Saving England's most threatened species from extinction

The complex life of a Narrow-Headed Ant

The fact is we know next to nothing.
Now is the field season and chance for ant observations, yet each new discovery prompts more questions, as on Terry Pratchett’s Discworld, pushing back the boundaries of ignorance.

We knew aphid honeydew was an important dietary component (an ant energy drink) and expected oak, birch, and gorse aphid farms, with the occasional caterpillar or spider scavenged for protein.
We didn’t anticipate fibrous bobbles of insect frass and wormy snail pooh fetched back to the nest, for purposes not quite certain, possibly building material. Also bracken nibbling, repeatedly at a bruised stalk, and tending moth larva in rolled up birch leaves.

And it’s not just eating habits. We GPS-logged locations of 135 nests, 140 nests, 138, 153, 146, 168 nests… The numbers change as quickly as the scurrying ants themselves.
The spring snapshot survey recorded 135 nest structures on the main site compartment, but we’re aware nest generation can be quick – one study found nest material shifted from one location to another within 24 hours. Not just moving house; it’s deconstructing a whole block of flats and rebuilding it, structure and contents. As well as nests moving around, we find new vigorous mini-satellites have popped up since the last site visit. Some small nests have grown to busy city blocks; others have disappeared; sometimes large nests lapse into inactivity and are abandoned; others have stayed put and gradually expanded their diameters over years.

An advantage of smaller ant colony sizes must be that they can be fleet of foot, or feet, in response to transient conditions. But it plays havoc with our nest census, and working out which nests might be the most thriving, and therefore promising, for raising new queens. It’s like keeping track of a multi-dimensional chess game.

We need to give it a try though.
We’ve embarked on some homemade low-tech citizen science, marking and watching ants, where they go and what they do, keen to discover more especially about Narrow-headed Ant foraging and ranging behaviour: how far from the nest, types and numbers of prey, whether returning to the same nest, or a different one. It seems there’s a multiplicity of answers and possibilities. Some individuals act as nest defenders, happy to bite first and ask questions later; whilst so engaged these can be dabbed deftly with marker paint. Others away from the nest, foragers and explorers, are more evasive, hard to catch, swift as orange-brown quicksilver. Strategically placed segments of apple or pear, proxy honeydew, preoccupy them long enough for us to add some careful paint blobs.

Worker takes prey item, queen to new nest – checkmate.

 

Stephen Carroll

Narrow-Headed Ant Back from the Brink Project Manager

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