How does Oedipoda germanica (Orthoptera: Acrididae) cope on the northern edge of its distribution? A demographical study of a completely isolated population

We studied a population of the Red-winged grasshopper Oedipoda germanica, which is a highly stenotypic and endangered species in Central Europe. The locality studied is completely isolated and at the northern limit of this species distribution (north-west of the Czech Republic). We used capture-mark-recapture in 3 consecutive years (2008-2010). We estimated the total population size using POPAN software to be 136 adults in 2008, 70 in 2009 and 122 in 2010. Estimated daily survival rate (Phi) ranged from 0.950 to 0.987. We constructed linear mixed models to test for apparent survival in relation to temperature data. Temperatures (i.e. mean air temperature and maximum air temperature) were found to have significant effects on survival. The population studied is small, isolated and thus threatened by extinction, as are other O. germanica populations at the northern limit of their distribution. The preservation of indigenous populations in their localities can be achieved by active management, including the removal of shrubs and trees.