CZ:Ref:DOI:10.1098/rsbl.2008.0469

Isler, K. & C.P. Van Schaik (2009), "Why are there so few smart mammals (but so many smart birds)?", Biology Letters: in press, DOI:10.1098/rsbl.2008.0469 ^[e]

Builds on the expensive tissue hypothesis proposed by Aiello & Wheeler, 1995 and provides evidence that the maximum rate of population increase, as defined by Cole 1954, is correlated negatively with brain size in mammals and birds, as long as parental care is not only provided (and thus the energetic costs of feeding borne) by the mothers.