Dragonfly Behaviour

[Ukwildlifeo]

Originally Posted by King Edward

Another point is that this species generally does very well in garden ponds, breeding in even very small ponds like Red Robin's above, so there's no need to make special arrangements for it other than to provide suitable pond habitat for the larvae.

Funny how things change. I rememeber reading a book a few years ago that dragonflies would not be attracted breed in ponds less than something like 2m across and 1m deep and having emergent plants. Having seen a hairy dragonfly trying to egg lay on a plastic sheet and common darters laying in vegetation free pools and puddles, it shows not all the advice in books is right!

[Red Robin]

Originally Posted by JohanJ

Had one emerge in my pond only yesterday and took a pic of it - Emerging Dragonfly | Flickr - Photo Sharing!

....Nice shot! - Thanks for sharing.

[King Edward]

Originally Posted by Ukwildlifeo

Funny how things change. I rememeber reading a book a few years ago that dragonflies would not be attracted breed in ponds less than something like 2m across and 1m deep and having emergent plants. Having seen a hairy dragonfly trying to egg lay on a plastic sheet and common darters laying in vegetation free pools and puddles, it shows not all the advice in books is right!

Now you mention it, I'm not sure if there is a minimum pond area that would attract these. In a recent thread I suggested that the same pond might be too small to attract pond skaters, so the same could be true for dragonflies. It's possible that Red Robin's nymph came in with plants rather than hatching there originally. Either way, this is a very common garden pond species. I doubt depth is all that significant, except so far as larger ponds tend to be deeper, and several dragonfly species can apparently survive periods of drought.

[JohanJ]

The depth stat is wrong for certain, I've had these for years in a pond just under 2 foot deep.

[Red Robin]

Originally Posted by King Edward

It's possible that Red Robin's nymph came in with plants rather than hatching there originally. Either way, this is a very common garden pond species. I doubt depth is all that significant, except so far as larger ponds tend to be deeper, and several dragonfly species can apparently survive periods of drought.

....Fossil records show that dragonflies have already survived over 300 million years so I don't think we need books to rely heavily on information.

It certainly is possible that the nymph came in with plants in June last year but my very nearby (~60ft) small river has loads of dragonflies patrolling its banks etc so we'll never know.

[Stinky Bob]

I only get southern hawkers laying and hatching in my pond and I only see them ovipositing (pretend or otherswise) on the stonework around the pond never in it and they are not always that close to the pond edge (about 6 - 9 inches in some cases). I counted 11 exuvia last year and 9 so far this year.

[RoyW]

The size of a pond isn't really important, with some species actually preferring very small, even drying out, ponds (something that was known before W. Lucas published his book "British Dragonflies, Odonata" in 1900).

Originally Posted by King Edward

and several dragonfly species can apparently survive periods of drought.

Evidence suggests that all dragonflies need water (or at the very least damp areas - in some species from more tropical areas) while they are in their larval form, and it is unlikely that many, if any, can survive completely drying out while in this stage of their life cycle (freezing is another matter!).

The life cycles of many species do allow them to live in ponds that dry out completely, but these species will spend the dry periods as eggs or in adult form, with the larvae developing quickly in water before it dries out.

Originally Posted by Stinky Bob

I only get southern hawkers laying and hatching in my pond and I only see them ovipositing (pretend or otherswise) on the stonework around the pond never in it and they are not always that close to the pond edge (about 6 - 9 inches in some cases). I counted 11 exuvia last year and 9 so far this year.

It would be interesting, though perhaps difficult, to try and find out whether they are laying eggs on the rocks. If there are plants growing on the rocks, or dead plant material, then I would expect that the eggs are being laid inside these. If not, then I guess that it is possible that they may be laying eggs into cracks and crevices in the rocks, although I have never heard of this before.

[King Edward]

Originally Posted by RoyW

Evidence suggests that all dragonflies need water (or at the very least damp areas - in some species from more tropical areas) while they are in their larval form, and it is unlikely that many, if any, can survive completely drying out while in this stage of their life cycle (freezing is another matter!).

The life cycles of many species do allow them to live in ponds that dry out completely, but these species will spend the dry periods as eggs or in adult form, with the larvae developing quickly in water before it dries out.

Some can survive in damp mud in ponds that have dried up. 'The Pond Book' by Pond Conservation quotes some examples, e.g. Common Darter larvae survived 5 weeks in mud and emerged the same year, and Four-spotted Chaser larvae apparently survived 12 weeks in mud. Original source: Corbet (1999) Dragonflies. Behaviour and ecology of Odonata.

[RoyW]

Originally Posted by King Edward

Some can survive in damp mud in ponds that have dried up. 'The Pond Book' by Pond Conservation quotes some examples, e.g. Common Darter larvae survived 5 weeks in mud and emerged the same year, and Four-spotted Chaser larvae apparently survived 12 weeks in mud. Original source: Corbet (1999) Dragonflies. Behaviour and ecology of Odonata.

Yes this is correct - but there is no evidence that they can survive if the pond completely dries up which is what I thought you meant (my apologies Ed - or should that be Your Royal Highness!).

To be honest, the extent to which different species can survive when the ponds that they are in dry up is something which is poorly known - worth studying if any ponds near you are drying up (probably not too likely at the moment considering the summer that we've had!).