Black Bird, Black Bird, What Do You See?
Have you spotted big, black birds while hiking our trails recently? Although they look similar, not all black birds are the same. Did you know the Credit River Watershed is home to three of these big, black birds from the crow family? These species are American crow, common raven and fish crow.
The species you’re most likely familiar with is the American crow. It’s the most common and widespread of the three species in the watershed. They’re found in a variety of habitats from forests to parks, to residential neighbourhoods, and urban areas. However, common raven and fish crow sightings across the watershed have increased as a result of their population expanding to new regions.
Historically, the common raven was widespread across southern Ontario. By the 1800s, as their primary forest habitats were transformed into agricultural land, the common raven population began to disappear south of the Canadian Shield.
Poison was another cause of their disappearance. Common ravens were accustomed to feeding on large mammalian predators, like wolves. Unfortunately, it was common practice for farmers at that time to poison predators to protect their livestock.
Luckily, common ravens are making a comeback with the protection of forests and legislation prohibiting the use of poison on large mammals.
Fish crows are not historically from Ontario but have expanded their range north. They’re found mostly along the American Atlantic coast, spanning from Maine to Texas and along the Gulf of Mexico. However, they have been expanding their range northward through inland river systems, and more recently they occasionally occupy areas along the northern shore of Lake Ontario.
How to tell these birds apart
Common raven is the largest of the three species and is about the size of a hawk. It has a heavier, curved bill compared to the other species and has shaggy feathers on its throat. In flight, it’s the only one that has a wedge-shaped tail. It also often soars in flight and flaps its wings less than crows.
An American crow is between the size of a common raven and fish crow and is about the size of a pigeon. It lacks the shaggy feathers along the throat and its bill is not quite so heavy or curved. In flight, it has a straighter tail and tends to flap its wings continuously. They are also quite vocal while flying.
Fish crows look and fly virtually identical to an American crow but is smaller, has shorter legs, its feathers are slightly glossier, and its bill is considered more “petite” than an American crow. However, this can still pose a challenge to differentiate the two and often cannot be done reliably unless they are side by side.
Listen to the sound of their call
Like many species of birds that look alike, often the sure way to tell them apart is by their voice. All three species have many calls, but the most common calls are described below.
Common raven has a deeper, louder and hoarser sounding croak.
The most common call made by American crows is a harsh caw caw, often repeated.
However, begging juvenile American crows can also sound nasally. Using both visual and sound can help in these cases.
It can sometimes be easy to forget about birds. However, a simple pause to look up can remind us of the amazing diversity of birds in the Credit River Watershed. Discover more about nature and wildlife in the Credit River Watershed.
Learn more about wildlife by following us on Twitter, Instagram, Facebook and LinkedIn.
By Christina Kovacs, Natural Heritage Management
That’s Amazing
Merci beaucoup ! Très intéressant ! Très bien expliqué !