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

‘Rassing – a surprise visitor – what a delight!

(Warning – this is a bit of a long blog!) Several years ago, what was likely a rufous hummingbird took up residence in my yard during the winter months. That was really unexpected — while it’s not uncommon for migrating or some resident hummingbirds (especially ruby-throats, Archilochus colubris, above) to spend wintertime in North Carolina, particularly along the coast, it’s not so common in the central part of the state. That experience taught me that it’s a good idea to keep up a nectar feeder in the winter as you never know when a stray migrant might show up. In 2015 and 2016, I traveled with fellow birders to visit people who had a buff-breasted (Amazilia yucatanensis) and calliope hummingbird (Selasphorus calliope) wintering at their homes. In actuality, however, I didn’t really expect a rare passerby in my yard.

 

It was consequently with great surprise that I saw a hummer hovering at the nectar feeder last week. “Oh, wow!” I thought; “a ruby-throated hummer is passing through as a very late migrant.” I grabbed my camera to take a few shots and immediately felt perplexed.

 

The bird looked like he had a purple rather than ruby or red gorget (throat feathers). The white patch behind his eye also showed prominently because of his very dark head.

To me, it also looked as if this hummer had blue patches on his tail feathers. (Most say his flanks are green and a hummingbird expert said he has iridescent black tail feathers; the way the light reflects off them made me see blue, however.)

I got a few photos and cautiously asked birding experts on a facebook group if he could possibly be a black-chinned hummingbird (Archilochus alexandri), also sometimes known as the Alexander hummingbird. It seemed unlikely as their normal range is the Western part of the Northern hemisphere, reaching north into Canada (Alberta and British Columbia), east to Oklahoma, and as far south as Mexico, where most spend the winter.

A couple people thought I might be correct, but most thought it was a ruby-throated hummingbird. My spring-summer ruby-throated residents had left at least a month ago but I thought perhaps a late migrant might have arrived. The next day, I saw the bird again and became convinced that it was a black-chinned hummer; his purple gorget was very obvious to me. I posted new photos and now the experts agreed that I was correct. That was very cool – I got a lifer without even leaving my own yard!

 

A couple days later, North Carolina’s hummingbird researcher, Susan Campbell, came to my home to band the unusual visitor. I invited a friend who had been to bird bandings in my yard before to come for the happy event.

Susan arrived early and first set up a cage trap for ‘Rassing (short for the Dutch word verrassing, which means surprise; I wanted him to have a name during his stay 😊). She left the door open with a long string attached and hung the nectar feeder on the outside. It wasn’t long at all before the bird arrived for a drink. When he left, Susan moved the nectar feeder inside the cage.

‘Rassing returned for another drink and flew right into the cage, which Susan shut promptly. She had already laid out her banding materials so she could remove him from the trap promptly.

He went into a small bag (the kind often used to hold birds for banding) which Lucretia held while Susan began filling out the paperwork.

Then the actual banding procedure began. Susan first checked his legs to ensure that he hadn’t been banded already – the hummers rarely show their legs so that was necessary.

Then she got ready to put a thin red metal band on his tiny leg with a silver band showing his numeric code for identification in case he is caught again some time (Band number 7100 (M)-41902).

She checked the length of his bill – 19.19 mm. She also advised that bird feeders with long slits are not preferred even if the birds like them. It turns out that the thin slots can rub against the bill and wear it down, damaging the bill and making it vulnerable to infection. (I afterwards enlarged the slots into ovals and circles and went back to a couple other feeders I had with larger holes.)

She blew on his stomach feathers to check his fat; he was not a hefty bird but certainly a healthy adult male. His weight turned out to be 3.09 g. She also recorded his body length.

She stopped for a moment so I could take a few photos trying to get a good shot of the purple gorget. It looked like ‘Rassing was trembling but this was the vibrations from his rapid breathing. (When resting at 91⁰ F, they take about 245 breaths per minute; at 55⁰ F, this rises to 420 breaths per minute!!) Susan thought he was acting fairly calm.

