Pumpkin Extinction?

Thanksgiving overload - REK

One more thing to be thankful for this Thanksgiving are the humans that saved pumpkins and squash from extinction.  An article in PNAS describes this close call and the role of both megafauna and their new biped enemies in saving them for us to eat.

Current science suggests that large fruits of the osage orange were spread following ingestion and defecation by megafauna.  Likewise the long bean pods of the Kentucky coffee tree and honeylocust contain hard shelled beans that require digestion to germinate, a perfect match for a mastodon or a 3 ton giant sloth.  Furthermore, the large honeylocust thorns may have evolved to protect against these giant mammals, as explained in Trees that Miss the Mammoths.

Cucurbita, large squash and pumpkins, were widespread in the New World and their seeds were found in mastodon dung as early as 30,000 years ago.  They grew in heavily browsed areas and were dependent on the dispersal of seeds by their mutualistic partners.  They contained cucurbitacins, some of the most bitter compounds found in plants.  The few remaining ancient species are distasteful to humans and existing mammals that have evolved more bitter taste receptor genes.  Without the megafauna browsing open spaces and dispersing their seed in dung, their survival was at risk.

Enter the humans who arrived around 13,500-14,500 years ago.  The bad news for Cucurbita was the extinction of megafauna with over hunting likely to have played a role.  The good news was human domestication of squash and gourds for food and containers dating as early as 10,000 years BPE led to the development of the pumpkin as we know it.  No precursor species is known to have survived.  See Popsci.com for more details.

We have now perfected a sweet tasting Cucurbita that we use in pies, coffee and even beer.  It is even tasty to deer and racoon.  Is that good or bad?.....it depends on whether you have two legs or four.

Thanks for the tip from our personal dendrologist, Dr. Matt Kaproth.

Chasing the American Kestrel

By Becky Swearingen

I spent the summer chasing one of my favorite raptors, the American Kestrel. They lead me a merry chase for most of the summer until the last two weeks. I have found these birds to be very shy. When perched on a fence post or on a power line, about the time you get your camera ready to take a picture, they move to the next fence post or power line. About two weeks ago, though, I began to get lucky.

I first ran into a cooperative Kestrel at Providence Prairie after spending time with the Greater Ozarks Audubon Society wandering around prairies looking for sparrows. At the end of the day, I decided to swing by Providence Prairie in Dade County just to see what was around. I have seen Kestrels here before, but they usually lead me around the perimeter going from pole to pole. This day, I saw a Kestrel on a fence post and inched closer and closer to try to get a shot and it, as usual, took to the wing landing on another fence post. This time, however, when I got to where it was, it stayed and I finally got a shot off.



Then the fun began as the Kestrel began hunting for insects in the prairie. It eventually came up with what I believe is a Katydid, landing on a nearby power line. Kestrels are the smallest raptors in the United States.  They often hunt by surveying their surroundings from a pole or fence post, which is what this one was doing.

Northern Mockingbird and Kestrel sharing a wire

To give a nice idea of size, a Northern Mockingbird lighted next to it for a few minutes and I got a shot of the two of them side-by-side.  This Kestrel was in the same location the next day and seemed to have decided the crazy lady with the camera was not a threat. In fact, it found me rather interesting.

I was very happy with my encounter with the Kestrel and with the opportunity to watch it hunt and to photograph this beautiful bird. The next weekend I decided to head to Wah’Kon-Tah Prairie in St. Clair County to see what was happening and what I did I find, but another very cooperative Kestrel. This one did something the previous Kestrel did not do, though. It hunted by hovering and striking its prey. This is a common way for Kestrels to hunt, but I had not gotten to see the behavior up close before. Lighting was not great, so getting this action in a picture was a bit challenging.

Kestrel hovering on the hunt

`My patience paid off, though, when the Kestrel caught a mouse.

Airborne mouse - the seating is like American Airlines out of Springfield, tight and painful.

