Control of the change from group to pair behaviour by Hodotermes mossambicus reproductives

Groups of Hodotermes mossambicus reproductives exhibit social behaviour. Maintenance of this behaviour by an individual depends on frequent contact of its body by the antennae of other termites. The antennae of the recipient do not play a rôle. Pairs on the other hand exhibit antisocial behaviour. Development of pair behaviour occurs when antenna to body contact is reduced or absent. Furthermore, at least the proximal parts of the antennae are required for full development of pair behaviour. Pheromones are not implicated in the change from group to pair behaviour.     

The influence of year-to-year variations in winter weather on the dynamics of Daphnia and Eudiaptomus in Esthwaite Water, Cumbria

1. Micro-crustacea of the genus Daphnia and Eudiaptomus have evolved different physiological mechanisms for coping with life in a rapidly changing environment. In this paper, we analyse some of the physical and biological factors influencing the winter abundance of the two species in a small lake (Esthwaite Water in Cumbria).
2. The results demonstrate that much of the year-to-year variation in their relative abundance can be related to long-term changes in the weather. The highest numbers of Daphnia were typically found in cold, calm winters when small flagellates were relatively abundant. In contrast, the highest numbers of Eudiaptomus were found in mild, windy winters when the phytoplankton community was dominated by colonial diatoms.
3. Year-to-year variations in the winter abundance of Eudiaptomus had no effect on their subsequent development but the numbers of overwintering Daphnia had a significant effect on the size of their first spring 'cohort'. The most important factor influencing the overwintering performance of the two species was the water temperature.
4. Winter air temperatures over much of Europe are influenced by the atmospheric pressure variation known as the North Atlantic Oscillation (NAO). Winter water temperatures in Esthwaite Water were strongly correlated with this empirical index and there was a significant positive correlation between the NAO and the number of overwintering Eudiaptomus.     

Passerine and secretive marsh bird responses to cattail management in temperate wetlands

Wetlands Ecology and Management - Hybrid cattails (Typha x glauca) are an invasive, emergent aquatic plant that often form monodominant stands, which can alter wetland vegetation structure and...