Black-bellied Tern,
Sterna acuticauda
J.E. Gray, 1831, is an Endangered species currently restricted to a few patches along the major rivers and lakes in the Indian subcontinent. I report it from ...Tungabhadra River at Siruguppa for the first time. Five individuals in breeding plumage were observed at a 6 km stretch of river, sampled using line transect method. Previous records, with this new locality, suggest that the population of Black-bellied Tern could be fragmented. This new site could be a promising breeding ground for the species; nevertheless, it is under threat owing to uncontrolled sand mining.
Crop raiding by wild herbivores close to an area of protected wildlife is a serious problem that can potentially undermine conservation efforts. Since there is orders of magnitude difference between ...farmers' perception of damage and the compensation given by the government, an objective and realistic estimate of damage was found essential. We employed four different approaches to estimate the extent of and patterns in crop damage by wild herbivores along the western boundary of Tadoba-Andhari Tiger Reserve in the state of Maharashtra, central India. These approaches highlight different aspects of the problem but converge on an estimated damage of over 50% for the fields adjacent to the forest, gradually reducing in intensity with distance. We found that the visual damage assessment method currently employed by the government for paying compensation to farmers was uncorrelated to and grossly underestimated actual damage. The findings necessitate a radical rethinking of policies to assess, mitigate as well as compensate for crop damage caused by protected wildlife species.
The nilgai (Boselaphus tragocamelus) is a widespread species in India that forages in forest as well as on agricultural lands. In Tadoba-Andhari Tiger Reserve, India, it typically takes to ...crop-raiding at night, while it rests and forages in forest during the daytime. We studied changes in herding and vigilance behaviour during foraging in forest versus in agricultural lands and monsoon versus post-monsoon in the years 2012–2015. We recorded number of individuals (herd size), sex-age composition and number of individuals per unit area of herd's spread (compactness) for every herd under observation using instantaneous scan sampling in forest (176 herds) and farms (321 herds), while spatial trends in herd size on agricultural lands were studied using transect sampling at night. Vigilance behaviour was studied using focal-animal sampling in forest (n = 91) and farms (n = 52) by choosing a single individual per herd under 15 min of observation. Herd sizes were significantly larger in forest (monsoon, median = 3, interquartile range (IQR) = 2–6, post-monsoon, median = 5, IQR = 3–8) than on farms adjacent to forest (monsoon = 3, IQR = 1–5, post-monsoon = 4, IQR = 2–5) and further decreased non-linearly with distance from the forest edge. Herds were more compact, i.e. with smaller inter-individual distance in forests than on farms. Crop-raiding was found to be female-biased, and adult males as well as newborn calves were observed on agricultural lands significantly less frequently. The median vigilance frequency was significantly higher on farms (1.4 min−1) as compared with forests (0.205 min−1) but the median unit scan duration was significantly less in farms (6 s) compared with forest (60 s). The observed differences are likely to be due to difference in the nature of risk faced in the two habitats. In forest, detection of ambush predators such as tigers that occur at a low density, requires careful watch and larger herds increase the chances of detection. In contrast, detection of guarding farmers on agricultural lands who are present at a higher density and make their presence conspicuous to drive away crop raiders would need a glance of smaller time duration. As crop-raiding occurs at night, moonlight is likely to affect the frequency of crop-raiding but we did not find evidence for any deterrent effect of moonlight on the frequency of crop-raiding. The data suggest that the nilgai exhibits substantial behavioural plasticity in response to different nature and levels of risks faced in the two habitats.
Ischaemum travancorense Stapf ex C.E.C. Fisch., an endemic species, earlier known only from the Western Ghats of Kerala, Maharashtra and Goa is reported here for the first time from central India.
We constructed a theoretical model of cost–benefit optimization for farmers who face continued economic loss due to crop raiding by wild herbivores, as well as for the wild herbivores that do so. ...Insights obtained from the model include: (i) In sustenance agriculture, a farmer needs to optimize net benefit rather than benefit-to-cost ratio, whereas herbivores need to optimize the benefit-to-cost ratio. (ii) It is imperative for a farmer to disinvest from agricultural inputs when threatened by depredation. (iii) Many mitigation measures that are highly successful on an experimental scale are most likely to fail when used on a mass scale. (iv) The effectiveness of mitigation measures such as fencing, trenching and culling will be non-monotonic, being counterproductive under certain conditions.
Ischaemum travancorense Stapf ex C.E.C. Fisch., an endemic species, earlier known only from the Western Ghats of Kerala, Maharashtra and Goa is reported here for the first time from central India.
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