A measurement of dispersal in the grasshopper Podisma pedestris (Orthoptera: acrididae)
Heredity, 48 (2):
237--249 (April 1982)Abstract
The dispersal rate of the grasshopper Podisma pedestris has been measured,
with the aim of interpreting the width of a chromosomal dine. 171 adults were
marked individually, and released within the dine. 169 movements were seen
over three subsequent scorings; the distribution of distances, after correction
for the loss of long distance dispersants, was close to a normal curve, but there
was an initial shift of ten metres, perhaps towards a better habitat. The linear
variance increased at about 214 m2 day1, which corresponds to a standard
deviation of 207 m gen112 over a 20 day life span. Statistical uncertainty in
this estimate can be expressed using a distribution-free maximum likelihood
method, which gives support limits of 186—270 m gen112. However, the main
errors come from extrapolating from this experiment to the dine as a whole.