The ecology and conservation of threatened damselflies

Survival
1.0
0.8
0.6
0.4
0.2
New males
Recap males
New females
Recap females
0.0
0 2 4 6 8 10 12 14 16 18 20
Capture occasion
Figure 4.5. Maximum likelihood estimates of survival probability, for 2005 mites
data, showing the difference in rate between new and recaptured individuals and
between males and females. Estimates for individuals with no mites are shown.
Lines connecting values for the same sex and state are intended for orientation
only. Estimates were calculated by MSURGE using the model Ψf*to+s φa2*s+t+f ps*to+t.
Survival probability
1.0
0.8
0.6
0.4
0.2
0 mites
1-4 mites
5+ mites
0.0
0 2 4 6 8 10 12 14 16 18 20
Capture occasion
Figure 4.6. Maximum likelihood estimates of survival probability, for 2005 mites
data, showing the effect of mite load on males after the first capture interval
(females show same pattern). Lines connecting values for the same state are
intended for orientation only. Estimates were calculated by MSURGE using the
model Ψf*to+s φa2*s+t+f ps*to+t.
Recapture rates varied interactively with level of parasitism and sex and varied through
time (Fig. 4.7). Individuals with a low mite load had the highest recapture probability in
both sexes. Probability of transition between levels of parasitism was dependent on
both previous and current mite load and also varied with sex (Table 4.3). Males were
most likely to remain at the same level of parasitism, regardless of the preceding state,
although transition from a low level to no mites was also common (0.395). Females
were also highly likely to remain in the same state overall, but those with a low level of
parasites were more likely to lose them all (0.542) than retain a low level (0.367).
80 Science Report – The ecology and conservation of threatened damselflies