Missouri Master Naturalists- Springfield Plateau Chapter

Tuesday, June 30, 2020

Leaf Miners


Leaf miner on Verbesina virginica - REK

We have all probably seen these discolorations on a leaf.  At that point we have either walked on or said knowledgeably "leaf miner," and then walked on.  Below is a great way to learn more about them from the expert, Charley Eiseman.
I first came across Charley when I became interested in plant galls and discovered his bible of natural signs in nature, Tracks & Signs of Insects and Other Invertebrates.*  It is full of interesting finds that continue to make me focus on the macro world.  If this sounds like a commercial, I plead guilty.
I run into his work everywhere, whether responding to a finding on INaturalist or contributing 10,892 photographs on Bugguide, all for free use through Creative Commons.  He is a member of  a community of fellow "macrophiles" and amateur and professional entomologists out there who are willing to give us junior members help as needed.
Leaf miner tunnels with trails of frass - REK
Red Velvet mite
While photographing a velvet mite,  I saw these scars on top of a frostweed leaf.  I had always assumed that they were caused by something browsing the epithelium but it turns out to be something much more interesting. They are made by tiny larva living between the upper and lower leaf epidermis, tunneling and pooping a faint trail of dark frass.  Depending on the species, they may occur on the upper or lower surface, sometimes on both.  Eventually they emerge, leaving through a small exit hole which you may see under magnification.
A leaf miner is any one of numerous species of insects in which the larval stage lives in, and eats, the leaf tissue of plants. The vast majority of leaf-mining insects are moths (Lepidoptera), sawflies (Symphyta, close relatives of wasps), and flies (Diptera), though some beetles also exhibit this behavior.  Wikipedia

Lately Charley has plunged into the world of leaf miners.  There are over 2,000 species of leafminers and since most are plant specific you have a good chance to identify them by their tracks.  If you want to pursue leaf miners beyond the Wikipedia reference, Charley has just published Leafminers of North America.  It is 1857 pages long (plus a 54-page table of contents, 20-page glossary, and 68-page bibliography), illustrated with thousands of color photographs.  To prevent injury to the UPS delivery drivers it is only available as an ebook but it is a great reference.  "Abandon all hope, ye who enter here" for I have sampled the incredible deep dive into my copy and it is hard to emerge.

Now he has done it again.  He has a 78 minute webinar, an introduction to leafminers at this Youtube link.  If you find it as interesting as I did, you might consider signing up for a series of webinars through August where he will be walking us through the identification of leaf miners, no hard hat required.

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From Charley Eiseman

"If you're interested in an interactive webinar that will help you become more comfortable using the book's keys, you can register for that here:

https://www.eaglehill.us/programs/sems-online/calendar-online.shtml

The course flyer will be available at the above link any day now, but for now I've copied and pasted the description below.

The first session will include a slide show/lecture providing an introduction to leaf and stem mining and other modes of herbivory; an overview of mine classification; and a discussion of methods for photographing, collecting, and rearing miners. In between classes, participants will photograph and/or collect leaf and stem mines and attempt to identify them using the hostplant-based keys in Leafminers of North America. At each subsequent meeting, we will discuss what people have found, working through the keys together for any mines that have caused difficulty. This will ideally be done by sharing digital photographs taken ahead of time, but for some specimens live sharing via webcam may be possible. Shortly after each meeting, the instructor will provide a list of relevant passages in Leafminers of North America to read that will reinforce what we have covered together.=====================
*He and Noah Charney wrote Tracks & Signs of Insects and Other Invertebrates which is an indispensable book for those who wander through nature wondering "what made that?" be it a gall, egg case, pupae, exuviae or an engraving left by an insect. 

Monday, June 29, 2020

Larry the Leech

Our great niece Taylor's friend, Luke found this leech in a puddle near the swimming hole.  Taylor said she recognized it from last year when it had a close relationship with her toe, then they named it Larry.  We explained that once you name an animal it achieves pet status and can't be killed or used for bait. I identified it as a Placobdella sp.  We renamed it "Della" and after the swimmers left it went back into the creek.

Ventral surface with stripes

Posterior sucker
The best match I found on INaturalist was a smooth turtle leech, Placobdella parasitica.  Wikipedia states that "P. parasitica is differentiated from other members of the genus Placobdella by its smooth dorsal surface, simple to complicated pigmentation, and abdomen with 8 to 12 stripes."  Positive identification requires dissection which Taylor was more than willing to do as payback.  Since some leeches can live up to 10 years she was certain this one had sucked her blood several times in the past.

