Clever Corvids

Common Raven, Corvus corax

Crows, ravens, and jays are members of the Corvidae family, or corvids for short.  Medium to large perching birds with strong bills and feet, and feathers that are predominately black or blue, they are bold, curious creatures, and are found in a wide range of habitats.  

Corvids are known for their high degree of intelligence in the bird world, especially crows and ravens.  Crows have performed as well as monkeys in psychological tests, and most employ intelligence in their daily routines, such as dropping nuts onto hard surfaces (like roads) to crack them.  Ravens can recognize groups of different sizes up to seven, and often show problem-solving insight when posed with an intriguing new task.  

Corvids are very social birds, with most living in extended family groups year-round.  Groups give the birds an ability to guard one another, and those posing as sentries can warn other birds and wildlife when predators such as hawks and owls are near, sometimes mobbing them and chasing them away.  While corvids are noisy birds with loud, often screeching calls, they are also excellent mimics of other birds, and those in captivity have been shown to mimic even human speech. During the winter, when food can be scarce and the weather harsh, corvids aggregate in large groups at abundant food sources and roost together to stay warm at night.  

American Crow, Corvus brachyrhynchos

Found primarily east of the Balcones Escarpment in our area, the American Crow (Corvus brachyrhynchos) is an all black, thick-necked bird with a straight, heavy bill and a short tail that is squared off or rounded at the end.  Their loud cawing gives them away, and many times you will hear them before you see them.  Highly adaptable, they will live in any open space that offers trees for perching and a reliable source of food.  The Common Raven (Corvus corax) is a very similar-looking all black bird, larger but more slender, and with a wedge-shaped tail.  It is found mainly in the Edwards Plateau west of the escarpment and in far West Texas.  An acrobatic flier, one adult was observed flying upside-down for more than a half-mile, and young birds are often seen dropping sticks and diving to catch them in mid-air.  

Western Scrub-Jay, Aphelocoma californica

Blue Jay, Cyanocitta cristata

While there are two species of jays in our area, they overlap only slightly in range.  The Western-Scrub Jay (Aphelocoma californica) prefers the juniper-oak woodlands of the Texas Hill Country while the Blue Jay (Cyanocitta cristata) inhabits the prairies and grasslands in the eastern part of town.  Gorgeous azure blue above with a slate gray back and light gray breast, Western Scrub-Jays lack the head crest and black barring with white patches on the wings that distinguish them from the Blue Jays.  Both species of jays have a mischievous streak, stealing other birds’ cached food and chasing off smaller birds to steal sunflower seeds and peanuts at feeders.   

Green Jay, Cyanocorax ymcas, this common resident of deep south Texas hasn't made it to Austin - yet.

In the wild, corvids are long-lived birds, often reaching over 15 years of age.  During their lives they clearly learn to act intelligently, and we have yet to determine how intelligence might be distinguished from instinct.  But the more we observe and record their behaviors, the more we can appreciate and enjoy these clever corvids!     

Dispelling Common Myths of the Ashe Juniper

Ashe Juniper, Juniperus ashei

The Ashe Juniper (Juniperus ashei), more commonly but incorrectly known as the ‘cedar’ tree, is not the bane of nature many people have come to believe.  It is as much a part of the Texas Hill Country as wildflowers and limestone.  The juniper tree can germinate on bare rock, quickly develop a thick canopy to protect the earth beneath it, and drop an enormous amount of leaf litter that can build soil and capture and hold water.  Let’s explore some of the more common myths surrounding this tree, and in the process begin to appreciate its purpose, beauty, and wildness.

Pollen produced on 'male' trees

Berries produced on 'female' trees

Shaggy bark of the Ashe Juniper

Myth #1:  The ‘cedar’ tree is not a native tree.  While you have probably heard some of the tall tales about how junipers may have arrived in Central Texas, the undisputable proof that they are native lies in fossilized juniper pollen found in our area, dating back to the last Ice Age. Additionally, in historical records dating back to the late 1600s and early 1700s, junipers are accurately described by Spanish trailblazers, missionaries, and other early settlers and explorers alike.  While native to our area, Ashe Junipers are invasive.  Naturally occurring on steep, west-facing slopes, they have spread to cover most of our terrain due to our tendency to suppress the normal wildfires that kept them within their typical boundaries.

