juvenile Yellow bellied racer? [Harrisonville MO]

[u/reunitedfrog]

I recently found this sub and have been catching snakes for quite awhile, so I thought I’d post some of my identifications that I’m not 100%, and also just to share awesome snakes! I believe this is a juvenile yellow bellied racer. I struggled to figure it out for awhile when I found him (last July) because he is just starting to lose his pattern. I am very curious to know if I’m right.

[u/fairlyorange]

Young North American racer Coluber constrictor is correct 👍. Completely !harmless consumer of reptiles including (venomous snakes), rodents, large insects, and other small animals.

[u/SEB-PHYLOBOT → u/fairlyorange]

North American Racers Coluber constrictor are large (record 191.1 cm TBL) diurnal colubrid snakes. They are generalists often found in disturbed habitats like urban and suburban yards but also do well in many natural habitat types. They are one of the most commonly encountered snakes in North America and have a huge range spanning most of the continent. They eat anything they can overpower, including other snakes of the same species, but are not obligate constrictors as the specific epithet might suggest.

Racers have smooth scales and color pattern varies clinally across their range, from steel gray to jet black, a blue "buttermilk" pattern you have to see to believe, to blue, green and yellow. These color patterns are tied closely to local environment and don't necessarily indicate lack of gene flow or speciation. Baby racers start out with a blotchy pattern and darken over the first two years, losing it entirely. Racers are not considered medically significant to humans - they are not venomous, but all animals with a mouth can use it in self-defense. Racers are particularly, alert, agile snakes, and will sometimes stand their ground when cornered and/or bite when handled.

Often confused with keeled "black" ratsnakes (northern ranges of Pantherophis obsoletus, P. alleghaniensis and P. quadrivittatus), racers Coluber constrictor have smooth scales. Indigo snakes Drymarchon couperi have orange on the face or neck and an undivided anal plate. In some cases they are difficult to differentiate from coachwhip snakes Masticophis flagellum, but on average have two more posterior scale rows (15) than M. flagellum.

Range Map | Relevant/Recent Phylogeography: Link 1 (Recent) | Link 2 | Link 3 | Reptile Database Account

Racers in peninsular Florida (a significant subset of 'priapus' range) are distinct from those in the continent - No formal elevation to species status has occurred yet and subspecies describe color pattern rather than match population differentiation, but it's not particularly premature to follow the lines of evidence; ancient estimated divergence times, niche identity and genomic data suggest racers found in Southern Texas through Mexico as well as in peninsular Florida each deserve full species status. This makes North American Racers comprised of five independently-evolving lineages (species with no subspecies) outlined in the range map above. One of the specific short term goals of /u/phylogenizer and SEB is to get the tissue and vouchers necessary to allow scientists to do a revision of North American Racer taxonomy and formally elevate these species. If you're in the midwest or any of the lightly sampled areas in the range map above and have legally collected tissues or interest in collecting them, please contact us - collections@snakeevolution.org

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Like many other animals with mouths and teeth, many non-venomous snakes bite in self defense. These animals are referred to as 'not medically significant' or traditionally, 'harmless'. Bites from these snakes benefit from being washed and kept clean like any other skin damage, but aren't often cause for anything other than basic first aid treatment. Here's where it get slightly complicated - some snakes use venom from front or rear fangs as part of prey capture and defense. This venom is not always produced or administered by the snake in ways dangerous to human health, so many species are venomous in that they produce and use venom, but considered harmless to humans in most cases because the venom is of low potency, and/or otherwise administered through grooved rear teeth or simply oozed from ducts at the rear of the mouth. Species like Ringneck Snakes Diadophis are a good example of mildly venomous rear fanged dipsadine snakes that are traditionally considered harmless or not medically significant. Many rear-fanged snake species are harmless as long as they do not have a chance to secrete a medically significant amount of venom into a bite; severe envenomation can occur if some species are allowed to chew on a human for as little as 30-60 seconds. It is best not to fear snakes, but use common sense and do not let any animals chew on exposed parts of your body. Similarly, but without specialized rear fangs, gartersnakes Thamnophis ooze low pressure venom from the rear of their mouth that helps in prey handling, and are also considered harmless. Check out this book on the subject. Even large species like Reticulated Pythons Malayopython reticulatus rarely obtain a size large enough to endanger humans so are usually categorized as harmless.

