The birdy breeding cycle 2020 – 1: courtship and mating

Although we in the Northern hemisphere are already a little more than a month into summer, many species among our avian friends have not yet completed their breeding cycle. In my yard, many parents are still feeding begging (sometimes almost adult) children. Others are feeding young ones in the nest and some appear to be busy constructing new nests for a second or third brood. So, after a long hiatus in blogging, I decided to feature some of my bird friends, including the American goldfinch pair below (Spinus tristis) as they have worked on their new family lives in 2020.

American goldfinch P7130178 © Maria de Bruyn resSome of these photos go back to early spring. A series of misfortunes (including a crash of my laptop hard drive, a broken camera, loss of Internet) meant that I had a backlog of photos to process and then suddenly a large gap in photos taken. But I managed to recuperate some of the work and hope you enjoy the coming series of posts about the birds’ breeding and family life!

belted kingfisher

Breeding season is heralded by increasing bird song in the meadows, forests, fields and our yards. Males especially sing to attract mates and establish territories, but females treat us to songs and calls, too. This makes it easier to spot birds as the tree foliage gets thicker, especially if you have good hearing!

pine warbler P4175086© Maria de Bruyn                     white-eyed vireo P4123164 © Maria de Bruyn res

Pine warbler (Setophaga pinus)            White-eyed vireo (Vireo griseus)

Eastern meadowlark P4279816© Maria de Bruyn res            Orchard oriole P4279889© Maria de Bruyn res

Eastern meadowlark (Sturnella magna)     Orchard oriole (Icterus spurius)

Carolina wren P3316544 © Maria de Bruyn res                 blue grosbeak P4291500© Maria de Bruyn res

Carolina wren (Thryothorus ludovicianus)      Blue grosbeak (Passerina caerulea)

summer tanager P4291520© Maria de Bruyn res

Summer tanager (Piranga rubra)

Indigo bunting P6308502© Maria de Bruyn

Indigo bunting (Passerina cyanea)

Courtship is usually a sweet behavior to watch in my view. The male Northern cardinals (Cardinalis cardinalis) are especially devoted suitors, seeking out nice morsels to present to their intended mates, while among the American crows (Corvus brachyrhynchos), it’s the females who loudly call to their mates for some tasty bites.

Northern cardinal P4164873© Maria de Bruyn res

American crow P4080661 © Maria de Bruyn res

A fact that perhaps many bird lovers do not know is that few male birds have a penis. Like the female birds, most species’ males have a cloaca, a cavity externally located just under the bird’s tail and internally at the end of the digestive tract. Feces, urine, sperm and ova are all deposited in the cloaca. Birds who reproduce with this organ briefly rub their cloacae together (an activity called the “cloacal kiss”) whereby sperm from the male bird’s testes are transferred into the female’s cavity to unite with her eggs. During breeding season, the cloaca is slightly swollen and protrudes a bit from the bird’s body, facilitating the transfer. In the photo of this Carolina wren, you can see a slightly darker area under the tail indicating where the cloaca is found.

Carolina wren P7059955 © Maria de Bruyn res

red-headed woodpecker P4217162© Maria de Bruyn res

When ready for mating, the red-headed woodpeckers (Melanerpes erythrocephalus) seem to focus mainly on chasing away rivals and then snatching a quick mating session. The female woodpecker then takes a break from the chase to rest and have a bite to eat.

Some cliff swallow males (Petrochelidon pyrrhonota) seem to take advantage of females who are preoccupied with gathering mud for their nests for a quick tryst.

cliff swallows 2G0A3283© Maria de Bruyn res

The brown-headed cowbirds (Molothrus ater) seem to take their time for mating. This pair was occupied for at least 5-10 minutes in preparing for the upcoming production of eggs. At times, it seemed like the male was giving the female instructions on what to do once “the deed” was done!

brown-headed cowbird P5097676 © Maria de Bruyn res   brown-headed cowbird P5097677 © Maria de Bruyn res

Many birders do not like the cowbirds because they are parasitic nesters, i.e., they lay an egg in another bird’s nest so that the other bird will raise the young. Since the cowbird baby usually hatches before the other eggs, they either monopolize the food that the foster parents bring or they may even destroy the eggs laid by their foster mother.

brown-headed cowbird P5097682 © Maria de Bruyn res      brown-headed cowbird P5097686© Maria de Bruyn res

