Some migratory birds are heterothermic, meaning they sometimes maintain a constant body temperature and other times allow their body temperature to vary. For example, on cold nights, they sometimes reduce their metabolic rate and allow their body temperature to drop as the air temperature falls. Which of the following hypotheses about this unusual strategy is consistent with what you learned in this section? A. Birds allow their temperature to drop in order to increase their assimilation efficiency.
B. Birds allow their temperature drop in order to increase their production efficiency.
C. Birds allow their temperature to drds in order to increase their consumption efficiency.

B. Birds allow their temperature drop in order to increase their production efficiency.

Explanation:

Most birds can drop the temperature a few centigrade degrees, while there are torpid birds capable of lowering much more. Birds can drop body temperature in response to environmental conditions. Bird species including, among others, swifts, hummingbirds and chickadees are capable of regulating body temperature during torpor state. There are different morphological and behavioral adaptative traits that enable birds to minimize the cost of thermoregulation. In the first place, epidermis surface allows heat loss to the environment, while arteries and veins in the legs help to retain heat in cold conditions.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

they both go up but then go back down. they both end lower than they started. lastly, they both are competitive/the second on.

explanation: