Busy birds

While we were walking around Bluestem Prairie in northern Minnesota a couple of days ago, we encountered a busy pair of Kingbird parents who were feeding their fledgling chicks. The parents continually cruised out from the bush’s top branches and brought back tiny meals to the chicks every few minutes.

Kingbird pair

One parent stayed on top of the bush watching out for the chicks, while the other cruised over the prairie.

The Nature Conservancy’s Bluestem Prairie in northwestern Minnesota borders Buffalo River State Park and preserves an expansive field of prairie grass and wildflowers. It is one of the few places one can see Prairie Chickens “boom” on their leks in the spring.

The parent’s appearance is enough to trigger the begging response from its chick.

It looked like they were feeding the chicks tiny caterpillars gleaned from the vegetation.

The chicks look pint-sized next to the adult. They still have a lot of growing to do and will remain with their parents for the next 4-5 weeks.  At this stage they probably can’t fly more than a couple of feet, but they can scramble around in the vegetation.

Bring on the bees

It’s prime time for summer flowers, and the bumblebees and honeybees are making the rounds carrying pollen from one flower to another and sipping nectar as their reward.

Tubular flowers of red bee balm (Monarda) are perfect for a slender honeybee or the long tongue of butterflies and hummingbirds. The nectar is deep down at the base of the flower, so it’s an effort for a small bee to get there.

Lead plant flowers open sequentially on a long raceme (flower stalk) exposing their yellow orange anthers to wandering bumblebee that collect and store pollen in sacs on their hind legs.

Milkweed flowers have special requirements of their pollinators — they need to stick their legs down slits in the female (pistil) parts of the flowers and drag out the pollen sacs (pollinia) on their hind legs. The slender leg of a honeybee is the perfect vehicle for this operation.  When they wander onto the next flower, the pollinia will get transferred as the bee’s leg drops into the appropriate slot.  To read more about how this is done, click on this link.

Bees love the pollen of the Cup Plant, a tall composite (daisy) with an abundance of bright yellow flowers.  Later in the summer, the Goldfinches will appreciate the fruits (well, seeds) of these pollinating efforts.  

In the fall, Goldfinches dissect the Cup Plant flowers, pulling the seeds right out of the flower head. Fortunately, there is a great abundance of flower heads to work on, and there are plenty of seeds left for the plant to fill up by backyard garden with its progeny.

Prairie birds

It’s a particularly busy time of year for prairie bird parents — all those open mouths to fill. And it doesn’t stop when they fledge and leave the nest because the youngsters just follow the parents around and continue begging for food.

Brown Thrasher

It seemed like every bird (like this Brown Thrasher) we saw at the Sherburne National Wildlife Refuge a few days ago had some sort of food item in its mouth to take back to the nest.

Eastern Kingbirds hawk insects in the air from a perch and they dive to the ground to capture insects wandering through prairie grass.

The chicks have a long period of dependency, up to 7 weeks, so the parents can only raise one brood per breeding season.

Eastern Meadowlarks used to be common in prairie grasslands, but there seem to be just a few in each grassy meadow. They might hunt from a fence line perch or from a stalk of grass, but they also walk through the grasses probing for insect prey by sticking their bills into the soil to uncover worms and grubs which they take back to their chicks.

This Eastern Meadowlark may have found a treat for his chicks in the grass, but he has perched high upon a small evergreen shrub in the middle of the prairie to check whether it’s safe to deliver this morsel to his chicks.

I didn’t think Common Yellowthroat warbers were prairie birds, but as long as there is a little water in their grassland habitat, these birds are one of the most common ones heard (and seen) on the prairie.  Hence, the name…

It’s a delight to see the Sandhill Cranes each time we visit Sherburne NWR.  The habitat here is perfect for them, lots of open grassy meadows interspersed with boggy wetlands, perfect for hunting frogs, snails, rodents, small birds, bird eggs, tubers, berries, seeds, whatever they come across.

Sandhill Cranes are long-lived, usually raising 1-2 chicks per breeding season, but the chicks develop slowly and follow the parents around for 9-10 months learning how to feed themselves. (Photo by Debbie Reynolds)

One bird is missing from the prairie grassland area these days — the American Kestrel or Sparrowhawk.  They used to be common along the prairie edges, hunting grasshoppers and other invertebrates from power lines or fence posts.  Their disappearance from the grasslands coincides with a drastic reduction in the number of bugs that hit your windshield as you drive through prairie grassland areas in the Midwestern U.S.

Prairies in bloom

Minnesota prairies are in full bloom, and the ones that were burned this spring (as part of the prairie maintenance) are especially colorful right now.

Prairies are typically grassy fields with a few flowering perennials mixed in.  This 40-acre prairie in the Lake Elmo area of the Twin Cities is the product of a restoration project, and has an exceptionally high diversity of  early-summer blooming and late-summer blooming flowers.

