Understanding and predicting animal movements is of crucial importance for the conservation and management of natural resources. Grasshoppers are ecological indicator species used to monitor the spatio- temporal changes, to help reduce further loss of biodiversity on open grasslands. However, their current decline on European landscapes as a consequence of intense agricultural practices has elicited the need to understand all aspects of their ecology especially their movement on these highly fragmented landscapes. With the use of a mesocosm, a mark and re-sight study was conducted in the Poitou Charentes Region of Western France, to investigate the movement dynamics of three widespread species in that area. With emphasis placed on the determinants of their rate and scale of movement in addition to the influence of individual behavioural trait variations on dispersal plasticity. Net square displacement and mean squared displacement was used to quantify rate and pattern of movement. Two sub populations were identified and classified as settled and yet to settle sub- population. Poisson regression analysis and generalized linear models were used to test significance of interactions between grasshopper species and microhabitat constituents. Average distance travelled by re-sighted individuals ranged from 3.50metres to 18.66 metres. However the variation in average distance estimated for each of the species, arose from species specific interactions with micro habitat conditions especially vegetation functional class found within the quadrat. Inter specific differences due to the possession of morphological correlates with dispersal; large body size and wing development, explained variation in magnitude of dispersal especially between C.dorsatus and P.giornae. However the rate of displacement exhibited by E.elegantulus suggest that possession of these traits in relation to proximity to food resources influences dispersal kernel. The study was conducted during grasshopper breeding season when sex specific reproductive traits were likely to be more apparent. As a result of this, average distance travelled by male individuals exceeded that of females, but then these differences were not statistically significant.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:678273 |
| Date | January 2014 |
| Creators | Adeniran, Oluwafisayo Hazeezat |
| Publisher | Swansea University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://cronfa.swan.ac.uk/Record/cronfa43157 |
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