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. 😊

 

        

Avian generations in the making – part 3A: raising and feeding babies

So here in North America, it’s approaching winter and it may seem a bit weird to have another blog at this time on birds raising their young. But I wanted to complete the series even though it has been delayed because of my volunteer activities and commitments the past month. Also, it is now late spring in the Southern hemisphere so for some people this is seasonal and there are other birds around them that are getting ready for babies, though different species than these American robins (Turdus migratorius). Because this part kept growing longer as I worked on it, I’ve divided it into two parts – this one on raising the babies until fledging and the next one on fledging and post-fledgling care. I hope all of you who read this will enjoy it no matter where you live.

It’s fascinating to me to watch the birds during their reproductive cycle; I always learn something new. Once parent birds have completed a nest to their liking, the female lays her eggs and proceeds to brood them, with some species sitting on the eggs almost full time right away and others taking breaks.

           

Carolina wren (Thryothorus ludovicianus)              Eastern bluebird (Sialia sialis)

An acquaintance recently told me about a friend of hers who commented that she had seen a very pregnant goose that was so fat, she was waddling. The acquaintance proceeded to give an avian reproduction lesson to her friend – a woman in her 80s – who apparently did not know all birds lay eggs! Even after babies hatch, the Canada goose (Branta canadensis) may still look well-fed!

Some bird species have young who are “precocial”, that is, they are covered with downy feathers and have open eyes when they hatch and are soon able to feed themselves. These species include turkeys and ducks, like these mallards (Anas platyrhynchos), and the young often leave the nest soon after birth (which makes them “nidifugous” – good Scrabble word!). The newborns may look fuzzy but it’s not long before they start to take after their parents’ looks.

Other birds, such as songbirds, are altricial (as are human beings) – they are naked and helpless at birth and require considerable care before they can walk, fly and feed themselves. If you have some in a nest that is easily observable (and you can take photos when parents are not there so you don’t distress them), it’s interesting to see how the babies develop.

               

Carolina chickadees (Poecile carolinensis) on 18 and 22 April           

Brown-headed nuthatches (Sitta pusilla) on 13, 25 and 29 April

 

 

Eastern bluebirds (below)

     

As the mother incubates the eggs, her mate will often feed her so she doesn’t have to leave the nest. This young osprey (Pandion haliaetus) was assiduous in bringing his female life companion fish. Then as the babies hatch, in many species both the male and female parents get busy bringing the young frequent meals.  It’s estimated that Carolina chickadees, for example, will bring over 5000 insects to their brood before fledging!

Northern mockingbird (Mimus polyglottos)

     

House finch (Haemorhous mexicanus)  and Red-headed woodpecker                (Melanerpes erythrocephalus)

              

Orchard oriole (Icterus spurius)                  Blue grosbeak (Passerina caerulea

  

Eastern phoebe (Sayornis phoebe)

In some species, the previous year’s young will help their parents with the new brood. Brown-headed nuthatches and American crows are examples of this. A pair of Canada geese that I observed this past spring seemed to have a domestic goose helping them out.

The parents have other chores, too. They must keep the babies safe from predators – Both American crows (Corvus brachyrhynchos) and common grackles (Quiscalus quiscula) will be chased away by songbirds, for example, because these birds will raid nests to eat eggs and babies. But the grackles must also protect their own young against the crows, pursuing them non-stop to drive them away.

 

For other birds, protecting the young can be more difficult. This mother wood duck (Aix sponsa) was raising her brood in a pond that was home to at least three large snapping turtles (Chelydra serpentina). Ultimately, another birder and I thought she only had two ducklings survive.   

Keeping the nest reasonably clean is another chore. The babies make this task a little easier than you might think because they defecate into a mucous membrane that forms a sac. When you watch a nest box, especially when it gets closer to fledging time, you can periodically see the parents flying out of the box with a white blob in their mouth, which turns out to be a fecal sac. They either discard it elsewhere or sometimes eat it for some nutritional benefit.

        

Brown-headed nuthatches

This year, I was surprised to have caught a female blue grosbeak during the cleaning – it appeared that she was actually pulling the fecal sac from the baby! Later, I read that some species stimulate defecation by prodding the babies’ cloaca so they can get on with the chore. I also caught a photo in which a baby bluebird had just presented its rear end to the parent for removal of a sac. I could imagine that some human parents might think a fecal sac would be a cool avian adaptation for their babies to have – no more dirty diapers and expense for diapers either! (An idea for an SF short story?)

     

 

After all their efforts, the parents are usually ready for those babies to fledge – the subject of the upcoming last blog in the series.

 

 

* Not all the photos in this blog are of great quality, I know, but my intention was first to show behaviors and secondarily to have some nice shots in the blog.

 

 

Avian generations in the making – part 2A: nesting and man-made construction

Hi folks — today I’d like to share with you some of my observations on the second part of avian reproduction — the process in which birds make a nest and lay eggs. (By the way, if you look up “bird nesting” on the Internet, the search will lead you to a human activity: a shared custody arrangement where children reside in one house and the parents take turns living there with them. In the bird world, some avian parents will actually share a home, such as this very old and enormous sociable weaver nest (Philetairus socius) that I saw in Namibia.)

