All about Ollie – barred owls at Mason Farm Biological Reserve

The end of winter and start of spring is a good time to look for some of the birds that you don’t see so often. They are not hidden by foliage and may come out more to hunt for a meal as they prepare to cope with the rigors of upcoming parenthood. That has proved to be a boon for me during visits to Mason Farm Biological Reserve where there are several pairs of barred owls (Strix varia) in residence. While these birds usually hunt at night, they have recently been seen out and about much more often in the daytime, perhaps getting ready for nesting and brooding in March and April.

These beautiful raptors sit quite still and often make no sound at all as they turn their heads scanning the ground or a creek nearby for small rodents, crayfish, fish, insects, amphibians and reptiles.


Their brown and white mottled feathers are a perfect camouflage to help them blend in with the bare gray and brown tree trunks and branches of winter. To spot them, you learn to scan trees in the distance looking for a “lump” which your binoculars or long camera lens can then help distinguish as an owl.

These owls tend to stay in one area; a study of 158 banded birds showed that none of them had ventured further away than 6 miles from the spot where they were first seen. At Mason Farm, we tend to hear the owls in specific areas – along a creek, near a couple of open fields and near a bog. These are likely different pairs who can live there for decades – the oldest known barred owl was 24 years old.

After hearing that friend Mary had been seeing one particular owl daily, I began going there more often to catch a glimpse of him/her. I nicknamed the bird Ollie – short for Oliver or Olivia. It turned out that I was fortunate enough to see both Ollies; the pair has become fairly tolerant of people nearby, sometimes perching in trees right next to the walking path.

One mid-afternoon, I was searching the fields for Ollie, noting some of the other birds who were easier to spot because of their movement, like the red-bellied woodpeckers and song sparrows. I was looking into the mid- and long-distance and then glanced up at a small tree next to the path – there was Ollie staring back at me! I had never been within about 5 feet of a wild barred owl before and was able to see him/her really well – what a beautiful bird!

To get some photos, I actually had to back up as I had a long-distance lens on the camera. Some runners came by and saw that I was focused on something, but they never looked up to notice that they were passing couple feet underneath this large raptor. Ollie just watched silently as they ran by and then returned to scanning the ground for prey.

Another day, Mary and I were following an owl from one field to the next. The hunting pattern appears to be: perch in a tree and look intently at the ground around for 10-20 minutes or longer, fly some 20 or more feet away to scan another patch. It appeared that the owl and caught something and s/he flew to a tree branch at the other side of the field. I happened to glance away in time to see the second Ollie flying toward and past us in the field on the other side of the path.  The owls fly completely silently so you have to be lucky to spot them.

Although I’ve seen the pair fairly often now, I continue to find them really beautiful.


When they spot some prey, the owls drop quietly but swiftly down to pounce on the animal. Sometimes they sit there for a minute or two, presumably swallowing the entire animal if it is small. If it is larger, they will carry it off to have their meal in a tree.

On one of our walks, Mary’s sharp eyes spotted an owl pellet and friend Lucretia and I dissected it. The pellets can contain the remains of several meals and we thought that a couple small animals’ remains were contained in the fur-covered mass. A tiny skull and pair of jaw bones with minuscule teeth could be distinguished – perhaps a vole or baby mole.

On one of my most recent spottings of Ollie, s/he was spending time taking little power naps in between ground scans. On other days, the owls had brief snoozing periods, too. The feathers on their eyelids are very cool! When a pair calls to one another, you can distinguish the male and female. The male’s call ends abruptly while the female adds a little trill to the end of her call.


On my last foray to the reserve to see owls, I was following Ollie’s progress along the field when another birder spotted me taking photos. After a while, about six or seven walkers were watching and Ollie finally flew to the top of a pine tree not far from the path so they could all admire him/her.

The one predator that goes after the large barred owls is the even larger great horned owl (Bubo virginianus).


When people go too close to a barred owl’s nest, the owls will become agitated, so we should keep that in mind and not bother them there. Oliver and Olivia seem not to mind people too much right now, since they will fly to perch near a path where people are passing. I do try to limit how much time I spend following them, though, even though they can fly away. Just like us, the owls do want to be able to go about their business in peace!


An under-appreciated bird?

In the area where I live, many birders are thrilled when spring migration begins and the wood thrush (Hylocichla mustelina) arrives. They find its song especially appealing and exclaim over the fact that they had the privilege of hearing the wood thrush in their yard or in the woods.



