, and tire squeals. One author describes their mimicry as “largely consisting of multiple plagerisms.” They’re known to sing without stopping for ten minutes straight, often repeating phrases in threes, though they may repeat the same phrase a dozen times before moving on to the next.

We watched the mockingbird walk along the ground and then jump into the air, raising its wings and flashing the very impressive white patches it has under its wings. The function of this behavior is unclear, but researchers speculate that the wing flashing may startle insects into flying up and being caught, or warn potential predators away (especially nest predators), or act as a component of territorial display.

7/23 – I gave a talk on birds at the Boulder Junction Library, and while speaking, a bird that looked at a glance like a ruffed grouse walked calmly by right outside the room. I watched it out the door as I spoke, and wrongly thought it was a grouse. Turns out it was a chukar, apparently released by a local hunter while training his dogs. Chukars are an upland game species in the pheasant family. They’re an introduced species from the Middle East and certainly don’t belong in the Northwoods, but this one apparently has become a common visitor in Boulder Junction.

7/24 – Jill Wilm on Van Vliet Lake sent me some great photos of a male American redstart, a common warbler in our area, looking utterly bedraggled after taking a dip in her birdbath.

7/26 – Dave and Kathy Vogt in Presque Isle observed a three-toed woodpecker land on their deck railing near their sunflower feeder. Dave noted, “It didn’t stay long and seemed uncomfortable on a horizontal surface. The last one we saw was in July 2003, on one of our hemlock trees.” Like our sighting of the northern mockingbird, Dave and Kathy’s sighting is a rare one. Three-toed woodpeckers breed farther north than any other woodpecker and are broadly distributed across boreal forests and north to the tree limit. No three-toed woodpeckers are known to nest in Wisconsin, so seeing one is a true rarity.

Migration Beginning But Some Birds Still Raising Young

It’s always hard for me to believe that it’s time for many songbirds to begin their southerly migration, but indeed it is. Even harder to believe, shorebirds have actually been migrating south for a month now.

Still, there are birds like cedar waxwings and American goldfinches that start nesting quite late, while grouse and wild turkeys can be found with young broods from second nesting attempts into August. Cedar waxwings in Wisconsin have been reported building nests from May 20 to August 22, with eggs still in nests as late as September 12. Similarly, goldfinch nests with eggs were found from June 8 to August 26 in Wisconsin, with the mid-date being July 25.

Whooping Crane Update

            It’s been a summer of ups and downs for efforts to establish a migratory population of breeding whooping cranes in Wisconsin. Things started off well for this endangered bird when 24 chicks hatched from 37 nests. However, only three of the new chicks have survived as of late July.

Still, whooping cranes continue to make slow progress at establishing a breeding population in the state. The current entire Eastern population is 92 birds (52 males, 40 fe- males), not including the newly hatched chicks.

Most nests are on the Necedah National Wildlife Refuge. There were 27 separate pairs, 10 of which renested. In previous years, nesting cranes have abandoned their eggs when swarmed by black flies. The loss of 21 of the 24 chicks, likely to predators, doesn’t bode well for developing a self-sustaining population, but if the three survive, that would tie the record number of fledglings from 2010.

Aging Hemlock Trees on Guido Rahr, Sr. Tenderfoot Preserve

            Matt Dallman, director of conservation in northern Wisconsin for The Nature Conservancy, sent me some data collected in 2014 from tree cores taken at the Guido Rahr, Sr. Tenderfoot Preserve, an old-growth hemlock-hardwoods site near Land O’Lakes. Among a host of interesting findings are the cores showing that size doesn’t always matter when it comes to age. One eastern hemlock was dated back to 1781 but was only 13 inches in diameter. Another hemlock dated to 1764 was just less than 13 inches in diameter. At over 28 inches in diameter, the largest hemlock on the two plots studied only dated back to 1877. Another hemlock in the same plot dated to 1880 was just 7 inches in diameter.

Hemlock less than two inches in diameter can be over 200 years old, while hemlocks less than a foot in diameter have been aged at 359 years.

So, while we like to think that size is the ultimate indicator of age, in fact it isn’t. Hemlock seedlings can wait in the shade for many decades without any apparent growth until the tree above them finally falls over, allowing enough sunlight to reach the ground and stimulate growth.

Three Currently Flowering Plants Without Chlorophyll

Indian pipe (Monotropa uniflora), American cancer-root or squawroot (Conopholis americana), and pinesap (Monotropa hypopithys) are all in flower right now.

Indian pipe and pinesap are saprophytes, meaning they derive their nutrients from dead organic matter in the soil.

American cancer-root, on the other hand, is parasitic mostly on the roots of red oaks and American beeches. We saw several of these odd plants over in the Cable area last week when we were leading a hike for their natural history museum. When blooming, they resemble a pine cone or a cob of corn.

Despite the common name of this plant, there is no scientific evidence that it has any cancer prevention or cancer causing properties. The name likely came from the parasitic growth form of the plant.

Fireweed in Full Glory

            Fireweed, a native flower common along our roadsides, is currently in full bloom. Don’t confuse it with purple loosestrife, a non-native invasive species, which is also now blooming, but in wetland areas. They’re easy to tell apart – fireweed has four petals, while purple loosestrife has five to seven.

Celestial Events

            Saturn is the only planet visible in the evening hours of August, thus is the brightest planet visible this month – look in the southwest at dusk. Later in August, just before dawn, look for Mars to appear very low in the northeast. Venus will return to the predawn sky near the end of August, also very low in the northeast.

            Our days are growing shorter now by nearly three minutes every day – enjoy the long evenings while they last!

Perseid Meteor Shower  

This year the peak Perseid Shower takes place late on the evening of August 12th and into the early morning hours of the 13th. Fortunately, this year the waning crescent moon will not interfere with viewing. The Perseids, usually the best meteor shower in the northern hemisphere, may generate between 50 to 100 meteors per hour in the predawn hours. Typically these are bright, fast meteors, which often leave trails.

Enjoy the comfort of a reclining lawn chair and look upward in a dark, open sky, far away from any artificial lights. Remember, your eyes can take as long as twenty minutes to adapt to the darkness. Give yourself at least an hour of observation time, because these meteors come in spurts and are interspersed with lulls (be patient). They fly across the sky in many different directions, but if you trace the paths of the Perseid meteors backward, you’ll find they come from a point in front of the constellation Perseus.

            Look also on the evenings of 8/11, 8/13, and 8/14 – there’ll be fewer, but still well worth watching.

In ancient Greek lore, Perseus was the son of the god Zeus and the mortal Danae. It is said that the Perseid shower commemorates the time when Zeus visited Danae, the mother of Perseus, in a shower of gold.