they’re on the move…

Thousands of birds are flying overhead right now, migrating south from their breeding areas in Canada.  Some might stop over along wooded streams for a few days to replenish their fuel resources, as dozens of small warblers, vireos, and sparrows did last week at our local reservoir.  But an even more impressive migration is taking place along the ridge that runs along the western shore of Lake Superior above the city of Duluth MN.

The forested ridge above the city of Duluth generates rising warm air currents in the fall that migrating raptors (like this Bald Eagle) use to gain the altitude they need to effortlessly soar south for hundreds of miles.

Migrating raptors by the thousands (and some in tens of thousands) are reluctant to cross the expanse of Lake Superior, but they funnel along the ridge line of its western shore, to be counted by volunteer observers of the Hawk Ridge Bird Observatory and photographed by the dozens of bird lovers and photographers who visit daily.

There’s always something to look at when the hawks, falcons, eagles, osprey, etc. are migrating through this area in the fall.

Information about the migration and the peak times of migration of particular raptor species is posted on E. Skyline Drive in northern Duluth, at the crest of the ridge where spectators gather.  Some species like Broad-winged Hawks and Peregrine Falcons have very short migration times, and we happened to be there on a day when 2000+ Broad-winged Hawks flew over.

Overcast skies bring the birds down low, closer to observers, which is ideal for photography, but we happened to be there on a sunny afternoon, and the birds were thousands of feet in the air above us.

Thousands of feet above us, Bald Eagles (large bird center left) circle in the thermals along with dozens of Broad-winged Hawks.  Photo by Debbie Reynolds.

Broad-winged Hawks are smallish, compact raptors common throughout southern Canada and the eastern U.S. during the summer, but they leave North America during a short span of time in September, largely because they are dependent on the thermals generated by warm air currents rising off the land in the fall.  If they wait too long to migrate, warm fall days become unpredictable and so do the thermals they use to gain altitude for migration.

Broad-winged Hawks exhibit unique formations in migration, when they form “kettles” of hundreds of birds circling in the thermals to gain the altitude they need to soar.  The term “kettle” describes the formation of these birds as they “bubble up” from low altitude to higher altitude circling in the thermal, until they reach several thousand feet when they peel away from the kettle to soar downwind toward the next thermal.  Photo from Brandywine Conservancy, Sept 2018.

Soaring, instead of flapping flight, is relatively inexpensive for raptors, and by using the thermals to gain altitude to then soar over long distances to the next thermal, they can travel hundreds of miles before running out of fuel stores.  For Broad-winged Hawks, the journey from southern Canada to northern South America might be 3-4,000 miles and take them about a month.  In optimal conditions, they can travel 300 miles in 6 hours.

Daily count totals were posted at 4:30 at the Hawk Ridge Bird Observatory site. Peak migration times are generally the warmest times of the day, 10 am-2 pm.  According to the chart, the 10-year average count of Broad-winged Hawks at this site is 37,000 birds, but in 2003, observers counted 101,698 in a single day!  That must have been an amazing sight, with birds literally filling the skies.

We weren’t fortunate enough to get close-ups, but we did see a lot of hawks during our short time at Hawk Ridge.

 

look-alikes (and not)

The Grass Lake slough at Snail Lake regional park is teeming with butterflies, especially Monarchs, which may be congregating here for their southward migration.  The Monarchs especially seem to like the meadow blazing star and don’t even mind sharing it with a lot of other butterflies, bees, etc.

The number of flowers present on meadow blazing star is one reason that butterflies congregate on it. The fact that it provides a lot of nectar at a time (late August) when butterflies are migrating is another.

Plenty of nectar to go around for Painted Ladies (also migrating by the thousands in late summer), Monarchs, bumblebees, honeybees, and a few stray beetles.  The orange, black, and white pattern of the Painted Lady is similar to that of Monarchs, but they are not mimics and the two are easily distinguished from one another.

But one of the many Monarch butterflies I photographed wasn’t a Monarch, but a Monarch mimic, the Viceroy, and these two unrelated species ARE difficult to tell apart.  Can you spot the difference(s)?

Both species exhibit the bold orange and black pattern on the wings as well as the pattern of white dots on the black head and thorax of the insect. 

The biggest difference in coloration of the two species is the bold black horizontal (sort of) stripe on the hind wing of the Viceroy, seen from above or below.  The thick black lines on the hind wing of the Viceroy are similar to those of a female Monarch but are much bolder than the male Monarch’s, which also has a distinctive dot on each hind wing.  In addition, Viceroy butterflies are smaller in size, only about 2/3 the size of a Monarch.