It’s been posited that the cowbirds evolved to use this strategy because they followed the bison in migration and therefore couldn’t stay in one place to raise their young. Others believe, however, that the birds developed the practice because dispersing their eggs over several nests gave their young a better chance of reaching adulthood.

brown-headed cowbird P5097689© Maria de Bruyn res

chipping sparrow P6256620© Maria de Bruyn sgd resThe quickest mating scenario I’ve witnessed came from a pair of sweet little chipping sparrows (Spizella passerina). I’d seen the two fluttering together at the feeders and had noted one sparrow chasing another away – which I now think was the victorious suitor driving away a rival. Then one July afternoon, the two flew to a dying cedar and sat close to one another on a branch. Suddenly, Mr. Victory mounted his mate but for what only seemed a few seconds – really very quick work indeed! She sat there with her rear end elevated for a bit and then the two went back to feeding – and soon after I saw them collecting nesting materials.

chipping sparrow P6256622© Maria de Bruyn res    chipping sparrow P6256623© Maria de Bruyn res

The birds in which the males do have a penis include some duck and swan species, ostriches, cassowaries, kiwi and geese. They differ from other birds in that development of the penis is NOT stopped in the male bird embryos during development (the case in cloacal birds).

The mallard males (Anas platyrhynchos), like some other ducks, unfortunately do not treat their partners well. They may mount the female very roughly. During a mating, she may be dunked underwater repeatedly and at length; occasionally, this results in her drowning. This behavior has been the subject of various studies and some newspaper articles with sensationalistic headlines (e.g., “The horrible thing you never knew about ducks)”.

Mallard duck P1232837 © Maria de Bruyn

Mallard duck P1232839 © Maria de Bruyn     Mallard duck P1232840© Maria de Bruyn

Once the actual mating is over, the birds devote most of their energy toward building a nest. While female ruby-throated hummingbirds (Archilochus colubris) must construct her nest and tend her babies alone, many other birds cooperate in the venture, like the Eastern bluebirds. Their efforts are featured in the next blog. (And if you’d like to see a previous post on courtship, it is here.)

ruby-throated hummingbird 2G0A4084© Maria de Bruyn res

Life on late winter-early spring farmlands

Although it’s taken me some time to process photos taken earlier this year, I’d still like to share what I was seeing in late winter and early spring when stopping at farm fields. These sometimes muddy and stubble-covered parcels of land can offer wildlife watchers nice views of birds and occasionally other animals, unobstructed by a lot of foliage. So visits to roadside farms and ponds were on my early 2019 nature-walk itineraries.

Farm fields are often bordered by stands of trees where animals can retreat if they become disturbed by humans standing around aiming long camera lenses at them. The white-tailed deer (Odocoileus virginianus) above were browsing one morning and seemed unconcerned as I photographed nearby birds. When I turned to watch them specifically though, they decided to move back into the woods bordering the field.

Many farmers put out bird boxes on fences bordering their fields; in early March, the Eastern bluebirds (Sialia sialis) were already checking out and starting to furnish potential nest sites. Here a male was flying away from a nest box while his mate was gathering pine needles.

The fences offer other birds a good vantage point for observation, too. A Northern flicker (Colaptes auratus) perched on a fence post to look around and then flew to a branch high above me.

 

A bird present in large numbers was the brown-headed cowbird (Molothrus ater). One morning, a friend and I counted some 200 birds in one small group of trees. Many people think they are an invasive species and dislike these birds intensely because they evolved a behavior that can endanger other birds. The cowbirds, who are native to America, were originally present in prairies where they followed the buffalo. This meant they did not stay in one place long enough to tend a nest, so they began laying their eggs in other birds’ nests. The young cowbirds hatch first and then may throw out the other eggs or hatchlings or they eat so ravenously that the other nest mates don’t get enough.

It certainly is disconcerting to see a small warbler feeding a large cowbird fledgling and a couple bird species have been endangered by the behavior. But I don’t dislike the cowbird because of this – they did not choose how to evolve and the behavior developed as an adaptation, not an “evil” practice. They are attractive birds. And the sounds they make are lovely, akin to water droplets falling into a pool.

