Reptiles of North Carolina
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NC Records

Rhadinaea flavilata - Pine Woods Littersnake


Zach Barfield, Grover Barfield
E. Corey and K. Bischof
Taxonomy
Class: Reptilia Order: Serpentes Family: COLUBRIDAE Subfamily: Dipsadinae Other Common Name(s): Pine Woods Snake
Taxonomic Comments: Rhadinaea currently consists of 21 species of slender, small-to-medium sized dipsadine snakes found in the southeastern United States and throughout Mesoamerica. Garcia-Sotelo et al. (2021) presented the most comprehensive molecular phylogeny of the genus to date. R. flavilata is the only member of the genus found in the United States, and together with R. laureata (Mexico) comprise the "flavilata group (Myers, 1974).

Other common names for this species include the yellow-lipped snake and pine woods snake.
Species Comments: Rhadinaea flavilata, the Pine Woods Littersnake, is endemic to the southeastern United States, and is the only species of Rhadinaea found in North Carolina. It was described by Cope (1871) as "Dromicus flavilatus" and later moved to Rhadinaea (and the specific epithet changed to "flavilata". Following some taxonomic instability in the early 1900s, its placement as Rhadinaea flavilata has been largely stable since Dunn (1932). No subspecies are recognized.

The type locality of this species is in North Carolina, approximately eight miles west from Fort Macon on Bogue Banks, Carteret Co.

The generic epithet Rhadinaea is likely derived from the Greek rhadinos, meaning “slender; lithe”. The specific epithet flavilata is likely a combination of the Latin flavus (“yellow”) and latus ("broad, extensive"), referring to the "extensive" golden dorsum (Myers, 1967).

Taxonomic References: Myers (1967, 1974), Walley (1999).
Identification
Description: Pine Woods Littersnakes are small snakes with heads slightly wider than their neck. Their body is typically uniformly golden brown to reddish-brown and iridescent. A faint mid-dorsal stripe–comprised of dark pigments on the posterior half of the medial dorsal scale row–is apparent in many specimens from NC, and there may also be some light stippling on the four lateral scale rows. The top of the head is a darker brown than the body, and extends onto the scales at the neck. There is a prominant dark stripe that extends from the nose laterally across the face through the orbit and down to the last supralabial; this may be separated from the dark head coloration by thin white stippling. The mental region and labials are usually white or yellow, often with prominant dark stippling, especially in individuals from our state. The golden brown dorsum fades into a uniformly white-to-yellow glossy venter. Hatchlings appear similar to adults, though may appear brighter and with more noticeable occipital spots.
Morphological Features: Pine Woods Littersnakes have 17 smooth scale rows at midbody. Ventral counts range from 112–141 ventrals (120-133 in North Carolina specimens examined by Palmer and Braswell, 1995), with paired subcaudals ranging from 59-83 (63-76) and a divided anal plate. Head scales are typically: 7 supralabials, 9 infralabials, 2 nasals, 1 small loreal, 1 preocular, 2 postoculars, and 1+2 temporals. Some variation in head scalation and patterning have been noted (see Myers, 1967, and Palmer and Braswell, 1995). The tail ends in a small, spine-like scale, and is frequently broken off.

These are small snakes with a maximum reported total length of 40.3 cm (15.9 inches). Tail lengths average approximately 30% (25-33%) of the total length. Females are larger than males, and typically have more ventrals and fewer subcaudals; adult males typically have weakly keeled body scales near the anal plate ("anal ridges"). There is no consistent color or pattern dimorphism in this species in our state.

Pine Woods Littersnakes have enlarged rear fangs and possess a mild venom secreted by their Duvernoy's gland that is used in prey capture (Willard, 1967; Rodriguez-Robles, 1994). The composition of their venom requires further investigation. Regardless, these snakes are completely harmless to humans and pets, and do not bite when handled.
Technical Reference: Myers (1967, 1974); Palmer and Braswell (1995); Walley (1999); Ernst and Ernst (2003).
Field Guide Descriptions: Palmer and Braswell (1995); Ernst and Ernst (2003); Beane et al. (2010).
Online Photos: iNaturalist, Reptile Database, HerpMapper   Google   iNaturalist   GBIF
Observation Methods: Pine Woods Littersnakes are usually found under loose bark and debris, or in and around fallen logs. They can be sampled using drift fences with pitfall trap arrays (e.g., Enge and Wood, 2002), and using cover objects (e.g., Seigel et al., 2002).
Distribution in North Carolina
Distribution Comments: Pine Woods Littersnakes are found primarily in the southeastern Coastal Plain, though records extend as far inland as Fayetteville (Cumberland Co.) and one record exists from the Sandhills in Scotland Co. (Beane and Alford, 1989). Inland records from other states have also been reported (Whiteman et al., 1995; McKelvy et al., 2016), suggesting more surveys are needed to determine. The northern limit of the species is in the Outer Banks (Dare Co.), though recent records from this area are scant.
Distribution Reference: Palmer and Braswell (1995); Ernst and Ernst (2003); Beane et al. (2010); McKelvy et al. (2016).
County Map: Clicking on a county returns the records for the species in that county.
Key Habitat Requirements
Habitat: Pine Woods Littersnakes occupy dry to mesic woodlands in the Coastal Plain with a substantial component of pines. These include maritime forests on the barrier islands; loblolly-dominated forests in tidewater sites on the mainland; and Longleaf Pine-dominated flatwoods and sandhill-bottomland ecotones further inland (Palmer and Braswell, 1995; Beane et al.,2010). Xeric sandridges do not appear to be occupied -- this species is only marginally found in the Fall-line Sandhills. Likewise, hydric peatlands dominated by Pond Pines may be largely unused.
Environmental and Physiological Tolerances: Pine Woods Littersnakes are most active in the warm spring months (April and May). Studies on temperature and moisture ranges of this species are lacking.
Biotic Relationships: Known natural prey of Pine Woods Littersnakes include anurans (frogs and toads), and small lizards (anoles and skinks). In Florida, they are known to predate non-native taxa including brown anoles (Anolis sagrei) and greenhouse frogs (Eleutherodactylus planirostris) (Palmer and Braswell, 1995; Durso and Smith, 2017; Smith et al., 2018). Per Myers (1967), it seems unlikely this species predates arthropods.