Leeches are parasitic or predatory worms, distant relatives of our earth worms.  Most leeches are blood sucking parasites without a specific host species. They inject their saliva which contains anesthetic and anticoagulant chemicals, making their bite with serrated jaws painless.  Once they have had their blood meal they drop off and may not feed again for many months.



The MDC Field Guide is a good resource to start with.  A leech has a sucker on each end of its underside and can use them to move like an inch worm, stretching and expanding dramatically.  The head with the mouth is actually located at the small tapered end.  The power of its sucker can be seen here when I picked it up by the head end and it was able to lift a rock with its tail sucker!


Leeches have a long medical history dating back 3,500 years.  Even the word “leech” is derived from the English word “laece,” meaning physician. (Ouch!)  They were used for bleeding as treatment for a wide variety of diseases, and are still used in digital transplant and skin flap surgery to treat venous congestion.  Sciencedirect

Removing a leech should be done gently, trying to peel it off with a fingernail to avoid leaving mouth parts in the skin.  Salt, alcohol, turpentine or vinegar will cause it to detach but makes it vomit in the wound. (TMI)

Finally, some people are keeping leeches as pets.  Even though they are easy to raise and you only have to feed them every 3-6 months, Barb said "NO!"

Saturday, June 27, 2020

Chub Mound


Our stream ecology research team took to the water for an afternoon snorkel trip down 2 miles of Bull Creek.  One cool find was these under water gravel edifices created by a male chub.  The species I have seen and caught in our swimming hole is the hornyhead chub (HHC)  Our common Missouri chubs are 5 to 7" long members of the minnow family.
Horneyhead Chub on Bull Creek - Dave Fleshman

Like males of some other species including us, when looking for love the HHC gets dressed up to attract a lady chub.  In this case he develops large pointed tubercles on the top of the head and a red or orange spot on the upper opercle behind the eyes.

HHC - Dave Fleshman
Like bower birds and other love-struck males that build a love nest to attract a female, the river chub creates a mound nest of gravel for mating.  He does it one piece at a time, first picking up pebbles in his mouth and moving them to the side, creating a shallow pit with a rock rim.  Next he picks up uniform 1cm pebbles from up and down stream, creating a mound.  This can have up to 10,000 pebbles!  Talk about chapped lips!



The mound will have a trough on top and when she enters it he will hold her down as she releases some of her 500-1000 ova.  From then on, the male will fiercely guard the nest, head butting intruders.

Ovisac with several hundred glochidia *


Chubs are an indicator of high quality water and are intolerant of pollution.  They are a valuable member of stream species and food for other fish.  Their diet includes insects, filamentous algae and even the eggs of mussels. 



"Fresh-water mussels release small masses of microscopic larvae known as glochidia in a loose gelatinous matrix or ovisac. The glochidia encyst on the gills of river chubs where they metamorphose into juveniles and then drop off. It is suspected that the river chub feeds on the gelatinous masses as it does drifting insects." Wikipedia

* Barnhart, M. C.  2008. Unio Gallery:  http://unionid.missouristate.edu.

Friday, June 26, 2020

Jumping Worm


I was kneeling on our concrete patio when I saw this worm crawling toward me.  It was 10 inches long and moved straight ahead.  It didn't look like any worm I had ever seen and crawling across bare concrete on a warm day was surprising.  It was even more surprising when I tried to pick it up and it went crazy, twitching and flipping around as you can see in this video.


This is a jumping worm, JW, (Amynthas spp.), also called a wiggler, wood eel, crazy snake-worm, Jersey wriggler or Alabama jumper.  This is an invasive species which originated in Japan and Korea, arriving in either horticultural material or as fish bait.  It is now found across Northeastern US and even into Canada.

