SciTech

Pittsburgh Ecology: Red-tailed Hawk, Garlic Mustard

This article is part of an ongoing series that discusses wildlife in the Pittsburgh region. Specimens in the accompanying photos are identified by the author, which may include the use of identification tool “iNaturalist.” As such, species identifications may not always be 100 percent accurate.

Red-tailed Hawk
Buteo jamaicensis

The Red-tailed Hawk is a bird of prey native to the United States. It is the most common member of the genus Buteo in North America and worldwide. It is identified by its red tail feathers and can acclimate to all environments. Red-tailed Hawks display sexual dimorphism in size — females are about 25 percent heavier than males. The cry of the Red-tailed Hawk is a two- to three-second hoarse, rasping scream that begins at a high pitch and slurs downward; it can be compared to a steam whistle. They are most often spotted between October and April, but are not uncommon during summer months.

Depending on the environment of the Red-tailed Hawk, they will have a varied diet. They usually eat small mammals like rodents and ground squirrels. Red-tailed Hawks also consume smaller birds and reptiles, though amphibians, fish, and invertebrates will rarely be a part of the hawk’s diet.

These hawks are considered partial migrants; most will only migrate during winter if food isn’t abundant. While Red-tailed Hawks tend to be territorial during winter, they may shift ranges if their food requirements aren’t met.

Eastern Tiger Swallowtail
Papilio glaucus

The Eastern Tiger Swallowtail is one of the most common butterflies in the eastern United States and is native to the region. Though most often seen in July and August, they are also commonly seen in April. They lay two to three broods of eggs from spring to fall and feed on flower nectar, especially those in the dogbane, aster, and legume families. They can be found near almost any deciduous forest.

Eastern Tiger Swallowtail females are a prime example of dimorphic pattern. Their yellow morph is similar to the male coloring with four black “tiger stripes” on each forewing, with a band of blue spots along the hindwing. The black morph, on the other hand, is completely black aside from blue along the hindwing.

Garlic Mustard
Alliaria petiolata

Garlic Mustard is a biennial flowering plant native to Europe, western and central Asia, and northwestern Africa. It is most commonly spotted in April and May. When its round, slightly-wrinkled leaves are crushed, they release the smell of garlic. The roots also give off a strong garlic-like smell. The plant is toxic to most vertebrates, containing up to 100 ppm of cyanide fresh weight.

In the plant’s second year, it produces cross-shaped white flowers. Its stem elongates into a spike-like shape. After flowering, Garlic Mustard plants produce upright fruits that release seeds in the mid-summer. Other names for the plant include Jack-by-the-Hedge, Garlic Root, Sauce-Alone, Penny Hedge, and Poor Man’s Mustard.

Western Honey Bee
Apis mellifera

The Western Honey Bee (also known as the European Honey Bee) is the most common of the seven to 11 recognized species of honey bees worldwide. They are believed to originate from Africa or Asia. They were one of the first domesticated insects and are still maintained by beekeepers today for their honey production and pollination activities.

Western Honey Bees reproduce in a process called “swarming” when the hive creates one to two dozen new queens, and a single colony splits into two or more distinct colonies. This usually occurs in spring or early summer when there is an abundance of blooming flowers to collect nectar and pollen.

The hive is divided into three castes: queen, worker, and drone. A queen is the female egg-laying member of the hive that feeds on royal jelly rather than the nectar and pollen diet of drones and workers. Virgin queens lay male eggs and exclusively lay female eggs after being fertilized; females make up about 90 percent of the hive population. Workers are the non-queen females that carry out the main tasks of the colony like foraging and raising other workers.

Drones are the males of the hive; they fertilize a new queen. They are 1.5 times larger than females and thought to play a significant role in temperature regulation in the hive. They do not have stingers and are expelled from the hive before winter in temperate regions.

Eastern Redbud
Cercis canadensis

The Eastern Redbud is a large deciduous shrub or small tree native to eastern North America, though they can thrive as far west as California and as north as southern Canada. The Eastern Redbud typically grows to be 20-30 feet tall with a 26-33 feet spread. Its bark is typically dark and smooth, turning scaly with ridges and maroon patches as the tree ages.

The plant flowers in spring to early summer with half-inch light to dark magenta flowers. Due to its far-back nectaries, the tree is particularly pollinated by long-tongued bees. Flowers of the Eastern Redbud can be eaten, both fresh and fried. In some parts of southern Appalachia, the green twigs of the Eastern Redbud are occasionally used as seasoning for wild game like venison and opossum.

Common Blue Violet
Viola sororia

The Common Blue Violet is a perennial flowering plant native to eastern North America. Their native habitats are moist woods and swamps. As they self-seed — dropping their seeds in the same location they sprouted — they are sometimes seen as weeds. They bloom most often in April and are commonly seen in May. The Common Blue Violet is also known as the common meadow violet, purple violet, wooly blue violet, hooded violet, and wood violet.

The Common Blue Violet has historically been used as food and medicine. Both the leaves and flowers are edible, and some sources suggest the roots can also be eaten (though not recommended!). It was used to treat colds, headaches, coughs, sore throats, and constipation. The leaves of the plants are high in vitamins A and C and can be eaten raw; the flowers have been made into both jelly and candy. The young leaves and buds of the plant are also used for tea.