Feeding on the algae and detritus in creeks are many aquatic insects and other invertebrates which live in these habitats.

Most people who go camping in the north are familiar with blackflies (eg. Simulium spp.) which live out the egg and larval stages of their lives entirely in moving water. They attach themselves to rocks in large numbers with thin threads from which they hang in the current. In this way they filter out floating particles using fanlike extensions that project from their bodies. Luckily for us, there are not very many blackflies in our area but we do have many other equally well-adapted insects which are born in creeks and do most of their feeding and growing there, emerging from their aquatic home as winged adults and flying away to mate and lay their own eggs in the creek.

Mayfly. Photo by Edward S. Ross.

Mayflies (Order Ephemeroptera) are just such insects, famous amongst fly-fishers and so fully aquatic that many of them do not have functioning mouth parts as winged adults. They emerge only long enough to mate, drop their eggs into the water and die.

Many aquatic insects are adapted to living in creeks and have flattened bodies so that they can move over rocks without getting swept away. They mainly eat algae and other material that clings to those rocks. Caddisflies (Order Trichoptera) are another group of creek insects that adapt in a different way. Many of them build cases out of sand or vegetation, some of which are quite complicated and beautiful. Some are algae-eaters and some of them feed from particles passing by in the current. They may even build special nets from fine filament that they attach to their cases to trap food. These cases are firmly attached to rocks often look like little underwater fishing huts.

The aquatic insects that most people are familiar with are dragonflies and damselflies (Order Odonata), but these are more often associated with the still waters of lakes, ponds and wetlands, as are mosquitoes. Larger invertebrates found here include Crayfish (e.g. Orconnectes spp.), which live under rocks.

Fish are the other major aquatic animal found in Hamilton creeks including trout, salmon, suckers and minnows amongst others.

Chinook Salmon. Photo by Mark Giovanetti.

Many fish in our local creeks are introduced, not native, including the popular salmon and trout.

Amphibians also inhabit creeks including species like the rare Dusky Salamander (Desmognathus fuscus) and the Two-Lined Salamander (Eurycea bislineata) which can be found in the water near stream banks or in the nearby and fish found in creeks.

Muskrats (Ondatra zibethicus), Beaver (Castor canadensis), Mink (Mustela vison) and even River Otters (Lutra canadensis) can be found living in creek banks or nearby.

Two other mammals that can be found living in the creek bank and feeding in the water are the Star-nosed Mole (Condylura cristata) and the Water Shrew (Sorex palustris). They both live in saturated soils near ponds, wetlands and creeks and feed on aquatic invertebrates.

Star-nosed Mole. Photo by Gary Meszaros.

Moles enter the water quietly, but the shrew jumps in with a great leap — sometimes running on the water surface before diving under.

Black-crowned Night Heron. Photo by Barry Cherriere.

Finally, many birds feed on fish in creeks or on aquatic insects as they emerge. If you are very lucky, you may come upon Black-crowned Night Herons (Nycticorax nycticorax) feeding at the lake outlets of streams on insects, crayfish, minnows or even mammals.

Because streams are used as corridors by many small mammals, birds of prey such as owls can be found waiting for their moment to strike. Small insect-eating birds are numerous here, such as the many swallows (e.g. Northern Rough-winged Swallow, Stelgidopteryx serripennis) that swoop through the clouds of emerging insects. In larger streams, the Belted Kingfisher (Ceryle alcyon) hunts for small fish, tadpoles and invertebrates. Rare birds can be found along creeks too, such as the Louisiana Waterthrush (Seiurus motacilla) and Blue-gray Gnatcatcher (Polioptila caerulea).