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.
History of Boston is described below.
Explanation:
- When workers cut down Copp's hill the only thing they left untouched was the old three-acre burying ground. The city built a retaining wall around the graveyard to prevent it from eroding. In 1814, the Boston and Roxbury Mill Corporation built the Boston & Roxbury Mill Dam across the back bay
- Originally called Tremontaine for the three hills in the area, the Puritans later changed the settlement's name to Boston, after the town in Lincolnshire, England, from which many Puritans originated.
- South Boston, which was front and center in the battle, is no longer that close-knit old school “tough-as-nail” Irish Catholic enclave. “Southie,” as it is still fondly referred to, houses the world today flaunting some of the best restaurants and expensive housing in the city
- Boston was founded in 1630 by English Puritans fleeing religious persecution. On 29 March 1630 a fleet of 11 ships carrying 700 people sailed from England to Massachusetts. They were led by John Winthrop (1588-1649). At first the people settled at Charlestown, which had been founded the year before.
- Much of Boston's coastline is man-made land. The original shoreline, from 1630, is visible in dark green on this map. Land made between 1630 and 1995 is light green.Boston is a safe city, but as with any major city, you should take the usual safety precautions. Stay in well-populated areas, travel with others, especially at night, and keep track of your belongings. The tourist areas in Boston are generally safe, but some areas deserve mention.