Assessment of Crop Damage by Protected Wild Mammalian Herbivores on the Western Boundary of Tadoba-Andhari Tiger Reserve (TATR), Central India.

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

Comparison of visually estimated loss and actual deficit in grain yield at harvest as compared to fenced control plots (both expressed in percentage).

<p>A: Rice (r = 0.062, p = 0.73, n = 32), B: Chickpea (r = 0.022, p = 0.86, n = 63), C: Wheat (r = -0.0519, p = 0.75, n = 39). All trends remained non-significant even after removing outliers. Apart from lack of correlation, note the orders of magnitude difference in scales. Cumulative visual assessment was dramatically lower than yield deficit.</p

Compensatory growth after artificial herbivory at different ages in chickpea.

<p>A: canopy height, B: canopy width, C: number of branches and D: number of seeds in plants cut when 25 days old (n = 53) and 45 days old (n = 51) with control (n = 50). Compensatory growth after artificial herbivory at different heights at pre-flowering stage in chickpea. E: canopy height, F: canopy width, G: number of branches, H: number of seeds of plants cut at 5 (n = 50), 10 (n = 51), 15 (n = 54) with control (n = 50).</p

Trend of grain yield at harvest with distance from PA boundary for 4 crops over 4 seasons.

<p>Soybean: A 2009 (r = 0.473, p = 0.0001, n = 95) and B 2010 (r = 0.448, p = 0.03, n = 22); Rice: C 2009 (r = -0.291, p = 0.08, n = 35), D 2010 (r = 0.53, p = 0.001, n = 20), E 2013 (r = -0.044, p = 0.73, n = 56) and F 2014 (r = 0.14, p = 0.28, n = 58); Chickpea: G 2009–10 (r = 0.466, p = 0.012, n = 27), H 2010–11 (r = 0.54, p = 0.01, n = 17), I 2013–14 (r = 0.378, p = 0.0029, n = 83) and J 2014–15 (r = 0.398, p = 0.0003, n = 78); Wheat: K 2009–10 (r = 0.147, p = 0.66, n = 10), L 2010–11 (r = 0.67, p = 0.01, n = 12), M 2013014 (r = 0.369, p = 0.004, n = 65) and N 2014–15 (r = 0.642, p = 0.0001, n = 67).</p

Artificial herbivory in Wheat: comparison of regrowth by wheat plants cut at different age.

<p>A: vegetative regrowth, B: number of seeds after regrowth (control, n = 125; age 25, n = 92; age 45, n = 202; age 55, n = 199) and comparison of regrowth of vegetative part in wheat plants cut at various heights at pre-flowering stage: C: vegetative regrowth, D: number of seeds. (Control, n = 125; height 5, n = 176; height 10, n = 178; height 15, n = 205).</p

Experimental design for artificial herbivory of wheat, soybean and chickpea.

<p>Experimental design for artificial herbivory of wheat, soybean and chickpea.</p

Comparison of grain yield at harvest in fenced and non-fenced plots for 4 crops in two seasons.

<p>A: rice, B: soybean, C: chickpea, D: wheat. Soybean in 2013–14 and chickpea in 2014–15 failed due to reasons other than herbivory.</p

Temporal overlap of methods.

<p>Temporal overlap of methods.</p

Regrowth after artificial herbivory in soybean at different ages.

<p>A: regenerated height, B: number of branches, C: number of pods and D: number of seeds 20 days (n = 87) and 45 days (n = 107) with control (n = 108). Regrowth after artificial herbivory at different heights in pre-flowering stage in soybean. E: regenerated height, F: number of branches, G: number of pods, H: number of seeds in plants cut at 5 (n = 125), 10 (n = 128), 15 (n = 100), 20 (n = 74) with control (n = 108).</p

Map and location of study area.

<p>Light gray shaded zones denote villages and dark gray denote Division Forest area; both together constituting the buffer zone. The buffer area comprises over 70 villages with agriculture as the main livelihood. The dotted ellipse represents our study area. Location of the experimental plots is indicated by the dark triangle and the three transect lines extending from forest boundary into agricultural lands are shown by dotted arrows.</p