Philopatry in the alpine grasshopper, Podisma pedestris: a novel experimental and analytical method |
| |
Authors: | P. L. MASON R. A. NICHOLS G. M. HEWITT |
| |
Affiliation: | School of Biological Sciences, University of East Anglia, Norwich |
| |
Abstract: | Abstract. - 1 Local dispersal and philopatric behaviour of the alpine grasshopper, Podisma pedestris, were studied at two sites in the Alpes Maritimes using a new mark—release—resight technique featuring marking in situ, and multiple resighting without handling. The time-consuming nature of the design was justified by the quantity and quality of the data yielded.
- 2 Philopatry is defined independently of any concept of home range as a phenomenon by which movements over longer periods are less than would be expected by extrapolation of measures over shorter periods.
- 3 By this definition, the grasshoppers are shown to exhibit philopatry. Nymphs comprise two heterogenous classes of those which move little and those which move considerable distances.
- 4 Daily dispersal estimates were obtained from movements of 1055 nymphs and adults at one site, and of 593 adults at another.
- 5 Differences are demonstrated in daily dispersal distances for age, sex and site combinations.
- 6 Some differences in microhabitat preference were observed.
- 7 The findings are compared with previous measurements of dispersal in this species, and the merits of the new technique are discussed.
|
| |
Keywords: | Grasshoppers Podisma pedestris dispersal home range philopatry habitat preference mark-release—recapture age hybrid zone |
|
|