stress (1) espèce (1) besoin (1) investissement (1) aliment (1) famille (1) évolution (1) conflit (1) taux (1) Food (1) Care (1) Communication (1) Struggle (1) Species (1) Parents (1) Negotiation (1) Hormones (1) Food (1) Families (1) Evolution (1) Corticosterone (1) Competition (1) Communication (1) Brothers and sisters (1) Birds (1) Begging (1) Barn owl (1) Evolution (1) Behavior (1) Family (1)