Purple coneflower stems rise high above the grasses in late June.

Fireweed is usually not found in established prairies because it likes disturbed areas, but it is a good colonist and would have been one of the first plants to flower on this restored prairie. Meadow sunflowers were also abundant on this prairie.

Musk Thistle is not a plant you want to see on an established prairie because it is an invasive introduced plant.

But the Musk Thistle blossom is an impressive 2-3 inch ball of hundreds (thousands?) of disc flowers.

Long Lake Prairie is dominated by brilliant orange and purple blooms now in early July.  Sandy soils here support some species not seen in the Lake Elmo prairie above, like Lead Plant (right) and clover species.

Bees love purple and white prairie clover, but the only insects on these plants were tiny syrphid flies this morning.

There were lots of well established Blue Vervain plants and very high density of Black-eyed Susans in patches of the prairie.

Big Blue Stem, the signature tall grass prairie plant that can grow 5-6 feet tall, was just starting to bloom and put out its long yellow anthers with pollen for the wind to carry away.

Small Coreopsis plants crowded around the base of Lead Plants, which are difficult to grow in a home garden, taking as long as 3 years to finally bloom.  They get bigger and woodier with age and resist fire well and can become a dominant plant in fire-maintained prairies.

Early spring fires burn up the thatch of previous years’ grass growth and release nutrients that prairie plants need to produce a wildflower garden.

a quiet celebration in 2020

It’s not your usual Fourth of July today, so I looked at what the Backyard Biology blog posts for previous years showed.  Here’s a post from 2014 that is appropriate for today’s world.

A red, white, and blue fourth of July flower bouquet was blooming in my garden on July 4, 2014.  Sadly I no longer have that rose variety or the larkspur in my garden in 2020.

For those of you who might have wondered why red, white, and blue were chosen for the U.S. flag, here’s the description from USFlag.org:

The colors red, white, and blue did not have meanings for The Stars and Stripes when it was adopted in 1777. However, the colors in the Great Seal did have specific meanings. Charles Thompson, Secretary of the Continental Congress, reporting to Congress on the Seal, stated:

“The colors of the pales (the vertical stripes) are those used in the flag of the United States of America; White signifies purity and innocence, Red, hardiness & valour, and Blue, the color of the Chief (the broad band above the stripes) signifies vigilance, perseverance & justice.”

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Perseverance in pursuing justice might be something to keep in mind from this holiday going forward in 2020…

Another beautiful (hot) summer day

Do the birds feel as hot as we do on a 90 degree day with 90% humidity?

Probably not, plus they can rise above the heated landscape, like these White Pelicans that ceased feeding in the shallow pools at Sherburne National Wildlife Refuge to ride the thermals above us.

Pelicans doing what they do best, with wings outstretched grabbing those upward rising hot air currents at Sherburne National Wildlife Refuge.

There was plenty of action going on in those shallow pools, with Black Terns, a Loon, a few Cormorants, and a couple of herons competing for fish with one lone Pelican, while Trumpeter Swans and some dabbling ducks foraged on the vegetation.

A perfect mid-summer landscape with blue sky, puffy clouds, and clear water, made more perfect by adding a Black Tern to the image (which is what we saw, but couldn’t quite manage to capture on the camera).

Double-crested Cormorant

A Double-crested Cormorant took a break from fishing on one of the many snags in the pool.

Black Tern

Black Terns continuously foraged over the pools, but always avoided flying right in front of us which made photographing them difficult! They seemed to be very successful catching fish, always leaving the pool to fly across the road with one in the their beak.  Sherburne NWR is one of the few places in MN where Black Terns breed.  Although they are distributed globally, they are uncommon across their breeding range in the upper Midwestern U.S.

Great Blue Heron

Great Blue Heron posing by a dead snag. He had already had lunch on the shore of the pool.

None of the pairs of Trumpeter Swans we saw had youngsters following them, which was surprising. Their trademark white heads are stained brown from foraging in water with high concentration of tannins in it.

The lone Pelican foraging along with a submerged Loon seems to have a gigantic hole in its pouch, either made by another pelican fighting this one for fish, or by the fish itself in its struggle to escape.

Some of the Black Terns have begun their molt to winter plumage already. Eventually their trademark black head will be white with a black cap and ear flaps, and their sooty gray breast will be white after the molt is complete.

Facial feathers are starting to be replaced in this bird at the beginning of its molt.

It looks like a completely different bird in its winter plumage, but this is a Black Tern.

the colorful Cardinals (family)

When I was looking up information on the Blue Grosbeak (previous post), I was surprised to discover it was a member of the Cardinal family, which turns out to be quite a large and diverse, but extremely colorful set of bird species.  It also turns out that I have blogged about this before, when I have photographed some of the other North American species in this family (short memory!).

