Search results
Results from the WOW.Com Content Network
Altricial birds are less able to contribute nutrients in the pre-natal stage; their eggs are smaller and their young are still in need of much attention and protection from predators. This may be related to r/K selection; however, this association fails in some cases. [18] In birds, altricial young usually grow faster than precocial young.
Some species, including woodpeckers, have two egg teeth; one on both the upper and lower bill. [4] After time the egg tooth falls off or is absorbed into the growing chick's bill. [5] Some precocial species such as the kiwi, and superprecocial species including megapodes, do not require an egg tooth to assist them in hatching. They are strong ...
Because of this, birds usually have a smaller number of bones than other terrestrial vertebrates. Birds also lack teeth or even a true jaw and instead have a beak, which is far more lightweight. The beaks of many baby birds have a projection called an egg tooth, which facilitates their exit from the amniotic egg. It falls off once the egg has ...
Female birds are able to produce more of a certain gender of birds that are more likely to survive under extreme conditions. In birds, the females' egg determines the gender of the offspring, not the male's sperm. In zebra finches, a study showed the effect of food on gender ratio production. For females, egg production is a metabolically ...
The variations usually lie in the morphology, number, development timeline, and types of teeth. [8] However, some mammals' teeth do develop differently than humans'. In mice, WNT signals are required for the initiation of tooth development. [9] [10] Rodents' teeth continually grow, forcing them to wear down their teeth by gnawing on various ...
When these birds grow up, they are sometimes mistaken for owls, but when they are babies, they are just about the cutest little balls of floof ever. Just check out this little guy!
The number of teeth and their function can vary widely between species, with some dolphins having over a hundred teeth in their jaws, while the narwhal has two functional teeth in its upper jaw which grow into long tusks in males. The tusk is used in feeding, navigation and mating and contains millions of sensory pathways, making it the most ...
Doctors are urging all parents to hold on to their kid's baby teeth after the tooth fairy comes to visit -- and not for sentimental reasons. According to a recent study, baby teeth contain an ...