The Garter Snake on the forest path…

The mating behavior of snakes is not so easy to see. The mating displays usually occur immediately after the snakes leave their hibernacula (this term is used for winter shelters, where snakes brumate of sleeping, similarly to hibernation of other animals such as mammals) places, where they sometimes congregate in large clusters. But getting to such a hibernacula without a special purpose and without knowing the peculiarities of the ecology of snakes is almost impossible.

In spring, garter snake likes to bask in the morning near forest path

But then one day at the end of April, on a forest path, the rustling of foliage attracted my attention. I did not immediately understand where the rustle came from, but looking around I spotted an extraordinary sight. On the dry foliage of last year, covering the first shoots of the breaking green growth, an unusual ball rolled, from which for a moment heads or tails appeared on the surface … Yellow stripes on the body made it possible to immediately identify the species – it was a mating procession of a Common Garter Snake (Thamnophis sirtalis). One larger snake was distinctive from another dozen and half snakes of smaller size that are literally hovered around it. Squirming, first merging into one large ball, then stretching in a chain, the snakes continued their movement along the invisible pass in the dry foliage. But as soon as I took a step towards this extraordinary procession, the ball instantly became alert, assessing the situation, and began to disintegrate. Individual snakes crawled on the sides, looking for cover under the foliage, in the cracks between the hard rocks and between the roots of trees. Nevertheless, about a dozen of the most persistent continued to follow the largest snake. The presence of a small rock in the forest indicated that the snake hibernacula was somewhere nearby: snakes usually hibernate in cavities under rocks or in natural depressions formed under the roots of dead trees, where they can gather from several tens to several hundred or even thousands of individuals.

The common garter snake is widespread in Ontario. In the forests around Ottawa, it is the most common snake species. The slender body of garter snakes with a light stripe running along the keel from head to tail, with yellow or reddish longitudinal stripes on the sides and an elegant narrow head that smoothly merges into the body, allow anyone to immediately unmistakably identifies this species. The average length of a snake with a tail is 50-70 cm. Sometimes there are specimens that are larger – up to a meter in length, but they rarely can be found. Females are much larger than males. Only one female, accompanied by more than a dozen males, led the mating procession that I observed. This feature of the biology of the species directed to the fact that there are much more males in the population than females. Garter snakes are also remarkable by the reproduction features: they can both lay eggs, from which small snakes then hatch, and give birth to alive little snakes. Usually, individuals living in the north latitudes give birth to live offspring, and more southerly occurring counterparts lay eggs. In Ontario, garter snakes give birth to live young. During the season, the female can give birth from ten to forty offspring. But only a few individuals survive to adulthood since snakes are a desiring prey for both four-legged and feathered predators. In addition, a significant number of snakes are killed on the roads, under the wheels of cars in populated areas with a dense road network. In Ontario, there are two subspecies that are externally different: in the south, the nominative subspecies of Eastern Garter snake has the bright yellow stripes on the sides of the body, and in the northern subspecies, the red-sided garter snake has reddish-orange stripes.

Garter snakes are found in a wide variety of habitats, both in forests and in meadow communities as well as around wetlands. In the Ottawa Greenbelt and around, it is definitely a forest species, inhabiting light deciduous and mixed forests. The main food items for snakes are amphibians and earthworms, but on occasion these snakes can catch small rodents and passerines, as well as small fish. Hunting strategy includes two types of behavior.  Sometimes, garter snakes wait for prey, attacking approaching animals. But more often they actively pursue their prey, effectively catching fast tadpoles and small fish.

Garter snakes are harmless to humans. But this does not mean that anyone can catch them. It must be understood that the capture of any living creature is a huge stress for the latter. Therefore, if you notice a garter snake near the forest path, walk by, or watch the snake from the side without trying to catch it.

Garter snakes often hide in construction near human settlements, especially near forest cabins

If you wish, you can also join one of the programs of Ontario Nature such as Ontario Reptile and Amphibian Atlas or Youth Circle for Mother Earth, and contribute to wildlife monitoring and conservation.