Myth #2: The ‘cedar’ tree is a water hog.  Scientific stemflow studies have shown that the juniper does not take in much more water than any other native woody plant its’ size.  Junipers are extremely drought tolerant, and their dense canopy breaks the impact of falling rain.  This allows a thick organic litter to accumulate under the juniper, which slows down erosion and provides flash flood control. When slopes are clear-cut of juniper and native grasses cannot establish themselves, we not only lose our soil, but we may also be losing water. Eroded soil can fill the recharge cracks and limestone karsts with silt, which ultimately decreases the amount of water that percolates into the aquifer.

Golden-cheeked Warbler, Setophaga chrysoparia

Myth #3: The ‘cedar’ tree is a useless tree.  One of our endangered species, the Golden-cheeked Warbler, uses the soft bark strips of old-growth Ashe Junipers to build its nest.  Many other species of wildlife use juniper thickets as escape cover and shelter, and in the winter, its berries feed several species of birds and mammals.  Butterfly larvae, such as the Great Purple Hairstreak (Atlides halesus) and Juniper Hairstreak (Callophrys gryneus), as well as the Tortricid or Leafroller Moths, all consume the foliage.  And from a human point of view, oils provided by the juniper are used to scent perfumes and soaps, and the wood itself has been used for fuel, furniture, tools, fence posts, and just about everything in between.     

Juniper Hairstreak, Callophrys gryneus

Myth #4: Cutting down all the ‘cedar’ trees in my yard will protect me from ‘cedar fever.’ December through March is the height of ‘cedar fever’ season.  This is the time of year that juniper trees (males only, the females produce the berries) produce copious amounts of pollen, up to several pounds per tree.  Once this pollen becomes airborne, it travels hundreds of miles to reach every allergy sufferer.  Let’s face it – ‘cedar fever’ is simply a natural part of living in Austin.

In short, the Ashe Juniper helps us to define what we call ‘a sense of place.’  Combined with the wild and tumbled terrain created by our ubiquitous limestone, the character of the juniper’s twisted limbs and the smell of its foliage in the deep summer heat define the essence of the Texas Hill Country.

Jolly Holly

Possumhaw, Ilex decidua

One of the brightest colors in the winter landscape belongs to the red berries of our native species of hollies.  While approximately 600 species exists worldwide in the genus Ilex, in our area we have Yaupon Holly (Ilex vomitoria) and Possumhaw (Ilex decidua).  The first is naturally found in both dry and wet habitats, while the second thrives in generally moist woods.  Each, however, has their own unique characteristics, and they are hinted at in their scientific names.

Yaupon Holly, Ilex vomitoria

Yaupon Holly is a large evergreen shrub or small tree with small, shiny alternate leaves that have rounded toothed edges.  Little white flowers appear in April and May, followed by quarter-inch bright red fruits in fall and winter.  The species name 'vomitoria' means exactly what it sounds like, as early Europeans witnessed Native Americans consuming large amounts of a 'black drink' to induce vomiting as part of a purification ritual.  Steeped from toasted leaves and bark of this plant, this tea-like drink contained large amounts of the stimulants caffeine and theobromine, and is related to yerba mate, which is a traditional and still popular South American drink brewed from a different but related holly species.

Possumhaw, Ilex decidua

Possumhaw is also a large shrub or small tree with simple alternate leaves that are round at the tip and tapered at the base, but as suggested by its species name 'decidua', it is deciduous and loses its leaves in the winter.  That's when Possumhaw shines, however, spending most of the winter season with its’ bare branches adorned by bright red-orange berries.  Sometimes referred to as Winterberry, Deciduous Holly, or Swamp Holly, it is the larval food plant for the Dusky-blue Groundstreak butterfly.      



Grouping both of these hollies in your landscape with Carolina Buckthorn, Mexican Buckeye, Texas Redbud, and Spicebush creates a colorful and natural understory for an attractive woodland garden. Hollies are dioecious, meaning each plant is either male or female. The male plant provides the pollen, which is carried by bees up to a half-mile to a female plant, and used to pollinate it.  The berries on the female plant, while slightly toxic to humans, provide an important winter food source for small mammals and many different bird species, such as American robins, cedar waxwings, and northern mockingbirds.

Hollies have long been associated with the holiday season, with the roots of this tradition beginning in Europe and eventually brought to the New World. Over hundreds of years ago, druids considered holly to be a sacred plant, and associated it with the Roman God Saturn and the celebration of the winter solstice.  Plant some of our native hollies in your yard, and both you and the wildlife will enjoy a jolly holly season!