2025/06/09 by Peter Chanas, Jan Frouz · 1 voice
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Neuroscience · #Insect and Arachnid Ecology and Behavior #Plant and animal studies #Neurobiology and Insect Physiology Research
paper · pdf · doi:10.1007/s00040-025-01043-z
openalex publication_date 2025/06/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/23
Abstract Red wood ants form dense clusters of ant workers on the sun-exposed surfaces of their nests, which is assumed to play an important role in rapid spring heating of the nest. Here, we explored factors affecting temporal occurrence of these clusters. Nineteen Formica polyctena nests at two sites were equipped with automatic cameras that took pictures of the nests every 20 min during daytime from March to June (87 days). At the same time, nest internal temperature and air temperature were recorded. Evaluation of more than 57,000 photos showed sunning clusters in all nests, but with variable frequency of occurrence among individual nests. On average, sunning clusters were present on 26% of observation days, with a range of 3% to 54% of observation days. When clusters occurred, they were present in ~ 32% of observations for a particular day, but with substantial variation, from 3 to 72%. The number of days when clusters occurred correlated with the number of cluster observations on each day. The daily frequency of cluster occurrence showed a unimodal distribution. In early spring, the frequency was low and increased as internal temperature and duration of daylight increased. Segmented linear regressions showed that cluster frequency decreased after breaking points of nest internal temperature at 7.04 °C and 13 h and 24 min of daylight. The daily occurrence of clusters in early spring correlated positively with air temperature, but as nest temperature increased, this correlation of cluster occurrence with air temperature gradually faded and eventually became negative at a nest temperature > 20 °C. Obtained relationship between clustering behavior and internal and external nest temperature allow us to model occurrence of this behavior, suggesting that with increasing nest temperature not only clustering tendency decreased but also clusters tend to less attracted to heat sources.