Urban wildlife, or “backyard wildlife” is often limited in diversity, however by allowing an area to grow naturally, and reducing the urban characteristics this limitation can be reduced. Diversity of plants and increased layering, or structuring of plant types can provide the food and habitat for many of the animals that naturalists enjoy such as birds, butterflies, mammals, reptiles and a myriad of small critters.
Riparian corridors and adjacent woodlands can provide outstanding habitat for birds, both resident and migrating. Depending on the structure, diversity and health of the vegetation in the corridor, an amazing number of birds can be found here.
- Chickadees, mockingbirds, warblers, vireos, woodpeckers, titmice, sparrows, towhees, flycatchers, blue jays and wrens, depend on the wealth of insects that live on the grasses, forbs, wildflowers, shrubs and trees.
- Cardinals, dove, goldfinch, junco, and cedar waxwing gleam and important part of their diet from seed and berry producing shrubs.
- Hummingbirds drink nectar from some flower-bearing plants and small trees.
- Eastern screech owls, barred owls, and sharp-shinned hawks, and other predatory birds use wooded areas for their homes and hunting ground.
New leaves in the spring and early summer provide the critical food for the caterpillars that become moths and butterflies. Flowers from forbs, shrubs and trees provide nectar to many resident and migrating butterflies. Often caterpillars will only eat a certain type of plant (this is called host-specific relationship) so an increase in the diversity of plants will increase the diversity of butterflies.
- Skippers, satyrs, wood-nymphs eat grasses and sedges as caterpillars.
- Swallowtails eat some tree leaves especially citrus, black cherry and willow in addition to herbs such as relatives of dill, parsley and carrot.
- Monarchs and queens eat milkweeds and milkweed vines.
- Whites and sulphurs eat relatives of the mustard and legume
- Admirals, viceroy, sisters and morning cloak eat tree leaves, especially willows.
- Painted lady and red admirals prefer thistles and nettles.
- Great purple hairstreak eat mistletoe while other hairstreaks prefer legumes and mallows.
- Heliconians and fritillaries eat members of the passion-vine family.
Reptiles are a fascinating and beneficial part of riparian function. The vast majority of reptiles are harmless, and we only have four venomous species in Austin. Common harmless reptiles include:
- Gulf Coast toads thrive in riparian woodlands with loose soil, thick leave litter, shade and access to insects for food.
- Rough earth snake is a very small harmless snake that lives in the soil and leaf litter eating earth worms and slugs, and the non-venomous Texas rat snake helps control the rodent population.
- Red-eared slider and common snapping turtles must crawl out of the creek to lay eggs in the loose soil of the upper banks in the riparian corridor.
- Skinks are small lizards that live in leaf litter and eat insects
- Anoles are medium sized green/brown lizards that are sometimes mistaken for chameleons.
The big winner of an improved riparian corridor is our ever-present fox-squirrel, however, the possibility remains for other native mammals to pass through if the corridor is wide enough and long enough.
- Fox-squirrels are frequent residents of parks and woodlands and primarily live in the trees.
- Grey squirrel (aka “rock squirrel”) are less often seen ground squirrels in steep hilly areas that burrow in the soil.
- Armadillos are crepuscular and nocturnal and may occasionally be found rooting around the loose soils and leaf litter in large riparian corridors.
- Grey fox are primarily nocturnal and usually stick to woodland areas that are undisturbed.
Small critters in the leaf litter
A myriad of small invertebrates live in the loose soil and leaf litter. They may be considered to be the most important animals since they often play a vital role in turning dead vegetation into soil and organic matter which plants need. These include crickets, earthworms, fly larvae, snails, slugs, beetles, etc. These small critters are also the primary food source for many of the insect-eating animals mentioned above.