But where Monarch caterpillars grow up eating milkweeds containing poisonous cardiac glycosides which they sequester in their bodies (and wings), Viceroy caterpillars eat willow, poplar, and cottonwoods — not at all poisonous. Bird predators find Monarch butterflies extremely distasteful and will regurgitate or spit them out. Viceroy butterflies that most closely resemble their poisonous cousins in coloration are better protected from predation, and thus, the mimics survive to reproduce.

And then there are these two, apparently dissimilar butterflies, flitting around the same plants, often displacing each other from the same flowers.

The Eastern Tiger Swallowtail comes in two colors: yellow and black, and black.

Not at all look-alikes, in fact, color-wise, they couldn’t look more different, except for the pattern of white dots around the margin of the wings and the distinctive iridescent blue splashes of color on the back end of the hind wings.  So, what’s going on here?

Male Eastern Tiger Swallowtail butterflies are almost always yellow with black stripes.  Females on the other hand vary between yellow morphs and black morphs.  And, the black morph is more commonly found in the southeastern U.S. where a similar-colored, poisonous and unpalatable Pipevine Swallowtail butterfly occurs.  These are the “look-alike” models for the Tiger Swallowtail (and other Swallowtail butterfly species) to copy.  Interestingly, the proportion of female black morphs of the Tiger Swallowtail is higher in southern populations because of genetic (sex-linked) process that makes black morph females produce mostly black morph females, and yellow females produce mostly yellow females!

Bottom line:  you have to look closely when identifying a butterfly, because it might be a mimic!

Comparison of three common swallowtail butterfly mimics and their model, the Pipevine Swallowtail. From butterfliesathome.com

return of the big, scary black wasp

I haven’t seen the Great Black Wasp (Sphex pennsylvanicus), a type of digger wasp, for eight years, when I first found this fearsome looking insect in my backyard feasting on the nectar of swamp milkweed.  But this week I found several of them pollinating the flowers of a wildflower I have never seen before — Spotted Bee Balm.

A 1.5-inch long, fearsome-looking all black wasp with long legs and blue-black wings.  

The wasp inserted its head all the way into the flower and came out again with a nice dusting of pollen to take to the next flower.

The Great Black Wasp is also known as the Cicada Killer, for its habit of stinging and paralyzing orthopteran insects (grasshoppers, cicadas, etc.) to provide food for their offspring.  The prey are paralyzed after being stung in the head and abdomen and are then deposited in an underground nest. A single egg is laid on the underside of just one of the two to six prey items placed in each nest chamber as the larva’s food source during its development.

spotted bee balm

Spotted Bee Balm is a relative of the more common pink or red Bee Balm.  Flowers are arranged in whorls along the stem of the plant.  Multiple stems bearing flowers present a rich source of nectar and pollen for pollinators, but the stems die back in the winter, and the plants regrow from the roots only 1-2 years before dying out.

White bracts separate clumps of flowers on the stem and the flowers seem to open sequentially rather than all at once, so pollinators would be encouraged to revisit particular stems and whorls of flowers.   

This fragrant flowering plant, found mostly in the eastern half of the U.S.,  is especially attractive to large-bodied bumblebees, carpenter bees, and digger bees, as well as a variety of other nectar- or pollen-feeding insects.  It flourishes in dry, sandy areas, disturbed areas along roadsides and railroads, old fields, and prairies.  I don’t know why I have never seen it before this, but I would certainly like to add it to my prairie garden.

Wildflowers at the Grass Lake slough include a wide variety of perennials like Spotted Bee Balm.

Sunset at the slough

Sunset on the slough — a delightful time of night, when things happen that you would have never predicted…

The golden light gives the slough a special character at this time of day.  All was calm and quiet for a while, and then…

There was a flurry of action when a pair of Bald Eagles terrorized some of the Great Egrets that had just settled down to roost in trees across the slough from me.

Six of them had just settled in the top of a tree when the eagles showed up.

No birds — instant evacuation as the eagles descended. No time to get a photo of their flight.  It looks like there might be one or two egrets still sitting there (the white blobs near the tree tops).

The Egrets wasted no time taking off before the eagles got close.  One eagle eventually landed in a tree near the Egret roost, spent a few minutes looking down at the water, and eventually decided it wasn’t worth sticking around in this hot, sticky swamp.

Unfortunately, the eagle was too far away to get a decent photo. The bird was panting as it sat there, and I was sweating so much I could hardly see through my camera viewfinder.

With no warning I could discern, the eagle took off, just when I had relaxed my vigil and put the camera aside to wipe off the sweat.

