A Glimpse into the Hidden World of Ant Nests

Wood Ant Monitoring at Greno Woods

Over the course of three months—May, June, and September 2023—I had the privilege of participating in a fascinating wildlife study at Greno Woods, one of the most beautiful woodlands in the region. Our task, to monitor the abundance and distribution of hairy wood ant (Formica lugubris) nests across the woodland, laying the foundation for future monitoring and research. As someone who has always had an affinity for the natural world, this was an exciting opportunity to take a deep dive into the life of these industrious insects and learn more about their role in the ecosystem. 

Developing this understanding is so important for shaping how we care for our reserves, making sure everything we do is both appropriate and effective. Monitoring like this is at the heart of our evidence-led conservation program.

Mapping the Nest Locations

The first step in our study was to track and map out the wood ant nests. To do this, we employed a combined transect and grid square-based sampling approach. This meant systematically walking along pre-set transects and grids within Greno Woods, carefully documenting every wood ant nest we encountered.

The results were astounding: we located a total of 496 nests across the site, each varying in size and location. The nests were spread out across various areas of the woods, including the coppice and heathland zones, and even along existing tracks. Interestingly, we didn’t find any nests in Hall Wood, though it’s possible they may appear further north in the coming years as we continue our monitoring efforts.

Nest Size and Distribution

© Wood ant monitoring_Nest Density_2023 (1)

When it came to the size of the nests, we were taken aback by the sheer range of volumes we recorded. The smallest nest we found had a volume of just 0.28 litres, while the largest one reached an impressive 1,190 litres! The average nest size across the study area was around 85.7 litres, showcasing just how diverse the nests can be, even within the same woodland.

Nests were spread widely throughout the woods, with a higher number appearing in open, less densely vegetated areas.

The Role of Light and Canopy Cover

© Wood ant monitoring_Light_2023 (1)

One of the more intriguing aspects of this monitoring project was examining how light levels affected nest density. While nests were more abundant in areas with higher light levels, the correlation wasn’t as strong as we’d expected. There are several potential reasons for this. For example, we noticed that larger nests, in particular, seemed to thrive in areas with lower light levels. This may be because larger nests are less dependent on sunlight to regulate their internal temperature, or simply because older nests tend to be surrounded by more mature vegetation that blocks out sunlight.

We also explored the relationship between canopy cover and nest density. It turns out that wood ants appeared to prefer areas with young trees or open spaces where there’s little to no canopy. The denser, more mature tree cover seemed to discourage nest formation, likely because the conditions underneath these trees weren’t as favorable for the ants.

What Does All This Mean?

For me, the results of this study were a reminder of how interconnected the natural world is. The distribution and size of wood ant nests are influenced by a complex interplay of factors, from light levels to canopy cover and even the age of the nests. As we continue to monitor these nests in the future, we’ll have the opportunity to track changes over time and learn even more about the behavior of these fascinating creatures.

In the end, this project gave me a deeper appreciation for the small things in nature, like the humble wood ant. It also highlighted the importance of careful monitoring and research to ensure that our reserve management works to preserve not only these insects but the entire ecosystem they help sustain. Here’s to many more years of uncovering the secrets of Greno Woods—and the wood ants who call it home!

© Made possible with Heritage Fund

Our Evidence-led Conservation is made possible with The National Lottery Heritage Fund.