Nature Blog

Ripples 6/21/18

Ripples from the Dunes, written by Jay MacKenzie, Woodland Dunes summer intern

During one of my first days as an intern at Woodland Dunes Nature Center, I was out at the Manitowoc Lakefront Birding Area helping staff members water and mulch some native trees and shrubs that they had previously planted.  As the name suggests, there were a variety of birds active in the area, from flocks of nesting gulls to purple martens.  I have almost no experience as a birder, so I was relying on the staff members to point out the calls and defining characteristics of the species we saw.  

photo of a killdeer in distraction display

Killdeer in distraction display

At one point, we saw a medium-sized, tawny brown-and-white bird with long legs hopping along the ground.  Jim, Woodland Dunes’ Executive Director, identified it as a killdeer – a species that I had not heard of previously.  We began to walk toward the bird to get a better look.  As we approached, the killdeer raised its wings.  I thought it was about to fly away, but instead, it began to walk around while emitting a loud, shrill call.  Jim explained that this killdeer was actually performing a distraction display – a behavior intended to distract a potential predator from its nest.  Killdeer lay their eggs on the ground and we were probably walking directly toward this bird’s nest.  It perceived us as predators, and was attempting to lead us away from its clutch.  

Abnormally positioned wings and distress calls mimic a wing injury, and thus signal an easy meal for a would-be egg thief.  Once the predator notices this and begins to pursue its dinner, the bird leads it away from its nest before suddenly “healing” and flying away.  We retreated from the killdeer, not wanting to disturb its nest.  However, I was impressed by this clever nest defense strategy and wanted to learn more.

Distraction displays are not limited to killdeer, or even to nesting birds.  Even though they are most common in birds, they have been observed in fish and mammal species as well.  Displays can take a variety of forms.  Plovers, a family of wading birds of which the killdeer is a member, are known for their use of “false brooding” displays in which the plover crouches and broods on a non-existent nest, drawing predators away from the location of the real nest.  Plovers, along with other types of birds, can also distract predators by ruffling their feathers, crouching and running away from their nest to mimic the flight response of a small rodent.  Killdeer are the most well-known practitioners of the “broken wing” display.

It’s obvious that the ability to lure predators away from vulnerable eggs or juveniles gives an adaptive advantage in the form of reduced infant mortality.  However, it is much less obvious how such apparently sophisticated behaviors could have evolved in animals that are not generally known for their cleverness.  One theory is that they arose as a instinctual fear response to the presence of a predator.  In species experiencing heavy predation pressure, a fear response that happened to distract predators would reduce predation and cause that specific response to undergo positive selection.  

Another theory is that distraction displays are the result of a nesting bird’s conflicting instinctual impulses to at once attack the predator, protect its young and escape the threat.  Through a process known as displacement, an animal experiencing such conflicting stressors may initiate an irregular “intermediate” behavior in response.  If this displacement behavior happened to distract predators, it would undergo positive selection.  Whatever the origin of distraction displays, they are fascinating examples of animal’s abilities to adopt ingenious and unexpected solutions to the problems they face.

photo of a killdeer doing a distraction display, taken by Nancy Nabak

Ripples 6/14/18

So often the things right under our nose don’t get the attention they deserve until they are seen in a different way.  This realization happens every year at this time when we travel all parts of our preserve to conduct summer bird surveys.  These surveys have been done for more than 40 years each June after the spring migration has ceased, usually starting June 10. 

Initially, 11 routes were walked, on and off-trail, and every bird seen or heard was counted.  Due to restraints on our time, and in an effort to make the data more useful, we have established 28 points throughout the main preserve in easily locatable places. These are visited for 10 minute periods.  Most birds are heard but not seen, thanks to the thick foliage on trees and shrubs. One of the wonderful things about birds is that their songs are often loud and distinct, so they can be detected under such conditions.

photo of Canada warbler

Canada warbler

There are two times of day when the world seems truly magical- dawn and dusk- and being outdoors at those times allows us to experience a different world.

The preserve in early morning is hazy and often still, with lush green leaves all around and wildflowers below.  It is anything but quiet- after a night’s rest birds are ready to advertise the location of their territories and their fitness as both a defender of that space and as a mate. 

That they all sing simultaneously makes doing surveys challenging sometimes.  While birds probably don’t care that much about the songs of other species, we frantically try to record each of them.  Some songs are much louder than others. For some, great volume is apparently not required to get one’s point across to others of its kind.  All the calls are noted during the 10 minute count period.  Thanks to technology, the species can be recorded using an app on a cellphone and the data immediately archived. 

