Ripples 10/3/19

By Jessica Johnsrud, Woodland Dunes’ Education Coordinator

photo of fall leaf tree topsOne of the greatest pleasures of my job is sharing nature with young children. For many of the kids attending field trips at Woodland Dunes, this is their first experience spending time in the forest or in a wetland. I’ve made it a habit at the beginning of programs, to ask the kids if they’ve walked in the forest before, and many shake their heads no.

I consider it a bit of an honor to show a child the wonders of nature. For many of the fall programs, we use Willow Trail and part of Goldenrod Loop as our outdoor classroom. When we walk down the trail, I ask the kids to notice nature using their “nature eyes.” I emphasize that while we are noticing nature, we want to make sure we use quieter voices and we don’t pick, squish (except mosquitoes) or throw anything. Since many of the kids haven’t spent time in nature, they aren’t sure how to behave. It takes a little time to walk down the trail to get to the areas where we do activities. I relish this time, listening to the kids’ chatter about their observations. 

This fall, I’ve been keeping a list of some of the things they say. Young children are photo of trail from Goodwin Rd, Two Riversnaturally curious and are fascinated by simple things that we, as adults, take for granted. Here are a few of the highlights from the last couple of weeks. All of these comments are from children ages 3-7 years old. “I didn’t know Woodland Dunes was going to be this beautiful!” “This is the best day ever!” When asked why trees are our friends, a young child answered, “because they make the world beautiful.”

As we walked down the trail, I heard squeals of delight. “Look! Look! The leaves are falling!” I turned around and the children were watching the breeze carry leaves away from the surrounding trees. The leaves gently twirled down to the ground and some even landed near our group, which caused more squeals of delight.
I was reviewing the parts of a tree with first graders and there was an old tree stump next to us. Suddenly one of the kids exclaimed, “Wow! A slug! I’ve never seen a slug before!” Then all the kids proceeded to encircle the wood and quietly watched the slug, mystified as it left behind a trail of slime.

It truly is a joy to hear their comments and witness how they engage with nature. It also reminds me to try to see the natural world through their eyes and with a renewed appreciation for the simple things.

Photos – Jessica Johnsrud. Autumn trees and the Goodwin Road trails at Woodland Dunes

Ripples 9/26/19

photo of bottle gentian and goldenrodAs I write this the world is preparing for another Packers game.  As I look outside around our headquarters it seems that the football team chose very appropriate colors for their season.

Right now, goldenrods are in their glory, or a little past. Their green foliage and yellow blooms are very attractive to a number of insects. There are a dozen or so species of goldenrods, three of which we find commonly at Woodland Dunes (Canada, lance-leaved, and giant) plus stiff goldenrod, which we plant specifically for the benefit of pollinating insects. Canada goldenrod is a species well-known to gardeners, because even though it’s a native plant which doesn’t cause hay fever (ragweeds cause that), it’s very aggressive and invades gardens. As much as I appreciate native plants, I have pulled my share of Canada goldenrod lest it take over flower beds. Interestingly, goldenrods seem to use chemical warfare to discourage competition, exuding plant-toxic substances from their roots. Many insects feed on the flowers of goldenrods, particularly native bees and beetles. Stiff goldenrod seems to be attractive to monarch butterflies along the Lakeshore. Not surprisingly, in other parts of the world our native goldenrods have become invasive species. In addition to goldenrods, there are a number of coneflowers and sunflowers all dressed in green and gold, blooming now.

At the same time there are a number of wildflowers which reflect the colors of the team from Minnesota and are beautiful despite that resemblance. Fall is the only time you’ll find both bottle gentians and fringed gentians on the preserve, along with New England asters. These flowers range from pale to deep purple. The gentians tend to grow in wet areas with rather poor soils. The fringed gentians looking like miniature purple tulips with ragged edges. The bottle gentians are rather unique- the flowers are closed tight which excludes smaller insects but can be pried open by bumble bees. Last week a group of pre-school children visiting for a field trip witnessed just such an event and were able to watch a bumble bee enter and leave a bottle gentian flower. They experienced something most adults never see.

While New England asters don’t reflect the team colors of the Patriots, their contrasting purple sepals and yellow center are particularly lovely and attractive to the surviving late season bees and butterflies. There are many other species of asters, including those that are blue like the sky-blue and smooth asters, and white such as the panicled, calico, and heath asters. In forests, we see the large-leaved aster.  They add to the variety of fall wildflowers. They help make fall our perhaps most colorful season, even before the leaves begin to change.

photo- bottle gentian and goldenrod at Woodland Dunes, taken by Nancy Nabak

Ripples 9/19/19

Birds were feeding quietly at the feeder this morning- house finches, gold finches, cardinals, and a brown thrasher that has been coming in for snacks for the last couple of weeks.  Suddenly they startled and disappeared into the shrubs surrounding the feeding station.  A few seconds later, a large female Cooper’s hawk came through like a missle.  Her efforts were wasted, though, and she came up empty-handed, or perhaps empty-taloned, and lighted on the branch of a large tree to plan for the next attempt.

