Photo by Andres Cadena
The 289 acre Heard Wildlife Sanctuary is a protected area of importance for wildlife and plant life, reserved for conservation and the educational and research programs that promote preservation of our natural resources. The Heard is home to hundreds of plants, birds, reptiles, amphibians, and mammals.
Your group is also welcome to pay regular admission and tour the Museum and Sanctuary on your own (admission is included with programs). Between the museum and live animal exhibits, miles of hiking trails, and picnic areas, there is something for every group!
Because most of the birds and animals that live on the Heard Wildlife Sanctuary have access to the entire preserve, there is no assurance that you will see any or all of the various species during each visit. If you do see an animal, for both your safety and the animal’s, do not approach or attempt to feed it. In our experience, visitors that respect the space of the wildlife (this is their home) are more likely to get to see them.
What may at first glance look like an open, uninhabited field is actually one of the few remaining pieces of Blackland Prairie in Collin County. Historically, the Blackland Prairie ecological area encompassed over 10 million acres. Today, it is the most-endangered large ecosystem in North America. Less than 1% remains. The plants that thrive at the Heard have few other habitats available to them. As a result, we ask that you please do not pick flowers or any other plant parts. Tip: this will also help you avoid possible contact with poison ivy!
During winter in North Texas, one might think that the hiking trails at the Heard Natural Science Museum & Wildlife Sanctuary would be uneventful. Because the plants have lost their leaves or turned brown, many of our birds have migrated south, and most insects have either died or gone into hibernation, one might assume our woods and prairies would not have much to offer those interested in looking for wildlife. However, life goes on, even in the “dead” of winter. A few interesting winter sights are detailed below.
The plants aren’t decked out in their green finery, but without the leaves obstructing our view, many other things become visible! Now is the time to really see the interesting form of all the trees and bushes, not to mention their beautiful bark patterns and each species’ unique bud shape and leaf scars. And, now you can see all the vines and how each species wraps around trees, bushes, and each other. Also, don’t forget to use all your senses in the woods, because the aroma of all the fallen leaves decaying on the forest floor is a pleasant gift!
If you are lucky enough to be out right after the first freeze, look for the Frost Plant. As the fluids exude from the base of the plant, it freezes and forms very interesting shapes and ribbons of ice!
Winter is also the time to look for the Goldenrod Gall. These swellings in the goldenrod stems contain a small white grub – long used by boys for fishing bait!
Perhaps the most striking winter plant attraction is the berries. Attractive to birds, squirrels, and other seed dispersers, berries are likewise very beautiful to us!
Possum Haw Holly
Hollies are known for their bright red berries, but our native species is deciduous, so its berries show up much better in winter!
The “kissing” plant of Christmas-time fame is everywhere in our trees. You can’t miss the evergreen clumps now that the leaves are gone! Hopefully, you can find a bunch growing low enough to examine their white berries. When squeezed, the mistletoe berries exude a sticky material that sticks to the beaks of the birds that try to eat them, inducing the birds to instead wipe the berries off on a branch. Then the mistletoe can send a root into the tree, tapping into the host tree’s sap to feed itself! What a beautiful parasite.
Commonly known as “horse apples”, these large chartreuse green fruits are really composed of multiple fruits like other members of the mulberry family. Paleobotanists theorize that the huge fruits evolved to be swallowed whole by the large, now-extinct, prehistoric mega-mammals that roamed the plains millions of years ago.
These attractive clusters of black berries are not really tasty (The new shoots are delicious!); however, I heard once that they were once called “stretch berries” because they were added to the gummy sap of Chittamwood to improve the texture.
The striking seed-heads of red fuzzy berries compliment the crimson fall foliage, but are even more distinct through the winter after the leaves have dropped.
Although the berries are small and almost all seed, the thin skin is quite sweet (hence the common name “sugarberry”).
The striking white berries that contrast nicely with the purple fall color of the leaves are mostly gone by winter. As a general rule, berries that are white are considered poisonous.
Carolina Moonseed Vine
Perhaps the most beautiful berries found in our area are the clusters of the red, translucent fruit of the moonseed vine. You might be tempted to plant some of these vines in your home garden, but this vine becomes a persistent weed that is hard to eradicate!
The beautiful clusters of translucent yellow berries of the soapberry tree are ideal for flower arrangements. Don’t confuse them with the opaque yellow berries of the non-native and invasive chinaberry tree. Although the tree gets its name from the saponins in the berries, not many suds are produced from the juice.
This small tree with berries gets its name from the long chain of seeds that look like a necklace of black pearls.
Most insects survive over winter either as an egg or pupae of some kind. Winter is a good time to look for the cocoons because there are no leaves to hide them. Nonetheless, it is surprising to see how many species spend the winter as adults. Most of these insects find a protective place to escape inclement weather (like crevices in the bark of trees or under a fallen log). On mild days some of these insects can be found taking advantage of the lack of competition from other insects and the presence of fewer predators during this part of the year. Following are notable insects to look for.