She measured his short tail (23.5 mm), as well as his wings (40.42 mm). The female black-chinned hummer would have more rounded wing feather tips than this male.

 

Susan took a few photos of ‘Rassing and he got a few long drinks from a feeder held by Lucretia. Then Susan gave me the honor of releasing him – and to my delight, he chose to sit in my hand for what seemed to be at least 90 seconds. I could feel him breathing and it was a real thrill to see him so close. With a little flutter of his wings he took off – and then stayed away from the feeder for quite some time.

 

I added a feeder in the backyard and ‘Rassing began preferentially feeding there – perhaps the front yard had acquired some unpleasant memories. However, at the end of the day, I would remove the backyard feeder so that visitors who wanted to see him had a better chance of seeing him dine at the front-yard feeders.

 

 

A fair number of birders were interested in being able to add him to their life, state and county bird lists, so I offered to schedule visits through a birding listserv for a few people at a time. ‘Rassing appeared more reticent to stay at the feeder when there were more than 2 or 3 people watching, which is understandable. Who wants an audience for each meal and snack you eat??

When it rained, the feathers atop his head clumped together, giving him a new “hair-do.”

 

 

It appears that this species of hummingbird has not been studied much. I found his behavior interesting and spent a good amount of time observing him (chores had to wait). When I watched him leave the feeder and go to a nearby tree, he would sometimes watch me (turnabout fair play, of course).

 

 

He seemed very comfortable with lots of other bird species at nearby feeders. Perhaps it gave him a safer feeling.

‘Rassing tended not to sit on feeders, as ruby-throated hummers often do. Instead, he mainly hovered and vigorously pumped his short tail quite a lot. I learned that this tiny bundle of energy was breathing at a flight rate of about 1260 beats per minute!

 

Occasionally, you could see the band on his leg but mostly he kept his legs tucked into his body.

In the evenings, he came around nearly the same time each day to have a longer drink and then he sometimes perched while feeding.

 

A Cornell University website says that black-chinned hummers rarely stay at a feeder longer than a day during migration, even when food is scarce. In my yard, he had access to lots of bugs (I have a small pond) and three types of sage/salvia were still blooming. Indeed, he sometimes came to the feeder with pollen covering the top of his bill.

Yesterday morning, ‘Rassing apparently had decided it was time to move on. After the warmest Halloween on record in our area, the temperature plunged during the night to the 30s. The next morning was the same and he may have decided it was time to go to warmer climes.

 

I did feel lucky that he graced my yard with his presence for a week; it gave me something to celebrate during a personally challenging time. The oldest known black-chinned hummer was more than 11 years old; if ‘Rassing likes going east during migration, perhaps he’ll stop by again next year – wouldn’t that be a tremendous surprise! 😊

 

Summer hummers – entertainment for free: part 2

In my yard this summer, the ruby-throated hummingbirds (Archilochus colubris) came late to the feeders (similarly to what other people in the area had reported). Now, there are at least four vying for the four feeders, claiming territory for their own.

 

 

One bird in particular is most likely to be seen enjoying the garden flowers, including blue-black sage (Salvia guaranitica) and hot lips salvia (Salvia microphylla ‘Hot Lips’). In the first two photos below, you can see as his throat starts to bulge more as he sucks up the sweet nectar to complement his mostly insectivorous diet.

 

 

The airborne nectar droplets indicate that sometimes this hummer is a messy eater — or must leave quickly as another hummer is almost literally on its tail.

A couple of the birds spend a lot of time near the nectar feeders, perching close by to chase off anyone who comes near.

 

 

 

They each have favorite perching spots from which they can observe if an “intruder” is coming near the feeder they have claimed.

 

 

Sometimes, they fly up to a higher perch so they can see both the front and back yards – a necessary vantage point if they want to keep an eye on where everyone is.

 

Most ruby-throats have 940 feathers, all of which are replaced each year. As they take little rests, they stretch their feathers and may also groom them.

