Wednesday, June 12, 2013

Burying the Beetles- II

Ready for the hole- Click pictures to enlarge
We discussed the endangered American Burying Beetle (ABB) in the last blog.  The St. Louis Zoo's Center for American Burying Beetle Conservation has an extensive program which propagates beetles, each individually identified by parents, generation, etc. The eventual goal is to reintroduce them into the wild and hopefully reestablish breeding self-sustaining populations.  Now it is time to get down and dirty.

Ben and friend
So how do we get the endangered American Burying Beetle (ABB) back into the wild?  By burying them!  You may remember in the last chapter we mentioned the importance of having a dead animal of the right size.  This is where the quail comes in.   Our job was to bury a mating (we hope) pair of ABB with a nice fresh...well more like slightly stinky... farm raised quail carcass.  Phew to us but home cooking to the beetle.  Ben Alleger, our young team member with experience in reintroducing ABB last year will lead us through the project in pictures.

We formed up in three teams, each headed by a member of the St. Louis Zoo team.  Each team would be responsible for 100 beetle pairs, each separately boxed and banded together.  Our leader gave out detailed, explicit instructions repeatedly, preventing any mistakes.  After all, these are federally endangered species and none of us wanted to end up in the pen!  Each step included another of his inspections, like a kinder and gentler drill sergeant without the expletives. 

Hole with quail in side chamber
The first task was digging 100 holes, evenly spaced along a straight line.  The hole had to be the right size and depth with a carefully removed lid of prairie turf, to be replaced when we were done.  Next a side chamber was dug out of the hole, all pointing to the same side so they could be found later.  (Editor's note- no volunteers were injured in this project)

Now came the fun- sort of.  A ripe quail was placed in each side chamber, being careful that it didn't stick out into the main hole.  We had to wear rubber gloves to handle the beetles.  Packing in the dead quail ensured that no one complained about wearing the gloves.
Male and female- separate quarters

For our burying project the beetles were carefully paired up, making sure that they were from separate families, no cousins or siblings allowed.  They were packaged in a pair of separate boxes.  They won't meet until the last minute when they get together on the quail.

The highlight was placing the beetles in the hole.  After determining that each pair was alive, we put them individually in the hole, herding them into the side chamber with the quail.  It is important to be sure that none of the valuable critters escapes for they have work to do.

Placing the beetles in their chambers, one at a time.
Release into the chamber

Aside from one which, after smelling the quail, was apparently considering becoming a vegetarian, they all scurried into the side chamber without encouragement, never to be seen again.  We were told that they might make audible squeaks as they mate, something that can take place almost immediately.  Since this was a family venture with pure of heart and mind MDC folks, we didn't watch.  What happens in quail chambers, stays in the chambers.

ABB male climbing over the quail into the chamber, looking for love.
Replacing the turf lid
Now back to work.  As soon as they were in the side chamber, we put the lid of turf back over the hole, using loose dirt to fill in the edges.  Once that was complete for 100 holes, we stretched chicken wire over the strip and tacked it down tight to prevent  marauding mammals from digging out the quail.

With three teams, we buried 302 pair of ABB in three separate plots.  Now it is up to the beetles.  What happens next is described on the St. Louis Zoo website.
"Pairs bury the carrion cooperatively. The female beetle lays her eggs near the preserved carcass. Within four days, the eggs hatch into larvae. Both parents feed their offspring by eating some of the dead flesh and regurgitating it into the larvae's mouths. This goes on for about 6 to 12 days, until the larvae begin their next stage of development, pupation. After 45 to 60 days, the new generation of beetles emerges from the carcass cavity. This process is repeated during the beetles’ one-year life span."
ABB Larvae- St. Louis Zoo
In ten days, the St. Louis Zoo team will return and assess one-third of the holes, carefully opening them to see if the larvae are present.  By this time they should be functioning and the male may have all ready escaped.  After last year's project, 1/3 of the beetle pairs were checked and found to have produced 395 offspring.  Future assessments will include looking for new adults on the prairie.  They have already seen one adult beetle from last year's class. 

The beetles we released have been notched, that is, marked by notching the elytra, the hard, modified forewings that encase the thin hind wings used in flight. The notch distinguishes captive-bred and wild beetles, and beetles are notched based on release location.

Rectangular notch on  right tip
If you look closely at the back tip of the elytra of the beetle on the right, you will see a tiny rectangular notch cut out.  This allows the team to determine if it is one we put in the ground or a member of the next graduating class.

More information on the project is at the St. Louis Zoo website.  A slide show from last year's reintroduction is here.

Team 2- we happy few   Click to enlarge

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