Hiyall,
I've been updating very irregularly. Main reason has been work and my master's. Work has been standard fare: nature surveys (mostly birds and habitats) in Helsinki area, including Inkoo, Järvenpää and Espoo. After that I worked as an intern in Finnish Enviroment Center's ecosystem service group in Archipelago Sea, interviewing people. Of course, I got some vascular plant ticks as well, including but not limited to: Agrimonia eupatoria, Melampyrum cristatum, M. arvense, Cardamine impatiens, Helianthemum nummularium, Polygala vulgaris and Carex caryophyllea. Right now I am theoretically working on another similar project, writing ecosystem service indicator lists and searching for raw data. "My work here is essentially cut and paste."
However! Since may I have also been working on my master's. My subject is generally aquatic communities, and more precisely "how does changing hydrology and fish predation affect Odonata communities?" I have gotten helpful advice and locations from a researcher in UEF, who focuses on Greater Crested Newt Triturus cristatus. GCN ponds are excellent study subjects due to absence of fish and highly variable enviromental gradients, randing from irregularly drying "aro/lössä" habitats to stable kettle ponds, prominent in glacifluvial formations of North Karelia. My comparison data is mostly from more stable, fishy ponds, and I intend to seek patterns in vegetation heterogenity, hydrodynamics and community structures. Hope it works! I will probably vent my anger and frustration here.
Yesterday me, Elina and Leo took a day off from office and drove to collect my last samples of my second sampling tour. We saw several GCN larvae - including some in very young habitat that is in very early stages of aquatic macrophyte succession - and an adult Aeshna crenata. Of course, of more common Aeshnas grandis, cyanea, juncea and subarctica were also prominent. My greates surprise was when we netted a F-0 crenata larva from a fishy pond. Handling it carelessly, I soon noticed that it can use it's cerci and paraproct (which, together with epiprocts, form a structure known as anal pyramid) to grab, slash and stab potential enemies, which happened to include my fingers. It actually drew blood, something I had never seen an Odonate larva to do successfully before. (Crenata larva is easy to identify in F-0, being very large and having obvious lateral spines in S5-9, often even in S4.)
That defence mechanism has been described several times before, even from almost fully metamorphized individuals (Corbet 1999), and I was both surprised and happy to see it in situ. Larvae use threats, waving their abdomen, when encountering conspecifics in nature (own obs., aquarium, 2007), so the stabbing is most definitely not just an aberration, but a real, concrete defence mechanism.
