Wednesday, July 20, 2016

Restoring Bottomland Prairie: A Tale of Two Julys (2015 vs. 2016, Part 1)

Some of these posts have given the impression of steady progress in the restoration of a native-plant community to our bottomground.   
And it's true--succession is unfolding before our eyes.  There are fewer non-native invasives, fewer weedy annuals, more native perennials, and a greater number of species.  

A Marine Blue (Letotes marina) nectars
on American Bellflower
(Campanulanum americanum, native annual volunteer). 
Creek Buffer.   July 15, 2015
However, it is not true in every area.   

For example, a year ago I photographed pollinators all over American Bellflower blossoms.  

Here are a Marine Blue, a Resin Bee,  a Longhorn Bee, a Brown-belted Bumble Bee, and a Cicada Killer, all nectaring or pollen-gathering on the same Bellflower plant and all from an hour or two on July 15, 2015.

A Resin Bee
(Megachile sp., sub-family Chelostomoides)
A member of the Leafcutter family, but   
lines cells with resin or dirt instead of leaf parts

Longhorn Bee (Melissodes sp.) on Bellflower.
Note long antennae & the yellowish-white hairs
on  hind legs.
Creek Buffer.  July 2015.

Brown-belted Bumble Bee (Bombus griseocollis)  
Creek Buffer, July 2015

Resin Bee, another view.
July 2015

A Cicada Killer (Sphecius speciosus)
Creek Buffer.  July 2015

All of these species appeared on a single clump of volunteer American Bellflower.   That one clump was accompanied by a rudimentary second clump a few feet away. That was it for American Bellflower on the Creek Buffer in 2015.  

Now a year later there are at least 8 clumps of Bellflower in that same area, while there are new patches getting started, one on the southern edge of the Creek Buffer and one at the northeast corner.

But there are no pollinators!

I've sat and watched one clump after another, but no luck.  Not a single butterfly, bee, or wasp has come to the blossoms.
All dressed up and ready
for the party--
but where are the guests?
Creek Buffer.   July 2016.

This clump of volunteer Bellflower shares with
Switch Grass an area newly liberated from Crown Vetch.
South end of Creek Buffer.  July 2016. 
This clump is north of where
Bellflower appeared last year.
Creek Buffer.   July 14, 2016

The setting sun breaks into spectrums of color
around a new bunch of American Bellflower, one
of  8 blooming in the original area.
Creek Buffer.  July  14, 2016
 American Bellflower is volunteering in greater numbers this year than last.

Where are the pollinators?  Why am I not seeing them this year?

Some possibilities:

1)  The greater number of Bellflowers means that pollinators have more to choose from.  That means my camera & I have less chance of being in the right place at the right time.

2)  The greater number of species blooming in the Creek Field means that pollinators aren't so dependent on Bellflowers.   Again, my chances of seeing them go down.

(I like those first two hypotheses.)

3)  A restoration means that flower numbers increase exponentially, in a big burst.    Perhaps insect reproduction is not synchronized with such bursts.   

4)  Perhaps pollinators are declining for reasons other than habitat-loss, so restoring habitat isn't enough to bring them back.

(Boy, do I hate that one!)

5)  Maybe this is just one of the changes--mysterious ups and downs--that characterize any ecosystem, with causes too numerous & tangled for us to ever understand.

(This one is always true to a certain extent--which doesn't dampen our desire to untangle & understand!)

5)  Perhaps our weird spring (repeated alternations of heat & cold)  set insects back.  Many Kansans have been talking about how few butterflies they've seen this year.  Perhaps this particular spring was hard on some pollinators.

6)  Some but not all.  I am seeing many Bumble Bees on the Creek Field flowers, mostly Southern Plains Bumble Bees (Bombus fraternus).   That's a species that's doing just fine.   But I have not seen the species I saw on Bellflower last year--the Brown-belted Bee, the Longhorned Bee, the Resin Bee, the Marine Blue--   

Where are they?  What has happened to them?

If any readers of this blog have thoughts on this topic, please leave  a comment--or email me at

Thank you!

1 comment:

  1. I think the cool wet spring has something to do with populations. I'm seeing quite a few larger bees at my bellflowers. FYI, bees love bellflower.