The Hidden Hordes of Lismore

yellow meadow ant

Yellow Meadow Ant Lasius flavus.
Image © Trevor and Dilys Pendleton or

I eventually realised in July 2011 my long-held wish to spend some time on Lismore. Partly I wanted to ‘add’ Lismore to my collection of islands, but I wanted in particular to see what it had to offer in the way of wildlife. My interests in wildlife are wide and varied, but I concentrate on insects of various groups, and particularly bees, wasps and ants.

Only a few hours after arriving, I realised that one of the most abundant insects around was the Yellow Meadow Ant Lasius flavus. This is well known farther south and east as a builder of large mounds of fine soil which provide a warm dry place to bring up the brood, but in W Scotland most of the colonies are in small mounds, or even just in soil under stones or dead wood. In Highland, it is locally common to the N and W of the Great Glen, and is commoner in Lochaber than elsewhere in the region, so I was expecting to find it on Lismore - just not quite so quickly. The Yellow Meadow Ant is often unsuspected unless you see (and are able to recognise) the mounds. Unlike most other ants, the workers rarely venture above ground, most their foraging happening underground where they feed to a large extent on aphids attached to roots - either the aphids themselves or the ‘honeydew’ they produce. They even store aphid eggs to keep them fed over the winter.

Over the next few days, I discovered just how prodigiously numerous these ants were. Almost anywhere on the island where the soil was dry and open to the sun, a gentle scratch of the surface would reveal the presence of the pale yellow ants, each a few mm long. In some places there are dozens of nest-mounds in sight, though the casual observer might never think that they were made and populated by ants. The mounds are often thinly vegetated with Wild Thyme, Bird’s-foot Trefoil, or other plants, but again gentle disturbance of the surface will bring a few ants to the surface.

The total number of Yellow Meadow Ants on the island must be beyond comprehension. A single colony might hold 20,000 or more workers, all the progeny of the queens, of which there may be several in a nest. Fifty nests gives you your first million, and you can find that many in a few hundred square metres in some places. More staggering than the numbers, though, is the fact that the queen ant may live for over 20 years, laying eggs all that time from just a single act of mating shortly after she emerged.

Where densities are high in Europe, it has been calculated that they move 7 tonnes of earth to the surface each year, and that their total fresh weight can reach 150kg per hectare. That biomass is equivalent to four adult wolves/ha - but much more finely divided and more widely spread!

Most attention to wildlife is given to spectacular birds or mammals, but I think Lismore’s top wildlife attraction must be these hugely numerous but mostly invisible insects, with a truly fascinating way of life. As you travel the island, think of them, and marvel.

Provided by Murdo MacDonald on 17th April 2012


Dr Tim King (Oxford) sent the following comments on Fri, 25 May 2012 06:07:18 +0100

Terrific article, beautifully written. Thanks

Pauline Dowling sent the following comments on Wed, 25 Apr 2012 12:29:59 +0100

Extremely interesting and thank you so much for this fascinating and off beat insight into Lismore wildlife.

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