Sunday, August 23, 2015

NWA 8/21/15

A Northwoods Almanac for August 21 to September 3, 2015  

Honeydew – And I’m Not Talking Melons or a Retiree’s To-Do List
I’ve received many phone calls in the last few weeks from folks perplexed and distressed by the sticky sap that has been covering their car windshields, decks, lawn chairs, etc., every morning for weeks. Many of the callers say they’ve lived here or visited for decades (one caller said 50 years!), and they had never experienced anything like this before. They’re able to wash the sap off with water if they’re under hardwood trees, but if the overhanging trees are conifers, then the issue gets stickier, as it were.
It turns out the cause of the sticky mists are tiny aphids and other species of scale insects that feed on sap in the tree leaves. The insects take in much more sap than they can hold, apparently requiring this extra volume of sap in order to get all the nutrients they need. They take out what they need and then excrete the excess, the fluid falling in a mist kindly referred to as “honeydew.”
In researching this, I learned that in some years, hikers are covered in a honeydew rain by the time they’re completed a hike, and find themselves being buzzed by yellowjackets. Yellowjackets collect honeydew from the scale insects infesting a tree and make forest honey out of it.
Further research found that some species of ants “farm” aphids. The ants eat the honeydew the aphids release, and then protect the aphids from predators. These “dairying” ants actually milk the aphids by stroking them with their antennae. This mutualistic relationship benefits both species, and is a great example of co-evolution.
A truly amazing variation in ant–aphid relationships involves Niphanda fusca butterflies and Myrmica ants. The butterflies lay their eggs on plants where the Myrmica ants tend the aphids. The eggs hatch as caterpillars, which then feed on the aphids. The ants, however, don’t defend the aphids from the caterpillars, because the caterpillars produce a pheromone that makes the ants think the caterpillar is actually one of them. So, the confused ants actually carry the caterpillars to their nests and feed them. The caterpillars, in turn, produce honeydew for the ants. When the caterpillars reach full size, they form cocoons and emerge after two weeks. The ants now attempt to attack the butterflies, but the butterflies exude a sticky substance on their wings that disable the ant’s jaws, enabling the butterflies to take flight. They return later to lay their eggs, and the cycle begins again.
Wow! This stuff is better than fiction.
Anyway, there’s nothing homeowners can do about the honeydew mist at this time of the year. The good news is that while the insects can stress the trees, they are not particularly harmful – just a nuisance to those walking, living, parking vehicles, etc. under them. Do a google search for “photos of scale insects on maple trees” to see some crazy-looking pictures of these insects.

            We have a paper wasp nest under our deck, which is causing some distress to us as well as to the hummingbirds, which are quite unhappy sharing their feeders with the sugar-seeking wasps. These fellows are yellowjackets, though which yellowjacket species I don’t know. Wisconsin boasts thirteen different yellowjacket species, all of which are slender and slightly shiny, and most of which have distinct yellow and black banding patterns on their bodies (a few species are black and white). They aren't covered with fuzzy hairs like bees, so they are actually wasps.
Yellowjackets are renowned for the beautiful architecture of their nests. From tree pulp, they scrape, they chew, they mix, and then they build masterful papery globes. They spread the mix in thin strips, forming stacks of combs. Depending on the yellowjacket species, the nest may hang from a branch, nestle inside a wall crevice, cling to the side of a house, or be concealed underground in a cavity (we have a second nest that was built inside one of our bird houses). The nest is occupied for only a few months each year, then abandoned.
To feed their sugar addiction, yellowjackets search out the honeydew produced by aphids and scale insects. Protein comes from predating on other critters like caterpillars, spiders, centipedes, flies and damselflies. Yellowjackets also scavenge from carrion, sharing a dinner table with eagles, coyotes, and crows. But humans are their favorite species to scavenge from. We offer them all sort of sweet entrees, from soda, to picnics, to beer, to compost and garbage. We offer the low-hanging fruit for yellowjackets.
That would not be a big issue if yellowjackets weren’t able to sting multiple times and live on, which is why these wasps apparently feel free to be aggressive. Since they aren't necessarily risking their lives to sting, yellowjackets will readily defend themselves from what they perceive as an attack (i.e. a mouth drinking from the soda can that they are trying to extract some sugar from).
Ah well. It’s important to remember that most wasps are beneficial, feeding on other insects like flies, beetles, caterpillars, and other garden pests. They also pollinate many plants. So, in the grand scheme of things, they’re good guys, just as long as you don’t inadvertently slurp one up while drinking soda.

