#critteroftheday

Believe it or not, it is still Snake Saturday, though this time with the Eurasian Blind Snake (Xerotyphlops vermicularis). Snakes are divided into two infraorders true snakes (Alethinophidia) and wormsnakes (Scolecophidia). The Eurasian Blind Snakes belong to the latter, and are in fact the only wormsnakes native to Europe [1].

They are burrowing snakes, and are generally found in open areas with sparse vegetation [2]. This has included being beneath stones at both the base and the top of a mountain [3], under stone fragments within the city walls of a castle [4], in a garden house, and in a bed in someone’s house [5]. They were originally discovered in Greece [3], but have since been found as far east as Tajikistan [2].

They are around 20-30 cm in length [4, 5]. Aside from all of the locations above, they have also been found in termite mounds and ants nests [2]. Unsurprisingly, they mostly eat ants and other small invertebrates [3]. They may also be found in holes pre-burrowed by actual worms [2].

Their labelling has been home to other species as well in the past, including some such as X. syriacus that were synonymised and then subsequently desynonymised (a process which isn’t helped when the museum holding the original specimen is destroyed in a bombing in World War II). Even now, the high genetic diversity within the Eurasian Blind Snake leaves suspicions open that there may be several species hiding under this name [6].

October has officially begun, and what better way to start than with a bat, specifically the Least Horseshoe Bat (Rhinolophus pusillus). They are one of the smallest horseshoe bats in the world [1], having a body length of only 3-4 cm [2], and are mostly from South East Asia [3].

Their species actually encapsulates many different populations including those who used to be believed to be different species, such as R. monoceros in Taiwan or R. cornutus in the main islands of Japan. They are also morphologically (as in shape-wise) similar to R. hipposideros in Europe, but unlike for the other ones, this is more likely to be convergent evolution, as opposed to coming from close genetic lineages [4].

They are insectivores, mostly feeding on flies and moths [5]. They’re from moist forests, and are in their largest flocks in caves, with groupings of up to 1500 Least Horseshoe Bats having been recorded roosting together. They may also be found in houses, though in that case obviously in smaller groups [3].

They do hibernate, with their hormonal production switching around to give them higher resistances to viruses, which bats in particular require. The exact changes may be as specific as to vary with only 5°C differences in different microclimates, depending on whether they are hibernating in a mine or in a canal [6]. Their echolocation calls also vary with climate, with those populations living in areas with heavier rainfall having higher pitched calls [1].

God, snakes can never have a simple taxonomic history, can they? Here is Russell’s Kukri Snake (Oligodon russelius). They’re at most 65 cm long and named after Patrick Russell, who was a British doctor [1], while the Kukri part of their name refers to the genus, who are named after their curved teeth, which resemble kukris, Nepali daggers [2].

Before we dive into taxonomies, here’s some background on them: they’re spread across northern, central, and eastern India, Nepal, and north eastern Pakistan [1], in deciduous jungle terrains. They have been observed to scavenge, willing to feed on dead garden lizards such as Calotes versicolor. They may also flatten the back of their head in order to intimidate potential predators [3].

Now originally the species name russelius was used for them in 1803. However, throughout the 20th century, they were considered synonymous with O. arnensis [1]. Then, in 2022 a paper found it most reasonable to revive the species based upon their body measurements and biogeography [3].

To confuse it a bit more, in 2021, a new species of snake was described, Oligodon churahensis [4], which was actually initially found via an Instagram post which then led scientists to further investigate [2]. Then, only two years later, a genetic analysis chose to combine them with the now resurrected Russell’s Kukri Snake [5].

Today I present you with the American Pika (Ochotona princeps). They are found across Western North America. While they used to be divided up into 36 subspecies, more recent genetic analysis has trimmed that down to 5 [1]. They’re around 15-20 cm in length [2].

They live on rocky mountain slopes, specifically in locations termed “talus patches” [3]. These are just piles of rocks and boulders in which they nest and store food, especially during the winter [2]. They are considered to be very aggressive and territorial, being willing to fight other American Pikas for their territory [4], however they have also been recorded to live in groups, and one time 35 individuals were found within a single talus patch [3].

They’re herbivorous, feeding on plants such as grasses, weeds, and tall wildflowers [5]. They are somewhat selective about which plants they will eat, considering both potential toxins and the nutritional composition (tending towards plants with higher caloric value). Some toxic plants may however still be taken to dry out and keep for the winter, as in this case the toxins will degrade and the plants become edible [4]. They also cache other plants, drying them out in the sun before storing them in their burrows in the winter [5], together with one of the two types of faeces they produce, which they also consume [4].

