Predation

Introduction

The mode of predation directly influences the survival or the extinction of the species and it is therefore up to each one to adapt. Studies on Trimeresurus albolabris revealed that age, and therefore height and weight, had no influence on the speed and striking distance between the juvenile and adult stages. That said, sexual dimorphism influences the typing speed. Indeed, although heavier, females hit faster than males. Although further studies are needed, this variation can be explained by the fact that during the breeding season, the arboreal females of the complexes change their habits, becoming terrestrial. This change implies an adaptation of the type of prey (Herrel, A., Huyghe, K., Oković, P., Lisičić, D., & Tadić, Z. (2011)).

prey

Their main sources of food are ectothermic at the juvenile stage, but an ontogenetic change of prey is achieved by growing, respecting a mass-predator ratio. In addition, the size and morphology of the head directly influences the type of prey. Thus, females, generally larger than males, are predisposed to such a change. This change is not devoid of meaning but is very well controlled by the animal that must adapt: ​​the energy spent to hunt, eat and digest his prey must always be as low as possible. By eating larger, females will be able to hunt less often than if they did not change prey type. (Strine, C., Silva, I., Nadolski, B., Crane, M., Barnes, C., Artchawakom, T., … & Suwanwaree, P. (2015)). Eating too big, in addition to energy lost in digestion, limit movements and speeds, among other negative situation such as the presence of predators.

A difference in the type of prey was also observed, particularly in Trimeresurus gracilis, with respect to sex, the females preferring rodents, while the stomach study of the males revealed shrews. (Lin, C.F., & Tu, M.C. (2008)). This differential study was not observed in other species of the complex, such as Viridovipera stejnegeri (Creer, S., Chou, W.H., Malhotra, A., & Thorpe, R. S. (2002)).

Snake localities also show an adaptive evolution of prey and the rate of digestion and evacuation of stool seems potentially due to the mainly arboreal lifestyle of the complex (Creer, S., Chou, WH, Malhotra, A., & Thorpe). , RS (2002)). Still further, studies on Viridovipera stejnegeri have shown that island populations ate fewer amphibians (including tadpoles that are also part of the diet) than on the green islands (Creer, S., Chou, WH, Malhotra , A., & Thorpe, RS (2002)).

In addition to the transition from terrestrial to (semi-) arbo, Craspedocephalus malabaricus experiences an ontogenetic change in staining during the transition from juvenile to adult stage (Sagar, U. (2016)).

Viridovipera stejnegeri, Popeia phuketensis and Trimeresurus gracilis demonstrate that the type of prey is large, placing the complex in the category of euryphages, as evidenced by multiple studies in the table below. Despite the latter, Duttaphrynus melanostictus, which is a common amphibian species, is not a prey due to its toxic skin.

Reign Specie
Mammal Apodemus semotus
Mammal Eothenomys melanogaster
Mammal Volemys kikuchii
Insectivore Soriculus fumidus
Reptile Eumeces elegans
Reptile Sphenomorphus florensis
Reptile Sphenomorphus taiwanensis
Reptile Takydormus hsuehshanesis
Amphibian Hynobius arisanensis
Amphibian Fejervarya limnocharis
Amphibian Ingerana tasanae
Amphibian Limnonectes hascheanus
Amphibian Occidozyga martensii
Amphibian Polypedates leucomystax
Reptile Hemidactylus frenatus
Reptile Hemidactylus platyurus
Reptile Calotis sp
Amphibian Rana swinhoana
Amphibian Rana sauteri
Amphibian Rhacophorus malabaricus
Amphibian Rhacophorus moltrechti
Amphibian Polypedates megacephalus
Amphibian Buergeria robusta
Reptile Japalura sp.
Reptile Gekko chinensis
Reptile Hemidactylus bowringii
Amphibian Polypedates megacephalus
Amphibian Rhacophorid sp
Amphibian Microhylid
Mammal Soricids
Amphibian Hylarana nigrivittia
Amphibian Meristogenys kinabaluensis
Amphibian Calotes Versicolor

It has been shown that the ambush sites selected by Trimeresurus macrops are not random, without defining the exact reason for this choice. Assumptions are currently focused on prey abundance (Strine, C. (2014)). Their choices seem to focus on more wooded, deeper areas, larger branches and a wider choice of shelters.

predators

Although the human being, because of its industrialization, the relocations, and its catches, often with a view to selling the individuals represents for the complex a real problem of survival, Trimeresurus ssp also has some predators of the animal kingdom as it presents the table below:

Reign Specie
Mammal Herpestes javanicus
Reptile Ophiophagus hannah
Anguillidae Anguillia marmorata
Reptile Dinodon rufozonatum walli
reptile Dinodon semicarinatum
Reptile Ovophis okinavensis
Reptile Trimereresurus flavoviridis
Mammal Felis iriomotensis
Mammal sus scrofa riukiuanus
Oiseau Butastur indicus
Oiseau Circus spilonotus spilonotus
Oiseau Spilornis cheela perplexus
Mammal Arctonyx collaris

Sources:

Herrel, A., Huyghe, K., Oković, P., Lisičić, D., & Tadić, Z. (2011). Fast and furious: effects of body size on strike performance in an arboreal viper Trimeresurus (Cryptelytrops) albolabris. Journal of Experimental Zoology Part A: Ecological Genetics and Physiology, 315(1), 22-29.

Lin, C. F., & Tu, M. C. (2008). Food habits of the Taiwanese mountain pitviper, Trimeresurus gracilis. Zoological Studies, 47(6), 697-703.

Creer, S., Chou, W. H., Malhotra, A., & Thorpe, R. S. (2002). Offshore insular variation in the diet of the Taiwanese bamboo viper Trimeresurus stejnegeri (Schmidt). Zoological science, 19(8), 907-913.

Sumontha, M., Kunya, K., Pauwels, O. S., Nitikul, A., & Punnadee, S. (2011). Trimeresurus (Popeia) phuketensis, a new pitviper (Squamata: Viperidae) from Phuket island, southwestern Thailand. Russian Journal of Herpetology, 18(3), 185-194.

Strine, C., Silva, I., Nadolski, B., Crane, M., Barnes, C., Artchawakom, T., … & Suwanwaree, P. (2015). Sexual dimorphism of tropical green pit viper Trimeresurus (Cryptelytrops) macropsin Northeast Thailand. Amphibia-Reptilia, 36(4), 327-338.

Hays, W. S., & Conant, S. (2007). Biology and impacts of Pacific Island invasive species. 1. A worldwide review of effects of the small Indian mongoose, Herpestes javanicus (Carnivora: Herpestidae). Pacific Science, 61(1), 3-16.

Tanaka, K., & Mori, A. (2000). Literature survey on predators of snakes in Japan. Current herpetology, 19(2), 97-111.

Devan-Song, E. A. (2014). Ecology and conservation of the bamboo pit viper: Natural history, demography and effects of translocation.

Sagar, U. (2016). Some observations on the Malabar Pit Viper Trimeresurus malabaricus in central Western Ghats, India. Newsletter of the South Asian Reptile Network, 18, 36.

Hiren Khatri (2017), communication personnelle

Strine, C. (2014). The ecological study of green pit vipers in Sakaerat environment research station, Nakhon Ratchasima.