Midwest Avian Foundation

Today is International Ear Care Day, and we’re going to look at one of the things that make owls so special: their ears.

Owls ears are not those feather tufts that stick up from the tops of their heads: those are just feathers. Their ears – like the ears of all birds – are merely holes in the sides of their heads. But owl ears are asymmetrical; one ear sits higher than the other.

This, combined with another feature, gives owls the ability to hunt exclusively by sound. That other feature? Their eyes.

Or, rather, the feathers around their eyes. These feathers form large circles around each eye, and they perform the same job as our ear-lobes do: to funnel the sound to the ears.

Here’s how it works: a mouse moving through the grass makes a rustling sound, and those sound waves spread out until they meet the owl’s face. The feathers around the eyes (“facial disks”) bounce those sound waves toward the ear on the same side of the face.

But since the ears are off-set, depending on the direction from which the sound came, the sound waves will reach one of the two ears more quickly (as in micro-seconds) than the other. If the owl turns its head from side to side, the timing of when the sound waves reach each ear will change – this allows the owl to fix the position of the origin of the sound.

Barn owls are exceptionally good at this and laboratory experiments have proven that they can successfully locate and catch their prey with no light at all!

Hooray! Let’s “ear” it for owls!

We’re at the end of National Invasive Species Awareness Week, and today we’re going to look at a species you probably see every day: the European starling.

These birds were intentionally released in a number of places throughout North America, but one of the most common stories is that the president of the American Acclimatization Society, Eugene Schieffelin, introduced 60 starlings into New York’s Central Park in 1890. It is rumored that he intended to introduce all bird species mentioned in the works of William Shakespeare to North America, but we don’t really know for certain.

What we do know is that, since then, the number of European starlings in North America has grown to an estimated 150 million. They can be found from Alaska and southern Canada all the way down to Central America, and from the east coast to the west. They’re everywhere.

These noisy birds can be found in all areas: wilderness, agricultural, suburban, and urban environments. The build rough nests of sticks or stems in any sort of hole: large business signs, cracks in walls, under eaves, on cliff faces. They are omnivorous, eating anything, including garbage; they often contaminate more than they consume. When they gather in large numbers, their droppings can accumulate.

They tend to be territorial during breeding seasons, but in the winter they will congregate into massive flocks that may number up to a million birds. These large flocks of birds sometimes form what’s called a murmuration – an aerial display in which the birds engage in complex and synchronized patterns. The flock appears to move as a single unit, expanding and contracting, flowing back and forth. It may serve to deter predators or even as sharing information on roosting sites.

There isn’t a lot anyone can do about invasive starlings. They are too numerous and too well-established. At most, you can prevent them from nesting on your property or destroy their nests if they do – just be sure it is really a starling nest and not one belonging to a native species.

Thank you for joining us this week for a look at some of the invasive species found in Kansas! We hope you found our posts informative and educational.

For more information on invasive species, visit the North American Invasive Species Management Association (NAISMA) at https://naisma.org/

Today’s invasive species is the Chinese bush clover. It’s a flowering plant in the legume family native to Asia. It is a perennial plant – meaning it regrows every year from the same root.

Chinese bush clover was intentionally introduced in North America in an attempt to control erosion and generate food for livestock. But this plant is suspected of being allelopathic, which means it produces biochemicals that can impair the growth of other plant species. When the plant species in an environment become less diverse – perhaps because this plant is crowding out other species – the area becomes less desirable for native wildlife.

Economically, this can increase the costs of managing the affected land. While cattle are not particular fond of the fresh plant, sheep and goats will readily chow down. However, since cows will consume other plants rather than this when grazing, using this method in an attempt to halt the spread will actually achieve the opposite.

While this isn’t a plant you are likely to find in your front garden, it can appear in native hay fields. When present, hay should be harvested before the plant begins to bud in mid-July; as it dries, the chemicals that make it unpalatable for cattle decay and it can result in high-quality hay. About six weeks after harvest, an approved herbicide can be applied.