The alkaline earth metals are six chemical elements in column (group) 2 of the Periodic table.They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.hey are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure.
Female killer whales reach sexual maturity when they grow to about 15-18 feet (4.6 m-5.4 m) long, depending on geographic region. The gestation period for killer whales varies from 15-18 months. Birth may take place in any month--there is no distinct calving season. Calves are nursed for at least 1 year, and may be weaned between 1-2 years old. The birth rate for killer whales is not well understood, but, in some populations, is estimated as every 5 years for an average period of 25 years. Killer whales are highly social animals that occur primarily in relatively stable social groups that often range in size from 2 to 15 animals.
Birth Seasons. The birth of a new baby whale, known as a calf, usually occurs during the birth season for that specific type of whale. Orcas, for example, tend to give birth in the spring or fall, while blue and humpback whales do so in the winter. Gestation also varies from whale to whale -- with orcas it lasts around 17 months, with humpbacks 12 and with blues 11. Almost all whale births are to single calves, but rare twin births have been observed in wild whales.