Back to the Sand!

“Bugs never bug my head. They are amazing. It is the activities of humans which actually bug me all the time.”

― Munia Khan
While the beach along the Wisconsin River near Sauk City is no longer under water, we could sure use some rain. With spring bird migration coming to an end, my focus returns once again to the sandy places of southern Wisconsin. Searching for insects in the sand can be an exciting and rewarding activity that allows one to explore the fascinating world of small creatures. Whether you're at the beach, in a desert, or even near a sand dune, there's a good chance that you'll find a variety of insects that have adapted to this unique habitat. Naturally, tiger beetles are my standard quarry, as they would be on this day.
Arriving early is important. By late morning tiger beetles warm up under the sun and become impossibly quick to sneak up on for portraiture. After leading a field trip at Pope Farm Conservancy on Saturday, I found this out by getting to the beach too late ― it was unseasonably hot for this time of year, though. It didn't take long for me to give up to try again another day. My plan was to return early Sunday morning before the beetles emerge from their nighttime burrows. 
Hello? Anyone home!? Well, until they come out there are other things to admire ...
Like Spiderwort! 
At last, Big Sand Tiger Beetles began emerging from heir nocturnal quarters to begin searching for food. This first one has to be one of the largest of this species I've ever seen ― I would estimate somewhere around 22 to 24 millimeters in length.
A different individual, this one tolerated extremely close approach ― look at those mandibles!
Long shadows in the early morning light ...
That's an Alfalfa Webworm Moth, Loxostege cereralis.
And a Map Turtle, Graptemys geographica.
A Dwarf Dandelion that's gone to seed.
On my way back to the parking lot I found this Rose Chafer (Macrodactylus spp.) on Common Milkweed. Pests to gardeners, this genus is native to North America.  
Not far from the canoe launch is one of my favorite tiger beetle haunts ― Sauk Prairie State Recreational Area, an outwash plain left behind by the melting glacier 14,000 years ago. Though there's a bike trail that runs through part of it, one doesn't see much in the way of recreation here. Under Governor Walker, there were plans for all sorts of activities including ATV trails, shooting ranges, model rocketry, and more. About a decade ago, dozens of conservation organizations signed a statement how such activities could negatively impact grassland birds. I'm not sure where this stands today, but in 2016 the Wisconsin DNR adopted a plan for motorcycle use on the land, though I've never seen it being used for that. Wisconsin DNR's website states: 
"Visitors may hunt, trap, hike, bird watch, pick mushrooms and berries, study nature, take photographs and other traditional outdoor activities. You may also drive, bike or ride horses on the roads within the complex that are open. Roads are in variable condition; some have many ruts and potholes."
It's still a restoration work-in-progress, but even now its prairies host a variety of grassland bird species like Bobolink, Dickcissel, Eastern Kingbird, Henslow's Sparrow, Field Sparrow, and Grasshopper Sparrow. Bell's Vireos can be found along some of the edge habitat. Though not observed by me, I've heard there have been Upland Sandpipers and Loggerhead Shrikes here.
And it's a great spot for observing and photographing tiger beetles.
As mentioned here before, tiger beetles are highly active predators that rely on their speed and agility to capture prey. However, excessive heat can affect their ability to function optimally. Seeking shade allows them to escape direct sunlight and reduce their body temperature. This regulation can maintain their metabolic processes and perform essential activities effectively. As ectothermic insects, spending just a minute or so in the shade can quickly lower their body temperature, as this Big Sand Tiger Beetle is doing. When retreating to shade doesn't work, they'll often return to their burrows. 
Earlier in the season there were numerous Oblique-lined Tiger Beetles here, but on this day I found just Big Sand and Festive. In a few more weeks there will be Ghost and Punctured Tiger Beetles, as well as a variety of other insects like robber flies and sand wasps. 
Concluding a weekend bug hunt can be a time to reflect on the discoveries made and the experiences gained during an insecting adventure. It's a chance to appreciate the wonders of nature and the intricate world of insects. For my part, educating others about the importance and diversity of insects can help foster a greater appreciation for these often-overlooked creatures. I suppose that's one o the reasons I continue to write this blog after all these years. It also serves as a way for me to embrace memories and retain knowledge ― let them inspire all of us for our future nature endeavors. 
All images © 2023 Mike McDowell


May Finale!

