Sunday, January 21, 2018

Mealworms and Stink Bugs...tasty winter treats for Carolina Wrens!

Mealworms
There's no denying the Carolina Wrens in our backyard love mealworms (beetle larva), so to keep them happy I hide a stash of the larva in a tiny ceramic birdhouse in a pot on our deck. The entry hole in the birdhouse is small enough for a wren but not a starling, so the mealworms don't disappear in a hurry when the starlings (who also love them) descend in a mad feeding frenzy. Funny thing is, when the little birdhouse runs dry, the happy Carolina Wrens let me know they are unhappy by perching above the tiny house and sending me accusatory glares...

If that's not an accusatory glare I don't know what one is. 
"Where are my mealworms, woman?" seems to radiate from his adorable puffed-up self.  

Waiting...waiting...waiting for a refill...
(Is he tapping his little bird toenail in annoyance?)

...emerging from the tiny house fueled up on mealworm protein and ready for dessert...stink bugs!

Marmorated Stink Bugs 
This winter the Carolina Wrens have been especially spritely and chippy on our deck, and Rick and I have loved watching them. They've also developed a new habit...scouring the curtains fastened at the corners of our "Big Tent." It's not really a big tent, I just call it that. It's one of those canvas gazebo things we've anchored to our deck. It works really well in the summer keeping the sun off us, and, apparently, it works really well in the winter as a super secret hiding place for stink bugs trying to overwinter in peace. Unfortunately for the stink bugs, our Carolina Wrens have found them out. One day I noticed the folds in the curtains moving when suddenly a Carolina Wren popped out. He had a clearly identifiable Marmorated Stink Bug in his bill. He threw the bug down and proceeded to peck at it and then eat it. "Whoa, that's cool," went through my mind, so I watched for more. He immediately flew back up to the curtain, dove in and came back out with another Marmorated Stink Bug. Over the next few weeks, our Carolina Wrens spent a lot of time searching for and finding stink bugs in the curtains. The activity has lessened, so I think all the tasty treats have been found.

Our "Big Tent" 

The folds in the fastened curtains have become a hiding place for stink bugs.
The folds have also become a treasure trove of a winter protein source for our backyard Carolina Wrens. 

I wondered if Carolina Wrens eating overwintering stink bugs was a thing, or if ours just stumbled on the pests and were "making do" in winter, so I looked it up, and it's a thing! Carolina Wrens love stink bugs, and stink bugs like to overwinter in groups, so when they find one stink bug, they look for more in the same location. Stink bugs release an "aggregation pheromone" to attract other buddies to their super secret winter hiding places or to good feeding sources, which is why so many were hidden the folds of the curtains. Carolina wrens are cavity nesters, and they regularly search crevices and cavities for insects. Since they also take well to man-made nest boxes, it was inevitable that the wrens would search in the man-made crevices of the curtains and end up finding their winter prey.  (When insects "overwinter" they enter a hibernation-like state called "diapause.")

We never use the curtains on the Big Tent, so early this summer I thought I might take them down, but then I forgot to do it! I'm glad I forgot...and I'm also glad I didn't know the stink bugs were slowly gathering for the big winter sleep (or I would have taken them down). Now...next winter our Carolina Wrens will again  have easy hidden treats to find.

Reference links to find out more about Marmorated Stink Bugs and the aggregation pheromone:

  United States Department of Agriculture (July 16, 2014): "ASDA Researchers Identify Stink Bug Attractant"

  EntomologyToday (July 16, 2014): "Scientists Decipher Stink Bug Aggregation Pheromone"

  Rutgers New Jersey Agricultural Experiment Station: FAQ "Monitoring for the Brown Marmorated Stink Bug"

  The Journal of Natural Products, 2014, 77 (7), pp 1708-1717: "Discovery of the Aggregation Pheromone 
  of the Brown Marmorated Stink Bug (Halyomorpha halysthrough the Creation of Stereoisomeric 
  Libraries of 1-Bisabolen-3-ols"



13 comments:

Sarah Wigser Carefoot said...

Great pics and great information! Love that you were able to figure out the Carolina Wrens were eating the stink bugs. :-)

Roy said...

Love the Wren shots! And thanks for the heads up on stinkbugs; the Wrens around here must be well fed this Winter considering the amount of the bugs I've been seeing this year in these parts!

Kelly said...

@ Sarah - Thank you! It was fun watching them....so fun the first time one popped out with a stink bug! Not only are those little fluff balls cute as can be, they are workhorses! :-)

@ Roy - ....or maybe your wrens have more discerning taste! :-)

Roy Norris said...

Lovely winter scenes Kelly.
Yes mealworms are definitely a nice treat for the birds.
I feed the nuthatches and robins etc during a photoshoot and they love them.

Elva Paulson said...

That was a great post! I didn't know about the stink bug gatherings, nor it hadn't dawned on me to hide meal worms in a bird house where the big guys can't reach.

Kelly said...

@ Roy - Thanks, Roy! Now....we need some blue sky to brighten things up a bit. Too much gray around here.

@ Elva - Thank you, Elva! You know absolutely everything about nature, so that makes me feel happy! My wrens were at it again. I had to refill again today. They are adorable, and they love their tiny mealworm house! :-)

Mary Ann Gieszelmann said...

The birds know a good place when they see it -- Your Yard!!

Janice K said...

Loved seeing your little Carolina Wren. I see one regularly at our feeders. I started putting out meal worms recently because during the ice and snow a couple weeks ago about three pairs of Bluebirds showed up. I don't usually see them this time of year, but last summer the pair that came had lots of babies. The funny thing was the day they arrived, they sat glaring in my window as if to say "Where's the worms you had here before?" Fortunately I still had some.

So nice to see a post from you. I still take birds pictures occasionally, but just don't seem to find the time to post. Have a Happy Day.




Janice K said...

Loved seeing your little Carolina Wren. I see one regularly at our feeders. I started putting out meal worms recently because during the ice and snow a couple weeks ago about three pairs of Bluebirds showed up. I don't usually see them this time of year, but last summer the pair that came had lots of babies. The funny thing was the day they arrived, they sat glaring in my window as if to say "Where's the worms you had here before?" Fortunately I still had some.

So nice to see a post from you. I still take birds pictures occasionally, but just don't seem to find the time to post. Have a Happy Day.




natureismytherapy.com said...

Excellent post, Kelly! I love how you investigate everything and teach us something every time you write. :) ~Kim

troutbirder said...

I don't recall every seeing them here in southern Minnesota but the can definitely cast an accusatory look or perhaps a guilty conscience has entered in to your observations. Still hope to see one some day...:)

David Gascoigne said...

There is not a doubt in my mind that backyard birds quickly recognize the people who feed them and do indeed figure out ways to let you know when the larder is empty.

Kelly said...

- Hi Mary Ann! Hahaha....your yard too, I bet!

- Hi Janice! Ahhhh...lucky you! Bluebirds! We haven't been able to lure bluebirds to our yard yet. Our yards might be too suburban. Glad they already showed up for you!!!

- Hi Kim! Thank you! I have to investigate because there is so much I don't know! Hahaha!

- Hi Trout! Hahaha.....yes...it's always fun to anthropomorphize a bit with our birds. ...but truly they have trained me to let me know when they need more mealworms! Haha!

- Hi David! So true....when I walk in the backyard with seed for the feeders, they chickadees are the first to see me and sound the alarm that a refill is on the way! I love hearing the chickadees get excited for more sunflower seeds!