Drunella vs. Pteronarcys

As I mentioned in last week’s blog post, competition for resources can lead to more bugs in the drift as cohorts of individual species reach maturity – this is what we call intraspecific competition (intra = within, and specific = species). But competition between different species (interspecific competition) is also quite common.

In this week’s Short Shots video, a Green Drake nymph (Drunella grandis) is feeding on a dead Baetis nymph it has found. Along comes a much larger and brawnier Pteronarcys nymph who, after a short altercation, claims the prize for itself. In this case, instead of the loser being cast into the drift, it just sits nearby and sulks.