My JW above stood out because of its length, but identifying them for certain is a little more difficult.  The Minnesota DNR website lists the features quoted below to help differentiate them from our "good" worms such as a European nightcrawler, (Lumbricus terrestris).
  • Look for soil with a similar appearance to coffee grounds. As jumping worms eat and excrete waste, the soil gets a unique texture like coffee grounds.
  • Jumping worms are very active, move like snakes and secrete yellow mucus when agitated (see video from Wisconsin DNR (link is external) showing their movement).
  • When a jumping worm is disturbed, its tail can break off and continue to flail.
  • The ring (clitellum) on adults is closer to the end than on nightcrawlers, milky pink to milky gray in color, encircles the whole body evenly, and is barely raised above the skin.
  • Setae (tiny hairs the worm uses to move) are evenly spaced around the entirety of each segment, not in pairs or concentrated on the bottom or sides of the body.
Most earthworms in the Northeast are imports.  The receding glaciers 10,000 years ago had wiped out any species that might have existed in the distant past.  In their absence, forests evolved to rely on bacteria and fungi to break down leaves and twigs that litter the floor.  The layers of leaf litter form an ecosystem of their own.  Their loss robs Northern forests of rooting soil as well and increasing erosion.  According to Audubon, it even threatens some species of ground nesting birds that require the litter.

European earthworms arrived hundreds of years ago, likely in ship ballast.  They burrow deeper in the soil, mixing the debris and aerating the soil.  JW specializes in the top soil and can eliminate up to 95% of leaf litter.  This also explains why it was crawling across the open concrete rather than burrowing into the mulch of our flower beds.

The spread of JW has been rapid.  "Where most European worm species move about 30 feet per year, jumping worms can easily cover 17 acres, or roughly the size of 13 football fields, of new ground in a single season."*  Another reason for their success is their parthenogenic reproduction, creating cocoons without mating.  If that isn't bad enough, you can buy 1,000 on line for $72 for gardening or bait!

Northern states like Wisconsin are working on control measures.  Whether they will be as big a problem here in our oak hickory forests remains to be seen.
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More in NY times

April 2021 update- Now in 15 states.

May 2022 update-  Now in California, this reviews their affects on soil habitat.

Wednesday, June 24, 2020

Spider vs. Snake

Click to enlarge

Friends were swimming in Bull Creek when they noticed a snake skin hanging from a deeply undercut high bank.  When they swam over to retrieve it they discovered that the snake was still in it.  A wolf spider had a firm grip on it and was munching away.  It was able somehow to hold the weight of the snake in spite of clinging on an overhanging lip.  This is not a spider you would want to run into in a dark alley, let alone your bathroom where we find them occasionally.  They were able to film this cellphone video.


The victim is a midland brown snake, aka Dekay's snake (Storeria dekayi). They are 9-13 inches long and live mainly in moist soil where they consume mainly slugs and earthworms.  They have long teeth that let them cling to a snail until it finally gives up and is pulled out of the shell.  Their scales have keels, a raised line down the center like the keel of a boat as seen in the picture above.

Click to enlarge
Dekay's snakes give live birth rather than lay eggs with babies 3" long. Their main defense against predators is flattening their head and putting stinky poop on their predators. Spiders can detect odors from special organs on their legs and pedipalps but this one didn't get near the snake's rectum. Smithsonian

I was unable to find any reference to a wolf spider eating a snake.  I will leave the final interpretation to you although the video is very convincing.

Thanks to Garin Ferguson for finding it and to "Snakebite Jon" for swimming over an 8 foot deep stretch of water with an Iphone to get the pictures and video.

Monday, June 22, 2020

Scatology or Not



Ben Caruthers sent me this picture with a note, "Do we have a scatologist in the group?" Blowing it up (the photo, that is) I could see what appeared to be pieces of the shiny black elytras of a beetle.  On further questioning he said it was an inch long, had insect parts and there were three on his back patio.  I suggested that they might be raccoon poop although theirs are usually neatly piled together and the site reused in what is called a latrine.

Ben emailed me back and identified it correctly as toad scat.  He frequently sees toads and insects on his patio.  Of course, unless you saw the amphibian in action you can't be toadly certain.  This was embarrassing to me as a retired gastroenterologist, being beaten to a diagnosis by a birder.  I found a good resource on scat identification which described toad droppings.
"Droppings can be found in the same area morning after morning, often near flood lights as toads are drawn to insects attracted to the night lights. You may see exoskeletons of insects in the scat."
I started sniffing out internet resources.   The OCTrackers Litter Box has a lot of detailed poop on poop.  Toad scat tends to be small and sausage shaped and breaking it apart you would expect to find undigested insect remnants.  Another thought I had was good old INaturalist.  I sent in this picture of coyote scat with its usual heavy load of hair and Bingo! the top choice was coyote.  They even have an INaturalist Scatology page.

