Bird migrations began with the recession of the glaciers during the ice age. You will notice a great increase in insects in the spring time and early summer.The birds moved North to take advantage of this increase in the food supply that followed the warming in the spring and early summer. Their reproductive organs temporarily developed so they could lay eggs and raise a family. Look at the early flush of Night crawlers in the moist times of the early rains. By mid summer most of the insects have matured, mated and died. Their eggs have hatched and turned to larva and moved underground until next spring. The shortening of the days causes the reproductive functions to decrease and signals the birds that the food will soon become scarce. They move back to the area that makes it the easiest to find food and avoid freezing. which of course is the warmer climates nearer the equator. Not all birds move past the Tropics at approximately 30 degrees. Some like Chickadees may move down from Mi or Mn or Canada only as far south as Indiana. Some migrations may be quite short. For example from the mountains down to the plains. They don't generally reproduce in the warmer winter climes they migrate to. In the spring time they migrate along paths of the retreating glaciers. As the climate warms away from the tropics the birds follow the emerging insects etc to the birds selected breeding grounds.with increased insects and longer days to feed the hatching's. It is necesary to understand why they move to cooler climates in the summer to under stand why they move to eh warmer ones in the fall. As the days shorten the food supply dwindles and the babies have fledged. They move to warmer climates in winter to rest and refuel for the next years migration.
Answer:
its like your own land but only sertin people can go on it... I'm no tired sure tho thats what I think it is
Explanation:
if I'm right mark me has brainliest??
Answer:
Explanation:the answer is not B since it's also asking for more then one continent in the question
Answer:
The right order is 3, 1, 2.
Explanation:
The most superficial layer is 3, which describes the Cornea. This layer, which is first hit by light, is made of transparent and resistant fabric. It protects the eyeball from trauma and contamination and helps shape the globe and refract light.
Then, the layer described as 1 is the pigmented part that has melanocytes, which may be the uvea that consists of the whole of the iris, choroid membrane and ciliary processes.
Finally, the deepest layer in this question describes the lens, which is a gelatinous biconvex lens. This important structure enables the eye to focus on objects.