 

The American robins (Turdus migratorius) were also present in abundance; they tend to flock together in the winter and early spring. One farm had a boggy area with some cyprus trees and the robins were busy looking for insects among the cyprus “knees” (Taxodium distichum). These woody structures that grow out of the roots may help stabilize the trees when they are standing in water but scientists have not yet definitively identified their purpose.

There were other trees near the cypresses; in one, the cocoon of a Polyphemus moth (Antheraea polyphemus) was hanging high overhead. It also pays to look around to see who is flying u[ ahigh above those trees and fields. It’s not uncommon to see Canada geese (Branta canadensis) flying from one farm pond to another.

Red-tailed hawks (Buteo jamaicensis) soared over different fields I visited.

Red-shouldered hawks (Buteo lineatus) also made an appearance.

And one of my favorite raptors often eluded my efforts to capture a portrait. Only a couple times was I able to catch a beautiful kestrel (Falco sparverius) speeding by in flight.

The robins were feeding in the fields as were several other bird species.

 

Yellow-rumped warbler (Setophaga coronata)

Savannah sparrow (Passerculus sandwichensis)

Pine warbler (Setophaga pinus)

A pair of Northern mockingbirds (Mimus polyglottos) was taking advantage of numerous cow patties left behind on one farm field in their search for insects. They were flashing their wings repeatedly; I’m convinced that this was behavior designed to scare up bugs so they can catch them easily.

 

 

Other birds were following them around in the field, apparently taking advantage of the insect smorgasbord. Two of them were a song sparrow (Melospiza melodia) and a field sparrow (Spizella pusilla).

This year, it was also my good fortune to see a bird new to me in one farm field, the lovely horned lark (Eremophila alpestris). Although these birds are not considered endangered, their numbers declined by 71% between 1966 and 2015.

I couldn’t get close to the larks but one day I did catch a bird taking a dust bath in a gravel and dirt road next to their preferred field. On a second visit to that farm, I again saw a lark in the road and then another lark joined it.

It turns out that female larks perform a courting display that looks very similar to actually taking a dust bath, so I got to see a mating behavior that I hadn’t expected!

Reading about the behavior, I discovered that if male larks see a female who is dust bathing, he may mistake what she’s doing and try to mate with her when she’s not ready.

So reproductive life is a bit difficult for those males, who look so adorable when they raise those head feathers to project two little black horns.I will leave you here with a few more views of a horned lark who was singing and foraging not too very far from the road.

 

Winter wonderland – sharing and spats at the feeders

I thought I had published this blog in early February and just discovered that I had only saved a draft. Since we had snowflakes last night (in April!), I’m going to go ahead and post this now – a break in the series about Costa Rica! When the snow began falling during our day of one-foot accumulation, the feeders were inundated by some of the dark-colored bird species who tend to come in crowds. At first, they were peacefully sharing space.

 

  

Although I sometimes have a couple dozen red-winged blackbirds (Agelaius phoeniceus) at the feeders, during the storm only one pair showed up for a brief visit and the other birds left them alone.

 

The mourning doves (Zenaida macroura) often share feeder space with other birds, including those that are smaller than they are.

The common grackles (Quiscalus quiscula) are known to other people as domineering birds at the feeder, but those in my yard have always been polite, even though they seem to have a permanent expression that expresses anger.

 

 

The brown-headed cowbirds (Molothrus ater) sometimes share space nicely and sometimes fuss at one another as they vie for a good perch. They don’t try to chase off other species though and are not apt to “yell” at other birds.

The birds who do “yell” are the European starlings (Sturnus vulgaris). Young ones yell at their parents after fledging, begging to be fed. Adults yell at each other when they are trying to all crowd together onto a feeder. And adults yell at other species to drive them away so they can have all the space for themselves.

At my feeders, however, they have found their match in the male red-bellied woodpecker (Melanerpes carolinus). One day, I watched as they managed to intimidate him for a few minutes, but he then returned to the feeder and refused to give up. Now he is no longer frightened of them and stands his ground when a starling does its best to make him move.

    

It turns out that studies have shown that the red-bellied woodpeckers are the birds most apt to resist attempts by other birds to displace them from feeders.

The red-bellied woodpecker also was not intimidated by me at one point. He doesn’t like it when he flies in and notices at the last moment that I am sitting or standing on the porch; often he will swerve away and wait for me to leave. During the snow storm, however, he decided to display his displeasure with my close presence, both from a frontal and dorsal view!

