Sentence examples for birds have two from inspiring English sources
Frogs, humans, crocodiles, and birds have two forelimbs and two hindlimbs; they are all tetrapods.
And some birds do, indeed, scan their heads this way when assessing the direction of magnetic north.It is possible, of course, that both hypotheses are right, and that birds have two magnetic senses, with one perhaps concentrated on north detection and the other on detecting dip.
Birds have two sexes: male and female.
Male birds have two Z chromosomes (ZZ), and female birds have a W chromosome and a Z chromosome (WZ).
As male birds have two copies of the Z chromosome versus one in females, reduction in the effective size of male breeding populations caused by sexual selection would reduce the effective population size of the Z chromosome more dramatically than that the autosomes [ 18].
Crocodilians, some lizards, and nearly all birds have one gonoduct; the other is not well developed.
Most fish and birds have four or even five cone types with different spectral sensitivities, including sensitivity in the ultraviolet.
Birds have one opening — the cloaca — from which both waste matter and (in females) eggs exit the body.
Birds have five different types of visual pigment and seven different types of photoreceptor rods, double (uneven twin) cones and four types of single cone.
Most birds have four toes, the fifth being always absent, but there are many variations in the number of digits, or phalanges, representing reductions of the basic arrangement.