The Cardinalidae family consists of Buntings, Grosbeaks, Tanagers, Chats, Seedeaters, and Cardinals, 14 species of which can be found in North America at some time of the year — so far, I’ve managed to photograph 12 of the 14.   Although the species look very different from one another and live in very different places, they are all medium-sized, stocky birds that use their somewhat overly large bill to consume seeds, fruits, and insects of all sizes.  As a group, the males exhibit bright coloration and females are more muted in color.

the Buntings — make liberal use of blue structural coloration, in addition to several other bright pigments in their plumage.

Blue Grosbeak (really a bunting), photographed in Eden Prairie, MN

Lazuli Buntings are most closely related to Blue Grosbeaks in the Cardinal family but weigh half as much as the bigger Grosbeak. Their version of structural blue color is more of a turquoise than the royal blue of the Grosbeak.  They are a western species, found mostly in dry, brush habitat west of the Rockies.  This bird was photographed in Madera Canyon, AZ.

Indigo Bunting, nicknamed Blue Canary, another small member of the Cardinal family, about half the weight of a Blue Grosbeak.  They have a phenomenal ability to navigate their way from wintering areas in Central America and the West Indies to breeding areas in North America at night, using cues from the patterns of stars overhead.  (Read more about this here.)

Painted Buntings are well-named, using pretty much every color in the rainbow in their spring plumage.  This bird was photographed on migration in Texas, on its way somewhere in the south-central U.S. to breed.

the Tanagers  (most of the Tanagers are in their own family — but ornithologists have decided several of them are more closely related to the Cardinalidae.)

Scarlet Tanager, another backyard bird, visiting from its winter headquarters in Mexico and southeastern U.S.

Western Tanagers are found in the western U.S.  This one was photographed in the UC Berkeley rose garden.  The birds don’t regularly consume seeds, so the red coloration of the head feathers comes from a rare pigment perhaps obtained from insects, rather than from carotenoids in plants. 

A Summer Tanager on migration in April, photographed in Galveston, Texas.  The only all red (sort of strawberry colored) bird in North America.  This bird uses its big bill to snare bees and wasps, rubbing the stinger off on a branch before eating it.

the Grosbeaks (well-named for their overly large seed-crushing bill)

Rose-breasted Grosbeaks, another backyard bird, add a spill of raspberry color down their breast to contrast with their striking black and white plumage.  Their melodic song, “like a Robin that has taken singing lessons” brightens a spring morning in MN.

Black-headed Grosbeaks, another western-only species during its breeding season, also accentuate the black and white plumage with bright color — a deep russet.   It is one of the very few birds that can tolerate the glycoside poisons in Monarch butterflies, and is a major predator of them in Mexico during the winter.   This bird was photographed near Portal, AZ.

the Cardinals (only two members in North America)

Northern Cardinals are year-round residents throughout their range in North America, and unlike the other members of the Cardinal family, they retain their bright red plumage all year.

Male Pyrrhuloxia

Pyrrhuloxia look like gray Northern Cardinals and are in fact closely related to them, so close that the two species are known to produce hybrid offspring where they overlap in habitat in desert areas of the southwestern U.S. (Read more about this here.)

lastly, the Dickcissel — not a member of any group

Looking like a miniature Meadowlark, but bearing the trademark over-sized bill of the Cardinal family, Dickcissels have been a puzzle to taxonomists. They were thought to be related to Sparrows, then Orioles/Blackbirds, and now Cardinals. Unlike the other Cardinalidae species, they are grassland, not forest birds.

A really blue bird

There are Bluebirds …

A male Eastern Blue in its striking breeding plumage of blue and russet.

and then there are really blue birds.

A male Blue Grosbeak sets the standard for blueness.

Blue Grosbeaks are a rarity in this part of Minnesota, but they are another example of a species that is expanding its range northward in recent decades as forest land is cleared for housing development and agriculture.  They favor patches of shrubs and deciduous trees and old farm fields to set up housekeeping and raise a family before flying back to their winter headquarters in Mexico and Central America.

A grassy, woven Blue Grosbeak nest was placed very low in the vegetation. The female perched above the nest and peered at us through leaves. Can you see her bright eye?  She is mostly a cinnamon color with faint blue on her head.

Indigo Buntings and their relatives the Blue Grosbeaks are some of the bluest of blue-colored birds. Blue Jays and Bluebirds pale (literally) in comparison to the deep blue color of the two buntings (grosbeaks are technically a type of bunting).

Bright blue birds: Blue Grosbeak and Indigo Bunting.  Although it doesn’t show here, the Blue Grosbeak (left) is half again bigger than the Indigo Bunting.  They are both members of the Cardinal family, but the Grosbeak’s closest relative is the Lazuli Bunting, not the look-alike Indigo Bunting.