And in the flash of an eye (or a camera shutter), transferred it to its mouth. You can just see the tail hanging down below its wing.

Dinner on the fly

My final shot before leaving this lovely bird to its dinner was a second catch it made after hovering over the prairie, catching its prey and landing on an old stump. Not sure what it has, but it is possibly a ground squirrel.

Kestrel with ground squirrel?

It was a pleasure to get to observe these raptors up close and personal. I know where both of these two hunt and I’ll be back to spend more time visiting them and, hopefully, getting more shots of them in their environment. I have found that no matter where I go in Missouri or what time of year it is, something interesting is always happening.

I was speechless to get this great set of pictures from our new Master Naturalist, Becky Swearingen.  OK, for those who know me, speechless is unlikely, more like blown away.  There will be more from our great new class over the next year.

Wahoo!

Wahoo seed capsules - Jennifer Ailor

From Jennifer Ailor

One of the most delightful native ornamental trees is the eastern wahoo, Euonymus atropurpureus, of the Celastraceae family. By type, it's actually a shrub. Its dark purple blossoms open in June, and in October/November they appear as delicate rosy red fruits dangling beneath the leaves or bare branches. Quite a show until the birds get them.

Wahoo fruit - easywildflowers.com/

Mine is shrub size growing under oaks and a walnut, but according to the Missouri Botanical Gardens, they also grow in full sun and can be found in open woods and thickets, near streams and on wooded slopes. They typically reach 10 feet. You can read more about the wahoo at Missouribotanicalgarden.org.

My wahoo, in mid-November, is still looking quite lovely. You can purchase your own from Missouri Wildflower Nursery, from online nurseries and from selected local nurseries listed at Grownative.org. You won't find them at a Lowe's or Home Depot garden center.

Editor's notes:
They are also available at the source of the above photo.

The fruit is in a pink four-lobed capsule that opens up to display the bright red seeds.  This has been called Hearts Bursting with Love.  This name is ironic as the fruit is actually poisonous to humans.  Fortunately, many birds eat it without harm, then flying off to transplant the seed.

The common name is also fun, emitted as a loud "Waa-hoo!" 

Water Fleas

Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum. 
                              -Nursery rhyme 

The WOLF school has been exploring life in a few drops of pond water.  While trying to photograph some tiny pond pygmy backswimmers flitting around in a single drop, I came across these indistinct creatures.  I could tell they were alive by the motion in their body in the video, but I could not make out any distinct features with my crude equipment.  I sent the video to Dr. David Bowles who identified them as water fleas of the Cladocera order of crustaceans.

Dorsal view - Click to enlarge

There is nothing to see at first glance to suggest that this is related to the noble order that includes lobsters, shrimp and crayfish.  There are over 600 species plus many more that haven't been identified for reasons I can understand, looking at our specimen.  The first evidence of life I saw was when it defecated in this video.  Be watching carefully at the 20 second mark.

It has a translucent carapace covering all but the small head, showing all the internal organs.  The green dots are eggs, something it produces usually on its own (parthenogenesis) except when under harsh conditions when it reverts to sexual reproduction as described in the Kansas Naturalist.  I can make out its single compound eye, mounted above the beak-like rostrum like a early prototype of a Cyclops.

From the Kansas Naturalist

Aside from its monocular vision, water fleas have several other interesting features.  It has two pair of antennae, the first having tiny olfactory hairs.  The second pair are well muscled and are used for swimming, its sole method of propulsion.  Its legs are covered with fine hairs which strain food particles such as phytoplankton, bacteria and organic detritus. 

As a herbivore, water fleas are at the very base of the food chain, the first consumers as well as some of the smallest prey of the tiny pygmy back swimmers we have been studying.  ..... and so ad infinitum.

Upside Down Goose

Upside down goose with right-side up head.- Dailymail.UK

Lisa Berger caught us asleep at the blog yesterday.  Wednesday I mislabeled an insect picture as "dorsal" while it was obviously ventral with its legs up in the air.  After making the correction, I was trying find a witty response to her email when I came across this fantastic fact.  Geese will on occasion fly upside down!