Red-shouldered hawk in flight photo

Red-shouldered hawk

A few days ago while out on the West Twin we saw a large bird on one of the osprey nest platforms.  I didn’t look closely at it, just assuming it was the osprey that nested there and that it hadn’t migrated yet.  Instead, the bird dove off the platform and began chasing nearby gulls, and I noticed the typical pointed wings and sleek torso of a peregrine falcon.

Along with millions of songbirds migrating south this fall come millions of hawks, and its not uncommon to see new birds daily.  Their methods and patterns of migration is quite different than their smaller cousins, however.  While many songbirds migrate at night when the air is calmer, hawks migrate primarily by day.  Many depend on wind patterns to aid them on their journey.  Some, like peregrine falcons, actually seem to migrate when the wind is from the southwest.  These birds do not soar like some hawks, and the wind in their face helps give them lift as they power southward.  Many, however, depend on thermal air currents to lift them high into the sky after which they point in the desired direction and glide for miles until they need to find another thermal.  Many other birds do the same, like sandhill cranes and pelicans, and it is a very efficient way to cover long distances.  Conditions are right for thermals to form when its a sunny day, and it’s best when the wind is from the north to further aid their gliding journeys.  Often they orient themselves to fly parallel to north-south ridges or in our area the shore of Lake Michigan, where winds are lifted by bluffs and other features.  Woodland Dunes is a good location to view migrating hawks on suitable days and often high in the sky.  

Other notable places for hawk migration include Hawk Ridge Bird Observatory in Duluth MN, which hosts a celebration of hawk migration this time each fall.  Hawk Ridge, at the tip of Lake Superior, is a place where hundreds of thousands of birds are counted, and some banded for research.  They have a team of hawk counters, and naturalists who point out the different species as they fly by.  The ridge is so high that sometimes one looks down on the birds as they pass by.  The Cedar Grove Ornithological Research Station just south of Sheboygan is another hawk banding site which captures and releases many birds each fall for research.  They are not open to the public due to their small staff and large workload, but they contribute much to the understanding of raptor migration in Wisconsin.  Woodland Dunes does not band hawks at this time, rather our focus is to manage our preserve to be an excellent migratory stopover area for both hawks and songbirds.

We are already at the peak of songbird migration this fall.  Hawks are moving too on good days.  Looking at Hawk Ridge’s observations- a lot of bald eagles have already been heading south along with peregrine falcons, and lately, sharp-shinned hawks.  When the broad-winged hawks of the northern forests begin to move on their non-stop migration to Central America, counters will record hundreds of thousands of birds.

The seasonal movement of birds is a complex and wonderful highlight of the natural year, and like so many natural events often goes unnoticed now.  On a sunny day with a north wind between about 10am and 3pm, look up, and you may be rewarded with an amazing spectacle unfolding right before your eyes. 

photo- a red-shouldered hawk soaring over Woodland Dunes

Ripples 9/12/19

photo of common duckweed

Common Duckweed

The other day I was driving over a bridge in Two Rivers and was surprised to see the surface of the lower West Twin covered with a light green haze of algae.  I was also told that the East Twin and Manitowoc Rivers are also experiencing similar blooms in their lower sections.  For some reason, this is a very good year for growing duckweed.

Duckweed is an interesting little plant- the smallest flowering plant there is.  The entire plant consists of a handful of tiny leaves which float on the surface of slow-moving or stagnant waterways, ditches, and ponds, with equally tiny roots that hang down. There are several species of plants in the duckweed family around here ranging from giant duckweed (which is still only ¼ inch across), lesser, little, and least duckweeds, and the even tinier water meal, which just looks like very small grains of green dust floating in the water.  And yes, ducks do eat duckweed, although I think it grows as fast as it is eaten.

Duckweed produces very tiny flowers which are mostly unnoticed. More importantly, it reproduces by budding and fragmentation, producing tiny leaves which become new plants. In that way it can quickly colonize new areas. 

So why is there so much this year? That’s a very good question. For one thing, duckweed grows abundantly where there are lots of nutrients in the water and we humans are really good at fertilizing our waterways. Nutrients include leaves and dirt that wash in with stormwater, lawn fertilizer, and any soil that is allowed to erode and flow into the rivers. Phosphorus is often a nutrient which limits growth of aquatic plants, and phosphorus accompanies soil that is washed into waterways. Tons of soil wash into the East and West Twins and the Manitowoc River thanks to human activity, and there are plenty of nutrients for duckweed to utilize. We are on pace for record precipitation this year, so there are lots of opportunities for nutrients to enter our river systems.

Duckweed also thrives in stagnant or low-flow conditions and I wonder if the high lake levels, which affect the levels of water and flow in the lower parts of the rivers, have reduced the relative water movement from the rivers to the Lake at the surface.  There just isn’t a lot of vertical drop between the rivers and the Lake. For whatever reason, something about the flow of water in the lower parts of the rivers also seems to favor the duckweed.