Pine Woods Littersnakes are known prey of ophiophagous snakes. They are likely also taken opportunistically by birds and mammals.
Life History and Autecology
Breeding and Courtship: Pine Woods Littersnakes are considered sexually mature at total body lengths 21.5-25.9 cm in males, 20.7-26.0 cm in females. Breeding is thought to occur in the spring.
Reproductive Mode: Eggs are laid in the summer months (May to August) in clutches of 1-4. Eggs are elongated, white with a granular shell, averaging 2.8 cm long and 0.7 cm wide.

Hatchlings emerge in late summer to fall (August to October), and are between 12.5-16.7 cm total length (Palmer and Braswell, 1995; Ernst and Ernst, 2003).
Terrestrial Life History: Pine Woods Littersnakes are primarily nocturnal, though diurnal activity has been recorded (Akcali, 2017). Activity peaks with the reproductive season in early spring; they have been recorded in North Carolina from January to October, with most records in April and May.

Home ranges have not been estimated for this species.

These snakes are completely harmless and pose no threat to humans or pets. When handled, they do not bite, but occasionally will release a foul-smelling, amber-colored musk from their cloacal glands as a defense mechanism.
General Ecology
Population Ecology: Few studies of Pine Woods Littersnake ecology have been undertaken, and information on population structure, abundance, etc., are largely lacking. Myers (1967) reported a 1:1 sex ratio across all samples, though individual populations may vary. These snakes are infrequently encountered across their range, but some reports of high local numbers in Florida exist in older literature. Whiteman et al. (1995) reported only ten individuals captured in a seven year period at the Savannah River Site, SC.
Community Ecology: Pine Woods Littersnakes feed primarily on small frogs and lizards. They may therefore compete with other small snakes with similar dietary affinities, such as ring-necked snakes (Diadophis punctatus). Direct interactions between this species and non-predator/prey species is not known.
Adverse Environmental Impacts
Effects of Introduced Species/Induced Increases of Native Species: Little is known about the effect of introduced species on Pine Woods Littersnakes. Feral hogs (Sus scrofa) may pose a threat to these and other semi-fossorial snakes, given their propensity for rooting in the leaf litter and ground surface. Red imported fire ants (Solenopsis invicta) are known predators of some small amphibians and reptiles, and their presence increases with habitat alteration (being most prevalent in clear-cut forests; Todd et al., 2008b).
Interactions with Humans: Pine Woods Littersnakes are occasionally killed by motorists when crossing roads, or bikes and pedestrians on trails. They may become trapped and drown in pools. Like all snakes in the area, they are occasionally killed when found by humans out of fear.
Status in North Carolina
NHP State Rank: S3
Global Rank: G4
Status in North Carolina: W2
Populations: Thorough population-level studies of Pine Woods Littersnakes in North Carolina are lacking. The species is considered rare, but relatively secure. It is likely more common than records indicate, given its semi-fossorial and mostly nocturnal nature. How connected or disjunct different populations are from one another (especially the Outer Banks population) needs to be investigated. The number and extent of pine woods littersnake populations cannot be estimated within the state at this time.
Protected Lands: Pine Woods Littersnakes are known from at least three state parks, one state natural area, and one national forest in NC (DPR NRID, accessed 2022-07-03; iNaturalist, accessed 2022-07-03; NCSM Online Collections, access 2022-07-03; VertNet, accessed 2022-07-03).
Status Comments: Given the lack of population-level data on Pine Woods Littersnakes in North Carolina, it is difficult to estimate the security of the species in the state. The susceptibility of this species to the emerging fungal pathogen Ophidiomyces ophidiodiicola (Oo; snake fungal disease) is not known at this time but could be detrimental to the species. Similarly, Ranavirus (Rv) infection may contribute to behavioral changes and mortality in reptiles. The only Pine Woods Littersnake sample included in a study of these pathogens in North Carolina tested negative for Rv (Lentz et al., 2021).

Photo Gallery for Rhadinaea flavilata - Pine Woods Littersnake

7 photos are shown.

Recorded by: Erich Hofmann
New Hanover Co.
Comment: 		Recorded by: Erich Hofmann
New Hanover Co.
Comment:
Recorded by: Erich Hofmann
New Hanover Co.
Comment: 		Recorded by: Jeremy Bivins
New Hanover Co.
Comment:
Recorded by: Zach Barfield, Grover Barfield
Columbus Co.
Comment: 		Recorded by: E. Corey and K. Bischof
Pender Co.
Comment:
Recorded by: E. Corey and K. Bischof
Pender Co.
Comment: