Heralding Herons

 

Snowy Egret, a type of heron, showing breeding feather plumes called aigretes.

A walk along the edge of a body of water often reveals wading birds known as herons. Herons are birds in the Ardeidae family that are long-necked, long-legged, with long tapering bills, large wings, and soft plumage. Egrets are technically a type of heron, distinguished by most species being almost entirely white. Herons display various colors in their feathers and egrets often display showy ornamental plumes (called aigretes) in the breeding season. 

Herons tend to be larger and more robust than egrets, and will often remain motionless to ambush prey while egrets are more active hunters that walk or shuffle along as they hunt in shallow water. In our area, some of the mostly commonly seen herons include the Great Blue Heron (Ardea herodias), Green Heron (Butorides virescens), and Yellow-crowned Night Heron (Nyctanassa violacea). 

The largest of the North American herons is the Great Blue Heron, standing 3 to 4 feet tall with a 5 to 6-foot wingspan. Overall they are blue-gray with a wide black stripe that is above and extends beyond the eye, and a long white foreneck streaked with black. Their hunting style includes a lightning-fast thrusting of the neck as they stab their prey of fish and amphibians with their strong pointed bills. In flight they are distinguished by very slow wingbeats, a tucked in S-shaped neck, and long trailing legs. Like most herons and egrets, these birds congregate together in colonies to build large stick nests in trees high off the ground during breeding season.

Great Blue Heron

Comparatively, Green Herons are short and stocky, 1 to 1.5 feet tall with a wingspan of about 2 feet, and a thick neck that is often drawn up against their bodies. They are deep green on the back with a rich chestnut breast and neck and broad, rounded dark gray wings. They hunt while standing on vegetation, rocks, or solid ground in shallow water, not wading in as far as larger herons. Sometimes they use small tools such as twigs, insects, or feathers as bait, dropping them on the water’s surface to lure in fish before they snatch them with their daggerlike bills.

Green Heron

Yellow-crowned Night Herons are also short and stocky herons, to 2 feet tall with a 3 to 4-foot wingspan, blocky heads and thick, relatively short bills. Overall cloudy gray, their distinguishing feature is their bold face pattern of a black head with a large white cheek patch, and a creamy yellow crown and elegant head plumes. Contrary to their common name, these herons hunt day or night, lunging forward from a bent over posture to catch their preferred prey of crayfish.

Yellow-crowned Night Heron

Historically, feather plumes from herons and egrets were used to adorn hats in the 19th-century, as they were highly prized for their soft texture and dramatic movement. Approximately 75% of hats at that time were adorned with these feathers, and the massive demand drove many species to near extinction. This helped spark early conservation movements such as the Audubon Society. Today, we herald these magnificent birds, and the sale, possession, and trade of their feathers is prohibited by the Migratory Bird Treaty Act of 1918 as well as by other environmental legislation.

Leaping Lizards

 

Warmer weather increases the activity of lizards

As temperatures rise and the days grow longer, it’s quite common to see different types of lizards basking in the sun, darting across driveways and sidewalks, and climbing tree trunks and other vegetation. Three common species observed this time of year include the Green or Carolina Anole (Anolis carolinensis), Plateau or Texas Spotted Whiptail (Aspidoscelis gularis), and Texas Spiny Lizard (Sceloporus olivaceus).

Green Anole - green form

Ranging from bright green to dark brown, the Green Anole possesses the ability to change color due to temperature and light. A small lizard, it has a pale colored underbelly, long claws, and a thin tail. The males have what is called a ‘dewlap’, a bright pink flap of skin that can be extended and retracted for purposes of intimidating rivals and attracting females during the mating season. These anoles are arboreal, spending most of their time in trees, shrubs, and vines, feeding on insects and spiders. While they have a small territory, the males will aggressively defend it, starting with extending their dewlap, bobbing their head, performing pushups, and ultimately ending in a chase or a wrestling match. All this posturing, patrolling, and jumping from one branch to another can make the males much easier targets for predators, however, and they tend to have higher mortality rates than the much more discreet females. If it is late spring and the right to mate is at stake, the winner will once again employ headbobbing and dewlap extension to entice the female, who will lay a single, softshell egg among the leaf litter. 

Green Anole - brown form

A male Green Anole extending his pink dewlap

A medium to large striped and spotted lizard, the Texas Spotted Whiptail is endemic to New Mexico, Oklahoma, and Texas. It grows from 6.5 to 11 inches long, typically tan brown to green-brown in color, with a pattern of seven distinct grey or white stripes that run the length of the body and stop at the tail. Light colored spots are present along the sides, the underside is uniformly light in color, and the tail is often close to three times the body length. This whiptail is highly active during the day, hunting for insects in a wide variety of habitats, and like other whiptails, is capable of tail autonomy or the ability to shed its tail to escape predation. Breeding occurs in the spring, with the female laying a clutch of 1 to 5 eggs in a separate chamber of their underground burrow, typically in moist soil, by early summer. 

Texas Spotted Whiptail

Primarily arboreal but preferring basking surfaces such as fence posts and rock walls, the Texas Spiny Lizard is quite common in all but the eastern and western thirds of Texas. A robust spiny lizard up to 11 inches long, it is grayish to olive brown with up to nine dark wavy bars spaced along its back, which gives it a very scaly appearance. Males have a narrow bright blue patch on each side of the belly, and while the females lack this coloration, they are slightly larger and paler than the males. An ambush predator, they feed on a variety of insects found on the ground in open areas or up in trees in wooded areas. Breeding occurs in the spring and summer, and mature females may lay several egg clutches per year.

Texas Spiny Lizard

As temperatures cool when evening approaches, most lizards will retreat into sheltered refuges until warming begins the next morning. As temperatures rise throughout the day, they will increase their activity levels and become leaping lizards once again!

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 the 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.