Breaking Slumber

 

Many small creatures awaken in Spring

In the winter months in central Texas, most cold-blooded reptiles and amphibians exhibit a form of hibernation called brumation. Triggered by shorter days and lower temperatures, this state can last for days or weeks, depending on the species. Brumation differs from true hibernation in that these animals remain semi-conscious and occasionally wake up to drink but not eat. During this period, body temperature, heart rate, and respiratory rates are greatly reduced.  This state of dormancy occurs with several common amphibian species, including the Rio Grande Leopard Frog (Lithobates berlandieri), Gulf Coast Toad (Incilius nebulifer), and Green Tree Frog (Hyla cinerea).

Rio Grande Leopard Frogs are medium-sized native frogs, to 4.5 inches, greenish-brown in color with a yellowish ridge along each side of the back. They have large dark spots on the back and sides, and a wide, light-colored jaw stripe that is poorly defined and fades in maturity. Their call is described as a short, low-pitched guttural rattle, either given singly or in rapidly repeated sequences. These frogs spend the winter months resting at the bottom of ponds, lakes, or other bodies of slow-moving water, but can become active during warmer, wet periods. Since they are semi-aquatic, they can also tolerate cold conditions by burrowing into mud or soil. They tend to enter brumation just before freezing weather, and often hide in deeper water to temporarily escape extreme temperatures.

Rio Grande Leopard Frog

The Gulf Coast Toad is a native, broad-headed, mostly terrestrial toad, to 5 inches, with prominent cranial crests that form a depression on top of the skull. Their background color is brownish-yellow to brownish-gray, with broad dark lateral stripes bordered by a light stripe, as well as a light central stripe, and they are covered in numerous small whitish to orange spots. Their vocal sac becomes large and rounded when calling, which sounds like a short, flat trill repeated several times. These toads are usually dormant from December to February, hunkering down in self-dug holes, abandoned animal burrows, under logs, or in leaf litter to protect themselves when the temperature dips below freezing. While they become active as the temperatures rise in early spring, they may also burrow to survive hot, dry conditions in the summer months, and this unique behavior is called aestivation.

Gulf Coast Toad

Green Tree Frogs are smaller, native arboreal frogs, to 2.5 inches, with smooth skin, a slender, flat body, and long slender legs with large toe pads on each foot. In warmer conditions, when the frog is active, they are typically a bright green color, but they can change to a dull color during periods of cool weather or to blend in with their surroundings. They also have a long white stripe on either side of the body. Their call sounds vaguely like a honking duck and is repeated 30 to 60 times a minute. These frogs brumate in the winter months, often hiding under deep leaf litter, in tree cavities, in potted plants, or even in the corners of garages and sheds. During this time of inactivity, they slow their metabolism and sometimes survive partial freezing by producing natural antifreeze compounds called glycerol that protect their cells. They also typically choose sheltered damp spots to avoid freezing completely, and may wake on warmer, sunny winter days to move about.

Green Tree Frog

As they days get longer and temperatures begin to rise, once again we will be treated to the sights and sounds of these marvelous amphibians, as they break their winter slumber!

Butterflies in Winter

Early blooming plants like Elbowbush attract butterflies  

While butterflies are most noticeable in spring, summer, and fall, seeing them in the middle of winter is often surprising.  Most spend the winter in the egg, larva, or chrysalis stage of development, concealed in leaf litter or in other forms of vegetation, but some overwinter as adults.  

Most of the adult butterflies observed in the winter belong to the Brushfoots, a highly variable group of primarily mid-sized butterflies, some with irregular wing shapes, and many that fly with distinctively alternating flaps and glides.  In our area, the adult butterflies in this group most often seen in the winter, usually on a particularly warm sunny day, include the Red Admiral (Vanessa atalanta), Question Mark (Polygonia interrogationis), and Painted Lady (Vanessa cardui).

The Red Admiral is a common butterfly, not to be confused with any other species.  Dark above with fiery orange-red slashes and white spots on the outer part of the forewing, their flight is fast and erratic, darting out at anything crossing their path. Their larval host plants include nettles and pellitories. 

Red Admiral

Question Marks are also quite common, and their orange forewings and hindwings are sprinkled with dark brown dashes and dots, especially in the winter form (oddly, in summer their hindwings are mostly black). Their wings have irregular edges with a somewhat hooked forewing tip and a short tail on the hindwing. But their most distinctive feature is the silvery comma and adjacent dot forming a question mark in the center of the hindwing’s underside. Their larval host plants include nettles, hackberries, and elms.

Question Mark

The Painted Lady is one of the most familiar butterflies in all of the US. They are orange and black with a black patch and white spots on the forewing tips and a row of small black spots on the hindwing. On the hindwing’s underside, they have a row of four small eyespots which help distinguish them from American Lady butterflies. Their larval host plants include mainly thistles and mallows.

Painted Lady

But how do these adult butterflies survive the cold? First, they begin to enter a period of suspended development in the fall, called diapause, which causes their metabolic processes to slow down considerably. Second, their bodies produce chemicals that act as natural antifreeze, preventing their body fluids from freezing. And third, they find protected locations to shelter from the cold, such as in tree hollows, under loose bark or leaf litter, in cracks between rocks, or among dense, dry brush. 

Those butterflies that overwinter in the egg, larval or pupal development stage have hidden homes in the colder months. Some are lying in leaf litter on the ground, while others are slumbering in silk shelters on spent stems and along grass blades. While it can be difficult to spot these hidden homes, be mindful that these vulnerable creatures are asleep in our yards and green spaces, and try to hold off on removing all leaf litter and performing cut back until the beginning of spring.