White Pine Cones
            In numerous hikes this late summer, we’ve crushed a lot of white pine cones underfoot. You may recall that last autumn was a bountiful year for white pine cones, and since white pine cones take two years to mature, that largesse now resides, or is still falling, onto the forest floor.
No conifer tree bears a heavy cone crop every year. White pines bear good numbers every three to five years. Good red pine cone years often have an interval of five or more years. And while good crop years are one thing, and good germination yet another, avoiding the appetite of white-tailed deer is the big key – white pine is well-loved by deer.
            White spruces are also starting to drop numerous cones, indicating a good year for them. Unlike white pines, their cones mature and drop in the first autumn, so something obviously went right for white spruce this spring.

            Keep an eye skyward near dusk for migrating nighthawks, particularly over open fields and low over highways. I saw the first report of flocks migrating through the Northwoods on 8/16.
            Nighthawks are aerial acrobats, darting in flight more like butterflies than birds. To ID them, look for the sharp-angled wings and the white slash across their wings.

The Secret Lives of Bumblebees
“Science on Tap” resumes in Minocqua on Wednesday, September 2nd, 6:30 pm, at the Minocqua Brewing Company. Jeremy Hemberger, a UW Madison graduate student in entomology, will give a short presentation on his current research on bumblebees, their habitat, and lives.
Since seventy percent of the world’s crops benefit from insect pollination, and bees are the best at this endeavor, understanding what landscape helps them thrive is crucial. Come early and join the usually large crowd to learn how bees are followed using new technologies, including RFID (radio frequency identifier tags).

Can’t Identify A Sound?
Over the years I’ve had many folks call me to ask if I can identify a sound they heard during the previous night. I often had no idea what it was, so I wasn’t terribly helpful – there’s lots of mystery out there.
But now there’s some hope for that mysterious ID. If you’ve heard a sound in nature that you can’t identify, capture a recording and send it in to NPR’s new series, “Decoding Nature” at If your sound is selected, experts at the Cornell Lab of Ornithology will try identify it for the radio segment.

Can’t Identify a Feather?
I found a website that helps greatly in identifying feathers: “The Feather Atlas.” Go to

Hummingbirds Gaining Weight for Migration
            Keep those hummingbird feeders filled over the next few weeks – hummers are clearly getting ready to migrate. During migration, a hummingbird's heart beats up to 1,260 times a minute, and its wings flap up to 80 times a second. To fuel this high level of energy, a hummingbird will typically gain 25-40% of its body weight before it starts migration.
Hummers have to leave early because they depend on insects for protein, and most insects die in the first hard freeze. Their initial urge to migrate is triggered by the shortening length of sunlight and has less to do with temperature or the availability of food – hummingbirds actually migrate south at the time of greatest food abundance.
For first-year hummers, there's no memory of past migrations, only an urge to put on a lot of weight and fly in a particular direction for a certain amount of time. The adult hummers leave before the juveniles. Once a young hummer learns its route, however, it may retrace it every year for as long as it lives.

Celestial Events
            The full moon occurs on 8/29. Known by some as the “Woodcutter’s Moon,” it’s a reminder to get the wood cut and stacked, because the “W” word is not that far off.

"August is tomatoes ripening and the insistent note of the cicada punctuating the heat of midafternoon. August is the smell of corn pollen, and the taste of roasting ears, and the stain of blackberry juice on the fingers. August is a languid river and a springhouse brook reduced to a trickle. August is the first sprays of goldenrod in the uncut fencerow. August is fledglings all feathered and on the wing. August is the heavy grapes in the vineyard, and the lacy leaf where the Japanese beetle feasted in metallic glitter; it is the algae on the pond and the fat green thumbs of cattails in the swamp and vervain in full bloom. August is a hastening sun, earlier to bed and later to rise. August is Summer thinking of the cut and color of her Autumn costume."  From Hal Borland, Sundial of the Seasons

Saturday, August 8, 2015

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.