16 June 2020

There should be more butterflies


At our latitude, when nature offers you blue skies, light breezes, and temperatures in the 70s, you take advantage of this blessing by heading outdoors.  Yesterday I hiked at Goose Lake, near Verona, Wisconsin.



TBH, the park exists not so much because of urban planning and civic-mindedness, but because in modern suburbia there needs to be somewhere for stormwater to collect.  This park is at a low elevation and is downslope from a variety of subdivisions and business centers, so not even aggressive developers wanted to build here, and it remains public land.

One feature of stormwater-collecting areas is shown above and below.  When the water level remains high, it smothers trees that are not adapted to having their feet wet for prolonged periods of time.  Thus the clusters of standing deadwood at the margins of the lake.


Standing deadwood is good habitat for beetles and woodpeckers, but I was here for butterflies, so I headed toward the open fields.  My walk took me from the viewpoint below to the edge of the pond in the far upper right corner of the photo.


I stood watching this patch of flowering vegetation for a good 5 minutes, seeing no lepidoptera.  Nada.  There should have been Cabbage Whites at least, Sulphurs, Checkerspots, and some Monarchs or Swallowtails cruising past.


Right next to this patch of flowers was one of the stormwater ponds.  If you enlarge the picture, you may be able to see the general pattern of vegetation - close to me on the higher elevation a mix of forbs and grasses and at the water's edge some riparian reeds.  In between is a wide swath of tall grass.


That tall grass became more evident as I walked from that nearby pond to the one at the other end of the park.  Along a path kept clear by city or county mowers the grass stood shoulder-high.  Some clover in the path itself, attracting skippers and a few other butterflies, but off to the sides just grass.

This is reed canary grass, an aggressive, invasive species.  In the past it has been used for erosion control, reclamation of deforested land, and as a reliable forage crop for cattle.  But those qualities also allow it to overcompete and dominate.


This was the end-point of my walk, at the most distant stormwater pond.  When I stood here about 10 years ago, the vegetation in front of me started near my feet as a prairie/field wildflower mix, then morphed toward the pond to water-tolerant plants, then to the usual reeds etc at the waterline.  Now it's a boring monoculture of reed canary grass.


As I walked back to my car I continued monitoring the butterflies.  Total count for the day: two Monarchs, five Least Skippers, two Silver-spotted Skippers, and one Checkerspot.


There should have been more on a perfect day on the cusp of summer.  There were more when I was young.  I'm not misremembering when I report that in the 1950s when you filled your car with gas, the attendant scrubbed your windshield to remove insect debris (the "windscreen phenomenon").   In that era people didn't stop what they were doing in order to point and say "Look, look, a butterfly!"  I'm a firm believer in the worldwide "insect apocalypse" (and here).  Coming generations are going to inherit a natural landscape that will be quite a bit less diverse and less interesting that those that came before.

12 comments:

  1. Probably not only less diverse and interesting, but also not good for the planet as a whole. Is there anything reasonable that could be done to reverse this, at least in that small patch of the globe? By reasonable, I mean something that does not take an overwhelming effort not large sums of money.

    Last night I could not sleep, so I took some iced tea out to the backyard and sat on the patio. Looking out over the yard, I felt like something was missing. It soon struck me that there very few fireflies. Just a few decades go my kids ran around this yard chasing fireflies. Where have they gone, I wondered...I mean the fireflies. I know the general location of my kids.

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  2. I have not seen a butterfly in 10 years in downtown Toronto, but I see a monarch now on my daily walk. A single, solitary butterfly.

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  3. I am 62 years old and I can tell you with certainty the earth is dying.

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  4. When was the last time you heard, "Close the screen door, you're letting flies in!" It's been years.

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  5. Quite possibly the only way to stem the devastation that follows man's footsteps is to remove the man entirely, a feat nature perhaps has been trying to accomplish just recently.
    Hoping that the powers that be will do something to save the world is a false hope when one realises that we collectively suffer the human condition.
    Twenty years ago in Auckland, N.Z. someone found a foreign moth that had a penchant for leaving its eggs in apples, so in an attempt to save the dollars generated by the apple export, the government aerial sprayed the entire city, .... large planes flying low over the rooftops, daily, saturating everything with a sticky insecticide.
    It felt like a coating of glue on the car windscreen, and I ensured my pets stayed inside when the planes were flying over.
    Needless to say, nearly every insect died, and I guess as a method of eradicating the Gypsy Apple Moth it was successful.
    But soon the birdsong stopped, not overnight but within a week or so, and the eerie feeling of waking up and opening the door of a morning to hear nothing is really disconcerting.
    The birds came back, or I guess other birds moved in from areas that were not sprayed, but it took months.

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  6. I make trips between Southern Michigan and Northern Michigan in the summer and can go 2 or three trips between windshield cleanings.
    I know some of that is better aerodynamics on the car, but the lack of insects worries me. Alot

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  7. i am still waiting to see my first tiger swallowtail of the year. usually, by this time, i am inundated with them! meaning, i will see two or three flying around. similar case with the red admirals - i saw one once so far.

    on the other hand, i did have house wrens wintering over, which means we had a mild winter here.

    I-)

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  9. As a birder, I am concerned about insect decline and the effect on bird populations. I did notice a healthy population of swallowtail caterpillars in my small pot of herbs (they devoured the dill and consumed the parsley with reluctance). But small changes in the environment can cause disruptions in populations. We are still trying to understand why the Inca dove population crashed in Tucson- they were a common yard bird 12-15 years ago. I haven't seen on in years, although the white winged and common ground dove numbers are strong.

    But to see invasive plants and animals is discouraging, knowing what is lost.

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  10. Wow, that's sad.

    Sue, I've seen a few butterflies in downtown Toronto over the years I've lived here, but it's so rare that I can remember every one.

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  11. Update to previous post:
    "I raised moths (Saturnia hyalophora) and butterflies (Speyeria, Nymphalis & Papilio) as a hobby for 5 yrs till I had to move into a space w/o good environment. 3 weeks ago I caught a female S. hyalophora that laid approx 60 eggs. None of them have hatched. I used to think the decline in numbers was due to imported Tachinid flies used for army worm control (they feed on pupated larva), but this looks like something else. The eggs are small except for 3 or 4 that look normal. They only lay if they're bred (as far as I know), so though the problem may be fertility, it isn't unique to this particular moth."

    they've begun to hatch in the order they were laid, only a week late, so I guess they're ok. cripes I'm gonna have my hands full in another 2 weeks. :)

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    Replies
    1. I had some fun with Prometheas about ten years ago -

      https://tywkiwdbi.blogspot.com/2009/07/cocoons-of-promethea-silkmoth.html
      https://tywkiwdbi.blogspot.com/2009/07/callosamia-promethea-giant-silkmoth.html
      https://tywkiwdbi.blogspot.com/2009/07/male-promethea-callosamia-moths.html

      But they are hard to find in my area, and I'm reluctant to buy them from commercial sites.

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