While it’s a nice song, however, I find that I’m more attracted to our winter visitor, the hermit thrush (Catharus guttatus), perhaps because this species seems less afraid to emerge from the vegetation when people are around. I find its song quite nice as well, even though it doesn’t seem to have as many trills in it as the wood thrush.



The past couple years, I seem to have been seeing the hermit thrush more and more often. Presumably, this is not because there are more of them but because I have grown a little more adept at spotting and identifying birds as time has passed. The past six weeks, I’ve seen them in various places and have very much enjoyed each spotting.

On the 15th of December, during a walk at Mason Farm Biological Reserve, I spotted one eating berries with gusto.



Ten days later, birds in different parts of the reserve came out on twigs, observing me as much as I was observing them. On the 2nd of January, one caught my eye when s/he was bobbing its reddish tail up and down. It gave me a good view of the bird’s underside, which looked nicely cushioned. That part of the tail is the most colorful part of the bird, which otherwise is a rather muted light brown with a cream-colored, lightly spotted breast.


On the 4th of January, we had a light smattering of snow and I saw a hermit thrush in a crepe myrtle tree, an unusual sight in my yard as their visits are usually few and far between. The next day, the bird returned to the red cedar trees (Juniperus virginiana) to make a few meals of the nicely ripe juniper berries.


The snow melted quickly but the bird was back the next day for more berries; fortunately, the American robins and cedar waxwings had not eaten them all.


In the spring and summer, the hermit thrush’s diet consists mainly of insects and sometimes small reptiles and amphibians. In the winter, they turn to eating berries and fruit. Here, a thrush at the Brumley Forest Preserve had been foraging on the ground and found a seed or fruit.

Back at Mason Farm, the 21st of January was a stellar day for seeing hermit thrushes; I must have seen at least six in different parts of the woods. At one point, I had stopped to listen to a downy woodpecker (Picoides pubescens) calling and then noted a thrush sitting on a sapling branch near the walking trail. S/he flew down to the path to forage and suddenly another one flew in landing atop the first thrush! The attacked bird spread its tail feathers on the ground while the other one glared at it.

The Cornell Lab of Ornithology notes that hermit thrushes may respond to predators by crouching and pulling in their heads; perhaps this was an adaptation of that response.

I always think of these little beauties as being peaceful birds so seeing one challenge the other in such a physical way was a real surprise. Then as suddenly as the attack had happened, all was sweetness and light as the two birds began foraging on the path about 2-3 feet from one another. The downy woodpecker even joined them on the ground for a little while.


The oldest recorded hermit thrush was almost 11 years old. Perhaps their generally sweet disposition helps them survive.


Depending on whether these birds are fluffing their feathers against the cold, they can either look like a sleek and slender avian or a puffy little ball of feathers. In both cases, I think they look quite appealing.


Whatever shape they take, I do look forward to seeing more of these lovely, usually demure and delightful thrushes!



Avian generations in the making – part 2A: nesting and man-made construction

Hi folks — today I’d like to share with you some of my observations on the second part of avian reproduction — the process in which birds make a nest and lay eggs. (By the way, if you look up “bird nesting” on the Internet, the search will lead you to a human activity: a shared custody arrangement where children reside in one house and the parents take turns living there with them. In the bird world, some avian parents will actually share a home, such as this very old and enormous sociable weaver nest (Philetairus socius) that I saw in Namibia.)

Females of a few species will deposit their eggs in the nests of another, such as some cuckoos and brown-headed cowbirds (Molothrus ater). Some people dislike cowbirds intensely because of their nest parasitism (the cowbird baby will hatch first and eat all the food or perhaps get rid of the other eggs or babies). I figure that this is how the cowbird evolved – it didn’t make a choice to wipe out other species so I can’t blame or hate the bird for it. But the cowbirds do appear to pick on particular species as involuntary “foster parents” and this may be affecting the success of the other species’ reproduction.

There are two general broad categories of bird nests – those located in or on man-made objects such as nest boxes, atop downspouts, in vehicles, in plant pots and other places and those constructed by birds in trees, shrubs and on the ground (i.e., the natural environment which I will discuss in the next blog so this doesn’t get too long!). When birds make a nest in a “human area”, people will often try to accommodate them, not using the object or vehicle or making the space safer. For example, when American robins (Turdus migratorius) put a nest on one of my downspouts, I covered the rainwater container underneath it so the fledglings wouldn’t drown when they leapt to freedom. (I did it just in time, too!)

