The Seasons

activity actually adaptation animals annual Arctic autumn average bear become birds breeding cause cave climate clock cold colour continue cycle dark daylength despite Earth effect entirely environment equator example exist experience extremely fact fall flower follow four further greater grow growth half happens heat hibernation hormone human important inches insects kind known lack land later latitude leaves LEFT less light living mammals March means migration miles million month moon natural night normal northern occur once organisms particular period pituitary plants polar poles possible pressure probably produced rain rainfall regions result rhythm round seasons sexual short similar situation snow southern species spring summer surface temperate temperature torpid trees tropical warm winds winter zone