Animal Adaptations: Evolution of Forms and Functions

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We calculated AVC probability ( P h) under different scenarios of traffic heterogeneity on 2-lane and 4-lane sections of the road using Eq. ( 1). The exposure risk in seconds i.e., the time on the road for which an animal would be vulnerable to collision as a function of road width and P h was also calculated. Influence of animal activity on AVC risk Ridout, M. & Linkie, M. Estimating overlap of daily activity patterns from camera trap data. J. Agric. Biol. Environ. Stat. 14, 322–337 (2009). Our framework can help inform mitigation of AVC and barrier effects in two ways: by identifying existing and proposed roads in a network that are or may become barriers to animal movement because of present and projected traffic volume, and by informing measures on existing roads with no structural mitigation measures based on traffic and animal activity. This is important for developing economies with rapidly increasing traffic loads on existing unmitigated road networks.

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.This study shows that both aMT and MT are physiologically active compounds inhibiting the testicular activity of this tropical mammal. The present results indicate a sensitivity of the animal to change in lighting condition. This result further confirms the previous finding that the pineal and testes of F. pennanti are sensitive to daylength ( Haldar et al., 1990). The results also demonstrate, for the first time, that the animal can distinguish between the time of the day when MI are administered. In other words, the inhibitory effects of aMT and MT are dependent on the period of the day when they are administered. While evening injections led to inhibition of testicular activity under both long and short photoperiods, MI administration during morning hours failed to produce any significant effect on the testes of F. pennanti under short or long photoperiod. LP was stimulatory to the testes whereas SP was inhibitory to the testes of the squirrel. Our results are similar to those on adult golden hamsters ( Mesocricetus auratus) in which daily aMT injections in morning, under long days result in gonadal maintenance ( Reiter et al., 1976; Stetson et al., 1983; Tamarkin et al., 1976; Tamarkin et al., 1977). Other studies indicate that morning injections of aMT under long to short days retards gonadal regression in the same animal ( Pevet et al., 1982b; Turek et al., 1980). We demonstrated the applicability of the traversability model to determine species-specific AVC probabilities and AVC risk across different traffic heterogeneity and traffic volume scenarios. We found that slow moving animals and animals with large group sizes were at higher risk of AVC as a consequence of greater time required to traverse roads. Further, AVC probability is expected to be greater on wider roads, particularly high traffic roads with predominantly heavy vehicles. Newmark, W. D., Boshe, J. I., Sariko, H. I. & Makumbule, G. K. Effects of a highway on large mammals in Mikumi National Park Tanzania. Afr. J. Ecol. 34, 15–31 (1996). Rytwinksi, T. & Fahrig, L. Do species life history traits explain population responses to roads? A meta-analysis. Biol. Conserv. 147, 87–98. https://doi.org/10.1016/j.biocon.2011.11.023 (2012). 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.

Administration of the test extract and standard drugs were done by oral intubations and lasted for 4 days at a single dose per day according to the following groupings: •

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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:

The traversability model 37 did not consider animal activity near roads. For an animal-vehicle collision to take place, an animal and a vehicle must co-occur on the road. We accounted for this by using animal activities near the road as a proxy for the probability of an animal encountering a road. Creation of edge habitats by linear intrusions like roads facilitate the use of such habitats by some ungulate species. Consequently for edge-tolerant species like chital and wild pig 38 that were found to use road-forest edges, hourly roadkill risk is a function of hourly traffic volume since their activities near the road coincide with peak hours of traffic activity (Chital and Traffic Overlap Coefficient Dhat1 = 0.82; Wild pig and Traffic Overlap Coefficient Dhat1 = 0.82). Hence use of roadside habitat by chital and wild pig, makes them more vulnerable to mortality effects. For gaur and sambar that are generally crepuscular and nocturnal species with low road-forest edge use, the roadkill risk is a direct consequence of its activity in the early morning or late evening hours (Supplementary Table S4). Schwab, A. C. & Zandbergen, P. A. Vehicle-related mortality and road crossing behavior of the Florida panther. Appl. Geogr. 31, 859–870 (2011). Rico, A., Kindlmann, P. & Sedlacek, F. Barrier effect of roads on movement of small mammals. Folia Zool. 56(1), 1–12 (2007). 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). Langevelde, F. & Jaarsma, C. F. Using traffic flow theory to model traffic mortality in mammals. Landsc. Ecol. 19, 895–907 (2004).The aqueous extract of A. boonei was formulated in distilled water corresponding to the dosages 100, 200, 400 and 800 mg kg -1 b.wt. of mice and the standard antimalarial Chloroquine (5 mg kg -1 b.wt. of mice) were also prepared.

The transportation infrastructure of a nation is vital for its social and economic growth, especially for a developing economy. However, the construction and operation of roads come at great costs to wildlife and forests dissected by linear infrastructure 1, 2. The most conspicuous impact of roads is wildlife-vehicle collisions, which is a major cause of decline in animal populations in human-dominated landscapes 3. Road-related mortality affects animal populations more adversely than natural mortality since it is non-selective, and affects healthy and unhealthy individuals of a population equally 4, 5. Erritzoe, J., Mazgajski, T. D. & Rejt, Ł. Bird casualties on european roads—a review. Acta Ornithol. 38, 77–93 (2003). The AVC probability across different heterogeneity scenarios showed variability, largely as a consequence of the speeds of traffic flow. Results show that the highest AVC probabilities occurred for traffic compositions with higher proportions of heavy vehicles. Since heavy vehicles impede the cumulative traffic flow speed, the probability of occurrence of a vehicle at any point on the road increases, consequently translating to higher probabilities of hit mostly for slow-moving and group living animals. On the contrary, in a traffic flow with high flow speed, there is greater inter-vehicular distance available which translates to higher probability of an animal to cross the road without encountering a vehicle. This finding has implications for speed-regulating mitigation measures like speed breakers and rumble strips that can potentially decrease inter-vehicular distances at medium–high traffic volumes, leading to creation of a barrier-like situation for animal movement. Effect of evening injections of melatonin (aMT) and 5- methoxytryptamine (MT), for 60 continuous days, on the seminiferous tubule diameter (μm) of testis in sham-operated (S0) and pinealectomized (Px) F. pennanti exposed to natural daylength (NDL), long photoperiod (14L:10D) and short photoperiod (10L:14D) during the gonad active phase. Table 3 Nomadic/pastoral herdsmen are particularly affected by movement restriction since their farming activities are heavily reliant on movement across grasslands in search of natural resources. The ease of access to extension services and technical experts to troubleshoot farm problems is hampered especially in rural areas with inadequate access to digital service for ready access to information. Regular on-farm visitation by extension agents is therefore difficult to navigate considering that this may be a possible route for farm-to-farm transmission of diseases.Dyer, S. J., O’Neill, J. P., Wasel, S. M. & Boutin, S. Quantifying barrier effects of roads and seismic lines on movement of female woodland caribou in northeastern Alberta. Can. J. Zool. 80, 839–845 (2002). Johnsingh, A. J. T. & Manjrekar, N. (eds) Mammals of South Asia (Universities Press, Hyderabad, 2015).