Swallows and phoebes will also use human constructions as places to situate their homes. The cliff swallows (Petrochelidon pyrrhonota) gather up mud, making countless trips to wad up small balls of the material to carry back to a place like this pier at Cane Creek Reservoir where they line up their nests in a row.


Barn swallows (Hirundo rustica) locate their nests inside, using rafters to place a nest; they may end up sharing space with paper wasps and organ pipe mud dauber wasps (Trypoxylon politum), which doesn’t seem to bother them.

The Eastern phoebe (Sayornis phoebe) may use an inside corner of a patio overhang as a site that is conveniently accessible from outside.

Purple martins (Progne subis) living east of the Rocky Mountains almost exclusively nest in homes provided by people. The hanging gourd nests can be seen in fields but nowadays other types of plastic constructions are also used.


In order to attract barn owls (Tyto alba) back to areas where many traditional barns have been razed, people are also placing special boxes in fields with plenty of open space in front of them so that the owls will have a hunting territory adjacent to their front door. Made of heavy plastic, these boxes may be monitored by organized groups in an effort to document their use.


At the Mason Farm Biological Reserve, an eagle scout project involved bringing in cranes to attach very large nest boxes to the tops of trees for barred owls (Strix varia) – so far, I have only seen Eastern gray squirrels making use of these nests.

And then there are the nest boxes that people put up to attract Eastern bluebirds (Sialia sialis), brown-headed nuthatches (Sitta pusilla) and screech owls. In my yard, other birds use these boxes, too, including the Carolina chickadees (Poecile carolinensis) such as my one-legged,  banded friend Chantal, Carolina wrens (Thryothorus ludovicianus) who may puzzle about how to get a long twig into the box and house wrens (Troglodytes aedon), who pile up twigs in a rather untidy stack inside the box.



Chickadees construct lovely mossy nests lined with hair, fur or plant fibers.


The nuthatches have nests with bark strips.


Sometimes people will intervene when a nest is in danger. A Carolina wren put her nest into a boat at Cane Creek Reservoir that was rented out to people and keeping the nest there was not a good option as she would be missing her nest for hours when the boat was gone. The land manager was so kind as to relocate the nest into a tree right in front of the boat’s resting place; unfortunately, inclement weather caused the nest to dislodge that evening.


Another danger may also threaten the birds and their nests – predators. A friend and I found it unusual to see a tree swallow (Tachycineta bicolor) putting a nest in a bluebird box on the edges of a farm. Several days later, we saw a black rat snake (Pantherophis obsoletus) peering out of the box and the swallows were nowhere to be seen.


If you can manage to mount your boxes on poles rather than trees, put both squirrel and raccoon baffles on them and also place them away from overhanging branches, they should stay relatively safe from the squirrels, snakes and raccoons. Next up: birds’ nests with no human connections.



The beautiful “baker” bird

Recently, I’ve had the good fortune to observe a small bird at close quarters that I had only seen in a couple glimpses in the past, the ovenbird (Seiurus aurocapilla). Like the ruby-crowned and golden-crowned kinglets, this little avian also has a stripe atop its head. Like the golden-crowned kinglet, the stripe is always visible and orange in color, blending in nicely with its other muted brownish and cream colors.


The ovenbird gets its name from the shape of its nest, which is built on the ground in a shape reminiscent of an outdoor or Hopi oven. It is domed and has a side entrance and can be difficult to see.

The ovenbirds spend the winters in the Caribbean region and Central America and then come North for the summer breeding season. My sightings of the singing male have been at our local nature reserve, Mason Farm Biological Reserve, where I volunteer as an invasive plant eradicator and sometime planter of native flowers.


The male sings a three- to-five note call in the spring as part of his courting behavior and the call varies among individuals. When males are in neighboring territories, they will sing together in duets and it can be difficult to know how many birds are singing.


The sound is so loud that you expect to see a much larger bird and his song inspired poet Robert Frost to dedicate a poem to him.


If he is sitting on a branch, you can eventually find him but it can be a challenge since they prefer to reside in forests with heavy canopy cover so that it is fairly dark.



Once you see him, you may be able to watch for a while as they don’t seem to be very wary of people. This individual let me observe as he groomed on a low tree branch, pausing now and again to let out a few notes.