Central Asian Tortoise and its Conservation

This tortoise is still widely distributed in the desert areas of Central Asia. Photos by Mark Pestov

If you will visit the desert plain near foothills of Nuratau Range in Uzbekistan in spring – from mid-March – until late May, more likely that you will be able to spot several individuals of Central Asian Tortoise, grazing on juicy spring ephemeral plants and cereals. This turtle has the huge periods of “hibernation”, hiding for harsh time of summer heat and winter cold in deep holes, and appearing again only next spring for the short period of breeding time. It is possible to distinguish “good” and “bad” years on the rings of the tortoise carapace. After “good” years, abundant with rains and juicy vegetation, the rings are wide and prominent; after “bad” years the rings are slightly distinguished. It is possible to identify the age of individuals counting yearly rings. Surprisingly, this tortoise could adapt to the extremely difficult conditions of cold Central Asian deserts and evolve for millennia, occupying all appropriate plain desert landscapes. This tortoise does not need too much that to survive in the modern world: habitats that are not disturbed and mild anthropogenic pressure. Many desert habitats are still virgin and cannot be transformed into agricultural lands due to lack of precipitation and water. However, anthropogenic pressure is a more serious threat…   

Development of road network is one of the threats for tortoise populations

Central Asian Tortoise (Agrionemys horsfeldii), the species widely distributed in Central Asia in the past, becomes more and more threatened in last decades due to species exploitation in the international trade, change and transformation of habitats, development of road network in the desert regions and other anthropogenic impacts. The species also called Horsfield’s Tortoise, Russian Steppe or Afghan Tortoise. This is an only tortoise species, which is an endemic of Central Asia. Species range and abundances significantly reduced last decades in the result of human development and transformation of virgin desert lands into irrigated crop production fields and due to international trade for pet markets. Central Asian Tortoise is included in IUCN Red List as a Vulnerable species (VU), however, its population status is unknown and not much is known about population trends (IUCN, 2021). The species is included in CITEC Appendix II and covered by agreement about international trade of wild plants and animals.

Central Asian Tortoise occurs in desert plains of Central Asia inhabiting sandy, gravelly sandy and loamy plains with sparse desert vegetation. It also can be found in stony-loamy foothills on elevations up to 800 m above sea level. Although there are known its findings on altitudes up to 1,600 m above sea level. But feeding conditions are better in the desert plains, therefore the population densities of tortoises in mountains are very low. Habitats with optimal conditions, providing a stable food base and reliable shelters, are represented by loess foothills and piedmont plains with ephemeral or wormwood-ephemeral vegetation, usually, below 800 m above sea level (Bondarenko & Peregontsev, 2017). According to assessment, conducted in Uzbekistan, the current range of Central Asian Tortoise in Uzbekistan occupies around 300,00 square kilometres. The population density varies significantly ranging from 0.1 – 0.9 individuals per hectare (rare) to 1.0 -9.9 individuals per hectare (common) and > 10.0 individuals per hectare (abundant).

Agricultural development of desert areas in Central Asia that took place in 1950-1980s led to expiration of this species within developed lands. Because tortoises ate seedlings of crops and green vegetation on agricultural fields. In some developed regions farmers collected and killed 2,000 – 3,000 tortoises a day.  At present, the Central Asia tortoise is extirpated from the developed regions. In some regions of Central Asia, for example, in Fergana Valley, the species is completely extinct. However, the greatest damage to the remained tortoise populations has been done by uncontrolled collection for trade.  

Males of tortoises are smaller than females

This species has an important value for local economies. Since 1990s until present, it is a subject of zoological trade, covering the needs of pet market, mostly in Europe. The tortoises for trade have been caught mostly in natural environment, therefore planning and control of animals collected for zoo-market are extremely important.

Collection of Central Asian Tortoise for trade started in 1960-1980s in southern Kazakhstan by Central Asian zoo-enterprise, located in Tashkent. Since independence time in 1990, this zoo-enterprise started to collect tortoises for trade in Uzbekistan, supplying for the market 4,000 -19,000 individuals annually. At the same time, the illegal trade to Russia and Ukraine on assessment of experts reached 50,000 individuals annually (Bondarenko & Peregontsev, 2006).  Until 1999, the CITEC quote was issues to Russia. Since 1999, it is issued directly to Uzbekistan. At the same time, since 1999 to 2016 the annual export quotas for collection of tortoises in natural environment increased from 35,000 to 80,000 individuals (UNEP-WCMC, 2016). A trend of sharp increase in trade took place from 2009. More likely, it is related not only high demand of the foreign markets in inexpensive turtles, but also by the increased number of organizations received official permits for catching. In total, according to expert evaluation from 1997 to 2015 only in Uzbekistan there were collected for trade legally 592,100 individuals. Besides, at least 430,000 individuals were exported for the same period of time illegally mostly to Russia and Ukraine (Bondarenko & Peregontsev, 2017).

Surveys carried out in Uzbekistan on the areas of long-term collection of tortoises for trade showed that uncontrolled catch caused the sex and age composition of the populations. After collection of individuals, suitable for trade (specimens with carapace’s length less than 12 cm), the populations are mostly represented by females over 15 years old (Bondarenko et al., 2001), because males are smaller than females and their share in catch is greater. The further research indicated that after 10 years of tortoise collection within surveyed areas, their density of populations significantly decreased and did not recover to the level before catching in next 9 years. The population density within the most part of the tortoise range does not exceed 3.0 individuals per hectare.