When a rival approaches, they spread their rectrices (tail feathers) – both when sitting and in the air.

 

Their feathers are beautifully arranged, looking like scalloped decorations.

 

They make frequent trips to the feeders and then occasionally “air out” their tongues.

 

The bill of the ruby-throated hummingbird is one of its most distinctive features. It measures about 0.59-0.79 in (15-20 mm) in length and is said to open no more than about 0.39 in (1 cm wide) at the tip. The hummers in my yard seem to be able to open their mouths to varying extents, however. They consume nectar by extending and contracting their tongues up to 13 times per second.

 

 

 

A quick, only few-second nap is also a frequent behavior. The hummers are almost constantly at the feeders and thus bulking up for their long migration, but they also expend considerable energy chasing one another away from feeders and flowers!

 

 

 

The hummers are not fazed by weather, zipping around rain or shine. Putting on weight and strength for their autumn migration down south is important for survival!

These minute marvels are such a pleasure to watch; I will certainly miss them when they begin their journeys to their wintering grounds.

 

Summer hummers – entertainment for free: part 1

 

When a hummingbird other than a ruby-throated hummingbird (Archilochus colubris) is seen in the Triangle area of North Carolina, it is listed as a rare bird on the Cornell Lab of Ornithology listserv. One year, I did have a chance to see a buff-bellied hummer visiting in a nearby town though; another year a rufous hummer frequented my own feeders in the winter. Mostly, however, it is the ruby-throats who take up residence at my address, which is just fine as these feisty tiny birds provide loads of entertainment.

 

During a trip to Quebec earlier this year, we also saw ruby-throated hummingbirds there – early arrivals during the spring migration.

 

A few years ago, one of my blogs focused on their preening and cleaning, so this time I’ll mostly feature some of my favorite photos of them taken this summer in various places. (When looking through the shots, I had a LOT I liked, so this is now going to be a 2-part blog!)

At Sandy Creek Park in Durham, one female hummer had made a coral honeysuckle (Lonicera sempervirens) one of her preferred dining spots.

 

 

A butterfly garden featuring blue-black sage (Salvia guaranitica) and bee balm (Monarda) also attracted her and some other hummers.

 

One female found the bee balm to be a good place to rest, understandable since these bundles of energy have a high metabolic rate. Their hearts beat up 1260 times per minute and they take about 250 breaths per minute even when they are resting! Taking a few sips while remaining perched has to be a welcome luxury.

 

 

 

 

The hummers’ main wing bone, the humerus, is adapted to hovering flight and they have very large deltoid pectoral muscles relative to their size.

 

 

Male birds produce sperm that flows through the vas deferens (sperm duct) to the cloaca. When they mate with a female, they transfer sperm by touching the tip of their cloaca to that of the female; they do not have a penis. Females only have a functional left ovary; the right one atrophies early in her development, which allows her to avoid the extra weight of a second ovary and makes her lighter for long migratory flights.

One big treat for me this year was finding two ruby-throated hummingbird females tending a nest, the first time I had been able to spot this.

 

Later, I was able to take a quick photo of one female collecting cattail fluff with which to line her nest.

Even when several ruby-throats are frequenting an area, the (temporary) coloring of their feathers can help distinguish them. This young male had a few olive-green dots under his eye and a bit of white on the crown of his head.

 

A somewhat more mature male has a little white patch behind his red gorget.

 

They are all little beauties! Second part of this blog is coming up and then on to Costa Rica!

Rain drops, dewdrops and frost – Mother Nature’s adornments

rain drops IMG_8843© Maria de Bruyn resDewdrops in the early morning, raindrops during the day, and frost covering everything outdoors can be seen merely as various manifestations of heavenly water on earth, but another way of looking at them can be as nature’s jewels. When light and sunshine illuminate the drops and crystals, they lend an air of elegance and beauty to whatever they have covered.