Within a minute, all of the Egrets returned — en masse.  I counted 31 birds at the roost before I left after sunset.

Some of them flew around in circles, making sure the eagles had left I guess. Others immediately settled into the trees, close to where the eagle had been.

A few birds flew over my edge of the slough, but most were too far away for good flight shots.  Interesting that white birds turn a golden pink color at sunset.

Demonstrating appropriate social distancing at the roost —

Great Egrets seem kind of fussy about who they roost next to, and some individuals are just not tolerated, as seen in the short-lived skirmish below. I wonder if this was an adult vs. juvenile interaction.

Successfully chased off.

Across the street from the slough, the light was changing dramatically…

As the golden hour slowly turned into the blue hour, it was time for Great Blue Herons and humans to give up fishing for the day.

a wetland restoration

One of our local county parks has been the recipient of a make-over, with beautiful results. The place was overgrown with buckthorn, thistle, and other noxious weeds.  But now, wildflowers abound along the shore of the Grass Lake slough in Shoreview, MN amid a mixture of photogenic stumps and wetland plants.  And apparently the ducks, herons, egrets, and muskrats have found this make-over very satisfactory for breeding and foraging this summer because the place is teeming with wildlife.

What a pleasant surprise to find this oasis on a sunny, summer day — popular with walkers as well as bird life.

I don’t know how this Green Heron could see any fish or invertebrates swimming around under the duckweed, but the bird certainly gave it a try.

Great Blue Herons and Wood Ducks (in winter, eclipse plumage) were foraging in the mucky part of the slough, which is completely overgrown with duckweed.

Does fluffing feathers get the duckweed off?

Great Egrets have always loved this slough, although they were quite difficult to see because of all the tall weeds, cattails, dead trees and branches between us.  Now, the shoreline has been cleared, replanted, and the birds have become somewhat accustomed to humans gawking at them as they walk along.

I spotted this Great Egret fishing along the opposite shore, and walked over to that side and right up to it, without disturbing its fishing efforts.

The bird caught three fish while I was standing there watching.

A dead tree on the shore of Grass Lake beyond the slough has served several photographers as a subject for fanciful photo compositing. So, yes, this image is a fake — the tree, the sky, and the background are real, but the eagle and the flowers in the foreground were added.  Fellow Shoreview photographer and Grass Lake enthusiast Jim Radford has composed some dramatic scenes of this tree — with sunset and evening backgrounds.  https://www.radfordpictures.com/Favorites/i-fcdQ6BT

Life on a restored prairie

The restored prairie at Tamarack Park in White Bear Lake is teeming with mid-summer activity.  Part of the restoration has included planting a very large 20 acre field with Big Bluestem grasses and other native forbs, and the grass “as high as an elephant’s eye” right now.  It’s amazing how much you can see in just an hour’s walk in such a place.

The Big Bluestem is already about 2 feet over my head. The park has cut paths through the prairie in places so you can see what being in the middle of a tall grass prairie is really like.

Most of Minnesota is part of the prairie-forest ecotone (the area where the two biomes intersect), and this photo is typical of that sort of vegetation.  Regular prairie fires, started by lightning or by native Americans, maintained the grasses and kept the woody vegetation from invading.  Trees competed better in wetter areas near lakes where prairie fires typically stopped burning.

Dozens of wildflower species are at or just past their peak, and add color to all the green.

Tall spikes of purple Blazing Star and yellow Tickseed and Black-eyed Susans stood out in the sea of green.

Several Goldenrod-Soldier Beetles were happily pollinating some of the Rudbeckia species plants.

Hundreds of dragonflies were flitting over and through the tall prairie grasses, hunting insects or perhaps a mate.

Halloween Pennant dragonflies (named for their orange and dark brown color) perched on the tallest vegetation in the prairie (on Mullein plant here) while they waited for something tempting to fly by.

Several male Widow Skimmer dragonflies were flitting around in the low grass near the edge of the path. These are mosquito specialists, so I like to see lots of them around.

Young fledgling birds were trying out their newly acquired hunting strategies to feed themselves.

A couple of young Bluebirds were eating fruit and looking for caterpillars. One was successful and immediately flew off with it — I guess to protect it from being stolen.

Two young Phoebes (with squeaky voices) were hunting by a small pond — competing with the dragonflies for flying insects.

Chipmunks, squirrels, and 13-lined Ground Squirrels scurried around, already storing up food for the long winter to come.

You don’t often see these 13-lined ground squirrels out in the open — and this one made a made dash for cover when he spotted me photographing him.

Life is busy on this prairie, and the only slow movements are those of the humans strolling along admiring all this beauty.

