Beavers and Dragonflies

Friends in damp places

heidi08 Beavers, Beavers elsewhere, Beavers or Social Ambasadors, Creative Solutions, Educational, Environmental November 4, 2012

Storm Sends Beavers into Pentagon City Streets

Humans aren’t the only ones suffering the effects of Superstorm Sandy. The storm apparently forced some beavers out of their habitats and into the streets of Pentagon City.

A few residents who live in a condo complex on S. Hayes Street were about to head out this morning when they were surprised by a wet, furry visitor.

The residents called animal control upon encountering the beaver scurrying from door to door. Desiree Lomer-Clarke said the animal control worker who came to the scene reported having to deal with two other beavers earlier this morning.

Wow, that qualifies as the kindest possible reception to some stray beavers from our friends in Virginia. Considering that folks were water soaked and very recently had the most famous rabid beaver attack in the history of the world just 7 miles away in Lake Barcroft, this was truly unexpected kindness.

The displaced beavers were not acting in an erratic manner to suggest they would have rabies — as happened twice this summer during beaver attacks in Fairfax County — so they were released near their homes.

As the area’s water levels return to normal, Zell said the beavers that wandered Pentagon City should be able to once again inhabit their dens. If the dens were damaged or destroyed by the storm, the animals should adjust easily to a new habitat.

Sounds like Mr. Zell is a friend of ours. You have to wonder what were the compassion strings that got pulled behind the scenes to let this happen so smoothly. Well, I never look a beaver gifthorse in the mouth. Thanks Pentagon city for showing some uncommon sense in a time of watery distress!

And to follow up on the dragonflies in beaver ponds report here’s a fantastic poster from their work in Germany. Click on the image for a better look.

St. George and the Dragonfly

heidi08 Beavers, Beavers elsewhere, Educational November 4, 2012

Brought to our attention by our beaver friends in Wales but based on a study conducted in Germany

The effect of the Eurasian Beaver on Dragonflies and Damselflies (Odonata)

In order to compare beaver ponds with woodland streams representative of large areas north of the Alps, but yet not influenced by the beaver, we studied the following habitat types:

1. Natural springs (definite woodland springs)
2. Streams (natural – semi-natural in woodland, not influenced by the beaver)
3. Beaver ponds (some 10 -15 years old, up to 2000 m², sunny to half-shaded).
4. Beaver ponds abandoned for 1 to 3 years.

Now, being as that I’ve been watching our own beaver ponds for the last 5 years and have seen the density of dragonflies wholly influsenced by the quality and quantity of dams, I’m going to guess the answer to this research question before I get to the end of the story. The year that our dams and lodge were totalled, and mom was dead and dad took off for a while, there was a huge drop in our summer aviators – partly because everything they wanted to eat was washed away. But let’s see what they found anyway? (And by the way, if you’re like me you would appreciate a reminder of the difference between dragonflies and damselflies) when at rest damselfly wings lay parallel to the body, while dragonflies are still perpendicular like airplanes. Now with that out of the way, lets read on:

Conclusion

Despite the relatively short period of time since the return of the beaver, and the rather small number of beaver ponds, the ponds already now make a remarkable contribution to the conservation and spread of rare dragonfly and damselfly species.

Beavers contribute markedly to nature and species conservation in the densely settled countryside of Central Europe. The species should therefore be more greatly integrated into plans to implement conservation measures and renaturisation of water bodies than it has been to date.

Particularly notable are:

– The extraordinary combinations of species (boreal alongside sub-Mediterranean species)
– The extremely different habitat requirements of the species
– The increase in typical stream dragonflies and damselflies in spite of damming by the beaver
– The increase in part of highly endangered species

Are you shocked? Me neither! Being that dragonflies eat the kinds of things that hatch in beaver ponds, it should be a surprise to no one that they actually do better with some beavers around to make and maintain the ponds. Still, we are always grateful when someone goes to the trouble of documenting the obvious, because it is apparently very hard for some people to see even with proof.

A dragonfly is a remarkable predator. Once I sat in the sun and a slender blue example decided to sit on my knee, and use that perch as a landing pad for his continued predation. He would wait with little twitches of his tale, discoball eyes on the gnats floating around my garden, spy one that looked a likely target and ZOOM zap out of his perch to snap the gnat up mid-flight and then settle again on my knee perch while he was still swallowing. He would repeat this as long and as often as I watched or waited. I remember once a million years ago rescuing a drowning dragonfly in my canoe off mirror lake in Lassen, and allowing its drenched form to dry in the sun while I paddled about. While the soaking creature dried at close range I was very surprised to learn that even though dragonflies have pretty remarkable wings, when you are in any proximity to them you realize fairly quickly that are also really big carnivorous bugs.

So there are more kinds of dragonflies and damsel flies at beaver ponds? Gee, I guess there must be things that eat these creatures too! Someone should do a study on whether their populations go up near a beaver pond next!

“The left hand doesn’t know what the right hand is doing”…

heidi08 Beavers elsewhere, City Reports, Creative Solutions, Who's Killing Beavers Now? November 30, 2011

Or maybe how many fingers it has…or whether there actually IS a right hand at all. Remember the beaver-dragonfly dilemma of Upton Massachusetts? They wanted the dams gone and the beavers dead but the ponds maintained to preserve the rare dragonfly. I heard from Mike Callahan that he had been out to present to the commission and they were half in favor of hiring him and half against. I guess they both got their way because this mornings article makes as much sense as any series of opposite contradictions I’ve ever not-read.

Upton commission decides to lower water level in war on local beavers

Conservation Commission members said last night they will give a beaver control specialist the go-ahead to lower the water level on the 30-acre bog by a foot over the next two weeks, 6 inches per week.

Michael Callahan of Beaver Solutions in Southampton will install a $1,280 pond leveler, a pipe system that pumps water out while keeping beavers away, over the next two weeks, but that is only a short-term solution, Conservation Commissioner Marcella Stasa said.

“Once the level is down, we have to trap all the beavers, because their inclination is to bring the level up to where it was,” she said.

Where to begin? I was excited at the beginning of this article but my hopes were well and truly dashed by the end. Seems one of the commissioners is a former trapper, which, well why shouldn’t he be on the conservation commission? Things that are dead are conserved, right? – well, preserved? After they finish paying Mike for getting in the near-freezing water and installing the pipe the former trapper has volunteered to pick them off one by one.

Commissioner Tom Jango has volunteered to trap the beavers free of charge, commission Chairwoman Christine Scott said.

Mind you, that quote is from the chair herself, which means the deep confusion in this committee runs from top to bottom. Are they keeping the beavers? Killing the beavers? Draining the pond? Not draining the pond? No one knows, certainly not the reporter who is not nearly as curious about this whole zen cohen as you might expect. Don’t you love how the flow device installation is a short-term solution but trapping is the real answer? I guess Upton thinks these are the LAST BEAVERS and once they kill off these castor-dinosaurs there will never be any others. Who has the heart to tell them?

The gnarled old trapper. The bright young scientist. The peacemaker who won’t take sides. I can’t help thinking that the commission meeting must look something like this.