Crafty crows

Two crows hop around a fast food restaurant, fighting over a lone french fry. Both are a deep black and appear to have the same attributes, except size.

Forty-five species of crows can be found worldwide. Two species roost in central Pennsylvania.

The most common is the American crow. A fairly large bird – measuring up to 20 inches and weighing as much as 22 ounces, with a wingspan of 39 inches – the American crow usually never is found alone.

The fish crow is nearly identical to the American crow. The biggest difference is their size, but the easiest way to notice that is to see them perched next to each other.

It takes someone like Dr. Kevin J. McGowan, of the Cornell Lab of Ornithology, who has 25 years of experience in the field, to be able to look at the birds and say, “Yes, that is a fish crow.”

“In the field watching a bird, I am at this point probably 90 percent confident I can distinguish it,” he said.

The fish crow is half the size and weight of the American species. It can grow to 15.7 inches in length and 11.6 ounces in weight, with a wingspan of about 33 inches.

“And they do mostly crow things – eat anything and hang out in groups and ‘talk,’ ” he said.

As all crows, “they do not like to do anything alone or quietly,” McGowan added.

The fish crow showed up on the 2012 Christmas Bird Count in Lycoming County, said Nate Fronk, a member of the Lycoming Audubon Society. The count yielded 18 fish crows, compared to 39 in 2010.

“In Pennsylvania, they are typically found along large rivers of the southeastern part of the state. Although, they are continuing to spread to the north and west, according to eBird data,” Fronk said.

“In Williamsport, as elsewhere, they are often found mixed in with large winter roosts of American crows. They can also be seen migrating up and down the river in the fall and spring,” Fronk said.

Fish crows are more agile than their American counterparts, McGowan said. They can drop into tight places and are more investigative and more curious.

“Fish crows are very happy to hang out in parking lots and grab your french fries. They seem to be a little more urban in more of their range,” McGowan said.

Although it is hard to differentiate between the species when it comes to size, their vocalizations are the tell-tale identifier.

An American crow makes a “caw-caw” sound.

“A fish crow is nasal, a little higher,” McGowan said, with characteristics of a two-note call.

If you ask a fish crow if it’s an American crow, McGowan said its call will sound like denial – “uh-uh.”

Another relative often mistaken for a crow is the common raven. However, the raven is much larger than either species of crow living in Pennsylvania.

An raven has a much larger and thicker neck, but a body that is slender and taller than a crow. The beak, feet and feathers are all black.

Often, the best way to tell the difference between a raven and crow is to wait for the bird to fly and look at the shape of its tail. The raven will have a long and rounded, wedge-shaped tail, whereas the crow has a fan-shaped tail.

The Cornell Lab of Ornithology said raven’s vocalizations range into as many as 33 different categories based on sound and context.

The raven often is referred to as one of the northern hemisphere’s smartest birds, according to the lab’s website,

The site said ravens can use their intellect to put together cause and effect. A study in Wyoming discovered that, during hunting season, the sound of a gunshot draws ravens in to investigate a presumed carcass. However, the birds ignore sounds that are just as loud but harmless, such as an airhorn or a car door slamming.

Young ravens just out of the nest pick up and examine almost anything new they run across as they learn what’s useful and what isn’t, the website reported.

Ravens are not social creatures. Instead, they often are found to be alone.

Fish crow distributions used to occur in the southeast United States but, in the last 50 years, they have spread, he said.

They were commonly found around Philadelphia and Delaware, but not this far north.

“Now they are usually found all the way to State College and certainly up the Susquehanna (River) and (into) New York,” McGowan said.

Like their relatives, fish crows will gather in large flocks in the winter. The flocks, which can number thousands of individual birds, will roost together communally.

Fish and American crows can be seen together, and McGowan even has seen young American crows hanging out with fish crows for a period of their young lives.

So why are they not seen much here?

“Because their population is much lower where you are and, in central Pennsylvania, there aren’t as many,” he said.