Friday, March 25, 2016

Episode 309 (3-28-16): A Pondside Temperature Tale

CLICK HERE to listen to episode audio (4:20)

Transcript of audio, notes on the audio, images, and additional information follow below.

All Web addresses mentioned were functional as of 3-25-16.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of March 28, 2016.

SOUND - ~ 4 sec

This week, the sound of boiling water opens a special episode for Virginia’s K-12 science students on temperature, and on two fundamental ways that different animals respond to temperature.  To start, have a listen for about 10 seconds to sounds around a Virginia pond on the morning of March 22, 2016, when the temperature was about 40 degrees Fahrenheit, and see if you can tell what animals were active then.

SOUND – ~ 12 sec

That morning’s sounds included Mallard Ducks diving for food and Red-winged Blackbirds singing out nesting territories.  A day later at the pond, but in the afternoon when the temperature was about 70 degrees, there were again active ducks and other birds, along with lots of people enjoying the water scenes.  But also active that afternoon was another winged creature that had been absent the previous morning:

SOUND – ~ 5 sec

At a sunny 70 degrees, bees were busy visiting cherry tree blossoms, and a few other early spring insects were also moving.  How come the birds you heard were active at 40 degrees, but the bees weren’t?  Birds, as well as mammals, are called endotherms, meaning they can generate body heat and regulate it with insulation, behavior, and blood circulation.   Endotherms are also sometimes referred to as warm-blooded, but that term isn’t really accurate, because not all of their blood is always warm.  Endothermic animals keep their core body temperature within a relatively narrow range, depending on species and their natural habitat; that allows the animals’ cells and tissues to continue to carry out temperature-dependent biochemical reactions.  Other animals—including reptiles, amphibians, fish, insects generally, and many others—are called ectotherms (also sometimes referred to as cold-blooded, again not really accurately because their blood isn’t always cold).  Ectotherms also need a certain range of temperature to carry out biochemical reactions, but their core body temperature changes along with the temperature of their environment.

Within this basic distinction between endotherms and ectotherms, however, many variations and adaptations exist.  For example, the body temperature of some hibernating mammals can fall almost to the outside temperature; and some insects use heat generated by their wings to keep parts of their body warm.

We close with two more set of sounds, of frogs, birds, and insects.  See if you can identify the ectotherms and endotherms.  You’ll find the answers in the online show notes for this episode.

SOUNDS - ~ 13 sec
1) March 9, 2014, Wood Frog and Spring Peepers (both ectotherms).
2) August 9, 2015, American Crow (endotherm) and cicadas (ectotherm).

For more Virginia water sounds, music, and information, visit us online at, or call us at (540) 231-5463.  Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment. Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close the show.   In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


All sounds in this episode were recorded by Virginia Water Radio in Montgomery County, Va.


Male (right) and female Mallard ducks at the Virginia Tech Duck Pond in Blacksburg on the morning of March 22, 2016 (temperature about 40 degrees F).

Ornamental cherry tree attracting bees at the Virginia Tech Duck Pond in Blacksurg, on the afternoon of March 23, 2016 (temperature about 70 degrees F).


Used in Audio

Cornell University Lab of Ornithology and American Ornithologists’ Union, “Birds of North America/Red-winged Blackbird,” online at

Richard W. Hill et al., Animal Physiology, Sinauer Associates, Inc., Sunderland, Mass., 2004.

For More Information about Different Animal Groups in Virginia

Virginia Department of Game and Inland Fisheries (VDGIF), “Virginia is for Frogs” Web site, online at

Cornell University Lab of Ornithology, “All About Birds,” online at; and “Birds of North America Online” Cornell University Lab of Ornithology and American Ornithologists’ Union, online at (subscription required for the latter).

VDGIF, “Wildlife Information/Species Information” Virginia Department of Game and Inland Fisheries, online at (amphibians, reptiles, and mammals).

Virginia Tech Department of Fisheries and Wildlife Sciences, “EFish—The Virtual Aquarium,” online at Has sections for each fish family. At each family section, has species numbers, distribution, uses, photos, etc

Freshwater Fishes of Virginia, by Robert E. Jenkins and Noel M. Burkhead (Bethesda, Md.: American Fisheries Society), 1994.

“Virginia Fishes” [freshwater game species], Virginia Department of Game and Inland Fisheries, online at

“Virginia Saltwater Angler’s Guide/Fish Identification Guide,” Virginia Marine Resources Commission (2006), online at; includes links to different PDFs on Virginia marine fish species, etc.

Iowa State University Department of Entomology, “BugGuide,” online at

Vincent H. Resh and Ring T. Cardé, eds., Encyclopedia of Insects, 2nd Ed., Elsevier Academic Press, Burlington, Mass., 2009.

Virginia Tech Insect ID Lab, online at


All Water Radio episodes are listed by category at the Index link above ( For episodes related to temperature and other physical characteristics, please see the “Science” category.

This episode may help with the following Virginia’s 2010 Science Standards of Learning (SOLs):

Grades K-6 Earth Patterns, Cycles, and Change Theme
3.8 – basic patterns and cycles in nature.

Grades K-6 Life Processes Theme
3.4 - behavioral and physiological adaptations.

Grades K-6 Living Systems Theme
4.5 - ecosystem interactions and human influences on ecosystem, including animal adaptations.

Life Science Course
LS.9 - adaptations for particular ecosystems’ biotic and abiotic factors, including characteristics of land, marine, and freshwater environments.

LS. 10 - changes over time in ecosystems, communities, and populations, and factors affecting those changes; particularly item a: phototropism, hibernation, and dormancy.

Biology Course
BIO.4 - life functions, including metabolism and homeostasis.

BIO.8 - dynamic equilibria and interactions within populations, communities, and ecosystems, particularly item a: interactions, including carrying capacity, limiting factors, and growth curves.

Virginia’s SOLs are available from the Virginia Department of Education, online at