Another misplaced migrant

Earlier this winter, I commented on what I thought was a case of misplace migrants when I saw a juvenile Yellow-bellied Sapsucker in my Minnesota backyard. Similarly, among the bevy of birds that crowded into the feeders in the past couple of days was an unusual one — unusual to see at this time of year at any rate.

chipping sparrow in Minnesota in January

I tried hard to make this little bird into a Tree Sparrrow, imagining that black fleck in the middle of its breast was the tell-tale spot of a Tree Sparrow. But the facial markings are the wrong color for a Tree Sparrow.  Instead I think it is a misplaced, non-migratory Chipping Sparrow.

It turns out the confusion over which species of sparrow one is seeing in the winter is not uncommon — for two reasons:  first, among northern-breeding bird species, some juvenile and even adult birds apparently do not always migrate (which might be a fatal mistake); second, some birds find the opposite sex of a different species more attractive than their own, and produce hybrid offspring that share some of both parents’ characteristics. So what is going on here with this supposed Chipping Sparrow?

Tree Sparrows and Chipping Sparrows are two of the seven species of Spizella in North America.  But…The two species are not supposed to be found in the same places in winter. So is this a case of failure to migrate?  Has this bird been here all winter, toughing out the frigid conditions when it could be basking in the warmth of Floridian sunshine?

chipping vs tree sparrow range maps

Tree Sparrows are the typical bird found in the northern U.S. in the winter, while Chipping Sparrows winter much further south, in Texas, the southeastern U.S., and Mexico.

The two species do look similar, except for a definite chestnut streak behind the eye in Tree Sparrows and a black one in Chipping Sparrows.  Tree Sparrows are somewhat bigger in body mass, although not necessarily longer in head to tail length and possess a definite central black breast spot.

chipping vs tree sparrow plumage

Photo from Project FeederWatch, sponsored by the Cornell Lab. Chipping Sparrows apparently are increasingly found north of their traditional winter range according to this website.

Tree Sparrows have a bi-colored bill, yellow lower with gray/black upper parts. Breeding adult Chipping Sparrows have a solid black bill.  Is my backyard visitor some kind of hybrid, with its bi-colored bill and faint central breast spot?

chipping sparrow in Minnesota in January

Black central breast spot is less obvious in this shot.  It was difficult to get a decent shot of the bird on a gloomy, gray day.

Well, it turns out that Chipping Sparrows only show the solid black bill during the breeding season, and it is, in fact bi-colored during the non-breeding season.  In addition, Chipping Sparrow breast plumage is somewhat variable, and some individuals do show black spotting.  So I assume this is not a hybrid product of cross-species interactions, but is in fact, a misplaced migrant (or it failed to migrate).

Which just leads me to wonder why, if migratory species can, in fact, survive harsh winters like this, why do they bother to migrate where they have to crowd in with the already established resident birds?  Do all the backyard bird feeders enable seed-feeding birds to remain in their breeding areas all year?  Is this an example of the effect of climate change (hard to think of warming in the middle of a Minnesota winter!) on bird distributions?

Tough choices…

Last year, I posted a look back at some of the best photos of 2013, and thought I might try that again this year. I managed to pare down the initial 63 selected photos of just the MN and CA backyard birds to the top 10 by making some tough choices.  Reasons for their selection are listed below the photo, but I would be interested to know if blog readers agree.  Which one of these is your favorite?

juvenile barn swallow

A juvenile Barn Swallow waiting patiently to be fed.  This one projects a lot of personality.

black-crowned night heron

A Black-crowned Night Heron fishing on Lake Temescal in California.  I picked this one for the nice reflection of the heron in the water below.

canada geese flying

Canada Geese on the move on the Mississippi River in the spring.  Action shots are more interesting to me.

cedar waxwing on hollyhock

Cedar Waxwings are such handsome birds, with their yellow and red accented feathers and black mask. I liked the composition of this photo, even if we can’t see the bird’s handsome facial markings.

cowbird chick begging

A cowbird chick begging for food from its foster parent, the much smaller Chipping Sparrow. This photo “begs” to be captioned. I’ll leave it to readers to make suggestions.

mallards at sunset

Three (Mallard) guys communing with nature at sunset. I picked this one for the color, and the symmetry of the three ducks. This was taken literally 100 yards from my back door.

