Data from: On fitness and partial migration in a large herbivore – migratory moose have higher reproductive performance than residents

• Main Authors: Rolandsen, Christer Moe, Solberg, Erling J., Sæther, Bengt-Erik, Moorter, Bram Van, Herfindal, Ivar, Bjørneraas, Kari, Saether, Bernt-Erik
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2016
• Subjects: Environmental variation; Alces alces
• Online Access: https://doi.org/10.5061/dryad.j0r00

Partially migratory populations comprise both resident and migratory individuals. These tactics may coexist if their demographic contribution to future generations (i.e. fitness) are equal or vary temporally with environmental conditions, or if individuals switch between being migrant and resident. Alternatively, the choice of movement tactic can be based on individual attributes such as age, competitive ability or personality. In the latter cases, the two tactics are not expected to have similar average fitness. In this study, we examined the effect of movement tactic on reproductive performance and survival of 82 GPS-marked female moose and their offspring in a partial migratory population in central Norway. The results indicated higher growth in the migrating part of the population because migrating females produced more twins than resident females. We found no differences in pregnancy rates or survival of adults or their offspring, indicating a net fitness benefit of being migrant. We found the average shoulder height of residents to be slightly lower than of migrants, but doubt that this affected their migration ability. A more likely explanation is that migratory females are both more fecund and grow bigger because of better conditions in their summer ranges. This may be a temporal phenomenon if the fitness differences between migratory and resident moose vary according to environmental fluctuations. Data - The effect of movement tactic on twinning rate Data used to analyze the effect of movement tactic on twinning rate. dryad_twins.txt Data - shoulderheight and twinning Data used to compare shoulderheight of resident and migrant female moose. And to test the effect of shoulderheight on the probabilty of having twins. dryad_shoulderheight.txt Data - moose and altitude Data used to examine if migrants and residents used different altitudes during the year. dryad_altitude.txt Data - summersurvivalcalves Data used to analyze summer survival of calves in relation to their mothers movement tactic. ...