Animal Behaviour Assignment - 2 Observation of Water striders Initially the aim of our project was to study the behavior of Water striders (Family – Gerridae) in Pashan lake, but the lake going through rapid eutrophication and as a result of which, the populations of Water Striders in the lake have disappeared. Hence, we have instead worked on a smaller population of them in a puddle adjacent to the lake. This observation itself gave us an idea of the habitat, ecology and behavior of the Water striders. However the timescale of change was too rapid for us to make any noteworthy observations on the Water striders response to the phenomenon. At the first glance, the Water Striders seem to be skittering randomly across the surface of the water. However, on prolonged observation, they seem to start moving in response to certain cues. Hence, we observed the population of Water Striders to qualitatively discern the cues that may cause a response in the Water Striders. These are some of the naive observation we made: Not territorial – 2 out of 14 were observed to stay at one location and occasional bumping into other water striders was observed with no aggressive behavior There is increase in movement of the Water Striders with the presence of dragonflies howering around. They don't move in large groups. (n=14) Stationary Water Striders tend to start moving when there is some wind. Mostly situated in calm waters and found nearer to the bank of the lake They stay in open waters away from vegetal growth Due to their ‘walking on water’ ability, a lot of the available literature is focused on the physiology and the physics behind their remarkable ability. However, some literature also focuses on the behavioral aspects of these organisms. Here are some of the things we learned from the literature: Water striders prey on dead or alive insects on the surface, of which injured dragon flies are a common prey. They are predated by birds mostly only and occasionally by fish and frogs. They are territorial during the mating season where both males and females establish territories.