The term "scatology" has two definitions, the first being "interest in or treatment of obscene matters especially in literature."  Our definition as naturalists is "the biologically oriented study of excrement."  There is now an official proposed term for the scientific study of poop, In Fimo, described in my old standby professional journal, Gastroenterology.

Friday, June 19, 2020

Painted Lichen Moth


"
Moth from Elbee Bailey

Elbee Bailey was visited by this colorful moth and sent us this photograph on the right for identification.  Frequently we find something and have no way to get a "decent" picture.  I would encourage you to try anyway.  This insect has a distinctive appearance that can be identified as a painted lichen moth, Hypoprepia fucosa.  I cropped her photo and sent it to INaturalist which ID'd it as its first choice.  This site is far more forgiving than Bugguide although it is less authoratative.  This is a common moth which also helps but common is always a good place to start thinking about an identification.

Another trick I find helpful is to Google a species name followed by "MDC."  The Discover Nature Field Guide has an amazing number of species common to Missouri.  Nothing in the first pages of Googling brought up any information on anything except photographs for ID.  In this case, "painted lichen moth MDC" brings up this site.  Here is a sample of the content.
"Larvae feed on lichens, the often crusty-looking plantlike growths that develop on trees and rocks. Lichens are made of a fungus and a symbiotic partner organism that has the ability to conduct photosynthesis (usually, this partner is an alga). The larvae also feed on mosses and algae that can grow on trees."
H. fucosa - Tom Murray
This is a common moth to come to our porch light.  It has bright aposematic colors that suggest to predators that it is toxic.  I didn't find any references to this and have not done a taste test myself.  The caterpillar has spiky hairs which in some species have a stinging chemical to discourage predators and curious naturalists.  I can't find any reference to that in H. fucosa  but haven't personally tested  this.  Let me know what you find!
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Some of my favorite go to resources.
Plants 
Illinoiswildflowers is a dynamite resource.  For a quick search, google "plant name Illinois" and it will usually come up as the first choice. The name is deceptive as they cover everything from trees to moss.  They also have databases on insect and mammal connections with plants including faunal associations.
Insects
The Entomology Department at University of Florida as a Creatures site with amazing details on most species.  Again Googling a "species name Florida" will usually locate it as one of the top choices.  Look for "entnemdept.ufl.edu"

For fun facts on selected species I hope to find something from my favorite Buglady at the University of Wisconsin Milwaukee Field Station.  Try Googling "click beetle
Buglady" or just click on this link for a sample.

Bugguide.net- Free to join and photos are reviewed by experts.
INaturalist.com of course.
Seek phone app is a new favorite, like INaturalist but you just point your camera and it responds.

Blue Mud Wasp

The last week we have been finding these iridescent dark blue wasps hovering around our windows trying to find their way out. They also enter through tiny gaps in the soffit above the front door. Fortunately they are easy to catch and transport outside where they probably start the same trip again, thinking "Didn't I just do this a while ago?"

These are Chalybion sp., a genus of blue mud dauber wasps in the thread-waisted wasp family, Sphecidae.  Mud dauber is a general term and many species have never daubed mud a day in their life.  Chalybions tend to nest in natural and artificial cavities such as holes in wood, walls, plant stems, etc.  Some even reuse old nests of other wasps, removing the larvae and residual materials.  They even bring in water and remodel the nest before laying in provisions and an egg.  A silken cocoon will soon be formed.

"Just chillin out" - refrigerator cooled for a still portrait
Cc from MDC
This is a blue mud wasp, Chalybion californicum (Cc), one of the most common mud dauber species in Missouri according to MDC.   I just had an inquiry from MDC about a "swarm" of wasps including this one to the right that looks just like ours.  Cc and other related Chalybions are solitary wasps, meaning that they form an individual nest.  They may have neighboring nests where there is good habitat giving the perception of a community.  The forest service website explains how a "swarm" might appear.
"Chalybion californicum is a solitary wasp, and the females build and supply the nests individually. However, clusters of both sexes have been reported in low-light situations like at night or on a cloudy day in the shadow of a building or a rock. There can be several generations of wasps in a year."Forest Service
Only female wasps have stingers which are actually modified ovipositors.  Most wasps are reluctant to sting, reserving it for defense when threatened.  Chalybion sp. are rarely aggressive and actually a beneficial species if they aren't hanging around inside the house.
Aa on golden Alexander

The adults feed on nectar and are pollinators for may common native plants such as Queen Anne's lace, Daucus carota, and golden Alexander, Zizia aurea. Meanwhile they catch high protein insects which they paralyze with their stinger and give them to their developing young. Frequently they catch black widow spiders! What is not to love about these cuties?