And so we travel through this mysterious world noting the music produced by those who live here.  On our first day this year, counting five points, we encountered 29 species, including such lovely and seldom noticed bird as the veery, blue-gray gnatcatcher, mourning and Canada warblers, and the Red-shouldered hawk. The last two species are considered of greatest conservation need. 

To be surrounded by such unusual wildlife in such a wonderful setting is better than any nature documentary. To immerse yourself in this world is good for you in probably more ways than we realize.  And then there are the other wildlife encounters – a mother possum covered with her clinging young, a curious doe, the occasional fox (red or gray), which glides silently through the forest and into our morning experience.

These surveys take some effort and forebearance- getting up early is not easy, and mosquitoes can be hungry, but being there is worth it.  Typically, 100 or so species of birds is recorded in the Woodland Dunes preserve, a reflection of the special place that it is.  The species list has changed over the years and that bears watching.

There are 23 points yet to be counted for this year, so a few more early mornings are in order.  Coffee works great to get the morning started, and the wonders of the preserve will keep us going as we document the amazing wildlife of our Lakeshore. 

photo: wikipedia

Ripples 6/7/18

I took a walk on the wild side the other day. If you can call it that. It was more of a walk on the gentle side – in the wild.

I made an early morning hike up Willow Trail at the Dunes to assess the conditions for our visitors. Sometimes Willow Trail can be really fun for those who want to muck around in rubber boots. While I was evaluating the trail, I noticed how many birds were singing their little syrinx out. (Bird Nerd Alert: The voice-box of a bird is called the syrinx, compared to the larynx in mammals.)

photo of Veery on limb

Veery

The variety of songs was so terrific that I recorded a minute and a half of bird music on my phone. In this short amount of time and space and out of all the hundreds of possibilities, I captured one of the pure, understated, yet dynamic thrills of the bird world, the Veery.

The Veery has a very unique and easily distinguishable song, a descending metallic, “veer,” that’s sometimes repeated and spirals downward as it sings. Actually, a group of nineteenth-century observers called its song, “an inexpressibly delicate metallic utterance…accompanied by a fine trill which renders it truly seductive.”

“Seductive.” What a powerful and important word for birds. Especially for males who are looking for a partner in the spring. For them, it’s showtime.

In reality, I actually captured two Veeries calling. However, this was not their seductive song, but rather a single, descending note. One called and then there was about a six second pause before another was heard from the north. The metallic calls continued, but at a four second space between the two, and eventually only 1 second between the first and second call. Finally, they were calling right on top of each other.

My assumption is that these were both males in some form of communication. (Another bird nerd fact: we are continually learning more and more about female call backs than we’ve ever known before.) Researchers believe this behavior may be a territorial claim. Or some statement of excitability – the calls quickening and bumping into each other. Until we can clearly speak bird language, no one is exactly sure what it means, but territorial issues are likely part of the purpose.

Although the Veeries had captivated me with their interesting behavior, they weren’t the only game in town. I realized that I had stumbled upon a Block Party already in progress. Other than the Veery, those in attendance were: Common yellow throat, Yellow warbler, Blue-winged warbler (a rare treat), Northern cardinal, House wren, Red-eyed vireo, Indigo bunting, Black-capped chickadee, American red-start, Gray catbird and the Alder flycatcher. I wasn’t invited to join, but I silently crashed their party anyway, and made sure not to disturb their morning jam session.

Come share in what I experienced! Treat your ears to a morning walk on our Trails. If you hear it, pause and surrender to the Veery seduction song. And let the songbird serenade lift you to an idyllic start of your day.

Photo: Veery taken by Nancy Nabak

 

Ripples 5/31/18

Not knowing what one will encounter is one of the joys of taking a walk in a natural area.  This time of year, there are new birds and wildflowers showing themselves every day, including insects, mammals, and everything else.  If we don’t see them it’s because we are preoccupied with other issues in our lives.  This is understandable, but we miss so much if we view nature as so much green.

photo of a red-bellied snake

red-bellied snake

Cold-blooded animals are no less interesting than their warm-blooded counterparts. It’s interesting to think about how both groups have been able to find success in the business of survival.  The herpetiles, reptiles and amphibians play a huge role in nature – although they often go unnoticed once the frogs and toads stop singing.  Around here our reptiles consist of turtles and snakes.  Turtles are a common sight right now, as females leave ponds to try to find a safe place to bury their eggs. (Mammals, like raccoons, make that a very unlikely proposition.)  And humans driving cars make it very dangerous for the adults.

