Lots of things are happening out there right now in the Northern Hemisphere as animals prepare for the coming winter. Today’s post is full of interesting facts about everything from black bears to butterflies, aspens and oaks.

WeightWatching – In summer, the North American black bear must amass weight to survive its winter hibernation. It gains as much as 30 pounds a week eating a variety of foods, such as berries, nuts, fish and leaves.

AntlerWars – During their late-summer rut, bull elk fight ferociously over mates by clashing antlers, which can grow to 4 feet and weight up to 40 pounds each, and often strip the velvet off their bony headgear.

FractalFlower – Although the sunflower looks like one big flower, it is composed of hundreds of tiny florets. The sunflower possesses motor cells that tilt its large flower bud toward the sun as it moves across the sky.

FleetingLove – During mating season, male moose bellow loudly and physically confront each other in an effort to win over a female. A bull moose’s bellow can be heard up to six miles away.

SageSupper – Big sagebrush flowers in early autumn across the western United States. Its flowers are an important source of food for sage grouse and several other animals in the region.

MassMigration – Because monarch butterflies cannot survive cold winters, they migrate south en masse when temperatures drop. Monarchs west of the Rocky Mountains fly to coastal California, and those east of the Rockies head for the mountains of Mexico.

PonderosaPicnic – By peeling away the scales of the ponderosa pine tree’s cones, Abert’s squirrels are able to reach the nutritious seeds inside. Ponderosa pinecones open in early September and shed their seeds as late as November.

PartingCats – Known for their solitary nature, young bobcats in the Appalachian Mountains leave their mother’s care in autumn and prepare to survive the cold winter months on their own.

ColorfulClones – Aspen trees can reproduce by root sprouting, which results in clusters of genetically identical trees. In autumn, the clones’ leaves turn slightly different shades of gold, making them easier to distinguish from one another.

FruitMast – Most years, oak trees produce small numbers of acorns. Every few years, however, acorn production increases dramatically. These years are commonly referred to as “mast” years and lead to a feast for acorn-eating creatures.

(The information in today’s post comes from Chris Hardman’s Ecological Calendar 2013, www.ecocalendar.info.)