"The ache for home lives in all of us ― the safe place where we can go as we are and not be questioned."

― Maya Angelou
As May ends, many species of birds, exhausted from their arduous migratory endeavors, complete their extraordinary voyages. They find solace in lush habitats, beckoning them with an abundance of sustenance and the promise of creating the next generation. These avian nomads find respite in tranquil prairies, dense woodlands, or along the welcoming shores of lakes and rivers. They replenish their energy, eager to engage in courtship rituals, construct nests, and raise their fledglings. What better place to observe birds on territory than Spring Green Preserve in Sauk County? 
May also serves as a reminder of the interconnectedness of all living beings. Bird migration epitomizes the resilience and adaptability of these magnificent creatures, while also highlighting intricate relationship between various ecosystems. Their presence enriches the environment, fostering pollination, dispersing seeds, and maintaining a delicate balance in nature. This Lark Sparrow, however, is likely not searching for seeds (it will eat them, of course), but for crunchy-juicy insects. Wait ... my beloved insects!? With Nature nearly everything that lives is potential food for something else. 
Spring reminds us of the ephemeral nature of life and the transient beauty that graces our world. It prompts us to cherish and protect these fleeting moments, to safeguard the habitats that sustain these winged wanderers, and to cultivate a deeper appreciation for the intricate tapestry of life that surrounds us. Even a place as wonderful as Spring Green Preserve renders trouble ― I saw some folks who were likely poaching reptiles judging by their nets, bags, and turning over rotting logs and such. By the time I got off the bluff and back to the prairie, they were nowhere to be found. 

Naturally, with all plants ― native and non-native ― my botanical foe returns. Urushiol, the oil found within Poison Ivy's leaves, stems, and roots, is its weapon of choice. While harmless to some, this oily resin triggers a powerful allergic reaction in many individuals (like me), leading to a dermatological nightmare. Even the slightest brush against its foliage can be enough to set in a horrific cascade of itching, swelling, and blistering persisting for weeks. Immune? County yourself lucky!
Pretty leaves, but let it be!
More than any other month of the year, Nature unveils its most vibrant and captivating hues during May. As the winter frost melts away, a symphony of life awakens, and the world becomes a canvas of resplendent beauty. It's a month of transition, where the embrace of spring fully manifests, and the air is alive with fragrant blossoms and the melodies of countless creatures. 
To demonstrate the hues and vibrance, here's Blue-eyed Grass, Prairie Phlox, and Columbine. 
Lastly, tiger beetles ...
There was only a single Splendid Tiger Beetle observed yesterday, so their time is pretty much over until their second emergence during late summer. Alas, I did not find any Common Claybank Tiger Beetles so far this spring, so that will also have to wait until summer's end. 
This one appears to have endured a bit of punishment, but I've seen them in far worse condition. You can see it's missing part of a rear leg and its elytra are a bit banged up. At least its mandibles and antennae are intact ― it's ability to fly and run were in no way impaired. 
There were a few Big Sand Tiger Beetles at both the East Unit and West Unit. So far this year I haven't made an effort to spend more time with this species, but I'll probably do so soon at the Sauk City Canoe Launch now that the Wisconsin River has gone down and revealed more of the beach. 
Festive Tiger Beetles were omnipresent, except for atop the bluff. It's interesting how the Splendids are seldom ever observed on the prairie path below, and the Festives never seem to venture to the rocky outcroppings ― specific microhabitats keep them from having to compete with one another. Six-spotted Tiger Beetles own the woodland trails and I did spot a few of them on my decent. Given the prevalence of Poison Ivy and mosquitoes, I did not bother to photograph them. 
Though a Yellow-breasted Chat was very vocal, I didn't hear any Blue Grosbeak songs during this visit. Lark Sparrows, Field Sparrows, Orchard Orioles, and Rose-breasted Grosbeaks were the primary participants of the prairie chorus. The gorgeous weather kept me out most of the day, but eventually one must head home while leaving another behind. As insects approach their summer crescendo, there will be more outings to Spring Green in the weeks and months to come. 