Central Asian Tortoise at the end of breeding season

All these facts indicate that sustainable catch of tortoises from natural environment should be only 10,000 – 12,000 individuals annually. But even in this case the international mechanisms do not solve the problem of tortoise conservation, because illegal collection and illegal export of tortoises through Kazakhstan to Russia and Ukraine. The conservation efforts should include strengthening of legislation and control, including other Central Asian countries, Russia and Ukraine. Monitoring of wild populations, public awareness and engagement in conservation of local communities in desert regions.         

References:

IUCN Red List of Threatened Species. 2020. https://www.iucnredlist.org/species/21651/9306759

Bondarenko D. A., Peregontsev E. A. 2006. Perspectives of Study and Protection of Steppe Tortoise in Uzbekistan // Chelonii. Vol. 4. P. 278 – 284.

Bondarenko D.A., Peregontsev E.A. 2017. Distribution of the Central Asian Tortoise (Agrionemys horsfieldii [Gray, 1844]) in Uzbekistan (Range, regional and landscape distribution, populations density). // Modern Herpetology, 2017, V. 17, issue 3/4. Pp. 124-146.

UNEP-WCMC. 2016 . Review of species selected on the basis of the Analysis of 2016 CITES export quotas. UNEP-WCMC. Cambridge. Available at:
http://ec.europa.eu/environment/cites/pdf/reports/

The Caspian Monitor in Central Asia

The Caspian monitor (Varanus griseus caspius) in aggressive pose – scaring possible enemies

If you will try to look for the global assessment of Desert Monitor (Varanus griseus) in IUCN Red List, you will not find this species, although many other species from this abundant genus (more than 70 species belonging to one genus – Varanus) have been already assessed. This widely distributed species, inhabiting deserts of North Africa, Central Asia and South Asia, is currently split into three subspecies by their geographic areas. The grey monitor (V.g. griseus) occurs in African deserts. The Indian desert monitor (V.g. konieczhnyi) is mainly distributed in deserts of Pakistan and north-west India. The Caspian monitor (V.g. caspius) inhabits deserts of Central Asia and neighboring southern countries: Afghanistan, Iran, Turkey and western Pakistan. In countries of Central Asia: Kazakhstan, Kyrgyzstan, Turkmenistan and Uzbekistan, it is included in the national Red Books as rare species with declining range and abundances.  

The Desert or Caspian monitor is the largest lizard in Northern Eurasia: the length of adult specimens from the tip of muzzle to the tip of the tail can reach 150 cm! The Caspian monitor is usually closely associated with large colonies of gerbils (Rhombomys opimus). In its complex burrows monitors find shelters, and the rodents themselves often make up the basis food diet of this predatory reptile. From shelters in search of food, the monitor can go up to 1 km or more. In case of danger, this large lizard may briefly run at speeds up to 120 m per minute. In search of bird nests, monitors, especially young ones, cleverly climb trees and shrubs.

Caspian monitor in typical habitat in the Kyzylkum desert

Female-monitor lays up to 20 or more eggs in deep burrows with relatively high humidity. When young lizards just hatched, they are about 25 cm long. The known life span of a monitor lizard is up to 17 years. Protecting from enemies (for example, when people trying to pick them up) the monitor lizard can bite quite a bit. Probably, their saliva contains anticoagulants, as wounds inflicted them bleed for a long time.

In 2012, the herpetologist from the Institute of Zoology in Almaty (Kazakhstan), Dr. Marina Chirikova received a grant from the Rufford Foundation (The Rufford Small Grants Foundation – www.ruffordsmallgrants.org ) for the implementation of project: “Attention! Grey monitor lizard! ”- aimed at studying and protection of this species. As a consultant to this species, I could take part in the expedition to the northern Kyzylkum desert – the main region of the habitat of the monitor lizard in Kazakhstan.