 

  

      

 

I guess that the little bird spats do make for sometimes more interesting birding observations. Seeing the tiny ruby-crowned kinglet (Regulus calendula) warning off a rival a few days before and after the snow melted did show off a gorgeous and brave little bird.

 

 

I’m looking forward to seeing what the springtime observations of animal behavior will reveal.

 

“Nuts” for nuts!

A primary source of nutrition for many birds is nuts.This high-calorie food provides them with dietary fat, which can be especially welcome during the colder months. As nuts ripen, you can see the birds flying by, carrying acorns and beechnuts, as well as seeds of various kinds. Some birds are especially suited to eating nuts with their thicker, cone-shaped bills, which are shaped to help them crack open pods and seed cases. Northern cardinals (Cardinalis cardinalis), sparrows, grosbeaks, finches and woodpeckers are seed and nut lovers.

I had been lax in providing my yard birds with these culinary treats except for sunflower seeds and the seed pods in my yard trees. So one day early last year, I purchased a nut and seed holder and proceeded to give them peanuts, which are not actually nuts but the seed of a legume (Arachis hypogaea). This makes no difference to the birds like the Carolina wren (Thryothorus ludovicianus) of course.

I first tried peanuts in the shell and an occasional blue jay and tufted titmouse would stop by. However, they didn’t seem to want to put much time into removing the nuts from the shells and I didn’t really want the shells littering the ground either.

Then in the spring I put out some shelled peanuts from a container I’d bought for my own consumption and the avian visitors were delighted. Reading about peanut feeding informed me that I should avoid giving salted peanuts. I couldn’t readily find unsalted ones at the grocery store, so I began removing the salt, either by shaking the nuts in a paper bag or by washing off the salt.

   

Northern cardinal                                            Brown-headed nuthatch (Sitta pusilla)

Before they left for the summer, the yellow-rumped warbler (Setophaga coronata) and ruby-crowned kinglet (Regulus calendula) tried the peanuts, too. Sometimes I wondered if the kinglet was also not looking for insects around the peanut feeder.

   

My choice to provide nuts was a big hit; I was rewarded with a procession of individuals of varied species who came by to quickly gulp or carry off a tasty nut. Some are pictured below – they came at different times of the day.

 

White-breasted nuthatch (Sitta carolinensis)     Tufted titmouse (Baeolophus bicolor)

    

Tufted titmouse                                                       Pine warbler (Setophaga pinus)

   

Red-bellied woodpecker (Melanerpes carolinus)      Northern cardinal

 

Gray catbird (Dumetella carolinensis)        Eastern bluebird (Sialia sialis)

       

Chipping sparrow (Spizella passerina)         Brown thrasher (Toxostoma rufum)

The common grackles (Quiscalus quiscula) will sometimes break down the nuts (and are quite messy about it, compared to the chickadees and titmice), but they will also swallow the treats whole.

  

Others are intent on breaking the peanuts into smaller pieces that are easier to get down; this seems especially true for the smaller birds like the Carolina chickadee (Poecile carolinensis) below. Here we also see Riley, my banded Carolina wren, enjoying a treat.

   

The blue jays (Cyanocitta cristata) often gulp down some nuts quickly and then try to carry off several nuts at a time.

One good thing about the peanuts is that thankfully the starlings (Sturnus vulgaris) and brown-headed cowbirds (Molothrus ater) don’t appear fond of them (they gulp down the dried mealworms, however, as if that food is going out of style). One will occasionally sample a nut, but they never seem to want a second.

As time passed, I realized that the peanut feeding strategy was rewarding me with frequent avian visitors, but was also rather costly. In the autumn, I began putting out a less expensive fruit and nut mix. This has also proved very popular and various species of birds are willing to share space at the feeders. The chickadees especially will feed alongside others, like the house finches and Northern cardinal below.

Species that usually forage on the ground, like the white-throated sparrows (Zonotrichia albicollis), also make occasional forays to the nut feeder.

When the nut feeders are empty, it’s not uncommon to see birds sitting atop them; when they see me, some will call out, as if saying, “Hey, fill up that feeder, please!” And I usually accommodate them, especially when it is very cold, as has been the case the first days of 2018 – we have had a record-breaking stretch of days in which the temperature did not rise above freezing, an unusual occurrence for our southern state of North Carolina.

