Response of small rodents to manipulations of vegetation height in agro‐ecosystems

Abstract

Some small mammal populations require human interference to conserve rare or threatened species or to minimize adverse effects in plant production. Without a thorough understanding about how small rodents behave in their environment and consideration of how they react to management efforts, management will not be optimal. Social behavior, spatial and temporal activity patterns, predator avoidance and other behavioral responses can affect pest rodent management. Some of these behavioral patterns and their causes have been well studied. However, their impact on pest rodent management, especially for novel management approaches, is not always clear. Habitat manipulation occurs necessarily through land use and intentionally to reduce shelter and food availability and to increase predation pressure on rodents. Rodents often respond to decreased vegetation height with reduced movements and increased risk sensitivity in their feeding behavior. This seems to result mainly from an elevated perceived predation risk. Behavioral responses may lessen the efficacy of the management because the desired effects of predators might be mediated. It remains largely unknown to what extent such responses can compensate at the population level for the expected consequences of habitat manipulation and how population size and crop damage are affected. It is advantageous to understand how target and non-target species react to habitat manipulation to maximize the management effects by appropriate techniques, timing and spatial scale without causing unwanted effects at the system level.

Rodent abundance, stone bund density and its effects on crop damage in the Tigray highlands, Ethiopia

“…It appeared that as the crops developed towards the reproductive stages, so did the availability and quality of food and cover (crop height) which may have been conducive for rodent population growth. Similar increases in rodent abundance in the course of crop development and increasing vegetation cover have been reported by Brown et al (2007) and Jacob (2008). The pattern we observed appears to occur with much regularity following crop development, making decision making for application of control measures somewhat less challenging.…”

“…Several reports showed higher rodent abundances correlated with presence of better vegetation and structural cover (Massawe et al 2006;Jacob, 2003Jacob, , 2008Birkedal et al 2009). However, at the species level only the abundance of Arvicanthis dembeensis varied significantly between the two stone bund densities, with more A. dembeensis in HSBD grids than in LSBD grids.…”

“…The seasonal changes in the abundance showed two sets of peaks each year; the highest peaks occurring early in the dry season (October to January) -hereafter called "early dry season peak", and the second peaks occurring in the wet season (July to August) -hereafter called "wet season peak". A drop in abundance was observed immediately after the wet season peaks across the study period (October 2007, 2008and September 2010, followed by a resurgence of abundance in the following months, resulting in the early dry season peaks. Note that the cropping stages are related to the wet and early dry season peaks correspond with milky stage and harvest respectively (Fig.…”

Expression plasticity of Phlebotomus papatasi salivary gland genes in distinct ecotopes through the sand fly season

“…The effect of the low elevation at the Swaymeh site also cannot be ruled out as a factor, as elevation can certainly influence the amount and diversity of vegetation [61]. Furthermore, changes in vegetation also can influence the diversity and abundance of vertebrate hosts available for blood feeding [62,63] and it is possible that the type of blood meal source available could modulate saliva expression patterns. Late season up-regulation effects could not be determined for North Sinai, as sand fly trapping was not possible due to security concerns.…”

Ecosystem services and disservices provided by small rodents in arable fields: Effects of local and landscape management

“…Moreover, edge effects shape characteristics of crop and associated removal rates, with lower weed seed predation rates at the headland of agricultural fields due to low vegetation cover (Navntoft, Wratten, Kristensen, & Esbjerg, ) and decreasing vegetation height (Díaz, ). Rodent abundances also decrease with increasing distance to field margins and decreasing vegetation height (Figure a; Jacob, ; Rodriguez‐Pastor, Luque‐Larena, Lambin, & Mougeot, ; but see Delattre et al., ).…”