the flower picker

I remember sitting in the dark before dawn near some feeders in southeastern Arizona two years ago, just to catch a glimpse of a rare visitor to the area, the Streak-backed Oriole.  After 3 hours we did catch just a brief glimpse of “the bird” (there was only one).  Now two years later, I find they are common in this part of Mexico, and seem to like to enrich their fruit diet with a few flowers (perhaps containing nectar) plucked from various vegetation.

Streak-backed Oriole, Jalisco, Mexico

This bird was exploring the purple Jacaranda flowers, pulling them off the tree at random. Note the streaks along its back behind its head. Well-named bird!

Streak-backed Oriole, Jalisco, Mexico

Another oriole attacked the much larger flower of a banana plant. Perhaps it was attracted to the large red sheath at the base of the banana bunches.

Streak-backed Oriole, Jalisco, Mexico

The bird pecked at several places on the flower, but didn’t seem to find much.

Streak-backed Oriole, Jalisco, Mexico

And off he went…with some part of the plant grasped in his toes.

Like most Orioles, males of the Streak-backed variety are the most colorful, with females being considerably duller and less orange.  However, the species ranges from northern Mexico (occasionally venturing into southern Arizona) where the two sexes are completely different in color, through most of Central America, where the two sexes become more and more similar in coloration going south.

Why would there be such a difference between coloration of females from the northern vs southern extent of their range?

Apparently, Streak-backed Orioles maintain permanent territories year-round in the southern part of their range, where the bright coloration of the females helps territory defense.  In more northerly areas, the orioles maintain only a breeding territory, and may undergo short migrations away during the non-breeding season!

the good provider

It’s springtime, and romance is in the air — males showing off their physical prowess and gaudy colors, females watchful and discerning.  One of the rituals of springtime courtship among some bird species involves the male bringing some delectable, nutritious food to his female.

courtship feeding-lilac-breasted roller

The male Lilac-breasted Roller (on the right) presents his female with a small insect. (Photo shot in Botswana in October 2015)

northern shrike-courtship food

Northern Shrikes impale their prey on a sharp object like thorns or barbed-wire fences. This male shrike is leaving his gift of a fresh vole for his intended mate.  (Photo by Marek Szczepanek)

Why do some male birds do this?  Is it to show what good providers they will be for their offspring?  Is it to further cement the bond between male and female, like human males might gift their sweeties with jewelry, roses, or candy?  Or is it really an important part of their pre-nesting behavior, to increase the food/energy intake of females that will shortly undertake big expenditures of energy laying eggs and incubating them for long periods of time.  Courtship feeding might be important for all of these reasons, but most likely it has evolved in those species for which the energy demands of reproduction are particularly high in the female.

northern cardinal-

Northern Cardinal males keep a close eye on their females, and offer them tidbits of sunflower seeds, even though the female is sitting right there next to or on the feeder.

northern cardinal female-

He’s looking at her (above), and she’s looking at him, wondering what he will bring her next.

I missed the actual feeding because the pair darted behind the leaves, but it looks like this.

cardinals-Rudiger-Merz

Photo by Rudiger Merz

northern cardinal-

Females have the luxury of choice, so this male has to not only be good-looking but savvy at providing food.

Courtship face-off

Male Brown-headed Cowbirds have been engaging in courtship display in the backyard this week.  Interestingly, they seem to display to each other in order to entice females closer.  This is sort of like the multiple male displays one sees at a grouse or prairie chicken lek (see my earlier post on this), and serves a dual purpose of stimulating males to perform, while giving females a chance to compare their performances and choose the “best” male to fertilize her eggs.

The sequence of alternating displays begins with first one bird and then the other puffing up, spreading wing and tail feathers and bowing to the other bird while emitting a blackbird-ish, high-pitched call note.

male cowbird courtship display-

Bird on the right begins the sequence…

male cowbird courtship display-

male cowbird courtship display-

male cowbird courtship display-

Back to neutral, bill up position…

male cowbird courtship display-

Male on left displaying in bowed head position…

male cowbird courtship display-

Another male pops in between the two displaying males — will this exhibition be a trio?

male cowbird courtship display-

I’m not sure if this is a threat display by the left-most male, but it doesn’t continue with the bow, and the middle bird took off quickly.  (Females are grayish, with some faint striping on the breast feathers.)

male cowbird courtship display-

Leaving the two original males to continue their dance…

The short video clip below by Bradley Yee illustrates the sequence of displaying male Brown-headed Cowbirds very well.