P2.98 Thursday, Jan. 5 Relationship between parental care and resting metabolic rate in Phodopus campbelli: testing parental care models for the origin of endothermy. CLAVIJO-BAQUET, Sabrina*; CUMPLIDO, Nicolás; BOZINOVIC, Francisco; Pontificia Universidad Católica de Chile email@example.com
The origin of endothermy represents a puzzling phenomenon in the evolution of vertebrates; in order to address this issue several models have been proposed. The Farmer’s and Koteja’s parental care models are the most recently proposed ones and they are also those with less experimental support. Both suggest that parental care had an important role in the origin the endothermy, whether to explain the raise of resting metabolic rate (RMR) through an increase in the activity (Koteja’s model) or an increase of body temperature (Tb) –due to an increase of tyrosine— during incubation period. For all this, we studied the relationship between RMR and parental care in the hamster Phodopus campbelli. Males of this species do parental care. This behaviour is well described permitting to manipulate males under controlled conditions. Each male was recorded three times. RMR increased as a result of subcutaneous tyrosine injections, in comparison to controls. Parental care was estimated through several tests during the first 12 days after pups birth. We measure time to contact, time to pick up and time to put the litter in the nest. We analyzed the relationship between parental care and RMR using mixed models which allows to analyze the fixed effect (RMR) blocking at the same time the male effect (random effect). We found that RMR has a negative effect on contact time, in other words, when RMR increases the contact time decreases. After that, we may point out that RMR has a positive effect over parental care supporting parental care models for the origin of endothermy. Funded by CONICYT AT- 24100180 PhD thesis fellowship and FONDAP 1501-0001.