 

Yellow-rumped warbler  (Setophaga coronata)  House finch (Haemorhous mexicanus)

The nut feeders have also been very attractive to the resident Eastern gray squirrels (Sciurus carolinensis), one of whom has been VERY persistent in devising ways to get onto the feeders. Each time s/he succeeds, I change the position of the feeders or stumps and branches nearby. Currently, that clever rodent hasn’t been able to get up there. In compensation, I occasionally throw a handful of nuts on the ground.

             

So, not all the birds are “nuts” for nuts, but plenty of species think they’re mighty fine! They are definitely a worthwhile addition to the birders’ array of feeder offerings.

American goldfinch (Spinus tristis)

 

 

 

Avian generations in the making – part 3B: fledgling and post-fledgling care

The number of days after hatching when young altricial birds leave the nest is fairly predictable for many species; knowing those approximate dates is helpful if you want to plan a day to watch fledging happen. I can often arrange to sit and watch a nest box on the appointed day for several hours.This has enabled me to see several broods of Eastern bluebirds and brown-headed nuthatches make their leaps to freedom on the path to adulthood.

When it is time for fledging, parent birds encourage their babies to leave the nest. They may entice them by perching nearby with some food but not bringing it to them. Or they fly to the box with food and then go to a branch instead of feeding. The Eastern bluebirds (Sialia sialis) in my yard will hover in front of the nest box like a hummingbird, sometimes with food in their mouths; perhaps they are showing the young ones that flight involves flapping wings.

While in some species, parents appreciate help from older children in caring for a current brood, Eastern bluebirds apparently do not. This may be because they see the previously fledged young as competitors for food. In my yard, father bluebird especially was chasing the young of earlier nests away from the feeders, not only when they begged but also when they fed themselves.

 

When fledging day arrived for the bluebirds’ third brood, one of the older siblings (I’m not sure if it was a female or male) was very interested in seeing the third brood fledge. He imitated his parents, hovering in front of the nest box so the young ones could see him.

 

Again, however, the parent bluebirds chased him away.

This did not deter the immature bird, however. He waited for the parents to go get food and again took on encouraging the young siblings. It was fascinating to watch!

 

The parents returned and drove him off with a show of bad temper.

Eventually, the babies did fly out of the nest box into a nearby crepe myrtle. There, they continued to call for food with a wide-open mouth.

    

This gaping behavior stimulates the parents to feed their offspring and the offspring can be very insistent and persistent in begging for food.

    

Eastern starling (Sturnus vulgaris)

     

Carolina wrens (Thryothorus ludovicianus)

  

Common grackle (Quiscalus quiscula)     Royal tern   (Thalasseus maximus)

This behavior can go on for days, especially when the young ones cannot yet fly, like this recently fledged Northern mockingbird (Mimus polyglottos).

 

 

The birds that feed their young ones on the ground, like the American robins (Turdus migratorius) have it a bit easier than those that feed juveniles perched on wires, like these barn swallows (Hirundo rustica).

   

I can imagine that the mother and father get to a point of thinking, “Enough already!” as those large fledglings continue to beg for food; this parent Northern cardinal (Cardinalis cardinalis) did not seem willing to go out for yet another bug for the young one.

But some young birds can be very insistent, even when it is obvious that they are now fully capable of finding some food on their own. This parent chipping sparrow (Spizella passerina) seemed willing to be a feeder for a while longer.

                        

The parent-child feeding routine that often catches people’s eye is when a young brown-headed cowbird is being fed by a (non-voluntary) adoptive parent. For example, here we see a male hooded warbler (Setophaga citrina) bringing food to a brown-headed cowbird baby (Molothrus ater) after the youngster spent quite a while loudly crying out for a meal and hopping around on branches after the parent to convince him that he needed to be fed.

  

Of course, at a certain point the parents do stop feeding and the young set off on their own. They may check out nearby nest boxes, either scouting homes for next season or looking for roosting boxes for the cold winter nights, like these Eastern bluebirds. They may groom a bit to remove the last bits of fluffy feathers, like this red-shouldered hawk (Buteo lineatus). And then they are ready to spend an autumn and winter getting ready to repeat the cycle, this time as the parent birds. And we can look forward to watching the process again. 😊