|Rocky Mountain National Park|
Monday, December 24, 2012
Friday, December 21, 2012
|♀ Mistletoebird, Dicaeum hirundinaceum|
Wednesday, December 19, 2012
|Flock of Cedar Waxwings, Bombycilla cedrorum|
Monday, December 17, 2012
The approach of cold weather results in a number of bird species to gather together in large communal flocks. Some of the more common species include the Common Grackle, American Robin, Dark-eyed Junco, Snow Goose, and sometimes even Blue Jays to name but a few. This flocking behavior is not sudden, but rather the gradual congregation of smaller groups into larger ones. This begins early fall and reaches a peak during mid-winter. There are two main explanations for flocking together: enhanced foraging success and reduced predation. With less time spent finding food and avoiding predators, foraging success can vastly increase. When in large flocks predator detection is higher, chance of death lower, and "strength in numbers" may deter predation. The behavorial dynamics of a winter flock are influenced by food availability, familiarity, and overall composition as not all flocks are composed of a single species.
Friday, December 14, 2012
|Bearded Dragon, Pogona vitticeps|
Another major form of dormancy, estivation is similar to the metabolic and temporal reduction of hibernation, but used by species found in dry, hot environments. It is a state of aerobic hypometabolism where those species retreat to estivate in sheltered sites. They are active for a set period of time during the year, sometimes only a few weeks, to feed and breed. One characteristic factor of estivation is the methods of water retention both physically and metabolically. Balancing water retention could be a change of concentration in the urine, it could be the burrow construction, or it could be taking advantage of the environment to prevent dehydration.
Wednesday, December 12, 2012
|Yellow-bellied Marmot(s), Marmota flaviventris|
Monday, December 10, 2012
|♀ Broad-tailed Hummingbird, Selasphorus platycerus|
The use of torpor also varies per species, and can rely on a number of factors. The migratory hummingbird retains the ability to enter nocturnal torpor all year round, but there is a strong seasonal component. For certain seasons, the use of torpor is for "energy emergencies" while at other times torpor may be used to minimize time needed for premigratory fattening.
Friday, December 7, 2012
|♂ Eastern Bluebird, Sialia sialis|
Wednesday, December 5, 2012
|Web of the Texas Brown Tarantula, Aphonopelma sp.|
Monday, December 3, 2012
|Strangler Fig, Ficus|