The Dailymail.UK had this posting about a technique called "whiffling"
that geese use to slow down for landing in a high wind.  The picture above shows an upside-down goose with its head turned 180 degrees.  If you still don't get it, (I had a hard time at first) check out this video.  This turns the phrase "dumb as a goose" on its head, so to speak.

Monarch Parasitoid

Monarch parasitoid from WOLF School

Ready to pupate at WOLF school

In front of the 5th grade WOLF School a few weeks ago we found a few Monarch caterpillars in their final instar, crawling on the late season butterfly milkweed while preparing to pupate.  The students came out and quickly also found aphids, small and large milkweed bugs and a milkweed beetle.  They checked the plants daily, bringing in the chrysalis to follow the developments.

While several of the Monarchs emerged, one chrysalis shriveled and tiny black insects emerged, a mere 3 mm in length.  The students kept the container covered with plastic wrap until we could collect them.  By microscopic photographs we were able to identify the parasites and here begins the tale of the Chalcidid wasps.

These are not the wasps I knew as a child.  For one thing they are tiny, 2.5 to 9 mm long, (0.1 to 0.34 inches for those allergic to the metric system).  They don't build nests or dig holes for their young but instead place their eggs on the larvae of lepidoptera or diptera (true flies), or less commonly other insect species.  Their larvae develop within the victim, their birth announcing the death of their host.

Ventral view of parasitoid wasp

Less than 10% of Monarch eggs produce a living adult butterfly.  When the caterpillar leaves its egg, it turns and eats the remainder of the egg, and sometimes eats a nearby Monarch egg.  Spiders, assassin bugs, lacewing larvae, birds and others attack the young larvae.  Parasites ranging from viruses and bacteria to nematodes and mites threaten their health by growing in them.  And then there are the parasitoids.  These are flies and wasps that lay their eggs on or in the larva where their larvae digest the caterpillar emerging from their victim as adults or even a pupa.

Chalcididae wasps are common parasitoids of other species.  However in the case of Monarchs they may also directly attack the pupa.  According to Monarchprogram.org, "Tiny wasps from the family Chalcididae unsuccessfully penetrate the pupa casing therefore leaving a small hole.  The pupa begins to turn dark and dies."

  Pteromalid Wasp -  Marci Hess

There is good evidence that Chalcidid wasp are Monarch parasitoids,  In our case, we know that there were multiple tiny wasps which emerged from the chrysalis.  Wasp identification is difficult under the best of circumstances, and my photographs fall far below this, failing to show the wing vein patterns and other details.  We will just have to be satisfied with the identification as a Chalcidid wasp.

House of Straw

Grass-carrying wasp nest - Chris Barnhart.

Little pigs aren't the only animals that build their house out of straw.  Chris Barnhart spotted this grass sticking out of a carpenter bee hole in the fascia of our cabin and taught me about grass-carrying wasps.

Isodontia - Robert Lord Zimlich

This is a nest of the Isodontia wasp species.  They use grass, or sometimes inner fibrous bark or Spanish moss to line cavities in trees, other species' nests and even house window edges, sealing a chamber which holds their brood of several larvae.  Their eggs are provisioned with paralyzed crickets or occasionally grasshoppers, usually picking the small ones for ease of transport.  Their prey will remain alive but immobile (think zombies) as they are consumed, fresh food without the freezing.

Generally benign, they are capable of stinging if handled although few of us would be tempted to grab a wasp, with or without straw.  You can watch them in action on this video by Dick Walton.

Isodontia mexicana - Styrulus EOL CC

One of the grass-carrying wasps has reversed the direction of the Columbian Exchange that brought us so many benefits and invasive species from Europe.  Isodontia mexicana has accidentally been introduced to France and is spreading across Europe, lacking natural predators.  Apparently French insects aren't aware of the three little pigs and the techniques of blowing the grass out.