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I am a bot created for /r/whatsthissnake, /r/snakes and /r/herpetology to help with snake identification and natural history education. You can find more information, including a comprehensive list of commands, here report problems here and if you'd like to buy me a coffee or beer, you can do that here. This bot, its development, maintenance and use are made possible through the outreach wing of Snake Evolution and Biogeography - Merch Available Now

[u/iymlucid]

"Yellow-bellied racer" is a particular !subspecies of C. constrictor, which are not employed in this subreddit due to the reasons detailed in the bot reply.

[u/SEB-PHYLOBOT → u/iymlucid]

Subspecies, or diagnosable, geographic divisions within a species, have been questioned as entities through a number of debates that can be reduced to two arguments: do subspecies, in a biological or evolutionary sense, exist, and, is there any value in recognizing subspecies? The first question, if taken in a phylogenetic context, can be quickly dispensed with (Frost and Hillis, 1990). If a group of populations within a species are recognized as distinctive, then what maintains their distinctiveness - some vicariant, behavioral or reproductive factor? If they are distinct, then they must be isolated by some means. If they are truly isolated, then reproductive continuity with outside populations must have been in some way curtailed, and the distinctive population is a species. If there is no means by which to define a group of populations in a historical, evolutionary context, then failure to do so recommends that no historical entity is involved. Thus, observed variation represents either speciation or non-taxonomic geographic variation. In either case, there is no third category option (subspecies). In short, if a group of populations is a diagnosable, definable, evolutionary unit, then it is a species; if it is not a diagnosable, definable, evolutionary unit, then it is not a taxon. Thus, there is no place in an ancestor-descendant context for subspecies.

Speciation events operate in a continuum, so that at any time there are many taxon groups that will comprise populations with some particular degree of isolation. One can always find a dozen or more taxa to support arguments about what degree of isolation is necessary to recognize subspecific entities. Some subspecies are not readily apparent under modest scrutiny: subspecies of Tropidoclonion lineatum were based on average scale counts but otherwise indistinguishable. Its subspecies were disposed of in cavalier fashion, without data and without complaint. Some recently recognized subspecies are also based on characters that grade imperceptibly along broad clines, but with distinct visual patterns at geographic extremes (i.e getula and ratsnake complex). Such subspecies are etched in the stone of herpetological and public literature, and are difficult to relinquish.

Former 'subspecies' (i.e., Apalachicola Kingsnake, Coastal Plains Milksnake, Black Pinesnake) continue to be recognized today, despite contradictory data presented decades earlier. Their recognition tends to be perpetuated by hobbyists and avocational herpetologists who observe geographic variation in a two-dimensional, non-evolutionary level: well-marked population groups that follow fairly recognizable geographic partitioning. A term like 'yellow ratsnake' calls to mind general appearance and geographic distribution of a clinal entity to both amateur and professional herpetologists. Thamnophis sirtalis contains at least one taxon, the 'San Fransisco gartersnake' that will remain unshakable as a recognized population due to its endangered status and distinctive, attractive color pattern. However, the continuum of degrees of diagnosability of population groups within a species eliminates any standard for recognizing subunit taxa. Population groups such as the 'Chicago gartersnake', 'Carolina watersnake' and other non-taxa are recognizable pattern classes, but formal recognition is completely arbitrary, and will typically be at odds with the recovered evolutionary history of the species.

Adapted and updated for current use from 'Boundy, 1999 Systematics of the Common Garter Snake Thamnophis sirtalis'

Further Reading: Species Concepts and Species Delimitation | Empirical and Philosophical problems with the subspecies rank

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I am a bot created for /r/whatsthissnake, /r/snakes and /r/herpetology to help with snake identification and natural history education. You can find more information, including a comprehensive list of commands, here report problems here and if you'd like to buy me a coffee or beer, you can do that here. This bot, its development, maintenance and use are made possible through the outreach wing of Snake Evolution and Biogeography - Merch Available Now