Question Mark Butterfly
On the mild, sunny days of winter, the Question Mark can be found sunning itself on the bark of a tree or drinking sap oozing from its upper limbs. This butterfly will catch your attention with the bright orange-red colors of the top of its wings, then disappear by lifting its wings up, exposing only the underside, which is camouflaged with mottled grays and browns and jagged leaf-like edges.
The Goatweed takes the Question Mark’s trick to a whole new level! One of the “Leafwing” butterflies, the underside of this butterfly’s wings look exactly like a dead leaf while the upper surface is solid red!
One of many “Sulphur” butterflies, so called because of their yellow or orange colors, the Alfalfa Butterfly has adapted to withstand very cold temperatures. This enables it to take advantage of the many winter blooming plants like mustards and dandelions. A white form of this species usually only occurs in winter.
Although many of the beautiful birds found on our sanctuary, such as the Painted and Indigo Buntings and the Scissor-tailed flycatcher, have migrated south for the winter, others like the Bluebirds, Bluejays, Red-bellied, Red-headed, and Downy Woodpeckers, Chickadees, and Titmice stay here all year long. Some resident birds, like the Cardinals, Crows, and Red-tailed Hawks, stay the winter but are joined by their Yankee cousins from the north, thereby having greatly increased numbers here during the winter. But many other species are only here during the winter and add greatly to our drab landscapes with their vivid colors and cheerful song. Although this is not a complete list by any means, some of our more interesting winter residents to look for are below.
This large woodpecker with its yellow breast and black moustache can’t be missed when it flies away because it flashes a large white rump patch.
A very interesting woodpecker, identified by the white longitudinal bars on its wings, the Sapsucker gets its name from the row of evenly spaced holes it drills on the trunks of trees. Although the holes are unsightly, they do provide nourishment for late-migrating hummingbirds and overwintering butterflies!
You will have to look hard to see this tiny brown bird creeping up the trunks of trees.
A true sound of winter is the whistle of a flock of these gregarious berry-eating birds. One of our most striking winter birds, their yellow breast, black mask, and topknot can’t be mistaken for anything else.
This small bird can be found in the woods shuffling through the leaves for worms or berries. Shaped like a small robin, its relative, it is brown above with a white breast covered with spots. This thrush’s tail is a reddish brown.
Many North Texans are very familiar with this dark gray bird with the red breast and white chin.
Don’t look for the bird you may have seen in pictures. The solid yellow bird with black wings changes to a much more drab greenish gray bird with darker wings with white wing bars for the winter. They usually fly in groups and can be found feeding on the seeds of thistles and other prairie plants. Luckily, we often have them feeding at our feeder too!
Ruby-crowned and Golden-crowned Kinglets
These very small birds are probably the smallest birds that you will see in winter. Always on the move, they can usually be identified more quickly by their constant flitting than their colorful crowns that often don’t show! Look for them in the trees and high bushes.
The Carolina Wren, with its white eye stripe, is here all year, but it is joined by the short tailed Winter Wren and House Wren during the winter.
The Winter Wren is a small, darkly colored bird characterized by a thin, pointed bill.
These energetic singers can be found hopping through tangles and low branches.
Both the Spotted and Eastern Towhees can be found here, easily recognized by their dark hood and back contrasted with the orange sides and white belly.
Look for our resident hawks all year: Red-tailed, Red-shouldered (banded tail, and cries like it’s in pain), sometimes Swainson’s (Dark Bib), and the Cooper’s, a grey hawk with a long banded tail that darts through the woods. The Cooper’s smaller duplicate, the Sharp-shinned Hawk is usually only here in the winter.
A sleek hawk with long wings and tail, the Harrier is a hawk of prairies and marshes, flying low over the fields in search of rodents and rabbits. Although the Heard’s prairies are too small to provide a home all winter, we often have them checking us out. Look for their conspicuous white rump patch.
Walking along the shores of our wetlands you might spy this bird with yellow legs and a long thin bill bobbing his tail frequently.
Likewise, this bird is found in the same area but is a smaller bird with a shorter bill. The sandpiper’s spotted breast disappears during the winter but reappears late winter into spring.
Sparrows & Juncos
Although most people think sparrows are common, they may be thinking of the ubiquitous English or House Sparrow that is not a true “sparrow.” The only sparrow that breeds on our sanctuary (and stays for the winter) is the Lark Sparrow. It is easily recognized by the striking facial pattern, the dark dot on its breast, and the outer white tail feathers you see when it flies. All of the rest of the sparrows that you might spot at the Heard are only here for the winter:
Reddish crown with pink legs and feet, buffy breast.
