Walker Nature Center
A LOOK INSIDE • Calendar of Events 4 • Kids’ Corner 6 • Reston Wildlife Counts & Classes 7
Nature Notes By Sharon Gurtz
JUNE
• Bats are born. • Wild Bleeding Heart, Threadleaf Coreopsis and Bee Balm bloom. • White-tailed Deer fawns are born. • Black Rat Snakes lay eggs.
JULY
• Tent Caterpillar Moths emerge from cocoons. • Fireflies and bats are active in the night sky. • Cardinal Flower, Purple Coneflower and Sweet Pepper Bush bloom. • Praying Mantis and Katydids are common.
BRANCHING OUT Catching Rays By Ken Rosenthal
Summer has as many temperature challenges as winter. We wear lighter fabrics and clothing with short sleeves and legs, and shed layers of clothing to cool off. Animals face similar dilemmas. Summer means trying to stay cool by finding shade or entering the water. For aquatic reptiles and amphibians, it can be more complicated. Reptiles and amphibians are cold-blooded, or ectothermic. Their bodies are not able to maintain a constant internal temperature, like mammals or birds. Consequently, body temperature fluctuates as a result of environmental temperature changes.
Ectotherms must rely on external sources of heat to raise their body temperature, and know when to limit exposure before they overheat.
No second helping
This may sound disadvantageous, but being cold-blooded has advantages. Maintaining your body temperature at a constant level requires a lot of energy. Consequently endotherms (warm-blooded animals) have to eat more often than ectotherms. For example, a crocodile only needs to eat 10-20% of the amount of food that a similarly-sized lion would need to survive. Some reptiles can go months without eating after a large meal.
AUGUST
• Stonecrop, Blazing Star and Goldenrod bloom. • Copperhead Snakes give birth to live young. • Southern Flying Squirrel young are born. • Eastern Box Turtle and Snapping Turtle eggs hatch.
Summer 14 Volume Sixteen