Are the Birds and the Mammals same?

Birds may be classified into domestic and wild birds. The domestic birds are those which are brought under close control by humans for communication, clothing and furnishing, garden ornaments, companionship and food. Of these birds, those which are reared under human captivity for economic purpose are called poultry. And it is interesting to know the meat of the these birds is also termed as ‘poultry’.

*Note: The chicken is called “Gallus domesticus” in scientific language.

It might be possible, as Darwin suggested in his theory of natural selection and evolution that the birds and the mammals share some common ancestor. But over a period, the life on our planet has diversified to such an extent that we can notice a lot of major differences in these classes of animals. Here in this article I would like to describe some obvious differences in the avian and the mammals.

Wings

They correspond to the arms and hands of the humans. Two digits are modified into claws.

Skin

Interesting thing about the birds’ skin is that they have no sweat glands. Sebaceous glands also are absent except preen gland (uropygial gland) present on the upper side of the tail. Skin color of the birds is yellow or white. Yellow is due to carotenoid pigments they take in their diet and use it in the formation of egg. Also, birds have an amorphous lipid layer on their skin which protects them from pathogens as it acts as a barrier.

Eyes

Eyes in the birds are larger relative to the size of the head. Cones are abundant in their eyes and they can distinguish colors with preference for violet and orange.

Ears

No external auricle is present in the birds, but hearing is equal to that of mammals.

Toes

Four toes on each foot are present in birds, but some breeds of chicken have five toes.

Combs, Wattles and Head appendages

Birds have combs whose development is related to gonadal development of the bird. There are 8 different types of comb that include,

Single, pea, rose, walnut, strawberry, cushion, V and buttercup.

Earlobes are white in Leghorns and Mediterranean breeds while American breeds have red earlobes.

Life span

As different species of mammals may have lifespans up to hundreds of years, the birds (chicken) has natural life span of 4-5 years only. The commercial chicken has even shorter lifespan. Broilers have a lifespan of 6-8 weeks only. Layers and layer breeders have a lifespan of 75-80 weeks. Broiler breeders have a lifespan of 65 weeks.

Physiological parameters

Birds have higher body temperature as compared to the mammals. Temperature of chicks up to first 4 days of life is 39ᵒC (102ᵒF) and they attain the adult body temperature of 40.6-41.7ᵒC (105-107ᵒF) in 10 days. Also, the heart beat/pulse and the respiration rates of birds are greater than that of the mammals.

To conclude from the above discussion I hope it would be clear to you that even though we believe that all species of the animals whether they are birds or mammals are related in the past through some common ancestors but they have undergone through evolution in such a way that nowadays it became quite a difficult task to think them as a single species. What do you think?

<< Go back