Bright reddish crown, distinctive white eyeline, unmarked breastFox Sparrow Large reddish sparrow, breast with large reddish spots.
Mottled sparrow with yellowish eyeline, speckled breast
Buffy breast with fine streaks, belly clear white, grey eyebrow.
Fairly large with strong moustache, breast streaks converge to a dot.
Black chin and forehead with a pink bill.
Most common ground sparrow, white throat, white crown and eyebrow, yellow between eye and bill, beautiful call.
Similar to the White–throated Sparrow, this bird has a broad white crown and pink bill.
Ground feeder, solid gray head and back, white belly, white outer tail feathers seen when in flight.
Other than the strikingly beautiful Wood Duck, the less common Hooded Merganser (fancy black and white “hair-do”), and possibly the green-headed Mallard, any other duck you see is only here during the winter. Some ducks commonly seen on our sanctuary only during the winter are below.
Green-headed like a Mallard, but they have huge bill and red side patches.
Small ducks, chestnut brown head with green ear patch.
Small with blue-gray head, large white crescent on face.
After the dormant appearance of winter in North Texas, spring is an exciting and invigorating time. This is especially true in the wild and natural places, particularly here on the Heard sanctuary. Mammals are more active now as they anticipate more plentiful and green meals to replace the meager fare they have subsisted on during the winter months.
The tree buds push out their leaves and flowers and the herbaceous plants begin emerging from their soil beds. Meanwhile, the insects and other invertebrates awaken from their protected crevices or crawl out of the envelope they created last fall, within which they have metamorphosed into spectacular winged creatures.
The emergence of these flying or crawling animals exactly coincides with the return of all of our feathered companions from their winter vacations in the south, providing them sustenance on the long journey home.
Likewise, the herpetological fauna (reptiles & amphibians) are warming up from their winter retreat to consume the invertebrates (or those creatures that feed on them) and the web of life again accelerates into high gear.
The woods, swamps, and prairies are once more alive with activity as Mother Nature recommences her annual cycle. What might a visitor to the Heard expect to experience during this time of resurgence? At this time of the year, every day is different and every time of day reveals new experiences as spring evolves from the first pioneer flora and fauna, willing to risk a late freeze to take advantage of the lack of competition, to the more conservative life that regularly inhabits this area during the spring and summer months. One thing is certain: more than one visit to the Heard Natural Science Museum & Wildlife Sanctuary is necessary to observe even part of this sequential parade of wildlife or fully appreciate the big picture of what “spring” really is! Below are a few inhabitants of the Heard to look for this spring.
Early spring at the Heard is synonymous with Trout Lilies! Emerging in February or March, before almost anything else has budded out, their spotted leaves and delightful small, white, down-turned flowers are a must for all nature lovers. But, you have to catch them quickly, because within a few weeks they disappear again.
Another small woodland flower, the Golden Groundsel begins displaying its bright yellow flowers at the same time, a striking contrast to the dull browns of the leaf litter.
The Golden Groundsel’s relative, the Prairie Groundsel, likewise brightens up the grasslands at the same time.
Not long thereafter, the Spring Herald, or Elbow Bush, displays its greenish-yellow blooms. Normally they would not be considered to be very showy, but at a time before most plants have any leaves, they can be quite striking!
At the same time, the Spring Herald’s cousin the Swamp Privet (not one of those nasty, invasive privets) shows off in our wetlands.
Early spring is also when many of our bulb-type perennials emerge.
Commonly seen throughout the sanctuary.
Wild Onion species
Commonly seen throughout the sanctuary.
The beautiful Wild Hyacinth is hidden in pockets of our sanctuary.
From winter into spring, the wild mustards, including the interestingly named Stinking Wallrocket, brighten open areas and waste places.
In the prairies look for the exotic purple blooms of the Ground Plum.
Milk Vetch and Loco Weed
The related legumes with similar flowers, the Milk Vetch and Loco Weed, are found on the calcareous escarpments, along with the delightful green clumps of Barbara’s Buttons.
Some early spring butterflies that overwinter as adults are the Question Mark and the Goatweed. Some butterflies can only be found for a few short weeks in very early spring, including a small hairstreak called Henry’s Elfin, whose caterpillars feed on the spring blooms of the Redbud and Mexican Buckeye. The most interesting is the small white Falcate Orange Tip, named for the orange on the wingtips of the males. Some of their offspring may emerge the next spring, but some may wait for the following spring or the year after that, insuring that even if a year or two passes without many of its food plant, the species can still survive. There are also some strikingly beautiful day-flying moths that only appear in early spring when their food plants, Grapes, Virginia Creeper, and related vines are just emerging. Both are small black moths; the Spotted Grapevine Moth has two large yellow spots on the forewings and two large white spots on the hindwings, while the Grapevine Epimenis has one large white spot on the forewings and one large red spot on the hindwings.
