Sunday, January 3, 2010

Creepers and Tiny Owls

Recently, I've not only purchased new eye-glasses (all the better to see the world!), but I've learned how to find the tiny Brown Creeper that lives near here. Friends have spotted them in the trees around the block and finally right here in my yard. I'm tickled pink...

The creeper is small (5.25" long), smaller than a House Finch (6" long) and not much bigger than an American Goldfinch (5" long). By contrast, an American Robin is huge; twice as large (10" long) and much heavier.

My friend and CBC leader, Dave Silverman, tried to teach me the call of this bird...but it is so high and so feint, even with my good hearing I had a hard time making it out. Reading about the bird I've learned the phonetic version is: "tseeeeeeee" or "see-see-titi-see"... a rather musical song of four to nine high, clear notes. It's a good idea to listen to calls online, where you can really listen to them. This makes it much easier to identify the call in the field. Just Google 'Brown Creeper Sound' and you'll find lots of examples and tons more information on this fascinating little bird.

I have finally started an early Christmas present; Small Mountain Owls" by Scott Rashid. What a treet! Scott tells in great detail his experiences with all four of the tiny owls that live and breed in the Rocky Mountain National Park, near where he lives. I had no idea owls could be so small; the Northern Pygmy-Owl is but an inch longer than a Brown Creeper!

This Northern Pygmy-Owl may be tiny, but it is fearsome! While most active at dawn and dusk, it is often seen during the day. The scientific name is Glaucidium gnoma; and is why he calls it the Gnome of the Forest. As you might see, this little bird has shorter wings and a much longer tail than do most owls. Not unlike a Sharp-shinned Hawk, this enables it to hunt in dense woods. Because this little owl hunts during the day, there is no reason for it to have the silent flight like other owls...and it doesn't; it lacks that special wing-feathering. Scott tells its flight is a direct, undulating burst of rapid flapping and short glides not unlike a woodpecker and that when it lands a hard-hitting 'thud' is heard. The little bird has tiny ear tufts that it can raise and lower which help to break up its silhouette and adds to its spectacular camouflage. Dark 'false-eye' spots on the back of the head also help keep the bird safe. They hunt smaller rodents and birds, but often capture and feed on creatures larger than themselves.

Scott also discusses the Flammulated Owl (6.75") and the somewhat larger Northern Saw-whet (8") and the Boreal Owls (10").

The Flammulated Owls are unmistakable with dark eyes, ear tufts and equally tiny size. However, this owl is extremely nocturnal and is almost completely inactive during the day. Unlike other owls, these are nearly entirely insectivorous, hunting mostly crickets, moths and beetles; an activity that forces them to migrate south to Mexico or further every fall. Unmistakable, but extremely well camouflaged; this little bird is a vermiculated-gray or brownish (not unlike a nighthawk) and blends completely in dense vegetation or against the trunk of a tree. It was once considered rare, but improved methods of counting has proven it to be quite numerous. It is the most abundant owl of the mountainous pine forests.

Northern Saw-whet Owls may be more numerous than other small owls and live throughout parts east, central and western North America. They are entirely nocturnal and highly migratory, are superb hunters of mice and sound remarkably similar to Northern Pygmy-Owls. While fairly common, these bull-headed, short-tailed owls are infrequently detected. They have no ear-tuffs; their defense mechanism is to sit completely still...sometimes making them seem almost tame.

Boreal Owls, while similar to Northern Saw-whets, are larger (~10"), have pale bills and are somewhat darker in color. They may be numerous, but like many owls are seldom seen; favoring dense forest and being nocturnal creatures. Their song is surprisingly like Wilson's Snipe. These owls are mainly sedentary and in winter time, roosting birds are quite approachable.

The Western Screech-Owl (below), is also found in this part of the country, but apparently doesn't nest where Scott does his research. It seems to be found even more westerly, though from Alaska through Central America. It is nonmigratory and found in western woods and riparian zones in arid country.

This little gray owl (8.5"), while similar to the Eastern version has distinct differences; the bill is dark and it has prominent vertical breast streaking.

It astonishes me to know there are even smaller owls that live south of where I am in Southern Colorado.

The Whiskered Screech-Owl (for which I have no photographs), is just over 7' long and otherwise much like the Western Screech-Owl...though with noticeable whiskers. This little owl lives in southern Arizona and Mexico and at higher elevations than the Western. This is a nocturnal owl with ear-tufts, yellow eyes and unusually small feet.

The Ferruginous Pygmy-Owl, just over 6" long, is similar to he Northern Pygmy-Owl though their range and habitat differ and seldom overlap; and the Ferruginous prefers a lower altitude. It has the unmistakable long tail and small size and dark eye-spots at its nape, but is more streaky than spotted. This is a stocky little owl with disproportionately large talons. While numerous in the southern American tropics, it is uncommon in its northern ranges of Arizona and Texas, where it prefers mesquite groves and low riparian woods. While most active at dusk and dawn, this owl often hunts during the day. This bird may be declining due to wildfires and urban sprawl.

The world's smallest owl is the Elf Owl, is also found in the Sonoran Desert, where it often nests in saguaro cactus, and in open, dry woodlands where it nests and roosts in tree cavities. The little gray-brown owl has pale yellow eyes accented by white 'eye-brows'. It has no ear-tufts. It is nocturnal an feeds mostly on insects, including scorpion. This little owl is just 5.75" long ...about the size of a Brown Creeper! Who knew an owl could be so small?



eileeninmd said...

Cool post, I love the Brown creeper. It was nice reading about the different little owls. They all be neat to see in person. That is could find them, they are so small.

Beverly said...

Thanks Eileen! I like the little creepers a lot; but am absolutely wowed by these tiny owls. I've only seen very large owls; it would be awesome to find some of these little ones.

Seems to me we may be able to hear them soon...doesn't breeding start these next couple months?

Thanks for stopping by!