12 replies to this topic

[Arjan van den Bosch]

Hi, thanks for your welcomes.

Snow is maybe a sensitive topic now for some of you, but for me snow is one way to do wood ant observations during winter. Because the ants, in this case Formica polyctena, isolate their nests very well, the warmth stays in. So, their dome keeps cooler than its surroundings. The effect is that when temperature is around zero, snow on the nests lasts longer.

 

In this case the snow tells me that this nest is populated, without seeing any ant.

Edited by Arjan van den Bosch, January 28 2015 - 4:27 AM.

[Crystals]

That is very interesting.  Where are you located again?

 

I am in northern Alberta (Canada) and the Formica mounds all face south to catch the most light.  Oddly enough, up here, the nests are the first things to melt.  We then see the ant nest with no snow and ants sunning themselves, while everything else is covered in snow.

The back side of the nest where there is a shadow may have snow, but the sun facing side is one of the first things to melt.

 

My spring is still 4 months away or so, so I will have to wait to get pictures. 

[dean_k]

He's a dutch.

[Arjan van den Bosch]

This photo was taken in The Netherlands january 25th, but the FB page from naturgucker.de posted a nice photo today with 'Scheeflohe' on snow.

 

When temperature and sunpower are richt, the ants start sunbathing. This year several colonies started with this spring behaviour, just days before the snow came.

On these nests, snow melted first, because the ants came out and opened the 'doors'. So heat can get out and snow melts first.

 

The nest on my photo was not active, because it is located in the shadow of large trees. Temperature and sunpower are not right. So, the dome is not opened yet and isolation function stays intact.

Edited by Arjan van den Bosch, January 28 2015 - 8:44 AM.

[BugFinder]

That's very cool!  Thanks for sharing that with us.  How did you discover or learn about that?

[Arjan van den Bosch]

Controling conditions inside greenhouses is partly based on measures on local outside conditions like solarpower, temperature and wind. I use these data for biological pestcontrol in the greenhouse. I noticed, not accidentally, that these influences also affecting woodant behaviour. I measured nestconditions like inside temperature and surface temperature and took outside-greenhouse data and compared it with the woodant´s behaviour. Since I am unemployed I use other local data from this local website.

 

This nest (photo) was active today. You can see one of the openings they created in their dome. It seems that the colder weather with snow that is comming in right now does not trigger them to close down for a second biopause. So they are an easy target for hunters like green woodpeckers now!

• Formica polyctena
• Temperature (5,5°C)
• Solarpower (469 W/m2)

[kellakk]

That is very interesting.  I have also noticed that the activity of the ants is very affected by solar radiation and other conditions. Just to be clear, the inside temperature of the nest was 5,5°C?

[Arjan van den Bosch]

That is very interesting.  I have also noticed that the activity of the ants is very affected by solar radiation and other conditions. Just to be clear, the inside temperature of the nest was 5,5°C?

I ment outside temperature, thanks for noticing.

[kellakk]

I'm curious now. What was the inside temperature?

[Arjan van den Bosch]

Last year the temperature 10cm below surface on the sunny slope was about 10°C, under same day conditions and ant behaviour. But that was after a period of colder weather. At this time I am not equiped to do more measurements.

[kellakk]

That's still quite a bit warmer than outside.  Amazing how ants have made such clever use of physics.

[Arjan van den Bosch]

They have the opposite behaviour when there is to much solar power. Some years ago I made a small video from wood ants hiding for sunlight and placed it on website... external link

[Trailandstreet]

Hello Arjan, you've got a nice website there.

 

Formica s str, especially the "regular" woodants, like Formica rufa  and polyctena are homoiotherm. That means, that they can keep their nest temperature nearly constant over the whole year.