Duckweed is a valuable part of the ecosystem, and they are native plants. Like so many aspects of life, too much is not necessarily a good thing. Although animals eat duckweed, it can become so abundant that it coats boats and makes water look less than inviting. It can also shade the lower part of the water column so that algae can’t grow below it, and when they die they consume oxygen in the process of decay, sometimes to the point of causing problems for animals.

 A type of algae – the blue-green variety, is also found in some waterways and lakes and builds up an unappetizing scum on the surface. Blue-green algae scum can be somewhat multicolored and in it you can’t distinguish the flat, floating leaves or buds of duckweed.  Blue-green algae can also be toxic to pets or cause skin rashes on people who come in contact, and you certainly don’t want to drink the stuff.

Soon, cooler temperatures will cause duckweed and other algae to die off, and generally in fall the water becomes clearer.  In the meantime, we should think about how we can keep excess nutrients out of our rivers and lakes so that they look and support life better.    

photo- from Wikimedia By Mokkie – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31954009

Ripples 9/5/19

photo of Kirtland's warbler

Kirtland’s warbler


As the season advances toward fall, our weather is more comfortable, even though we still experience the occasional rainy day.  For many of us, it is our favorite time of year, and that opinion is largely based on the weather.  And if the weather doesn’t remind us of the change of season, the birds do.  Have you seen the thousands of nighthawks that have been migrating along the Lake these last several evenings?  Many of these are streaming southward from their nesting areas in Canada- unfortunately they don’t nest on rooftops here anymore.  Like us, they rely on the beautiful fall evenings for opportunities to migrate. 
 
The same can’t be said for folks who are at the mercy of tropical weather systems, like hurricanes.  I have never experienced one personally, but I know people who have, and its an understandably terrifying experience.  These storms are generated by warm ocean water, and the warmest water is found during this time of year- late summer and fall.  The warming of the sun is cumulative, so its understandable that the warmest water occurs now.  Unfortunately, this time of year is when birds are migrating from the north, and some of them no doubt encounter habitats that are ravaged by these enormous storms.
 
Hurricanes affect wildlife in a number of ways.  Some birds may be “blown off course”- usually those are local birds such as waterfowl and seabirds which try to stay in the eye of a storm, where winds are lighter, and may end up traveling with the storm to new places.  For example, a brown pelican was found along the coast in Canada a few years ago, presumably dislocated by a storm.  Small birds have to “hunker down”- fortunately their feet are made to lock down on small branches and they do their best to ride storms out.  Woodpeckers and other cavity nesters take to their nesting holes in tree trunks. However, the effects of high winds and heavy rain, or inundation by either fresh or salt water can ruin many plants and kill trees, drastically reducing the quality of habitat for birds and other animals.  Storm surges and flooding can wash ground dwelling birds out to sea, and can be hard on waterfowl and turkeys.  The effects will pass over time, and plants will regrow.
 
The fact that hurricane Dorian happened to impact the Bahamas may have an effect on wildlife in Wisconsin, believe it or not.  In the last few years, a very rare and endangered bird, the Kirtland’s warbler, has been found nesting in the State.  The only other place it had previously nested was in Michigan, but some birds found a few stands of jack pine at several places in Wisconsin, and in Canada, and nested.  Having multiple nest sites increases the likelihood that a bird species will survive, so finding the Wisconsin birds was a big deal.  The jack pine habitats were carefully managed, and the birds were studied thoroughly- many were captured and banded so their movements could be tracked.  The same is being done for the birds in Michigan.   At their lowest, there were less than 200 birds seen in 1974.  In 2011, more than 1,800 birds were found, and 2,300 in 2018, and they are considered to be on their way to recovery.  Because there are so few, the locations of nesting places are kept secret to avoid disturbance to the birds. 
 
It was known that Kirtland’s warblers migrate from the Great Lakes states to the south-east U.S.  A few years ago a banded bird was found during winter in the Bahamas, and we finally had a complete picture of their annual life histories.  These tiny birds, weighing just a few grams, launch themselves out and over the ocean to winter on a particular island in the Bahamas.  An island which has almost certainly been significantly damaged by Dorian.
 
How will this event affect the birds’ winter survival?  When they arrive in a few weeks, they will likely find a very different habitat than normal- one in which leaves have been torn from the trees and perhaps has been flooded for weeks.  They are insect-eating birds, and I wonder what the storm has done to local insect populations.  We have, however, seen that these birds, like other living things, work hard to survive.  As biologists have learned to manage their summer habitat up here, their numbers have increased in kind.  I hope that as their winter habitat recovers, that it will still provide what they need for the next few months and that they are able to return to nest again.  Kirtland’s nest on the ground and so are used to being there, and perhaps enough plantlife and the insects that use it exists so as to give the birds a source of food and cover.
 
People didn’t cause this problem for the birds, although warmer than normal ocean water may have made things worse.  And in light of the human suffering that resulted from this recent storm, the problems of small birds may seem unimportant.  We can, and already have, learned from the challenges faced by wildlife like the Kirtland’s warbler, and it gives us a better understanding of how our fellow creatures cope with incredible problems, and perhaps what we can do to help even from thousands of miles away.
 

  photo- Kirtland’s warbler by Joel Trick of the US Fish and Wildlife Service