American Pikas have a very high metabolism and an internal body temperature of around 40°C [4]. This together with their thick fur means they’re prone to overheating, as only 2 hours in 28°C weather may cause them to die [3]. However, the exact risk that climate change poses in this is uncertain, as some research may suggest they’re more resilient than previously thought [1]. Mainly, different American Pika populations appear to react differently, so specific management plans are needed [3].

At this point I’m not sure if it is just genuinely this many snakes who’re only known from one individual from over 100 years ago or whether I just keep getting unlucky with random snake species. Anyway, today’s Snake Saturday is taken up by the Guerreran Hooknose Snake (Ficimia ruspator) [1].

They were initially categorised in 1941, however the snake the species is based on was collected in 1894. She was found in Mexico and at first thought to be F. publia. She’s just under 15 cm long in total. The main thing that separates her from the remainder of the species is the high number of blotches, those being 43 [2].

Obviously they are classified as Data Deficient by the IUCN, as they’re only known for certain to have appeared in Guerrero once in 1894. They write that there is doubt on their taxonomic validity [3], which may be true. In 1975, authors of one research paper insisted it’d be good to keep them around until more is known about the natural variation of F. publia [4] and more recently in 2014 they were included in Snakes of the World by Wallach et al. [5].

Much like yesterday’s frog, today’s snake is also arboreal (living in trees), though in this case on the other side of the Pacific ocean [1]. This is Cope’s Vine Snake (Oxybelis brevirostris). They‘re around a metre in length [2] and are found in Central America and Northern Columbia and Ecuador [3].

At night, they can be found perching in trees, usually not above 2 m in height. This can vary based upon their length though, as longer Cope’s Vine Snakes will generally be found higher up on woody branches as opposed to leaves. This difference may be either because it’s not worth it energy wise or because it’s just physically harder especially for smaller snakes to climb that high. There was one that managed to get 10 m up though. There has also been no recorded sexual dimorphism in body length, though males tend to have longer tails [4].

They primarily feed on frogs and lizards when foraging during the day. This can either be on the ground or still in the trees. Aside from streams and forest trails, they can also inhabit secondary forest [2]. They are considered uncommon in certain areas, but overall of Least Concern, as the conversion of rainforest for cattle ranching and other agricultural use tends not to affect their habitat as much [3].

We’re getting near Halloween, and thus it’s time to turn our eye to some more spooky/Halloween-themed critters. What better way to start than a bright-orange bat: the Painted Woolly Bat (Kerivoula picta). They’re under five centimetres long [1] with a wingspan of 18-30 cm [2]. They live for over 10 years [1].

The reason for their colour is for camouflaging while roosting during the day. Unlike some other bats, which might be found in large flocks, they mostly roost alone or in mating pairs. Their preferred location is dry banana plant leaves, though other plants and wet leaves will do as well. Because of the temporary and fragile nature of these abodes, they frequently change these roosts, but generally stay within the same area. Home ranges also don’t tend to overlap between individuals [3].

Even if they sleep in (at times) monogamous pairs, they still split up to hunt. They are mostly focussed on web-building spiders, at most supplementing their diet with insects. Their flight patterns, focussing on high manoeuvrability but low speeds reflect this choice of prey [3], while their echolocation calls, suited best for cluttered spaces such as banana plantations and sugar cane fields reflects their habitat [4].

Unfortunately their cool looks are to their detriment, as this has led people to sell them online on websites such as Ebay, Etsy, and Amazon [1], despite their status as Near Threatened [5]. As captive bat breeding for insectivorous bats is considered infeasible, any individuals would have been wild caught (even if certain listings would imply otherwise) [1]. It is also just straight up illegal, both the hunting itself and any import to the United States, where most of the sales occur [6].

This Snake Saturday we are looking at a viper, specifically MacMahon’s Desert Viper (Eristicophis macmahonii), who are found around the area where Pakistan, Afghanistan, and Iran meet. They are also the only species within their genus [1].

They are primarily found in dry, sandy dunes, with minimal plant life. There they will oftentimes be buried in loose sand, with only their snout exposed [2]. They are also considered rather short, reaching a maximum length of 72 cm [3]. They are generalist feeders, eating rodents, arthropods, lizards, and occasionally even birds [4].

Their venom is a strong cytotoxin, meaning it affects cells directly [4], and is actually quite complex and made up of many different parts [3]. While this may be thought to be affects by their broad diet, this isn’t necessarily a direct connection that can be drawn, as other snakes go against this trend [4]. When they bite humans, it can end quite badly, with anecdotal reports of death [3], as well as recorded instances of swelling, inflammation, permanent stiffness of the hand [2]. 

They are also sometimes called the Leaf-Nose Viper [2], as they have a unique feature where the rostral scale at the tip of their nose looks like a butterfly [3]. Under a microscope, their scales also appear to have a honeycomb like pattern, which can be used to place their evolutionary lineage relative to other vipers [5].