During the early spring, most of the migratory birds that flew to Central and South America haven’t arrived yet, but most of those that spent the winter here like Robins, Hermit Thrush, Cedar Waxwings, Orange-Crowned and Yellow-Rumped Warblers, Kinglets, Brown Creepers, Phoebes, Goldfinches, most Sparrow species, the Yellow-bellied Sapsucker, the Flicker, and numerous Ducks, and Shorebirds are still around. Additionally, there are the resident birds that never leave, like the Mockingbird, Bluejay, Cardinal, Red-headed, Red-bellied, and Downy Woodpeckers, Chickadees, Titmice, Carolina Wrens, Bluebirds, House Finches, Mourning and White-winged Doves, Wood Ducks, and many others.
The reptiles and amphibians have been inactive most of winter, but with the advent of spring many can be seen sunning themselves to raise their body temperatures since they don’t have internal heat production like us. Turtles, like the Red-Eared Slider, which can be seen on logs in our wetlands even on warm days during the winter, are now regularly visible. Likewise, the Yellow-Bellied and Diamondback Water Snakes sun on debris in the water or on land adjacent to water. Woodland reptiles, like the Texas Brown Snake or the little Ground Skink, a shiny lizard, sun themselves in the leaf litter and are more difficult to observe. Early in the spring when the water is still cold, frogs begin calling. The Bullfrog is often sunning himself conspicuously, but you may only know that the Leopard Frog is present when you hear its odd bird-like call.
Spring in North Texas is punctuated by several flowering trees and shrubs.
A popular, well-known tree. The showy flowers display various shades of magenta and are pollinated by long-tongued bee species.
Typically found on woodland edges or in open fields, the Mexican Plum has dark green, simple ovate leaves and fragrant white or light pink flowers.
Rusty Blackhaw Viburnum
Less familiar are the Rusty Blackhaw Viburnum with its large white flower clusters.
The delicate pink blooms of the Eve’s Necklace hang in wisteria-like clusters. They can grow in the sun or as an understory tree.
The very interesting dark purple spikes of the False Indigo rise 2-4 feet high, forming a bushy perennial.
On the prairie, numerous wildflowers show off their spring colors.
Several Thistles and the thistle-like Basket Flower are pink.
Some Gaura species and the False-Gaura are white.
Wild Indigo (Baptisia), Baby Blue Eyes, and Blue Flax are blue.
Spiderworts are purple.
The Missouri Primrose, the Corydalis and the Narrow-leaf Gromwell (Pucoon) are yellow.
The two most spectacular prairie flowers are the pale bluish to pink trumpet flowers of the Wild Foxglove and the Standing Cypress’ thin delicate stalks topped with clusters of crimson trumpets.
The most unusual spring bloom would be the curious green pitcher of the Green Dragon, which is found in the wet stream beds along the Wood Duck Trail.
Just as spring produces bountiful flowers, numerous insects time their emergence to coincide with all of the available nectar they produce. This is of mutual benefit, as the flowers produce the nectar to attract the insects to spread their pollen. Thus, spring is literally abuzz with flowers and their pollinators. Look closely at the flowers and you will see many hairstreaks like the Red-banded Hairstreak and the unbelievable blue Great Purple Hairstreak sharing a flower with several species of Bees and species of Syrphid Flies that often mimic bees but have only two wings A common day-flying moth in the spring is the Snowberry Clearwing, which looks just like a bee as it hovers from flower to flower. Many other species of moths emerge early to mate and lay their eggs on food plants while the leaves are still young and tender. So, too, their caterpillars can begin to be found in spring, especially since many species go through several life cycles during a season. Spring is also when hordes of Boxelder Bugs can be seen congregating on the trunk of a tree or grouped together under a piece of bark or other object.
Beginning in late April or early May, the migrants begin arriving. Many, if not most, of the brightly colored Warblers that live throughout the eastern U.S. and Canada travel through this area, perhaps stopping for a day or two, or, if the south wind is strong, don’t stop at all! Some we see fairly often, including the Black-Throated Green, the Common Yellowthroat, the Yellow Warbler, the dainty American Redstart, the Tennessee and Nashville Warblers, the Northern Parula and the Black-and-White Warbler. The beautiful yellow Prothonotary Warbler arrives to stay and nest in our wetlands. Other striking migrants we often see are the gorgeous Summer and Scarlet Tanager, the vivid blue Indigo Bunting and its gaudy cousin the Painted Bunting, Blue-headed Vireo, the delightfully musical Swainson’s Thrush, the striking Rose-Breasted Grosbeak and the vividly colored Orchard and Baltimore Orioles
Below are a few of the recently spotted species within the Heard Wildlife Sanctuary that have been documented in iNaturalist. Click through to see more. Or download the app and add your own!