The Northern mockingbird boundary dance

In between searching the web and bird guides for plant and other IDs for my (long-time coming, I know!) next Costa Rica blogs, I’ve taken time for nature walks so that I can continue to see lovely wildlife and plants here in my home area. A recent discovery came up unexpectedly when I was with a couple friends looking for migrating warblers at a local lake.

Previously, I’ve written about how Northern mockingbirds (Mimus polyglottos) engage in wing-flashing behavior, which scientists continue to study in an effort to pinpoint its various functions. I’ve seen the wing-flashing every year since I began watching the mockingbirds, but a few days ago I saw a pair of mockers exhibiting a different type of behavior that was very interesting to watch. (If you click on a photo, you can see it larger.)

The two birds landed on a section of parking lot and proceeded to face off against one another.

They slowly drew closer.

Then they stretched to stand very erect.


They confronted each other face to face.

 A little hop by one or the other followed. A shifting from side to side ensued.

Occasionally, they flew up with flapping wings to confront one another in the air (I tried to video this but obviously don’t know yet how to take proper videos with my new camera). According to research, they might actually have an airborne physical tussle but that didn’t really happen with this pair.

So why do the mockingbirds do this? These displays are called boundary dances, where male birds go to the edge of the territory they claim to ensure that another male does not encroach on their domain.

After several confrontations, this pair eventually decided that they had made their point. It has been reported that they stop when one dominates but these males seemed evenly matched. Or perhaps they were not feeling very aggressive. Each one flew off and presumably they settled in to patrol the areas that they had claimed as their own. It was nice that there was a peaceful end to the show of masculine bravado!

Going out in nature is such a delight – you never know when you will discover something new (at least to yourself!)

Russet-colored shorebird beauties – feminists among the waders!

ruddy turnstone IMG_8605©Maria de Bruyn resOne of my favorite shorebirds is the small sandpiper called a ruddy turnstone (Arenaria interpres). Their coloring is a mix of black, white and reddish colors, with adults being more brightly colored when mating and breeding.

These birds are very territorial during the breeding season; they recognize variations in plumage patterns and can identify individuals, which helps them chase away intruders into their territories. Pairs are monogamous when breeding and may mate for several years.

ruddy turnstone IMG_0329©Maria de Bruyn resruddy turnstone IMG_8596©Maria de Bruyn res

ruddy turnstone IMG_8651©Maria de Bruyn resWhen they fly, a stunning pattern is revealed in their spread wings, with striking white patches and bars.

The name turnstone comes from the fact that the birds tend to turn over stones while foraging for insects, crustaceans, worms and mollusks. Several birds may cooperate to overturn larger rocks. This carnivorous diet is supplemented with moss, fruit and berries. Occasionally, the turnstones have also been seen to prey on the eggs of other birds but this behavior appears to be uncommon.

ruddy turnstone IMG_0337©Maria de Bruyn resruddy turnstone IMG_8654©Maria de Bruyn res

They search for their food on rocky outcroppings, among stones, in sand and the ground, inserting their bills into the earth or flipping over seaweed to find meals hidden there.

ruddy turnstone IMG_8629©Maria de Bruyn res ruddy turnstone IMG_8619©Maria de Bruyn res

ruddy turnstone IMG_8782©Maria de BruynThese small birds breed in Northern arctic and tundra regions and then migrate South in the winter, quite often returning to the same wintering grounds each year. Their chicks leave the nest within hours after hatching and abandon the nest within a day. It is the males who take on the major childrearing tasks, guarding the territorial perimeters and warning the female when predators (owls, merlins, gulls, foxes) are near. They also show the young fledglings where to find food after the females have left to pursue other activities.

Outside breeding season and during winter migration, the birds are quite sociable. They have been seen preening and grooming for long periods.

ruddy turnstone IMG_0284©Maria de Bruyn res ruddy turnstone IMG_0305©Maria de Bruyn res

ruddy turnstone IMG_0278©Maria de Bruyn resruddy turnstone IMG_0317©Maria de Bruyn resruddy turnstone IMG_0206©Maria de Bruyn res

The populations of ruddy turnstones are fairly stable and they are not threatened at this time – good news for the bird lovers among us!