Identifying “Black Snakes”

This is a piece out of my field guide I am working for for the Herps of Virginia.

The term “Black Snake” is a colloquial term to describe any snake that is black. This covers several species, but it mostly describes either the Eastern Ratsnake or the Northern Black Racer. The two are very different, but hard for most people to identify. This said, almost everything, except color, is different in these two species.

The Eastern Ratsnake (Pantherophis alleghaniensis)
The Eastern Ratsnake has a wider, flat head. The eyes are typical for a colubrid, and are separated from the nostril by three long scales. The lower half of the upper labials are white. The tip of the nose is blunt, and black. The first third of the underside is white, yet checkered, with a slate under side for the rest of belly. The skin on the ratsnake is white, and is visible between the scales when bent, or the snake has inflated. Scales are glossy, except when shedding. Dorsal scales are slightly keeled.

Here are plenty of examples:

Adult: https://www.inaturalist.org/observations/22328888

Adult: https://www.inaturalist.org/observations/21876192

Adult: https://www.inaturalist.org/observations/26563543

Adult: https://www.inaturalist.org/observations/26563509

Adult: https://www.inaturalist.org/observations/26554782

Adult (Note locomotion): https://www.inaturalist.org/observations/26343884

Adult: https://www.inaturalist.org/observations/25771955

Transitioning juvenile: https://www.inaturalist.org/observations/17612993

Juvenile: https://www.inaturalist.org/observations/25962238

Juvenile: https://www.inaturalist.org/observations/25028649

Juvenile: https://www.inaturalist.org/observations/24786660

Juvenile: https://www.inaturalist.org/observations/23467841

The Northern Black Racer has a narrow head. The eyes are very large, and are separated from the nostril by three short scales. The only white on the upper labials is on L1. The tip of the nose is sharp, and brownish. The chin is typically white, and the belly is a blue-gray. The skin is gray, but scales overlap where skin is not visible. Scales are dusky. All scales are smooth.

Here are plenty of examples:

Adult: https://www.inaturalist.org/observations/24940095

Adult: https://www.inaturalist.org/observations/13592626

Adult: https://www.inaturalist.org/observations/13189733

Adults: https://www.inaturalist.org/observations/19227821

Adults: https://www.inaturalist.org/observations/23035814

Adult: https://www.inaturalist.org/observations/19227788

Adult (in shed): https://www.inaturalist.org/observations/17203474

Subadult (note "coachwhip" shape): https://www.inaturalist.org/observations/20410397

Transitioning juvenile: https://www.inaturalist.org/observations/26559348

Juvenile: https://www.inaturalist.org/observations/26997543

Juvenile: https://www.inaturalist.org/observations/15043658

Finally, posture and locomotion are good ways to identify at a distance. Racers tend hold their heads high and their long body tapers. This gives them a “coachwhip” like appearance. Ratsnakes only hold their body strait or kinked when moving, or on a narrow perch. When they are strait, the hold their head close to the ground, as long as they are not attempting to climb. When sitting, a Ratsnake holds a posture like a dropped piece of yarn.

Ratsnakes can move when they need to, but they are nothing compared to the Racers. To put it in simple terms, imagine a typical two-lane highway. The road is about twelve feet wide. A Ratsnake can enter the road, and exit the other side, in about six seconds. A Racer, going full speed, can enter and clear the road in less than two seconds.

Racer live a high speed lifestyle. They are so built for speed, Racers cannot constrict their prey. Instead, they pin down small animals and swallow them whole. This is very different from the Ratsnake. Ratsnakes are constrictors.

Thank you all who have submitted to the project, and are members following this project. Please, invite anyone who you believe would enjoy to join. I am excepting recommendations for the next times ID Tip. I hope everyone has a wonderful week!

Thank You,
-Ty Smith

Publicado el junio 15, 2019 08:46 MAÑANA por tysmith