Wednesday, June 17, 2020

Wild Ginger and Ants



I spend a lot of time looking for the shyest wild flower of spring, wild ginger, Asarum canadense.  To find the blossom you have to get down to its level and start lifting up the heart shaped leaves.  The petioles are pubescent with soft short hairs requiring close inspection.  You can't find the buds unless you push aside the leaves and push away any leaf litter. 

The flower lays on the ground at the base of the plant, three rusty brown petals with pointed tips.  It looks depressed, too humble to bother lifting itself up to look around.  Why would a plant have its flower hidden in the ground litter?  "The better to pollinate, my dear."  Since the ginger spreads by multiple rhizomes the flower has to attract pollinators the hard way.  It emits the scent of decaying fruit, attracting beetles and flies which are fooled into picking up pollen then fall for the same trick at a neighboring ginger next door.


Ant hauling an elaiosome - Eva Colberg

That is not ginger's only insect trick.  Its seed has an elaiosome, a fatty cap which is like the finest cuisine to an ant.  After a little taste, the ant drags it back to its nest where it is consumed by the clan.  Then they drag the seed out to the trash heap which may also be their toilet.  Seed + fertilizer = growth plus it was protected from seed eating animals along the journey, a win-win for the mother ginger.  This ant-seed dispersal is called myrmecochory and is fully explained by Eva Colberg from Missouri Botanical Garden.

Taste testing a wild ginger treat
Lifting off the ground

Naturally I had to see this for myself.  I put the tiny wild ginger seeds on the deck and waited for the ants to show up.  Nothing would happen for several hours and then they would all disappear while I stepped away.  Finally I caught this one above taste testing an elaiosome.   After rolling it around it finally got a grip, lifted it slightly off the ground and then took off at a frantic pace as seen in this video.  This is the eastern black carpenter ant - Camponotus pennsylvanicus or Campy for short, which we discussed in this blog.

Campy is a very common ant.  Dr. Eleanor's Book of Common Ants calls them "one of the largest and friendliest ants, black carpenter ants that lumber through your lumber."  They are omnivores and will supp on fruit and dead insects.  The workers will groom aphids like a dairy herd, collecting honeydew from their backs to take back home in their tunnels in dead wood.  I found this one in an open hickory leaf stem gall as the aphids were leaving it.

Back to the flower of A. canadense.  It is a shame that it hides in the dirt as it is actually attractive if you look deep inside.   My favorite photograph is the one looking like a little bird with a Santa Claus beard.











More detail on Wild Ginger is at Illinois Wildflowers.
Dr. Eleanor's Book of Common Ants is an excellent introduction to the world of myrmecology and it is free here!
Thanks as always to Dr. James Trager for the ant identification and education.

Monday, June 15, 2020

Cryptic Caterpillar



Lois Zerrer sent this photograph for identification. 
"I found it about a week ago as I was picking up sticks in the backyard after the heavy overnight storm. I picked up the branch and immediately felt something soft definitely not twig like.  What a surprise I had when I turned the twig around."
I sent the photographs on to Chris Barnhart who identified it as a noctuid larva, "probably Catocala (underwing moth)."  The caterpillars in
this genus can be round or flattened like this one.  They have lichen-like coloration on the back but some have bright colors underneath.  When approached by a predator they can twitch as seen in this video and flash the bright warning colors called startle coloration.  They then drop to the ground where they blend in and virtually disappear.

Beloved underwing - Wikipedia
There are more that 60 species of underwing moths in Missouri alone.  Their forewings are dull tan to brown, resembling tree bark.  The hind wings are usually bright orange or red and are hidden unless seen in flight.  Like the startle coloration above, this is a trick similar to goatweed leafwing butterflies, cottontail rabbits and the white flag tail of a deer.  In motion your eye follows the bright spot, then looses the animal when that color disappears.




