A Northwoods Almanac for June 9 – 23, 2017
Wood Turtle Study
With turtles now beginning to lay their eggs, it’s time to shine a light on turtle biology. Most people in the Northwoods are very familiar with snapping and painted turtles, but our area also supports one other turtle species, the state threatened wood turtle. On May 5, I was privileged to join a DNR team paddling the Manitowish River in search of wood turtles. A semi-terrestrial species, wood turtles spend nearly half of their time away from water, thus earning the name “wood” turtle. So, to find them, we spent most of our time searching shrubby stands of alders near the river’s edge.
In the Upper Midwest, little field work has been done on wood turtles, so Minnesota, Michigan, Iowa, and Wisconsin are sharing grant money from the U.S. Fish and Wildlife Service to track the turtles and to find ways to improve their conservation.
Headed by Carly Lapin, a conservation biologist for the DNR, the first phase of the study took place from 2013-15 with the intent to:
1. increase turtle nesting success by reducing the effects of natural predation at a minimum of 12 nesting areas
2. reduce mortality of adult turtles at a minimum of 10 road or bridge crossings by a variety of methods in a minimum of 5 river stretches
3. restore a minimum of 100 total acres of habitat that could be used for foraging by wood turtle at 3 project sites
But first they had to assess the life history of wood turtles, and so set about capturing and marking wood turtles on two stretches of the Squirrel and Tomahawk rivers in Oneida County (study area 1) and two stretches of the Totogatic and Namekagon rivers in Washburn and Burnett counties (study area 2). A survey crew consisting of 2 to 4 observers paddled canoes in search of the turtles within 30 feet of the water. Upon capturing a turtle, they took a series of measurements, and then marked each turtle with a passive integrated transponder (PIT) tag and with a spot of brown paint on the rear carapace for easy field identification during future encounters.
In 2014, they marked 37 wood turtles in study area 1, and 14 in study area 2. In 2015, they marked another 36 wood turtles in area 1 and another 12 in area 2.
The researchers also conducted telemetry studies on wood turtles each year by attaching ultra-high frequency radio transmitters about the size of a half roll of nickels to the right rear edge of the turtles’ carapaces. They monitored 22 and 30 adult wood turtles with radio-transmitters in 2014 and 2015, respectively. They also attached 10 GPS geolocating tags to mostly female turtles to collect GPS locations, and thus discover their nesting sites.
Additionally, they installed predator exclusion devices on 30 wood turtle nests and added cameras to document predator activity and nest hatching success.
Overall they documented 69 individual wood turtle nests during the two field seasons. Of these, 17% (6/36) of protected nests and 52% (17/33) of unprotected nests were depredated, all of which appeared to be caused by mammals.
Interestingly, no turtle eggs were found to have hatched in study area 1 in 2014. The researchers attribute this complete nesting season failure to an unusually cool and prolonged spring, followed by the relatively cool summer in 2014. This weather likely delayed nesting and provided insufficient ground heat to fully develop the turtle embryos.
From the geolocator data, the researcher found the average home range size for adult male wood turtles in Study Area 1 was 42 acres. The average home range for adult female wood turtles were 18 acres and 50 acres for Study Areas 1 and 2, respectively.
It’s a tough life being a turtle. During surveys, they also observed that 28% of adult male wood turtles were missing whole or partial limb or limbs likely due to encounters with mammalian predators. However, the injuries were completely healed and the turtles did not appear limited.
The study is now in Phase 2, conducting wood turtle surveys this year and next year on the Wisconsin, Manitowish, Wolf, and Pine/Menominee Rivers. We all can help. The DNR is collecting information on turtle mortality through citizens reporting locations and dates they see dead turtles on roads. If photos are provided, biologists can determine the species. Dead turtle reports can be sent to: http://wiatri.net/inventory/witurtles/. In previous years, roughly 400 reports of roadkill turtles were filed with the DNR.
