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Monday, January 23, 2017

Winter Chorus


Clear and bell-like, consisting of a single, quickly repeated note, the call of the male Strecker’s Chorus Frog (Pseudacris streckeri) is unmistakable.  In the midst of winter, especially in the peak calling season from January to early March, multiple males call at the same time, their alternating notes resulting in an unexpectedly delightful winter chorus rising up from the canyons!

Reaching an adult length of 1 to 1.5 inches, this largest chorus frog is identified by a stout gray, brown, olive, or green body, a dark brown mask-like stripe through the eye and a dark spot under the eye, dark longitudinal stripes along the back, and a deep golden or orange color in the groin. Males are slightly smaller than females and have greenish-yellow vocal sacs.  The genus Pseudacris comes from the Greek pseudes meaning ‘false’ and akris meaning ‘locust’, and is likely a reference to the repeated rasping calls of most chorus frogs, which are similar to and can be mistaken for those of an insect.


Although Strecker’s Chorus Frog is mainly a nocturnal frog, its call can be heard day or night. Males call as they hang on to or sit on vegetation, or from the bank above the water’s surface. Typically feeding on insects, this chorus frog is seen most often in moist woodlands, rocky ravines, near streams or in swamps.  While its range includes portions of Kansas, Illinois, Missouri, Oklahoma, Arkansas, and Louisiana, the individuals in Texas are of the subspecies P.s. streckeri, and occur in most counties in the eastern half of our state.


Aside from its distinctive winter chorus, Strecker’s Chorus Frog is also distinguished by its ability to use its forelimbs to burrow headfirst, unlike other amphibians that typically use their hind legs to back into a burrow.  It burrows deeply in sand or mud and hides under rocks and woody debris to protect itself from heat and predators, emerging mainly after heavy rains. Following these rains, it migrates a short distance to a preferred breeding site.

Strecker’s Chorus Frog is a cold-tolerant, winter breeding frog, breeding anytime between November and March when rains are adequate. While most frogs prefer to breed in flowing water, Strecker’s Chorus Frog prefers still, clear, temporary water bodies such as ditches, ponds, and pools in wet weather creeks.  Females attach their small, jelly-covered clusters of eggs to vegetation below the water’s surface, and the time to hatch, while water temperature dependent, is usually just a few days.  Tadpoles take around two months to transform into adult chorus frogs.  In spring, at a time when most other frogs are just beginning to seek their breeding ponds, Strecker’s Chorus Frogs terminate their breeding activities.

Named after John Kern Strecker, Jr (1875 – 1933), a Texas naturalist and Curator of the Baylor University Museum (renamed the Strecker Museum in 1940 in his honor), this chorus frog with its peculiar and unusual habits and haunting winter chorus might have been a perfect candidate for “Strecker’s Cabinets of Curiosities”!  

If you’d like to see and hear the chorus for yourself, check out the video at https://texaswild.me/2014/03/31/streckers-chorus-frogs-calling/


Saturday, January 7, 2017

Flowers of Ice



While many plants can be damaged or killed by freezing temperatures or frost, this varies by the type of plant and tissue exposed to these conditions.  In our region, there is a plant called Frostweed (Verbesina virginica), which is commonly found in low-lying areas near streams, creeks, canyon bottoms, and in dappled shade at woodland edges. 


For much of the year, Frostweed goes unnoticed while it grows tall and leafy, the top of each of its stalks crowned by clusters of small white flowers.  It begins to bloom in the August heat, and continues until first frost, well into fall.  In fact, this leggy plant is a rare late-season nectar and pollen source, as its blooms are a magnet for fall migrating hummingbirds and Monarch butterflies, as well as a host of other insects.


However, it is with the first frost or sub-freezing temperatures that this plant really puts on an unexpected show.  When temperatures dip, the water contained in each plant stem expands, causing the stems to crack.  Via capillary action, more water is drawn through the cracks, freezes when it hits the cold air, and forms long curls of ice, reminiscent of petals of an intricate flower or of a delicate, abstract sculpture.


These very delicate ice forms are fleeting in nature, and can only be found in early morning, as the rising temperature of the day quickly melts them away.