Yellow meadow ant
In my role as a Farmland Biodiversity Advisor at the GWCT, I have the privilege to work with lots of people, farms and estates who are either doing great things for biodiversity or are wanting to, so I get to see some fantastic places and give advice on array of land management topics.
Doing so, I have built some good relationships with farms and estates who I work with. So much so, one gamekeeper in particular likes to offer suggestions for the Species of the Month. Recently, the gauntlet was thrown down after advising the estate on the management of a chalk downland site, but why make things simple? He made it trickier by suggesting two species rather than one and how they have a very interesting symbiotic relationship. I am not one to walk away from a challenge, so I give you the yellow meadow ant (Lasius flavus) and blue butterflies (Chalkhill and Adonis).
The yellow meadow ant is the creator of the characteristic spherical lumps and bumps (ant hills) on chalk grassland and downland habitats, which also sometimes appear in garden lawns if the grass is not cut too often (#NoMowMay has definitely increased the little anthills in our garden lawn!). Ant hills, also known as ant mounds, are small structures that serve as nests for ant colonies. The formation of ant hills begins with a queen ant establishing a colony and laying eggs. As the colony grows, worker ants excavate soil, creating these impressive mounds and digging intricate tunnels and chambers.
The workers build the soil dome above the nest (which can extend a metre below the ground), which helps to regulate the temperature and humidity of the chambers below. As with all ants, the yellow meadow ant is social and forms colonies; the workers are mainly active underground and are not often seen above ground unless the nest has been disturbed, as an example, by our largest woodpecker in the UK, the green woodpecker (Picus viridis), which peck at the anthills so they can unearth and feed on yellow meadow ants.
During summer, winged yellow meadow ant adults pair and mate, the females dispersing to form new colonies.
Identification
So, what do these little insects look like and where are they? The yellow meadow ant is widespread and as its name suggests, a yellowy-brown colour.
Ecologically important
Did you know that ant hills are of ecological importance to rare chalk downland plants species (when active or not), butterflies and birds (when feeding on the ants)?
When ant hills are active, they bring chalk to the surface and produce a light, airy soil, which is not found elsewhere, and due to their shape and increased elevation they create their own mini climate around them, which hosts a number of important plant species communities as they become vegetated.
Ants also play a crucial role in seed dispersal, as they collect and transport seeds to different locations, aiding in plant growth and the distribution of plant species.
Even when they are not active, the plant communities growing on the outside of the ant hills, namely horseshoe vetch, attract the chalkhill blue and Adonis blue butterflies. These butterflies have a very important symbiotic relationship with ants, a phenomenon called myrmecophily. The larvae produce a sweet secretion from a ‘honey’ gland, which is a food source to ants. The ants are attracted to this and tend to the larvae in their ant hills, who in return are offered a level of protection from potential predators and parasites.
Therefore, think twice before you manage your grassland with these incredibly important ecosystems, which have been built up over many years and support a large number of species of plants, insects and birds. The best form of management is grazing, outside of the flowering season, and do not mechanically manage the sward as this would level the ant hills to the ground, thus destroying something so important.
Megan Lock
Advisory
Image credit: AJC1