BAA (been answered already) - four.
There are 4 chambers in a bird's heart.
A hummingbird has four heart chambers, has do all birds.
A cats heart has four chambers, like humans.
All humans have four chambers in their heart.
Depends on the species. Three for amphibians and some reptiles, four for mammals and birds. The heart has 4 chambers.
Alligators have a 4 chambered heart, just like birds and mammals
Birds have a 4-chambered heart, a characteristic in common with mammals.
Yes
Mammals, birds, and crocodilians have a four-chambered heart.
Their are 2 heart chambers.
There are 4 chambers to the heart.
The bald eagle, a bird, has a four-chambered heart, as do all other birds and mammals.