rose-breasted grosbeak

Rose-breasted Grosbeaks don’t usually pose so nicely for me. I like the just opened leaves surrounding him, as he cocks his head to inspect the bird feeder below him.

mourning dove billing

There was some foreplay going on between these two Mourning Doves. I guess you could call this “billing”, and they may have been cooing as well.

chestnut sided warbler

Of course I had to include warblers in my top 10 selection, and what better than the stand-out Chestnut-sided Warbler.

yellow warbler

Couldn’t bring myself to throw the Yellow Warbler out of the top 10 either. I like the way the bright yellow pops out of the darker background.

white pelican

White Pelicans flying over the Mississippi — such photogenic and graceful flyers. Another action shot to finish off the top 10.

Oops, I just recounted, and there are 11 birds here. I can’t decide which one to reject, so I’ll leave it up to my readers.

Be quiet, you big baby!

There is a lot of racket in the backyard these days — cowbird chicks have fledged and are once again driving their Chipping Sparrow parents crazy with their persistent chirping demands to be fed.  I have recently written about the Cowbird’s “Mafia strategy” for getting other species to raise its chicks (you can click here to (re)read that post).  The unfortunate Chipping Sparrows seem to be regular hosts for the Cowbirds in my backyard.  This is the third year I have seen the diminutive little sparrows foraging intensely to satisfy the appetite of chicks that are twice their size.

Cowbird chick waiting patiently (?) for its foster parent to return with something good to eat.

Cowbird chick waiting patiently (?) for its foster parent to return with something good to eat.

Doing a little preening while waiting.

Doing a little preening while waiting.

Then a foster parent arrives and the cowbird chick goes into a frenzy, fluttering its wings and tail, chirping loudly.  The Chipping Sparrow looks little intimidated, doesn't it?

Then a foster parent arrives and the cowbird chick goes into a frenzy, fluttering its wings and tail, chirping loudly. The Chipping Sparrow looks a little intimidated, doesn’t it?

The chick looks big enough to swallow its foster parent whole.

The cowbird chick looks big enough to swallow its foster parent whole.

And back the parent goes to find something else for this voracious eater it has mistakenly raised.  Chipping Sparrows feed their own young, as well as their foster kids, insects, even though they themselves eat a varied diet of seeds, fruit, and insects during the summer.  As I watched these host-brood parasite interactions, I saw the adults spend a lot of time hunting damselflies, flies, bees, etc. in the grass around the base of the buckeye tree in which this big baby was sitting.

On this trip, it looks like the sparrow nabbed a damselfly.

On this trip, it looks like the sparrow nabbed a damselfly, judging from the long, slender abdomen and wings sticking out of its beak.

No problem fitting this tiny little damselfly in that great big maw.

No problem fitting that tiny little damselfly in the chick’s great big maw.

Even though they get fed by both parents, they just keep screeching for more.

Even though the chick was getting fed by both parents, it just kept screeching for more.

The Chipping Sparrows didn’t spend all of their energy feeding the cowbird chick — I could hear them feeding a couple of their own babies that were hiding in the shrubs on the side of the yard.

Much smarter than a fifth grader

There is no doubt about it — Cowbirds exhibit ingenious methods of manipulating other bird species into raising their little brown-headed offspring.   Cowbird eggs have been found in the nests of 220 bird species, ranging in size from hummingbirds to raptors.

Brown-headed Cowbirds are n

By watching the nesting activities of particular target bird species, Brown-headed Cowbirds time their reproduction with that of their host, forcing the host to raise their chick for them.  A single female, laying just one egg in a host nest, may produce up to 36 eggs in a breeding season.

Cowbird chicks are usually larger than the host species chicks, hatch a little earlier, and grow a little faster, so they may consume the bulk of the food that parents bring to the nest, to the detriment of the host’s own chicks.

The end result is a single large Cowbird chick that follows its host parent (in this case, a Chipping Sparrow) around incessantly begging for food.

The end result is a single large Cowbird chick that follows its host parent (in this case, a Chipping Sparrow) around incessantly begging for food.

Some species, such as Robins, Gray Catbirds, and Brown Thrashers, physically eject cowbird eggs from their nest and seem less susceptible to nest parasitism. Blue-gray Gnatchatchers desert their nest if they find cowbird eggs in it and Yellow Warblers simply build another nest on top of the one that was parasitized, hoping the cowbirds don’t find them again.

