Animal Adaptations: Evolution of Forms and Functions

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Fellendorf, M. & Vortisch, P. Microscopic Traffic Flow Simulator VISSIM. In Fundamentals of Traffic Simulation. International Series in Operations Research and Management Science (ed. Barcelo, J.) 63–93 (Springer, Berlin, 2010). https://doi.org/10.1007/978-1-4419-6142-6_2. The threshold traffic volume at which AVC probability was equal to probability of successful crossing ( P h = 0.5) varied for different species. Under present traffic heterogeneity, this threshold traffic for group living animals like chital, gaur and wild pig was 300–400 vehicles/h. This threshold traffic volume was higher for sambar (700 vehicles/h), and highest for tiger and leopard (1100–1300 vehicles/h). Across all simulated scenarios, traffic volumes of 200–300 vehicles/h decreased the chances of a successful crossing by half for gaur. For chital, this traffic volume lies above 400–500 vehicles/h in traffic composed of light vehicles (H 0, H 1, H 4, H 7). This threshold volume is higher for sambar (1100 vehicles/h) in traffic composed mostly of heavy vehicles (H 3, H 5, H 6). Hourly traffic volumes above 1000 vehicles/h posed a barrier to < 50% successful traverses for tiger and leopard at most traffic heterogeneity scenarios. The threshold traffic volume for solitary species was lowest (800 vehicles/h) at scenario H 3 which comprised of only MAVs. Beyond this threshold traffic volume, higher fatalities are expected to occur.

The study was performed during the testicular active phase (Apr-June) of the annual testicular cycle of the animal ( Haldar et al., 1990). Adult males (100–120 g body weight) of F. pennanti were obtained in the äfirst week of April and acclimatized, for two weeks, in a room fully exposed to natural environmental conditions. They were housed in wire net cages and provided with food (soaked gram seeds) and water ad libitum. They were divided into different groups of eight animals each, in accordance with the protocol in Table 1. Pinealectomy (Px) was performed following the technique of Haldar-Misra ( Haldar, 1986). Besides NDL animals were exposed to LP of 14L:10D and SP of 10L:14D. The environmental temperature during the period of experimentation was recorded as a maximum of 37.02°C and a minimum of 28.11°C. The animals exposed to experimental LP and SP were maintained at 37°C. Two such sets of animals were maintained. One set. received injections in the morning at 7 hr. and another during evening at 16.30 hr. Animals under LP received morning injections 2 hr after lights on and evening injections 2 1/2 hr before light off. Animals exposed to SP received morning injections 15 min after lights on and 15 min before lights off. Solutions of aMT and MT (Sigma Chemical Co., USA) were made following the method of Pevet and Haldar-Misra ( Pevet et al., 1982a). The animals were injected subcutaneously with 10μg MI/animal/day. Control animals were injected with vehicle (normal saline, 0.90% aqueous NaCl)/animal/day. After completion of 60 days the animals were sacrificed by cervical dislocation and their body weights noted. Testes were removed, weighed on a microelectrical balance and fixed in Bouin's fluid. They were processed by the routine paraffin method for histological observations. Seminiferous tubule diameter of testes was measured by an ocular micrometer. The data was statistically analysed with the help of Student's ‘t’ test and analysis of variance, ANOVA ( Bruning et al., 1977). Table 1According to the U.S. Food and Drug Administration, the Centers for Disease Control and Prevention, and the U.S. Department of Agriculture, there is at present no proof to propose that COVID-19 can be transmitted through food consumption or food bundling, but food safety practices are highly encouraged [15]. Among the six study species, lowest AVC probabilities were observed for tiger and leopard, primarily because these are solitary fast moving species. Body size had negligible effect on AVC probability 23, but increase in group size increased the probability resulting in higher AVC probabilities for group living species. Among social species, lower group size of sambar translated to lower AVC probability than chital and wild pig, despite having similar maximum running speeds. Group size of gaur was similar to that of wild pig; yet gaur had the highest AVC probabilities across all heterogeneity scenarios as a result of its low running speed. Sarkar, D. Lattice: Multivariate Data Visualization with R. (2008). Springer, New York. ISBN 978-0-387-75968-5. accessed 25 Mar 2019; https://lmdvr.r-forge.r-project.org/.

At higher traffic volumes the barrier effect sets in due to continuous flow of traffic, where road crossing by animals may not occur. Thus higher traffic volumes would result in a barrier-like situation because of avoidance of animals at high traffic segments 6, 7 reducing the number of attempted crossings by wildlife. This avoidance would reflect as low roadkill counts on high traffic roads 22. Trombulak, S. C. & Frissel, C. A. Review of ecological effects of roads on terrestrial and aquatic communities. Conserv. Biol. 14, 18–30. https://doi.org/10.1046/j.1523-1739.2000.99084.x (2001). During the study period, we recorded the walking speeds (in m/s) of the study animals in their natural habitats inside PTR, Maharashtra, to calculate the average moving speed. For each species, we averaged 14–20 observations of various walking speeds which was found to be close to 1/6th of the top running speed (Supplementary Table S2). Influence of road and traffic characteristics on AVC probability Avadh Saxena, the American Group Leader of Physics of Condensed Matter and Complex Systems Group (T-4) at Los Alamos National LaboratoryPN Saxena (1925-1999), Indian academic and founder Chairman of the Department of Pharmacology, Jawaharlal Nehru Medical College Rhodes, J. R., Lunney, D., Callaghan, J. & McAlpine, C. A. A few large roads or many small ones? How to accommodate growth in vehicle number to minimise impacts on wildlife. PLoS ONE 9(3), e91093 (2014). Evening injections of aMT and MT significantly reduced testes weight and tubule diameter of SO and Px animals maintained under NDL, LP and SP ( Fig 1, Table 2). Morning injections, under all conditions, were without any significant effect on the testes ( Fig. 2, Table 3).