Spring Green Preserve, Wisconsin, US
May 27, 2023 8:30 AM - 12:30 PM
50 species

Mourning Dove  
Yellow-billed Cuckoo  
Black-billed Cuckoo  
Turkey Vulture  
Cooper's Hawk  
Red-tailed Hawk  
Yellow-bellied Sapsucker  
Red-headed Woodpecker  
Red-bellied Woodpecker  
Northern Flicker  
Eastern Wood-Pewee  
Acadian Flycatcher
Great Crested Flycatcher  
Eastern Kingbird  
Yellow-throated Vireo  
Red-eyed Vireo  
Blue Jay  
American Crow  
Black-capped Chickadee  
Horned Lark  
Northern Rough-winged Swallow  
Bank Swallow  
Barn Swallow  
White-breasted Nuthatch  
House Wren  
European Starling  
Gray Catbird  
Brown Thrasher  
Eastern Bluebird  
Wood Thrush  
American Robin  
Cedar Waxwing  
American Goldfinch  
Grasshopper Sparrow  
Field Sparrow  
Lark Sparrow
Eastern Towhee 
Eastern Meadowlark  
Orchard Oriole  
Baltimore Oriole  
Red-winged Blackbird  
Brown-headed Cowbird  
Common Grackle  
Blue-winged Warbler  
Common Yellowthroat  
Yellow-breasted Chat
Scarlet Tanager  
Northern Cardinal  
Rose-breasted Grosbeak  
Indigo Bunting  

All images © 2023 Mike McDowell



"Maths is at only one remove from magic."

― Neel Burton
A while back I was invited to participate in a podcast for work on the topic of Field of View (FOV). In a nutshell, there are three ways sport optics companies list it:
  • Linear FOV (most common)
  • Angular FOV (next most common)
  • Apparent FOV (rarely ever)
Each means something slightly different, but essentially all work with the same angle. With binoculars and spotting scopes, the Linear FOV is expressed as a number of feet at 1,000 yards. For example, you've probably seen something like "360 feet at 1,000 yards." Linear FOV can be converted to Angular FOV simply by dividing the 360 by 52.5. The reason we use that number is a single degree at 1,000 yards gives a linear distance of 52.5 feet. It's actually 52.365, but 52.5 is accepted. 

In my reduced hypothetical FOV diagram, the optic would have the following specifications:

Linear FOV = 210 feet at 1,000 yards
Angular FOV = 4 degrees

And the formula to calculate Apparent FOV:

Apparent FOV = Angular FOV x Magnification

Thus, if the above were an 8x binocular, the Apparent FOV would be 32 degrees from 8x times 4 degrees, so all FOV specifications would be:

Linear FOV = 210 feet at 1,000 yards
Angular FOV = 4 degrees
Apparent FOV = 32 degrees

Here are the formulas to convert one FOV type to another:

Linear FOV = Angular FOV x 52.5 * 
Angular FOV = Linear FOV / 52.5 *
Apparent FOV = Angular FOV x Magnification 

There's no magic or voodoo here — it's just basic math and trigonometry. Apparent FOV is merely the "naked eye" FOV multiplied by the magnification. In other words, if you were looking at the two ends of the optic's FOV angle at 1,000 yards without the binocular, that distance is the FOV as a pie slice taken away from 360 degrees.

Anyway, the following comment was made to the podcast:

1 degree at 1,000 yards "is" 1 degree. It "subtends" to 52.5 feet.

I replied:

Another way to state it would be "1 degree at 1,000 yards in linear feet is 52.5". Technically the conversion is linear FOV to angular FOV and vice versa, which was the point of offering the 52.5 figure.

