Interaction between the prey and an intermediate predator follows the Volterra scheme (with Holling type IV functional response), while that between the top predator and its prey depends on Beddington DeAngelis type functional response.
As mentioned above, the heightened tail morph induced by dragonfly larvae appears to provide greater protection against predators, although Rana pirica tadpoles are able to adopt another morphology in response to an intermediate predator, i.e., larval salamanders.
One important component of the predator-prey relation is predator's functional response, i.e., the rate of prey consumption by an average predator.
The alterations to the tail in tadpoles in the presence of either the top predator (dragonfly larvae) or the intermediate predator (larval salamanders) may provide protection through enabling an increased swimming speed to escape from the former or by prevention against swallowing by the latter.
The wolves killed intermediate predators, coyotes mostly, which in turn caused a rebound in the number of small mammals, including voles, gophers and ground squirrels.
These intermediate predators prey heavily on eelgrass epifauna with amphipods and isopods representing a significant proportion (51 95%) of the fish community diet (Bobsien, 2006).
As it develops, the parasite attacks hosts higher in the food chain, alternating between herbivore and predator or between an intermediate and a top predator in the food chain.
The global taphonomic signature of the small mammal bone assemblage appeared close to that of owls, but it placed the raven in an intermediate category of predators (between owl categories 1 to 3), according to the classification by Andrews (1990) [Andrews, P.J., 1990. Owls, caves and fossils, Natural History Museum Publications, London.].
Based on these results, we suggest that this tritrophic interaction (pollinator/larval predator-orchid-aphid) may represent an intermediate stage between plant-predator mutualism, or indirect defense (see [ 28- 30]),) and floral deception.
The tritrophic interaction (pollinator/larval predator-orchid-aphid) may be ancestral within Epipactis and may be an intermediate stage between plant-predator mutualism (or indirect defense) and floral deception.