Our expedition began in May from the Shardara regional center, located on the Syr-Darya River near borders with Uzbekistan. From local truck drivers we knew that most recently on a dirt road going to the Bimirza village, they saw several monitors, crushed by cars, and explained how to get there. After driving on this road about 50 km our expedition discovered three monitor lizards, recently roadkill under wheels of trucks. These were large adult specimens, each is more than a meter long. We stopped, fixed coordinates of locations, described the terrain, photo-graphed dead animals, took tissue samples – pieces of the tail, phalanges of the fingers … Perhaps in the future will find partners for genetic analysis of our samples, and on thin sections of tubular bones will determine the age of dead reptiles … Definitely, we were unpleasantly amazed to see in the first day three dead monitor lizards, which are rare and formally protected in Kazakhstan! We were surprised to find all these lizards on dirt, sandy road, where cars moving with low speed. Why so many dead reptiles? We drove up to the camp of livestock breeders, began to communicate with local residents and found out that often the monitors are crushed by cars on purpose. Many people, as it turned out, traditionally believe in prejudice, believing that this large lizard can suck goats and sheep milk, brings misfortune, and if he runs between a man’s legs, then this person will remain childless… All these circumstances cause persecution of the monitor lizard by people.

Monitors often move along dirt roads, probably here they find more prey or scavenging on small roadkill animals. One such “hunter” or “scavenger” walked towards our car. When he spotted us, he turned and ran the other way. But he did not guess to move from the road and go into the sandy dunes. When the distance to the car catching up to him is reduced up to 10 meters, the lizard turned to our side and took the aggressive pose, maximally swelling and hissing, threatening large enemy…

Exactly so – face to face – fearless monitor lizards for hundred thousand years met their enemies – four-legged and feathered predators. And often the enemy retreated, not daring to attack on a formidable dinosaur armed with sharp teeth. However, against a man driving a car such a success tactic does not “work”, especially if this man since childhood does not like and is afraid of the “horrible” lizard. That’s the main reason why these rare animals are threatened: one hand, hostility to them by the local population, on another hand, this is a behavior stereotype of monitor lizard… Of course, small monitors are hunted by many desert predators, like any lizard. But large adult monitors do not have enemies except for man.

The most vivid impression of this expedition again was related to the negative impact of man, although this time it ended well … Near the northern border of the monitor lizard’ habitats, which almost coincides with the border of Kyzylkum sands, we met with a group of zoologists from Kyzylorda anti-plague station. Zoologists told that they usually see this large lizard 5-6 times per season. But this time, they found the monitor recently in an old, dry well, located at the abandoned camp of livestock breeders. Our expedition went to the mentioned place and found still an alive monitor in a narrow well with a diameter of two meters and a depth of about 4 m.

It took some time to save the monitor, because he made several holes inside and did not indent to communicate with “scaring” people. However, we found ways how to capture him and take out from the well, where this lizard could die after while without food. We watered the saved monitor lizard – poured into it one and a half cup of water, because the animal was dehydrated. However, the monitor id not look very exhausted: in the well, we found the remains of a hare – a skin and a skull. Apparently, hare fell into the well and became the food of the monitor lizard. Obviously, the monitor fed up by falling down bugs, lizards and other small animals … It was a really large specimen – a female, 126 cm long. According to literature, maximal sizes of monitor lizards in Kazakhstan reach 130 cm, in Uzbekistan – 150 cm. However, local people said that they observed larger specimens.

We released the saved lizard away from the dry well, so that this monitor does not fall there again. By the way, after sitting half-hours in a bag and having been in the hands during the measurement process, the monitor calmed down, his aggressiveness greatly diminished, and before liberation, he thanked us with a good photo-session. We wished her reproductive success in the continuation of the ancient line of this unique lizards, still inhabiting deserts …

During the expedition to Kyzylkum, in addition to the monitor lizard, we found other species such as a green toad, two species of geckos, three species of toad-agamas, steppe agama and Central Asian tortoise. All these animals, even small turtles, serve as potential food of the monitor lizard.

According to preliminary assessment, in southern Kazakhstan the remained stable population of Caspian monitor accounts, at least, several thousand individuals. Key species habitats are located in the southern part of northern Kyzylkum desert near borders with Uzbekistan. The main causes of the population decline are the death of monitor lizards under the wheels of cars on numerous dirt roads, covered Kyzylkum by dense network.

Obviously, there is a need to preserve the remained habitats of this rare and vulnerable animal, increasing protected area network in the Kyzylkum desert. There is a need also in a public awareness campaign that to change the attitude of the local people to desert animals.  Basing on collected materials and photographs, taken during expedition, we printed a colorful poster and pocket calendars with a portraits of monitor-lizards and disseminated them in schools.

The portrait of the Caspian Monitor

More information about the project “Attention! Caspian monitor lizard! ” can be found on the website telling about Herpetofauna of Kazakhstan, created by colleagues from Almaty. Naturally, in one year it is impossible to solve all problems associated with the protection of the Caspian monitor. Therefore, we continue to work on study and conservation of desert wildlife in Central Asia. We hope to achieve the good results in the protection of desert wildlife and this unique lizard through cooperation with national authorities and local people.