However, Cowbirds have learned to retaliate against some egg rejectors with “mafia-like” behavior.

Ever watchful.  It's not enough to just find a nest in which to lay an egg

Ever watchful, Cowbirds not only monitor the nesting activity of the host, but watch what becomes of their eggs in the host nest.  If the host rejects the foreign egg, cowbirds return to the nest and destroy the host eggs!

And the “mafia” behavior works.  Prothonotary Warblers that rejected cowbird eggs managed to raise only one chick because cowbirds punctured the other eggs or threw the host’s offspring out of the nest,  Those that tolerated the presence of a cowbird chick in their nest raised three of their own chicks.  So, it pays to be tolerant of a nest parasite if you’re a Prothonotary Warbler.

Cowbirds have even learned to “farm” their host species by manipulating the hatch time of host eggs to match their own chick’s hatch time.  This is achieved simply by destroying those host eggs in the nest laid earlier than their own.

Who knew that becoming an accomplished nest parasite required such intelligence?

Feed me!

All over the backyard, a persistent squawking and chirping alerts us to the presence of newly fledged young birds.  In fact, the noise of these youngsters has entirely replaced the melodic singing of breeding adults.  Weaning is a difficult process as any parent knows, because the youngsters understand that the best way to get something is to annoy the parent until they finally give in (sound familiar?).  Some examples I have seen in the past couple of weeks:

Four fledgling House Finches bombarded their dad, urging him to find them some food.  At one point they all sat on the fence directly above him, noisily chirping away.  He looks unconcerned about it.

Four fledgling House Finches bombarded their dad, urging him to find them some food. At one point they all sat on the fence directly above him, noisily chirping away. He looks unconcerned about it.

Dad led them over to the bird feeder, showing them I suppose that this is where you eat.  But they wanted him to stick the seed in their mouths, by chirping continuously and fluttering their wings.

Dad led them over to the bird feeder, showing them, I suppose, that this is where you eat. But they wanted him to stick the seed in their mouths, by chirping continuously and fluttering their wings.  Two young sat next to him, two others perched right above him.

They haven't quite connected the appearance of seed with food -- still too fixed on being fed instead.  A cowbird looks on; she didn't have to worry about feeding her babies, because she left her eggs in someone else's nest!

They haven’t quite connected the appearance of seed with food — still too fixed on being fed instead. A female cowbird looks on; she didn’t have to worry about feeding her babies, because she left her eggs in someone else’s nest!

This is what happens to some of the local birds when cowbirds are in the area.

A Cowbird chick begs incessantly from its foster "parent", a Chipping Sparrow.

A Cowbird chick (left) begs incessantly as it follows its foster “parent”, a Chipping Sparrow around the yard.  Note that the Cowbird is is almost twice the size of the sparrow, and probably developed at the expense of some of the sparrow’s own chicks.  Chipping Sparrows apparently can’t tell the difference between their own eggs and one twice as large!

Brown-headed Cowbird egg in the nest of an Eastern Phoebe (By Frankie Rose (This is my own work.) [Public domain], via Wikimedia Commons

Brown-headed Cowbird egg in the nest of an Eastern Phoebe (By Frankie Rose [Public domain], via Wikimedia Commons).

Cowbirds are infamous as nest parasites, and lay their eggs in the nests of several different species of small birds.  This isn’t as easy as it sounds because they have to find the nests of suitable species, determine the incubation stage of that nest, and deposit one egg, at will, while parents are off the nest.  If they lay the egg too early, the parents might abandon the nest with a strange egg in it; if they lay the egg too late, their own egg might not get sufficient incubation time for full development.  Having found an appropriate nest, then they have to quickly lay their egg in it.  For comparison, it takes a hen more than 1/2 hour to get her egg out.

Why do they do it?  Brown-headed Cowbirds once followed bison herds across the prairie, moving nomadically with the herds and feeding on the insects flushed by many hooves and the seed heads of prairie grasses.  Nesting in one spot was thus impossible with such a nomadic lifestyle, and “egg-dumping” in other species’ nests became advantageous.

My question is...how does this little guy know who he is?  They obviously avoid the problem the ugly duckling experienced when he fell out of his swan parents' nest.

My question is…how does this little guy know who he is? A cowbird chick apparently avoids the problem the ugly duckling experienced when he got displaced from his swan parents’ nest.