Catocala ilia - Clark Creighton
Our friend Clark Creighton sent us this caterpillar for identification a few years ago.  It was distinctive enough to recognize as the caterpillar of the beloved underwing moth, Catocala ilia.  You can see it changing its color by flipping over in this video.



Sunday, June 14, 2020

Variegated Cutworm Moth


Barb found this pretty pupa in the soil while planting a basil.  It danced like Chubby Checker when she put slight pressure on its head as seen in this video.  The outline of its future wings, head and abdomen was vivid and she put it in a small container with potting soil to see what emerged.
Pearly underwing before takeoff
Several weeks later she brought me the box, saying it had emerged but appeared dead.  Instead of chilling it I opened the box, took this photograph and off it flew!  Fortunately the one clear view was enough to identify it as a Pearly Underwing Moth, Peridroma saucia

Its other common name is Variegated Cutworm Moth although farmers and gardeners would probably call it @#%^.  It feeds on a wide variety of plants, especially fruits and vegetables. 


Cutworm - MJ Hatfield
The larvae aka. cutworms hide in the soil and other cover during the day and comes out at night to feed.  They rip the leaves and fruit from plants and can climb a tree to eat the buds and stems.  They can strip a garden or field in a matter of days.  The adult moth meanwhile cuts off the plant where they emerge from the soil.

I suspect that they refer to us as the Great Providers or some other term of worship.  Not only do we plant, fertilize and water their sustenance but we put it in neat rows and eliminate the non-nutritious "junk food", i.e. weeds.  Traveling in the rows they are protected from predators that would be patrolling open ground.  What is not to love?



P. saucia produces two to four generations a year.  It requires warmth and will migrate northward as the year progresses.  Its origin is uncertain but it is found worldwide.  It was first recorded in the US in 1841 and is found mainly in the northern United States.

The only good news about this cutworm is that it feeds a wide variety of predators and parasitoids.  That and it has some wicked dance moves.

Tuesday, June 9, 2020

Hawk and Mockingbirds

During a native plant walk in our backyard, Patty Hatcher noticed mockingbird fledglings in the indigo bush with a parent scolding us from the chimney. Then she pointed out a red-tailed hawk perched at the top of a neighbor's tall pine tree.  She thought she saw babies as well but without binoculars  wasn't sure.  The next day I set the tripod up just as the hawk appeared on top.  Seconds later the mockingbirds nesting across the street were attacking the hawk.  Over several minutes two or three of them took turns while the hawk never flinched, as calm as the eagle on the US seal.

They gave up the attack after 5 minutes and continued their scolding in the distance.  The hawk continued to survey the territory, looking regal,  then several minutes later it suddenly launched and flew away.  You can see all the action on this Youtube link.

I had seen a hawk fly about 30 feet overhead the week prior.  It was clutching a snake that would have been nearly 2 feet long.  I hadn't seen where it had landed but I suspect it was from the same tree.  If there is a nest in the tree, it is well hidden. According to Audubon* they nest "usually in a tree, up to 120' above ground; nest tree often taller than surrounding trees."  This is the tallest tree in the neighborhood with dense foliage.



Red-tailed hawks forage on rabbits, squirrels, snakes, and other small animals.  We learned more when our young neighbor, Vivian, found a number of dead animals on the pine needles at the base of the tree and sent the picture above.  Her mom then went above the call of duty and put them in a plastic bag for me so I could examine them.

By this time they were fully "ripe" and loaded with maggots.  All six mammals were rodents, possibly voles.  The baby bird has a beak that looks like a mockingbird, possibly one more reason why the attacks were so persistent. It may have been a fledgling on the ground.

The mystery now is what were these apparent victims doing on the ground?  Aside from a few possible little pecks on the abdomen of the bird, the bodies were intact.  According to Audubon*
"Female remains with young most of the time during first few weeks. Male brings most food, and female tears it into small pieces to feed to the young. After about 4-5 weeks, food is dropped in nest, and young feed on it themselves. Young leave the nest about 6-7 weeks after hatching, but not capable of strong flight for another 2 weeks or more. Fledglings may remain with parents for several more weeks."
Lisa Berger suggests that the parents may have been overfeeding them and the chicks responded like a strong willed toddler pushing food off the plate.   Another possibility is that a neighborhood cat is storing its treasures under the tree after its family failed to appreciate its gifts.  I am open to any other suggestions from our more learned "bird brains."