Brown-headed nuthatches – examples of conscientious and industrious parenthood!

IMG_3634©Maria de BruynLast weekend, when walking the woods along Jordan Lake in order to write a blog for the NC Audubon Society, I happened upon a thin dead tree standing in the water at the shore’s edge. Just then as I was looking it up and down, a brown-headed nuthatch (Sitta pusilla) flew up and made its way down the trunk to a hole where it obviously had a nest. That was a treat and I watched the mom and dad fly to and fro with provisions for the brood.

Yesterday, I decided to return and see if the industrious pair was still working on meals for their brood. They were indeed and I watched for quite a long time, wondering how they could see anything down in the nest where it has to be pretty dark.

brown-headed nuthatch IMG_3690©Maria de BruynresThese lovely little birds are native to the Southeastern US and there is a small population in the Bahamas; they don’t live in any other countries so they really are kind of special. In addition, since 1966, the population has declined by 45% because they are losing nesting habitats (dead and pine trees) to deforestation and urbanization.

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The parents were most often alternating their meal runs, but occasionally they would arrive simultaneously or very close in time. They would usually alight on the trunk above the nest hole and then work their way down – they can descend head-first, which is a handy trait.

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Occasionally, though, they would alight right by the hole or work their way upwards from a little further down the tree trunk. They seemed very concentrated on their task but I learned that they were definitely keeping an eye on me because when I took up a position a bit closer to the tree for some better shots, they just hopped about in other trees waiting for me to step back again. Which I did, of course.

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Though I didn’t witness it, these small birds are tool-users, sometimes using a piece of bark to pry up tree bark in search of insects; they may even carry the tool with them. They certainly were bringing their babies varied meals, including moth caterpillars and insects of various kinds.

IMG_4164©Maria de BruynThese parents were fastidious, too, removing fecal sacs from the nest with some regularity. I had hoped to see these birds in action when using a nuthatch box I put up in my yard, but a pair of Carolina chickadees (Poecile carolinensis) are currently raising a brood there.

 

 

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The nestlings fledge after about 18 days so I may be too late to see anything when I return sometime this coming week, but it sure would be cool to see them leave the nest!

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So, you may ask – what happened to the blog on springtime creatures I announced last time? Well, the various birds species are working so hard and demonstrating their parenting skills so nicely right now, I decided to focus on that for a little while! Next time – those squatter Chickadees in my yard!

Owls – raptors with fantastically functional feathers

Barred owl IMG_9617© Maria de Bruyn resThe owl is the wisest of all birds because the more it sees, the less it talks. – African Proverb

The world likes to have night-owls, that it may have matter for wonder. – German proverb

Sayings about wise owls are well known and may account for the names given to a group of owls – a wisdom, study or parliament. On the other hand, in some cultures, owls are associated with bad luck, death and the stealing of souls. Owl fossils date back as far as 58 million years ago! These appealing birds have been depicted in in cave paintings in France, in Egyptian hieroglyphics and in Mayan art. There are about 200 species of owls around the world and they are found on all continents except Antarctica and a few remote islands.

Owl anatomy

Barred owl eye feathers IMG_9802©Maria de BruynresOwls have interesting anatomical features. Like humans, they have binocular vision as a result of their upright posture and forward-facing eyes. A circle of feathers around each eye, as seen in the barred owl  (Strix varia) here, can be adjusted to focus and channel sound to their ears (which are asymmetrical in many species!). These feathers can magnify sound as much as 10 times, giving them acute hearing.

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Like bald eagles, owls have three eyelids: one is used to blink, another for sleeping and the third – the nictitating membrane – helps them keep their eyes clean and healthy. Because they cannot turn their eyes within their bony eye sockets, owls must rotate their heads up to 270 degrees to look around. They are far-sighted and cannot see clearly right in front of their eyes, but their distance vision is very good, especially in low light.

Barred owl IMG_9117©Maria de Bruyn resOwl feathers have fringes with different degrees of softness, which helps muffle sound when they fly.

Screech owl IMG_3069©Maria de Bruyn resSome owls, like the Eastern screech owl (Megascops asio) have tufts of feathers on their heads; the function of these might be to indicate a bird’s mood, to show aggression or to help keep the bird camouflaged.

Screech owl rehabilitated by CLAWS that serves as an educational bird

Behaviors

Different owl species make different sounds for finding mates or announcing their presence to potential competitors. These sounds help ornithologists and birders locate and identify species.  For example, the barred owl is said to have a call that sounds like “who cooks for you?”

These carnivorous birds usually swallow their prey whole (depending on the size of the animals such as fish, mice, rats, hares). Scientists who study their diets use owl pellets as an aid; the owls regurgitate bones, scales and fur in these pellets. The larger owls will also detach body parts they don’t wish to eat. For example, colleagues speculated that it was a great horned owl (Bubo virginianus) that took down a red-tailed hawk (Buteo jamaicensis) at a local nature reserve recently, leaving behind an entire wing that wouldn’t have provided much nutrition.

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Great horned owl rehabilitated by CLAWS in Chapel Hill, NC. This bird was shot in the eye and cannot be released again; it serves as an educational bird.

The main threats to owl survival today include habitat loss, pesticides and human predation due to negative superstitions. There are fortunately efforts to preserve owls where they may be seen as beneficial. For example, a barn owl may eat up to 1000 mice each year, so that farmers try to attract them to help control rodents in agricultural fields. Projects to re-introduce barn owls (Tyto alba) are taking place in the Czech Republic and the United States. The local Audubon Society to which I belong has a barn owl project, in which they have placed barn owl nest boxes in various places in an effort to attract these birds as more permanent residents. It would be very cool to see the boxes occupied one day!

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Check out CLAWS, a wildlife rescue and rehabilitation center in North Carolina! http://www.nc-claws.org/