I could hear (but not see) frogs calling in the pond, and dragonflies were busy hunting along its edge. I love the clouds reflected in the clear water of a prairie pond.

Mid-summer on the Minnesota Prairie

There is a lot going on out on the Minnesota prairies these hot summer days.  With plenty of rain this summer (as well as plenty of heat), the grasses are tall, the flowers are abundant, and the birds are busy fledging their latest crop of offspring.  We had glorious views of the prairie remnants on top of the rolling hills in central Minnesota where farmers’ plows never ventured because of the thin soil and rocks.  These patches and the larger tracts of preserved prairie land in central and western Minnesota make up the remaining 1% of the original prairie land here.

Flatter areas are still intensively farmed with corn and soybeans in central Minnesota. The rugged and rocky terrain of the hillsides formed from the rubble of the last glaciation are safe harbors for native prairie plants and animals.  A pair of Sandhill Cranes watched us climb an adjacent hill and then took off.

Prairie potholes that collect rainwater are interesting places to explore. We didn’t find any ducks there, but there was a diversity of other birds foraging along the shore of the pond — and of course, the Cranes flying overhead, announcing themselves with their primitive croaking calls.

A couple Solitary Sandpipers explored the mud around the pond and bathed in the water. Solitary is a good name for these birds that rarely are seen together, including during migration.

A pair of Kildeer were also running around the muddy edge of the pond. I wonder if they had a nest nearby?

A Kingbird perched on dead stalks and sallied out looking for flying insects.

A Cedar Waxwing was doing the same thing — I never realized these fruit-loving birds sometimes act like flycatchers, continually dashing out, snapping at a flying insect, and landing again on the same perch.

There must have been a lot of good insects at this pond, because the Catbird was trying to act like a flycatcher too.

A glorious day for a prairie walk, and a pleasure to see so much life going on around us!

At the headwaters of the Mississippi

We spent two days at Lake Itasca State Park last week and enjoyed a little sun and a little rain, par for the course in northern Minnesota.  This iconic spot is notable as the headwaters of the Mississippi River, and is extremely popular with tourists.

You can’t miss the headwaters of the eventual mighty river with all the signage pointing out the slender stream that emerges from Lake Itasca.

The grandkids did the ritual walk across the Mississippi headwaters.

Itasca State Park was established in 1891, the first state park in Minnesota and the second in the U.S. (after Niagara Falls).  Extensive logging of the native red and white pine timber had already begun in this area, since the 1830s, but one man’s lobbying effort persuaded the MN legislature to preserve an area near the Lake Itasca outflow for future generations — by a margin of just one vote!

red pine forest

Some of the state’s tallest red pines, although both record-holding trees have recently lost their tops during severe weather.

Itasca is a popular state park, not only for its natural beauty but for the recreational activities available.

Multiple spots along the lake shore are popular as fishing spots.

And of course, there was bird watching and photography, at least by some members of the camping group.

We got a great close-up of a Red-eyed Vireo, close enough to see that its iris is really red.

A Least Flycatcher stopped by for a quick photo.

Likewise, an Eastern Phoebe posed in between chasing insects.

And of course, the ever-present Common Yellowthroat was heard and seen everywhere.

And plenty of good sunsets at Lake Itasca

 

a walk on Bluestem Prairie

How do you get a 15 year-old video game aficionado interested in photographing birds?  Give him a camera with a big telephoto and point him toward his target — his super video game reflexes do the rest.

No. 2 grandson picked up the technique for photographing moving targets quickly and took some excellent photos.

We spotted a Great-crested Flycatcher flitting around in the bushes, and it posed nicely for a few moments.

It was a cool, sunny morning on Bluestem Prairie, perfect for spotting a few birds and walking through the meadow full of blooming wildflowers.

A Clay-colored Sparrow sang from a milkweed plant.

Bluestem Prairie and adjacent Buffalo River State Park together make up one of the largest tall grass prairie preserves in Minnesota.  Over 10,000 acres of restored and native prairie, located east of Moorhead, MN are managed by the MN DNR and The Nature Conservancy.  A great diversity of grassland birds breed here, including the Greater Prairie Chicken.  You can read more about them here.

Driving down a road around the edges of the prairie at sunset, we were delighted to find a family of American Kestrels flying from tree to tree.  We also scared up a female Marsh Hawk from the ground where she may have been dining on some little critter.  Every few hundred yards down the road, White-tailed Deer bounded through the prairie to get away from us.

I caught one of the deer with all four feet in the air as she bounded away.

Acres of native prairie and all the wildlife within make Bluestem Prairie a special place.