These birds prefer areas with heavy leaf litter for their homes – the leaves provide cover for their ground nests and they blend in really, really well as they scurry about foraging in the leaves for insects, worms and snails to eat. Both the females and males participate in feeding the fledglings until they can fly at about 30 days.

When they emerge into a patch with a bit of sunlight filtering down through the leaves overhead, you have a bit better chance to see them. Otherwise, you may end up staring at ground cover until you catch a bit of movement and can zero in on the motion to see them.


Photographing the bird is a challenge since they spend their time in areas with so little direct light. My first photos were a bit dark, but then I increased the ISO on my camera considerably (a tip from fellow photographer, Mary – thanks!) and the photos were a bit better. Still, the somewhat darker photos reflect the environment in which you discover these little troubadour warblers. Now that I know where to look for them, I hope to see them more often in years to come.

Pulling privet, banishing buckthorn and mimicking Mother Nature

The (somewhat) varied life of a Mason Farm Biological Reserve volunteer


Today marks the third anniversary for my work as a Green Dragon – volunteers who help maintain the 367-acre Mason Farm Biological Reserve in Chapel Hill, North Carolina. On Tuesdays, a small group gathers to carry out tasks assigned by Neville, who is the Land Manager for this and two other preserves managed by the North Carolina Botanical Garden/UNC.


Neville, string-trimming Japanese stiltgrass (Microstegium vimineum)

winter-wren-i77a8901-maria-de-bruynWhile we work, we can listen to the songs and calls of lovely birds, like the winter wren (Troglodytes hiemalis), and if we’re lucky, we can see wildlife like painted turtles, raccoons, opossums and coyotes (Canis latrans).







Being outdoors and helping keep the Reserve a peaceful and beautiful area for research and enjoyment of the natural world provides me with a feeling of civic contribution, as well as satisfaction, chances for discovery and learning, and well-being. So I’d like to share with you a bit of what we do in a lengthier blog than usual.

sign-img_0076-maria-de-bruyn-res sign-dk7a2339-maria-de-bruyn-res

wisteria-cutting-img_0427-maria-de-bruyn-resOne of our major tasks is helping make a dent in the eradication process for invasive plants. Some have found their way to the Reserve through natural dispersal mechanisms (seeds carried by the wind and wildlife), while others were unfortunately introduced by humans who didn’t know at the time just how destructive the plants would become in overshadowing native vegetation. Cutting down Chinese and Japanese wisteria vines (Wisteria sinensis, W. floribunda) is a recurrent job.

Some invasives are really beautiful and it’s easy to see why they are still sold in some garden shops, like oriental bittersweet (Celastrus orbiculatus) and porcelain berry (Ampelopsis glandulosa); they are really attractive plants – nevertheless, we remove them when feasible. Autumn and thorny olive (Elaeagnus umbellata and E. pungens) are two others that grow as vines or shrubs.

oriental-bittersweet-8-oriental-bittersweet-img_5343m-de-bruyn-signed   porcelainberry-img_0739-2maria-de-bruyn

buckthorn-i77a2455-maria-de-bruyn-signed-resAnother botanical foe is buckthorn (Rhamnus species), a shrub which can grow into a small tree when unchecked. It has nasty thorns which can pierce clothing and shoes and when it gets older and larger, a weed wrench and extra manpower may be needed to get it out of the ground. On the other hand, pulling up the “baby” buckthorns, especially after rain, can be much easier, though unkind work for your back.


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Volunteer Pete wields a weed wrench; the small buckthorns can be pulled by hand

marbled-salamander-img_3320maria-de-bruyn-resWhen digging holes into some areas, you may come upon salamanders – this female marbled salamander (Ambystoma opacum) was guarding her eggs when we uncovered her (and quickly covered her again).

The buckthorn produces prolific black berries which are a great favorite of the cedar waxwings (Bombycilla cedrorum) – flocks will descend to enjoy the sweet treat.

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The cedar waxwings also really like privet (Ligustrum sinense and L. japonicum), which produces numerous black berries a little smaller than the buckthorn. The privet also produces many offspring but when they are very young, they are quite easy to pull up. The privets that grow into trees, however, pose the same challenges as the large buckthorns, calling for multiplied manpower to extract them from the ground and resulting in exhaltation when success is achieved.

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While working on invasive eradication, we often come upon smaller wildlife, like American toads (Anaxyrus americanus, formerly Bufo americanus), bullfrogs (Lithobates catesbeianus), green and gray tree frogs (Hyla cinereal and H. chrysoscelis/versicolor), spring peepers (Pseudacris crucifer) and rat snakes (Pantherophis obsoletus).