Which rendered this response from the same individual:

I respectfully disagree. Degrees are units of angle, not units of length or distance. 1 degree at 2769 yards "is" 1 degree. It isn't some length of inches or any other unit of length. Not being picky or snooty. It's just better when technical information transfer is done literally, not colloquially. When I first got into shooting and optics in a serious way and was trying to learn from all the different "experts" on YouTube and from manufacturers' websites, I found it very frustrating trying to understand what they were trying to communicate, simply because they were speaking colloquially rather than literally. Take for example all of the YouTube videos you can find going into all this detail and talking in circles describing "What is MOA or minute of angle." One even wrongly related it to minutes on a clock, and another related it to a compass. What? Gosh, it's just simply an angle that is one minute in size, one angular minute, 1/60th of one degree. Even so, I greatly appreciate everyone's time and effort being great guys and  giving away their knowledge.

There's nothing to disagree with here. He's kind of correct, but on the wrong track. I responded by stating the 3 FOV types, conversion formulas, and provided the following examples:

When an optic has a linear field of view of 390 feet at 1,000 yards, what we're saying is that the diameter of the circle is that many feet across when observing something at that particular distance. Think of a drawing of a subtended angle and at some distance draw a straight line across it — it's the linear length of that line. This same linear number can be converted to the subtended angle as you say with the number 52.5. With 390, it's 7.42. If you look at any Sport Optic manufacturer's website, you will see you can convert the linear, angular, and apparent using these formulas —  I didn't invent them; they're an industry accepted standard. 

Randomly picking Maven Optics and their B.2 9x45 binocular, they list the following FOV specifications on their product page:

Angular FOV = 7.2 degrees
Linear FOV = 377 feet at 1,000 yards

Showing the work:

7.2 x 52.365 = 377 

It works!

Let's say you have a binocular that you don't have the FOV specification for. You can set a yardstick 10 feet away from it, note how many inches you can see from one side of the field to the other, and then use a proportion to get the linear FOV at 1,000 yards. The angle is the same all the way out to infinity, but the linear changes depending on how far out one is observing. The 1,000 yards for binoculars and spotting scopes is just a standard distance that was chosen decades ago.

Doubling down, the individual replied:

Obviously, that's not what I'm talking about. I'm talking about the unfortunate common misuse of units in descriptions like "2 minutes of angle equals about 2 inches at 100 yards." They do not "equal" any number of inches or other length of measure. Units of degrees and portions of degrees of angle "equal" an equivalent number of radians or other unit of angle, but they do not "equal" any unit of length. In your using colloquial language to address technical topics, you make it difficult for new users who are thinking people and who are trying to figure out the meaning of your colloquial descriptions. Colloquial language is great for chilled out casual discussions. But when someone is new and trying to figure out technical things by listening to your technical descriptions, they are depending on your words to carry their correct meanings. I think you would sell more products, especially to new customers who will become lifelong customers, if you, along with the other merchants, wouldn't make things so much harder to understand than they need to be. As is, it's like being dumped into a strange land with a different language and learning the new language without the benefit of a teacher who knows both languages. Okay, I'm finished with this. Listen and improve you program and your sales, or don't. Your choice. I don't care either way.


I replied one final time:

I think it's quite easy to understand even for a novice when picturing FOV as an isosceles triangle — any line drawn across the triangle from one leg to another has a measurable length. Linear FOV is analogous to one of those lines, one that just happens to be 1,000 yards from the optics user. Naturally, the angle is constant from the user to infinity. What changes is the factor you would use to run the various FOV formulas. For 1,000 yards, that number just happens to be 52.365 (rounded to 52.5). Because, at 1,000 yards, 1 of those degrees across that line is equal to 52.365 feet. If you wanted to measure linear FOV at some other distance rather than 1,000 yards, it wouldn't be 52.365. But you could get all the pertinent numbers using the formulas above.  The angle is exactly the same and the math will still work out — this is basic trigonometry and nothing more and it's how FOV is measured in the Sport Optics Industry. It's exceedingly easy to picture, and easy run the conversion formulas. They work, and that's all optics users need to know.

And that was the end of the thread. 