As you may know, birds do not have blue pigments in their blue feathers — the color is achieved by structural elements in the feather (keratin deposits that surround small air pockets) that reflect the short wavelength blue color back to the viewer’s eye.  Without this structural interference in the transmission of light through the feather, it would look brown — the color of the underlying melanin pigment.

How blue birds create the blue color without using a pigment.  To read more about how birds make colorful feathers, check out this website.

So, why are some birds so much bluer than others, males bluer than females, Indigo Buntings and Blue Grosbeaks bluer than Blue Jays?  Inquiring minds want to know…but there don’t seem to be answers, other than vague references to the importance of bright colors in males compared to females.  And here’s another thought to ponder:  are “blue birds” blue to other birds — or can they see patterns in the blue reflected light because they can see/process shorter wavelength light than humans can?

Young robin discovers fruit!

The youngster didn’t want to be photographed, but it just couldn’t resist the red serviceberries, and had to pluck a few.

The berries aren’t really ripe yet, but that didn’t stop junior from trying them.

young robin in serviceberry bush

The wing coverts haven’t finished growing over the flight feathers, and there are a few bald patches on its head, but this fledgling has no trouble flying — or landing in a bush.   Juvenile Robins have a spotted breast like a thrush (which they are).  During its next molt to full adult plumage, the breast feathers will be orange in color.

Why are some birds so common — Part 3

In previous posts, I made the case that some bird species adapt well to the human urban/suburban landscape, increasing in numbers as they make use of the rich resources of our gardens and backyards.  Other species, not fussy about where they live, what they eat, or how inclement the weather have also increased in numbers in our backyards because they are generalists whose survival strategy is simply to make use of whatever is available.

Everyday birds — common for several reasons

A third and more recent influence on the local abundance of particular birds is the changing climate in the last 100 years. Not only has the average winter temperature here in Minnesota increased 4-6 degrees F, but the winters are shorter, less snowy, and more unpredictable in severity.

Two species in particular have responded to that warming trend:

It’s hard to believe that Northern Cardinals and American Robins haven’t always been common in our Minnesota backyards.

A monograph published in 1916 by Thomas S. Roberts MD for the Minnesota Geological and Natural History Survey listed Cardinals and Robins as “accidental” occurrences in Minnesota during the winter.  Dr. Roberts even stated:  “Records of the occurrence of this common cage bird [Cardinal] are always open to the suspicion that the individuals seen are escaped captives.”  In 1916 there were just two dozen records of Robins having been seen in sheltered locations in southeastern Minnesota.

Two other common residents of our backyards most of the year, Crows and Goldfinches, were listed by Dr. Roberts as mere “visitors” to the Minnesota winter landscape, being rare occurrences 100 years ago.  Of course it may not just be a response to changing winter climate that has caused increases in numbers of these birds.  Goldfinches are attracted to backyard bird feeders, which makes it easier for them to find sufficient food in the winter.  Crows are adept at avoiding cars while feasting on road-killed animals, and there certainly are more of those than 100 years ago.

Goldfinches are one of the most common visitors to my bird feeders in the winter.

The northward expansion of bird species includes migrants coming from tropical areas as well.  For example, Blue-winged Warblers and Orchard Orioles migrate much farther north to breed than they did 100 years ago.  In fact, because of their northward expansion Blue-winged Warblers now encroach on breeding areas of closely related Golden-winged Warblers and may be a cause of marked population decrease in Golden-winged Warblers.

Orchard Orioles have expanded their breeding range northward into southern Manitoba and westward into Colorado.  The birds feed on nectar, pollen, and insects so perhaps they have found an open niche in shrubby areas with plenty of flowering plants in northern latitudes in the summer where temperatures are more amenable and food is more reliably available.

Northward expansion includes birds moving their year-round residence from tropical areas that are heating up to cooler areas in northern North America.  For example, there were no Great-tailed Grackles north of the Mexican border except in southern Texas in 1934. Steadily moving north, they reached southern Arizona, then Houston, Oklahoma, California, on to Missouri and Nebraska, and finally Iowa by 1983. The species has become a common sighting throughout a vast area where it was completely unknown a century ago.

I went to south Texas to see (and photograph) this bird, but it’s just a short hop from Iowa to Minnesota, so we should expect to see them here soon.

The real problem with this northward expansion of breeding and winter ranges of birds is that birds use the changing photoperiod (daylength) to time their annual cycle and come into breeding condition, but the plants and insects on which they rely to sustain themselves and raise their chicks depend on the temperature cycle of the local area — which may not necessarily be synchronized with photoperiod.  In a warmer year, insect and flower blooms may take place before birds arrive at far northern latitudes, and birds may not have the resources to produce young that year, or even sustain themselves for their southern migration.

Here’s an interesting read on the subject from Audubon.