Table 1 Life history parameters of 4 songbird species that may have independently evolved similar life-histories, but different control mechanisms for similar behavior (T= testosterone, breed= breeding, non-breed= non-breeding, Rmale-male= androgen responsiveness to male-male interactions).
From: Endocrine mechanisms, behavioral phenotypes and plasticity: known relationships and open questions
| Â | black redstart | European robin | European stonechat | western song sparrow |
|---|---|---|---|---|
migration | yes | yes | yes/no | no |
territoriality | breed/non-breed | breed/non-breed | breed/non-breed | breed/non-breed |
occurrence of song | breed/non-breed | breed/(non-breed) | breed/(non-breed) | breed/non-breed |
egg-laying period | 3-4 months | 3-4 months | 3-4 months | 3-4 months |
Rmale-male | no | no | no* | yes |
breeding aggression T-dependent | no | yes | yes | yes** |
non-breed aggression T-dependent | no*** | no | no | yes |
linearity between behavior and T | no | no | no* | ? |