Last weekend, Mary and I taught a three-day birding skills class for Nicolet College, and one of the highlights was having Bruce Bacon, a master bird bander, demonstrate bird banding for our group. After Bruce banded the birds and discussed their life histories, individuals in the class were able to hold and release the birds. Interestingly, when Bruce would place the birds on their backs into someone’s hands, the birds would often calmly lay there, seemingly unaware they were now free to fly away. Only when the birds were gently rolled over onto their feet, would they fly away.
|female black-throated green warbler|
|Jean Wiggins holding a red-eyed vireo|
Our group was able to identify 51 bird species over the course of the three days, a number which would have been much larger if we didn’t have consistent rain on one of the mornings. But on that rainy morning, we also had the opportunity to meet with Vanessa Haese-Lehman, an excellent birder who has volunteered for many years to help on a study of golden-winged warblers. What’s most exciting about this study is the use of tiny geolocators that can be placed on the warblers in order to track their habitat needs, their migration routes, and where they are wintering. The project started in 2016 by capturing 28 male golden-wings on their breeding territories and fitting them with geolocators, essentially a small back-pack with leg-loop harnesses. This year, they are attempting to recapture the golden-wings and recover their geolocators to download the logged migratory route data. Using this data and aerial imagery, they will then be able to describe the broad-scale habitat used by these birds and help identify forests of greatest conservation need for golden-wings.
Last weekend, Mary and I took a lichen class through the Natural Resources Foundation. The class met in the Johnson Lake Barrens State Natural Area on Jute Lake Rd. near High Lake, and was led by two excellent lichenologists. Why did we meet in such a remote location? In a study of lichens in northern Wisconsin in 2002, they had identified 130 lichen species just at this one location! Wisconsin is home to over 700 species of lichens, so it was great fun to get an insight into the life history of these amazing organisms and just to begin to notice how many there really are and where they are!
The most common lichen they described is called common greenshield lichen (Flavoparmelia caperata), and it covers many, many trees of all species in our area. They called it “40 mile/per/hour lichen” because it’s the only lichen large enough to be identified as you’re driving along at 40 mph!
There’s a misconception of many people that lichens kill trees. Lichens don’t harm a tree in any way, shape, or form – they merely utilize the tree as a surface on which to grow.
The instructors began the class by showing us an herbarium sample of old man’s beard (Usnea longissima) collected in northern Iron County in 1896, now an extinct lichen in Wisconsin. Why did it go extinct here, I asked? Because it’s associated with old-growth forests, and we cut nearly every one of those down. When Mary and I spent a couple weeks in an old-growth douglas fir forest in Oregon, these long, draping lichens were common.
Usnea is very sensitive to air pollution, especially sulfur dioxide. Under polluted conditions, they may grow no larger than a few millimetres, if they survive at all. Where the air is unpolluted, they can grow to 8 inches long. Usnea lichens can sometimes be used as a bioindicator, because they tend to only grow in those regions where the air is clean.
The Wisconsin State Herbarioum has just put out a new booklet called “Common Lichens of Wisconsin” – if you have any interest in lichens, I recommend getting it.
The UpNorth Hammerheads Birdathon team ended up counting 112 bird species on May 21. Kudos to Sarah Besadny for leading the effort!
|The "UpNorth Hammerheads"|
Peggy Richmond in Natural Lakes sent me a photo of a beautiful copper-colored wood frog. Wood frogs are done calling already. The males only call for about two weeks in late April and early May during which they mate, the females lay their eggs, and then they depart the water.
|wood frog photo by Peggy Richmond|
Dragonflies are hatching! Nancy Burns in Manitowish Waters was able to photograph a dragonfly as it climbed up onto a wooden bench next to the water and slowly emerged from its larval case. This metamorphosis is every bit as amazing to watch as the emergence of a monarch butterfly from its chrysalis. Spend some time along any shoreline in the Northwoods and look closely at emergent vegetation, or on any vertical object (pier posts, etc.), to see this remarkable event.
|photo by Nancy Burns|
The full moon (the “Strawberry/Rose/Honey Moon”) occurs tonight, June 9. The year’s earliest sunrises (5:08 a.m.) take place from June 10 to June 20. These sunrises are 3 hours and 32 minutes earlier than our latest sunrises at winter solstice.
June 16, 1963 marks the date of the first woman astronaut in space – Russian Valentina Tereshkova. Sally Ride was the first American woman in space, her journey occurring on June 18, 1983.
Summer solstice takes place on June 20, giving us the year’s northernmost sunrise and our longest day – 15 hours and 45 minutes. This also means our shortest night – just 8 hours and 15 minutes.
Look before dawn for Venus on 6/20 and 6/21 near the waning crescent moon.
Thought for the Week
Making a profit is no more the purpose of a corporation than getting enough to eat is the purpose of life. – Kenneth Mason, former President of Quaker Oats
Please share your outdoor sightings and thoughts: call 715-476-2828, e-mail at email@example.com, snail-mail at 4245N State Highway 47, Mercer, WI, or see my blog at www.manitowishriver.blogspot.com