Incubation in Desert-nesting Doves: Mechanisms for Egg Cooling

Mourning doves (Zenaida macroura) nesting in the Sonoran Desert maintain their eggs at viable temperatures (≤ 40 C) in spite of higher (above 45 C) environmental temperatures. Egg cooling is accomplished by contact with the adult's body, which is held at relatively low core temperatures (X̄ = 38.3 C). A similar reversal of the normal temperature gradients associated with incubation occurs in a second xerophilic dove, Streptopelia risoria. Relatively low adult body temperatures apparently are maintained by increased reliance on evaporative cooling and may subject the attending parent to substantial dehydration.