When it rains, leaves and blooms may look uniformly slick with moisture but we often see them covered in rain drops. Have you ever wondered why the rain drops are of different sizes?

dewdrops IMG_7571© Maria de Bruyn res day lily with rain drops IMG_5259© Maria de Bruyn res

The US Geological Survey’s Water Science School reports that water vapor wraps around particles in the air (salt, smoke, dust) which are of different sizes; then when the drops begin falling to earth, they bump into other drops and merge. The drops that merge with more “neighbors” become larger. Rain drops suspended from branches and leaves are quite lovely.

rain drops DK7A8019© Maria de Bruyn res rain drops DK7A8052© Maria de Bruyn 2 res

rain drops DK7A8020© Maria de Bruyn resruby-throated hummingbird DK7A8190© Maria de Bruyn resThey often roll right off birds’ feathers but occasionally adhere, as was the case for this ruby-throated hummingbird (Archilochus colubris) at a feeder sheltered by a roof overhang.

Dew – water droplets on surfaces of objects and vegetation – forms when an exposed surface cools down by radiating its heat and the moisture in the atmosphere then condenses faster than it evaporates. It looks beautiful on flowers and other plants, such as these grasses, the Virginia meadow beauty (Rhexia virginica) and the Orange mahogany esperanza (Tecoma stans “Orange Mahogany”).

dewdrops DK7A2989© Maria de Bruyngrass dewdrops DK7A3012© Maria de Bruyn res

Virginia meadow beauty DK7A3083© Maria de Bruyn res

Orange mahagony esperanza IMG_6425© Maria de Bruyn res Orange mahagony esperanza IMG_6414© Maria de Bruyn res

Some plants actually mimic dewdrops, like Tracey’s sundew.

Tracy's sundew DK7A5228© Maria de Bruyn res Tracy's sundew IMG_4952© Maria de Bruyn

On spider webs, water and ice droplets outline the architecture created by the arachnids, showing off the symmetry and beauty of the lines.

spider web DK7A6479© Maria de Bruyn res spider web with dewdrops IMG_2683©Maria de Bruyn res

spider web with dewdrops IMG_6438© Maria de Bruyn res spider web with dewdrops IMG_6396© Maria de Bruyn res

sheetweb dwarf spider IMG_0959©Maria de Bruynsigned

 

The webs of sheetweb dwarf spiders (Florinda coccinea), often not so visible in the grass, become quite noticeable when covered in dewdrops and then you can often spot the little red spider hanging underneath waiting for its prey.

sheetweb spider DK7A4086© Maria de Bruyn sheetweb dwarf spider DK7A4076© Maria de Bruyn res

spider web splendor IMG_2727©Maria de Bruyn res

 

In this case, the plant looked like a natural jewelry stand for strings of glass or diamond beads.

It was interesting for me to learn that the Indian Institute of Management Ahmedabad (IIMA) and the International Organisation for Dew Utilization (OPUR) created a dew harvesting system for a semi-arid area in India. Their condensers can collect more than 200 liters of dew each night from October through May and could provide an additional water source for people in arid coastal regions.

Leaves and flowers, like this coral honeysuckle (Lonicera sempervirens) can seem bedecked with glistening jewels when the ice crystals of frozen dewdrops adhere to their surfaces and edges.

Coral honeysuckle DK7A6792© Maria de Bruyn resCoral honeysuckle DK7A6805© Maria de Bruyn res

frosty morning leaves IMG_7351©Maria de Bruyn Nat GeoFrost may appear to be translucent or crystal clear; when a mass of crystals are together, they look white in color because they scatter light in all directions. The ice crystals of wind frost (also known as advection frost) arise when a very cold wind blows over tree branches, leaves and flowers; they can form gorgeous borders on these surfaces.

Early morning can be a great time for nature walks – beautiful sunrises, brisk (or cooler) temperatures and awakening wildlife make for interesting viewing. And raindrops, dew and frost can add extra scenes of beauty for us to appreciate!