Weekly Species Highlights

Here are the weekly species highlights for the third week of May:


Bird: Barn Swallow (Hirundo rustica) - As the fields, meadows and lawns in our city parks are being cut by armies of lawnmowers, look for swooping flocks of Barn Swallows snatching up insects in the machine's wakes. These adaptable birds regularly nest on sheltered ledges within our urban parks and take advantage of summer's abundant food source, especially near water sources.

Barn Swallows are common and easily recognized by their deep blue upper plumage, orange breast & belly and deeply forked tail. In Europe their common name is just "Swallow".

Their breeding range extends from Alaska east across Canada to Newfoundland and south through all of United States except southern Texas, Gulf Coast, and peninsular Florida. These neotropic migrants winter as far south as Argentina.

Amphibian: American Bullfrog (Rana catesbeiana) - These largest of native North American frogs are nocturnal. Their diet includes insects, crayfish, other frogs, and minnows, but large individuals have been known to take small birds. Their range extends from Nova Scotia to central Florida, from the East coast to Wisconsin, and across the Great Plains to the Rockies. They have been introduced into southern Europe, South America, and Asia where they are considered an invasive species in many locales. One notable field mark is their large external eardrum. On quiet mornings their deep, booming calls can be heard as far as a quarter mile away.

Shrub: Azalea (Rhododendron spp.) - The spectacle and variety of blooming Azaleas may rival the world's annual Spring Cherry blossom festivals. Azaleas are flowering shrubs of the genus Rhododendron. One difference between azaleas and most rhododendrons is their size. They are generally much smaller. Azaleas flowers bloom all at once and create a solid mass of colour.

Horticulturists have been hybridizing azaleas for several hundred years making identification of native North American species challenging. There have been over 10,000 different cultivars registered.

US cities that hold annual azalea bloom festivals: Wilmington, North Carolina; Norfolk, Virginia; Valdosta, Georgia; Palatka, Florida; Pickens, South Carolina; Muskogee, Oklahoma; South Gate, California; Mobile, Alabama; and Dothan, Alabama; Tyler, Texas. In Brooklyn, Green-Wood Cemetery is a great location to see hundreds of flowering azalea shrubs.

Tree: Horsechestnut (Aesculus hippocastanum) - The Common Horsechestnut (or Conker tree) is native to the Balkans in southeast Europe, in small areas in northern Greece, Albania, the Republic of Macedonia, Serbia, and Bulgaria. They are not related to the Chestnuts, but rather the Buckeye family. The fruit of the horsechestnut are slightly poisonous but some mammals can tolerate the toxins. They have been planted throughout North America for their shade and showy white flowers.

Horsechestnut extract is used as a dietary supplement in Europe to improve vascular functions. From the Memorial Sloan-Kettering Cancer Center website: "Studies show clinical efficacy in chronic venous insufficiency, but no data support the reversal of varicose veins. Horse chestnut extracts that contain esculin may interact with anticoagulants and increase the risk of bleeding. Patients with compromised renal or hepatic function should not consume horse chestnut products." It's probably safer just to enjoy this species as a shade tree.