Day and night in the subterranean: measuring daily activity patterns of subterranean rodents (Ctenomys aff. knighti) using bio-logging

Author(s)

Jannetti, Milene G. ^[1] ; Buck, C. Loren ^[2] ; Valentinuzzi, Veronica S. ^[3] ; Oda, Gisele A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biociencias, Dept Fisiol, Lab Binacl Argentina Brasil Cronobiol, Sao Paulo - Brazil

^[2] No Arizona Univ, Dept Biol Sci, POB 4185, Flagstaff, AZ 86011 - USA

^[3] Ctr Reg Invest Cient & Transferencia Tecnol CRILA, Lab Binacl Argentina Brasil Cronobiol, Entre Rios & Mendoza S-N, RA-5301 Anillaco, La Rioja - Argentina

• Document type: Journal article
• Source: CONSERVATION PHYSIOLOGY; v. 7, JUL 19 2019.
• Web of Science Citations: 2

Abstract

While most studies of the impacts of climate change have investigated shifts in the spatial distribution of organisms, temporal shifts in the time of activity is another important adjustment made by animals in a changing world. Due to the importance of light and temperature cycles in shaping activity patterns, studies of activity patterns of organisms that inhabit extreme environments with respect to the 24-hour cyclicity of Earth have the potential to provide important insights into the interrelationships among abiotic variables, behaviour and physiology. Our previous laboratory studies with Argentinean tuco-tucos from the Monte desert (Ctenomys aff. knighti) show that these subterranean rodents display circadian activity/rest rhythms that can be synchronized by artificial light/dark cycles. Direct observations indicate that tuco-tucos emerge mainly for foraging and for removal of soil from their burrows. Here we used bio-logging devices for individual, long-term recording of daily activity/rest (accelerometry) and time on surface (light-loggers) of six tuco-tucos maintained in outdoor semi-natural enclosures. Environmental variables were measured simultaneously. Activity bouts were detected both during day and night but 77% of the highest values happened during the daytime and 47% of them coincided with time on surface. Statistical analyses indicate time of day and temperature as the main environmental factors modulating time on surface. In this context, the total duration that these subterranean animals spent on surface was high during the winter, averaging 3 h per day and time on surface occurred when underground temperature was lowest. Finally, transport of these animals to the indoor laboratory and subsequent assessment of their activity rhythms under constant darkness revealed a switch in the timing of activity. Plasticity of activity timing is not uncommon among desert rodents and may be adaptive in changing environments, such as the desert where this species lives. (AU)

• FAPESP's process: 16/25058-0 - Seasonality of daily surface activity patterns on a subterranean rodent, the tuco-tuco
• Grantee: Milene Gomes Jannetti
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/09324-6 - Field and computer simulation studies on the chronobiology of subterranean rodents (Ctenomys aff knighti)
• Grantee: Milene Gomes Jannetti
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 14/20671-0 - Chronobiology of South American subterranean rodents, in laboratory and field
• Grantee: Gisele Akemi Oda
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/19680-2 - Photoperiodism in South American subterranean rodents under field and laboratory conditions
• Grantee: Gisele Akemi Oda
• Support Opportunities: Regular Research Grants