animal animalcommunication arteries carbondioxide cardiopulmonarysystem carotidbody cellhypoxia chemicalsenses chemistry chemoreceptors congresses genetics kumar metabolism oxygen oxygenconsumption peers pheromones physiology ql776 qv312o96852000 respiratoryphysiologicalphenomena sexualbehavior territoriality wg510i608c2003 wk375w333p1966