Alright, so take another look at my diagram above. Each "dx" linear value is 52.5 feet only at 1,000 yards. Add them up and you get the Linear FOV of 210' at 1,000 yards. Of course, each angle is 1 degree (4 degrees divided by 4 angles) all the way out. The point of expressing FOV as a linear number in sport optics is to offer a way for end users to visualize and compare brands and models. What I think the commenter is missing is the red line I've drawn across the triangle — those really are linear distances. We're not redefining what a degree is with any of the FOV specifications; we're measuring linear distances of a line intersecting the FOV triangle.

Make sense? :) 

In a future blog post I'm going to trash the junk phrase: Let's agree to disagree. 

FOV image © 2023 Mike McDowell


The Colors of May

"Everything is blooming most recklessly; if it were voices instead of colors, there would be an unbelievable shrieking into the heart of the night."

― Rainer Maria Rilke
I'm done birding.

Well, for the spring season, anyway. Overall it was a very enjoyable migration. I got to see most of the expected warblers, vireos, flycatchers, thrushes, and sparrows that come through southern Wisconsin. I put little to no emphasis on shorebirds or waders, but I still managed to cross the 200 species threshold. That's plenty good enough, as I'm in competition with no one. Perhaps the biggest surprise of this spring was the Evening Grosbeak at the Pheasant Branch Creek Corridor followed closely by a pair of White-eyed Vireos that were fun to watch. I guess there were no notable songbird misses, but I didn't find an Olive-sided Flycatcher at the corridor for the second year in a row. That I don't have one this year or last is of no consequence to me ― I don't need one and won't chase one.
Perhaps the most enjoyable aspect of spring migration is simply helping other birders find birds, and help them listen and read the woods. A birder who'll go unnamed wrote me a lovely 'thank you' note, conveying precisely the reason I spend as much time birding as I do:

"You know, the last few days, I have been thinking a lot about my years of apprenticing with you and what a gift they have been. To be able to recognize so many birds by now has enriched my life so much. I look at and experience the world and the seasons differently now. Especially the 'empty' months if March-early April, knowing how many creatures are returning each in their appointed time makes the world full of wonder and companionship."

Such sentiments keep me interested and engaged. It's kind of like watching a movie you've already seen with someone who hasn't ― watching them enjoy it for the first time is part of the thrill even though you know how it'll go. Observing that individual evolve into a really good birder is the juice for me. Do you tutor new birders? If not, why not? Don't be selfish with your time.
And then there are those people I regret forming friendships with over the years. I do bump into them at the creek corridor on occasion and my better sense thinks not to interact with them. Still, sometimes it can't be helped when there's a good bird nearby ― letting them know where the WEVIs and BTBWs have been seen. But if my help is met with the cold-shoulder, then I quickly realize it was a mistake to be generous with my observations. Oh, I do know there isn't anything the matter with me apart from suffering from an abundance of personality, but here's a donut for them.
This is part of the reason I think not to bird at the creek corridor during spring and fall migration ― while I do enjoy the company of the birders I refer to as being members of my posse, there are a few people I just do not want to see or interact with. I enjoy helping people find birds and mentor them to become better birders, but sometimes I'd rather just stay home or go elsewhere. But that dang creek corridor is just so good during migration that the gems almost always trump the poo; the unrequited and the domineering.
I've birded these trails for over 30 years and know Pheasant Branch like no one else does. There have been many changes and I know its evolution that even precedes my discovery of it. Though fragmented, this blog chronicles a good share of that time. Perhaps the 20-year mark will be a good time to retire it this blog for good. Though time consuming, it's about the only record that remains on account of wiping out all my eBird data a few years ago as a multifaceted protest. 
But even once this blog ends, or I end ... the birds will keep coming back ...
Just as its wildflowers will blossom ...
In endless forms and colors ...
Both large and small ...
A Black Swallowtail on a dandelion ― oh wait, it's two!
Such interesting creatures ...
Just for a moment ... the butterfly and I ...
And then just like that ... it's gone. 
And then in a whisper ...

And then a shout ...

Bring on the insects!

They're what summer is all about.

All images © 2023 Mike McDowell