Of all the big cat species, the tiger is the largest. Tigers are easily identified by their striped orange coat and long, striped tail. An adult Bengal Tiger can reach a length of up to 3 meters, including the tail, and weigh more than 250 kg. Adult tigers have white spots of fur on the back of each ear to make it easier for their young to follow them in poor light. There are never two tigers with the same stripes. Individual tigers can be distinguished by markings on their body, face, or tail, which can vary in number and thickness. The Bengal Tiger, like all tigers, is a carnivore. Rather than chasing down prey, the Bengal Tiger uses the “stalk and ambush” approach, which involves silently stalking prey and then striking it from behind. Tigers are solitary animals, except a mother and her cubs. Tigers have the potential to turn into man-eaters. People at risk can put a mask on the back of their heads, which has been used in the past to avoid Bengal Tiger attacks on humans. This gives the impression that the human is looking from behind.
According to the Guinness World Records website, the 2018-19 tiger survey was the most extensive to date in terms of both resources and data collected. Camera traps (outdoor photographic devices with motion sensors that start filming when an animal passes by) were set up in 26,838 locations over 141 distinct sites in India, covering an area of 121,337 square kilometers (46,848 square miles). The states of Madhya Pradesh (526), Karnataka (524), and Uttarakhand (442), which together host about 1492 tigers, have the highest number of tigers. The Corbett Tiger Reserve in Uttarakhand has the most tigers (231), followed by the Karnataka reserves of Nagarhole and Bandipore, which have 127 and 126 tigers, respectively. Dampa in Mizoram, Buxa in West Bengal, and Palamau in Jharkhand are the last large cats surviving. Only 2,967 tigers were predicted to live in India in 2018, according to the National Tiger Conservation Authority.
A study conducted on the skin of Indian carnivores by Rajani et al. (2020) revealed that the skin of Bengal tigers has a Stratum Basale, Stratum Spinosum, Stratum Granulosum, and Stratum Corneum. The presence of compound hair follicles was a distinguishing trait. A single big primary guard hair was ringed by compound follicles in Bengal tigers. In Bengal tigers, the number of surrounding compound follicles ranged from three to seven. One to two coarse primary hair follicles and multiple fine secondary hair follicles were found in each compound follicle.
Tiger samples from the Sundarbans were tested for mitochondrial and microsatellite markers and compared to mainland Bengal tiger populations in India (northern and peninsular). In comparison to other mainland tiger populations, Sundarbans tigers were found to be genetically unique and to have reduced genetic variation. The Sundarbans tiger was recently isolated from the mainland (600—2000 years ago), according to a demographic study. Until recently, historical and genetic evidence suggested that the Sundarbans tiger was genetically related to mainland tigers. Finally, genetic isolation from mainland tiger populations and adaption to the mangrove ecology may have altered the Sundarbans tiger’s genetic architecture. As a result, the Sundarbans tiger needs specific conservation care to preserve its unique ability to adapt as well as its genetic uniqueness. The adaptive evolutionary conservation (AEC) criterion should be used to manage it as an evolutionarily significant unit (ESU) (Singh S. K., 2017).
The chemical composition of the territorial marking fluid of a male Bengal tiger, Panthera tigris, was investigated. It was discovered to be made up of urine and a little amount of fatty material, which could operate as a controlled-release carrier for the fluid’s volatile contents. In the marking fluid, 98 volatile chemicals and elemental sulfur were detected using gas chromatography and gas chromatography-mass spectrometry. A total of 16 more volatiles have been tentatively discovered. Alkanols, alkanals, 2-alkanones, branched and unbranched alkanoic acids, dimethyl esters of dicarboxylic acids, – and -lactones, and compounds containing nitrogen or sulfur made up the bulk of these substances. Pure (R)-3-methyl-2-octanone, (R)-3-methyl-2-nonanone, and (R)-3-methyl-2-decanone were found in many samples of the marking fluid, although these ketones were racemized in others. The saturated (R)—lactones and (S)—lactones (S)-(+)-(Z)-6-dodecen-4-olide (S)-(+)-(Z)-6-dodecen-4-olide (S)-(+)-(Z)-6-dodecen-4-olide (S)-(+)-(Z)-6-dodecen-4-olide (S)—lac 2-methylnonanoic acid, 2-methyldecanoic acid, 2-methylundecanoic acid, and 2-ethylhexanoic acid were racemates among the chiral carboxylic acids. The presence of ketones, fatty acids, and lactones in high concentrations in the headspace of the marking fluid shows that these chemicals are key pheromone ingredients (Burger et al., 2008).
For DNA extraction and subsequent genotyping of tiger species, non-invasive samples such as scat, hair, or scent are preferred. DNA was isolated from Bengal tiger scat samples and a fragment of the cytochrome b gene was sequenced after PCR using species-specific primers in a study conducted by Alam et al. (2021). Tiger DNA was effectively recovered from scat samples using tiger-specific primers, based on the size of the PCR result and the sequencing of the cytochrome b gene. As a result, the presence of tiger DNA may be detected using this method only based on the size of the PCR product in the gel.
Sources and references : https://www.worldlandtrust.org/species/mammals/bengal-tiger/