Abstract:
Differences in individual locomotor activity patterns may be linked to a number
of ecological factors, such as changes in ambient temperature or photoperiod.
Observations on subterranean mammals suggest that they exhibit diel rhythms despite
the lack of visual cues in their underground burrows, but it is unknown how seasonality
and individual characteristics affect their activity. In this study we use RFID technology
to monitor daily activity patterns of wild, social Natal mole-rats (Cryptomys hottentotus
natalensis) during the summer and winter to investigate how their activity varies with
season and whether their activity depends on individual characteristics such as body
mass, sex and reproductive status. We found that in winter, individuals were more active
during the time with the highest soil temperatures, whereas in summer, they showed
a bimodal activity pattern during early morning and late afternoon coinciding with
cooler soil temperatures. Individual characteristics, including reproductive status, did
not affect general activity indicating that reproductive and non-reproductive individuals
contribute equally to cooperative behaviors. We suggest that the activity patterns may
be a behavioral adaptation to avoid extreme burrow temperatures and a mechanism
to maintain a stable core body temperature. We highlight the advantages of RFID
technology to study wild small mammal movements.