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The many brush piles dotting the landscape in the Reserve, both in wooded areas and fields, are the result of our labors – providing birds and small animals with ready-made homes and hiding places.


Volunteer Giles and Neville pile up privet and buckthorn

A second major task is planting native plants in various areas of the Reserve – seedlings and young plants are provided by the Botanical Garden and Land Manager and may include flowering species such as Hibiscus and cardinal flowers (Lobelia cardinalis), fruiting shrubs like common elderberry (Sambucus nigra Canadensis), and varied grasses.

grasses-are-hollow-img_0274maria-de-bruyn-signed-res   planting-img_0217maria-de-bruyn-res

bill-resting-sore-back-img_0284maria-de-bruyn-signedWhen we do this in summer, the temperatures can get quite high early in the day; water breaks are welcome, as shown by Mason Farm Green Dragon supreme – Bill, who has been volunteering since 2004!

We put in flags to mark the new plantings in case they will need some watering to thrive. When the weather is hotter and drier, watering takes place right away to give the young vegetation a better chance at survival. It’s a real pleasure to see the plants take hold and flower!

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flame-i77a0237-maria-de-bruyn-resSome plants are fire-dependent, meaning their environment must be burned with some regularity if they are to survive and thrive.

Prescribed burns are therefore done at Mason Farm to mimic the natural fires which took place centuries ago before development took over many areas. Woods and fields are burned every few years and great attention is paid to the weather, taking care that no high winds are predicted that could carry embers far away to start fires in unwanted areas. The Green Dragons helped clear fire lines last week for a recent burn – raking away leaves and twigs and bark from areas where the fire will normally die out.

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neville-i77a0232-maria-de-bruyn-resMembers of the fire team receive instructions on their roles – the fire starters ignite the leaves and grasses in stages, pausing to see how fast the fire is moving and how the wind is blowing.



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Several people will serve as spotters, watching the fire lines to ensure that any escaping embers are put out and some team members clear areas around trees and snags that will be protected against burning (e.g., because they provide homes for woodpeckers).


Where the leaf litter is not 100% dry, some areas will burn and others will remain untouched.


Dry grasses can catch quickly and the spreading fire generates intense heat as the flames spread rapidly across a field.

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broad-tipped-conehead-katydid-neoconocephalus-triops-img_1403-maria-de-bruyn-resMy concern is always that not all animals will make it out in time. Fellow volunteer Giles spotted a broad-tipped conehead katydid (Neoconocephalus triops), which he carried to a safe spot. I hope that the Eastern box turtles (Terrapene carolina carolina) have dug down deeply enough to be unharmed by the spreading fire. We saw grasshoppers and bugs fleeing the field being burned this past week and I was happy to see a pair of hispid cotton rats (Sigmodon hispidus) rush out.

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After the fire is mostly burned out, the team walks the edges to tamp out still burning places. The next day, the woods and field look mostly gray, black and sere but experience has taught me that in a few weeks they will begin turning green again.

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There is one more task we carry out which is less frequent but also important – aiding in construction and some clean-up in the Reserve. When funding was received for a boardwalk to make a bog area more accessible after rain, volunteers associated with the Botanical Garden and New Hope Audubon Society as well as Green Dragons built the sections of the board walk, transported them to the site and installed them.

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flooding-img_1936-maria-de-bruyn-resVisitors were very happy with the new walkway but it turned out that the flooding which occurs when Morgan Creek overflows its banks with heavy rains can sometimes be strong enough to lift up boardwalk sections, necessitating repairs. When funds are available, a new solution will be sought to hold the boardwalk more permanently in place.


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The researchers who make “temporary” structures when conducting their studies (e.g., bird blinds, platforms, etc.) unfortunately do not always remove these when their research is done. When time permits, we have helped clear away some of this garbage. We also helped repair a sign and the entry road and parking lot after flooding.

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Our volunteer crew is usually a small group of retired persons and a couple students (2-5 people). We’d love to have more people join us so we could get more done and have more input for our conversations covering a range of topics such as botany, geology, wildlife observation, music, sports, travel and current events. The volunteer time of Tuesday mornings unfortunately rules out people who have jobs requiring their presence there on weekdays but we remain hopeful that new volunteers will join us. If you live in the local area and are interested, contact the volunteer coordinator at the NC Botanical Garden!