The present study reveals, for the first time in a tropical mammalian species, that besides aMT there also exists a diurnal rhythm in the sensitivity of the animal to exogenous MT injections. Pinealecomy and constant release of aMT and MT have been reported to cause atrophy of gonad in male European hamsters kept under long photoperiod ( Masson-Pevet et al., 1986). aMT implants have been reported to hasten recrudescence in male hamsters on short days (Turek et al., 1976). aMT implants cause testicular regression in long-day intact. male Peromyscus leucopus ( Johnston et al., 1980; Lynch et al., 1976) but do not retard testicular regression on short days ( Petterborg et al., 1981). Also varied results have been observed on the effects of photoperiod and melatonin on gonadal function of prepubertal and adult animals of Microtus and Peromyscus species. Although in the case of F. pennanti silastic capsule implants of aMT and MT lead to testicular regression in both intact and Px animals, ( Saxena, 1988) the effects of this continuous mode of MI administration under different photoperiods remains to be assessed.

References

Leblond, M., Dussault, C. & Ouellet, J.-P. Avoidance of roads by large herbivores and its relation to disturbance intensity. J. Zool. 289, 32–40. https://doi.org/10.1111/j.1469-7998.2012.00959.x (2013). Jacobson, S. L., Bliss-Ketchum, L. L., de Rivera, C. E. & Smith, W. P. A behaviour-based framework for assessing barrier effects to wildlife from vehicle traffic volume 1. Ecosphere 7, 1–15 (2016).

Human risk assessment has been investigated to find out the potential hazard resulting from human exposure to poisonous substances present in various foodstuffs and environmental matrices. These investigations are generally used to help with meeting guidelines like those specified by administrative bodies like WHO and numerous others [42]. The major point of human risk evaluation is, to ensure the protection of consumers against the impacts of poisons in water or foods. Thus, it is important to guarantee that contaminants of interest in food or water don’t surpass the normal daily intake. The model assumes that traversing of roads by animals is ‘blind’ for animals in that they do not respond to the presence of vehicles (i.e. do not stop or turn around), and for drivers in that they do not respond to the presence of animals on the road by braking. Therefore, we define P h as the probability of hit of an animal that is attempting to cross the road, as we cannot account for the number of crossing attempts that translate into actual presence of animal on the road for an AVC to occur. Also, hematological profiles were normalized in the groups of mice infected and treated with effective dosages of A. boonei except for the MCV and MCHC values which did not vary significantly in the different groups of experimental mice, an indication of a typical feature of normocytic-normochromic anemia ( Menezes et al., 2004). Plant extracts have been very useful sources of medication for various disease conditions ( Ataman et al., 2006; Gill et al., 2012). The use of medical plant extracts which are rich sources of natural inhibitors and pharmacologically active compounds can be very promising especially in the area of chemotherapeutic-based approaches against malaria ( Gatsing et al., 2010).Shepard, D. B., Kuhns, A. R., Dreslik, M. J. & Philips, C. A. Roads as barriers to animal movement in fragmented landscapes. Anim. Conserv. 11, 288–296. https://doi.org/10.1111/j.1469-1795.2008.00183.x (2008). Jaarsma, C. F., van Langevelde, F., Baveco, J. M., van Eupen, M. & Arisz, J. Model for rural transportation planning considering simulating mobility and traffic kills in the badger Meles meles. Ecol. Inform. 2, 73–82 (2007). Ibisch, P. L. et al. A global map of roadless areas and their conservation status. Science 354, 1423–1427. https://doi.org/10.1126/science.aaf7166 (2016). When the aqueous extracts of A. boonei was administered at the different dosages 100, 200, 400 and 800 mg kg -1 to mice infected with P. berghei, it was observed that the net effect of this extracts was such that it appears to normalize hematological indices in the groups of mice infected and treated with the plant extract when compared with the data obtained for the experimental control groups of mice ( Table 3, 4). Table 1: We present a framework to identify species and roads vulnerable to AVC as a function of road, traffic and species characteristics, using data from traffic simulations under different traffic heterogeneity and volume scenarios, and morphometry and behavioural data of six widespread large mammals of Central India. The study was conducted on a 60 km stretch of the National Highway 44 (NH 44) passing through the Pench Tiger Reserve (PTR) in Madhya Pradesh and Maharashtra states.