Daily activity patterns in free-living tuco-tucos (rodentia: ctenomyidae) from anillaco, La Rioja province, Argentina

AMAYA JP; LOPEZ PJ; CUELLO PA; LACEY EA; VALENTINUZZI VS

Mastozoología Neotropical

Buenos Aires

Año: 2022

The South American subterranean rodent found in Anillaco, a semi-arid locality in Northwestern Argentina, known as the Anillaco tuco-tuco (Ctenomys sp), displays nocturnal wheel-running behavior under an artificial 12:12 light-dark cycle in the laboratory. However, reports in the field demonstrate substantial amount of epigeous activity occurring during daylight hours. Detection of activity rhythms in the field is difficult and time consuming specially in such small animals where size and weight of any used device is an important limitation. Telemetry is the most used method when analyzing activity in the field however, resolution of detection may be too low for identification of daily patterns of activity. Additionally, hourly monitoring during a 24h interval is the minimum minimorum required and still, this is not enough to reach solid conclusions. Here we compared the activity patterns of 17 free-living animals (6 males and 11 females) obtained through telemetric devices, with the activity patterns of 9 animals ( males, females) in captivity but in a natural photoperiod, obtained with wheel-running devices and intra-abdominal sensors. During 72 consecutive hours monitoring occurred in both groups simultaneously. In the first group, the locations of the 17 radio-collared adults were recorded hourly while in the second group, the hourly ?distance travelled? in the wheels and gross motor activity was computed. Field telemetric data showed slight diurnal activity while wheel-running and general activity revealed robust nocturnal patterns. The differences between field and lab data are discussed through two different scopes. On the one hand, the obvious environmental differences between lab and field conditions (temperature, humidity, food quality-availability, predation pressure, space accessibility). On the other hand, the different sensibility and characteristics of the monitoring methods used in each case. These data become a good baseline for comparison of different monitoring systems to detect activity rhythms in the field.