Snakes can be very numerous in spring as some species congregate in large numbers. These congregations of snakes can emerge at once in large numbers from their hibernacula, the below-ground places they spend the winter.  Garter snakes do this, and to some people, it can be startling to see a mass of snakes in one location. 

Mating also takes place at this time, and the larger females become entwined and covered with many males.  If you see this, you are lucky, as you have to be at the right place at exactly the right time.  Other large snakes such as fox (pine) snakes do this also. They tend to hang around throughout the summer near an underground refuge, causing some distress if they are near people.  Northern water snakes are another large species that brumate with others- and it is possible to find several species together in winter colonies.

Surprising to many of us, there are a number of smaller snake species found in our area that often go unnoticed.  A recent walk on one of our trails revealed a sunning red-bellied snake, a gentle little species not that much bigger than a nightcrawler.  They have a brown color on its back with an orange belly and can be picked up gently without fear of being bitten.  At least I’ve never seen one attempt to bite.  The ring-necked snake is the same size and almost identical in appearance but with a noticeable ring of lighter-colored scales just behind the head.  Another small brown snake with a light gray belly is the Brown or DeKay’s snake, again a non-aggressive little creature.

Another small snake is the milk snake, which has an interesting pattern of black and silver on it’s back.  Again, they offer no harm. The green snake is true to its name and is a beautiful emerald green color – very well camouflaged this time of year.  Both are gentle and worth taking a close look at if the opportunity arises.

Although these snakes are small and gentle, that doesn’t mean they’re defenseless- some are able to exude a foul-smelling liquid if they are handled.  If that happens, all it requires is some hand-washing.  One wouldn’t want to get that liquid in one’s eyes I’m sure, but that doesn’t seem too likely.  As with most things, a little common sense is all that’s needed.

There are no poisonous snakes recorded in Manitowoc County so we can feel free to explore the outdoors without that concern.  And when we do so, we can watch for the many creatures that fly “below our radar” and are often unseen.

photo is a red-bellied snake from iNaturalist.org

Ripples 5/24/18

Chestnut-sided warbler

Written by Nancy Nabak, Communication Coordinator

There are songs and poems written about spring. Authors wax the beauty, the smells, the sounds…all trying to capture a perfect moment in time when their hearts and minds were lifted beyond an endless season.

I’m no different and I’ve got it bad. Colors are bursting into dark greens, mauve-tinted purples and deep blues. But it’s just not the colors; the smells that go with them are intoxicating. I hesitate to use that word in fear of sounding trite, but in reality it’s true. Last night when I pulled into my driveway, my crab tree blossoms were so fragrant that I skipped my usual routine of going into the house, taking off my shoes, and figuring out what’s for dinner.

Trillium

Instead, I walked around to my back yard and slowed everything down. I noticed that my Jack-in-the-Pulpits were almost knee-high, that my trilliums were still smiling their snowy white, 3-arrowed face at me, and my sensitive ferns were tenderly leafing out. Nothing dull here. Not in the least.

But eventually, I did notice something dull. It was a thud. The sound was so unusual that it caused me to look up from my bed of blossoms and take notice. Two bright red male cardinals were challenging each other – fighting to the ground in a dull thud upon impact. Cardinal A landed on top of Cardinal B and spread his wings and self over Cardinal B.  After a while, the two untangled, flew up, chased each other around a blue spruce, through tiny branches, and then out into the open again, but always landing near each other.  They continued to challenge each other with calls and encroachments. I watched this go on for hours. My son watched it, too. For hours these two boys had nothing more important to do than show might, defend territory, and let spring instincts drive them.

Male cardinal

 

Back to my intoxicating crab tree, this morning as I was backing out of my driveway, those blossoms forced me to put on my brakes, get out of the car, and trim a couple of small branches before driving in to work. They’re now in a vase on my desk. The office smells like Heaven. I’m pretty sure that if Heaven has a smell, this is it.

And as I work at my desk, writing grants and spreading the word about Woodland Dunes, we’ve got Chimney swifts chittering inside our Nature Center chimney. I’m assuming they’re building a nest to bring another generation of insect eaters into the world. (More mosquito eaters – yay!) Their high-pitched chorus from our inner walls is a treat; we’re so happy they’re back.

Let this be the spring where your senses take you on an intoxicating journey.  Listen to the bird songs in your yard. Find the bright colors of warblers in your binoculars, and breathe in the treasure of scents during this beautiful time of blossoms.

Photos by Nancy Nabak