Females of a few species will deposit their eggs in the nests of another, such as some cuckoos and brown-headed cowbirds (Molothrus ater). Some people dislike cowbirds intensely because of their nest parasitism (the cowbird baby will hatch first and eat all the food or perhaps get rid of the other eggs or babies). I figure that this is how the cowbird evolved – it didn’t make a choice to wipe out other species so I can’t blame or hate the bird for it. But the cowbirds do appear to pick on particular species as involuntary “foster parents” and this may be affecting the success of the other species’ reproduction.

There are two general broad categories of bird nests – those located in or on man-made objects such as nest boxes, atop downspouts, in vehicles, in plant pots and other places and those constructed by birds in trees, shrubs and on the ground (i.e., the natural environment which I will discuss in the next blog so this doesn’t get too long!). When birds make a nest in a “human area”, people will often try to accommodate them, not using the object or vehicle or making the space safer. For example, when American robins (Turdus migratorius) put a nest on one of my downspouts, I covered the rainwater container underneath it so the fledglings wouldn’t drown when they leapt to freedom. (I did it just in time, too!)

Swallows and phoebes will also use human constructions as places to situate their homes. The cliff swallows (Petrochelidon pyrrhonota) gather up mud, making countless trips to wad up small balls of the material to carry back to a place like this pier at Cane Creek Reservoir where they line up their nests in a row.

   

Barn swallows (Hirundo rustica) locate their nests inside, using rafters to place a nest; they may end up sharing space with paper wasps and organ pipe mud dauber wasps (Trypoxylon politum), which doesn’t seem to bother them.

The Eastern phoebe (Sayornis phoebe) may use an inside corner of a patio overhang as a site that is conveniently accessible from outside.

Purple martins (Progne subis) living east of the Rocky Mountains almost exclusively nest in homes provided by people. The hanging gourd nests can be seen in fields but nowadays other types of plastic constructions are also used.

    

In order to attract barn owls (Tyto alba) back to areas where many traditional barns have been razed, people are also placing special boxes in fields with plenty of open space in front of them so that the owls will have a hunting territory adjacent to their front door. Made of heavy plastic, these boxes may be monitored by organized groups in an effort to document their use.

   

At the Mason Farm Biological Reserve, an eagle scout project involved bringing in cranes to attach very large nest boxes to the tops of trees for barred owls (Strix varia) – so far, I have only seen Eastern gray squirrels making use of these nests.

And then there are the nest boxes that people put up to attract Eastern bluebirds (Sialia sialis), brown-headed nuthatches (Sitta pusilla) and screech owls. In my yard, other birds use these boxes, too, including the Carolina chickadees (Poecile carolinensis) such as my one-legged,  banded friend Chantal, Carolina wrens (Thryothorus ludovicianus) who may puzzle about how to get a long twig into the box and house wrens (Troglodytes aedon), who pile up twigs in a rather untidy stack inside the box.

   

   

Chickadees construct lovely mossy nests lined with hair, fur or plant fibers.

      

The nuthatches have nests with bark strips.

    

Sometimes people will intervene when a nest is in danger. A Carolina wren put her nest into a boat at Cane Creek Reservoir that was rented out to people and keeping the nest there was not a good option as she would be missing her nest for hours when the boat was gone. The land manager was so kind as to relocate the nest into a tree right in front of the boat’s resting place; unfortunately, inclement weather caused the nest to dislodge that evening.

   

Another danger may also threaten the birds and their nests – predators. A friend and I found it unusual to see a tree swallow (Tachycineta bicolor) putting a nest in a bluebird box on the edges of a farm. Several days later, we saw a black rat snake (Pantherophis obsoletus) peering out of the box and the swallows were nowhere to be seen.

   

If you can manage to mount your boxes on poles rather than trees, put both squirrel and raccoon baffles on them and also place them away from overhanging branches, they should stay relatively safe from the squirrels, snakes and raccoons. Next up: birds’ nests with no human connections.

 

 

A cuckoo causing confusion and consternation, delight and distress….

In the spring this year, I and another birder had the uncommon pleasure of seeing yellow-billed cuckoos (Coccyzus americanus) courting at Mason Farm Biological Reserve. These birds often stay high in trees, hidden by leaves, so it is always a treat to see one of them out in the open. Seeing two together, as the male tenderly offered his lady love a gift, was an unexpected pleasure.

 

 

Also unexpected have been my more frequent sightings of cuckoos in my yard. Last year, I had caught a glimpse of one in a crepe myrtle tree; I thought it was a lucky fluke. This year, I began to see cuckoos in the large trees of my front yard more often, though frequently they were half hidden behind the leaves of the willow oak, red cedar and persimmon. I did hear their identifying calls so I knew when they were around but not in sight.

Then, this past Sunday afternoon as I sat on my front porch photographing birds and insects visiting my flower garden, I suddenly caught sight of a cuckoo flapping about on a makeshift trellis I had arranged around an oak stump where I hope Carolina jasmine and other climbing vines will create a pleasing area.

The spot is popular with chipmunks and Eastern gray squirrels (Sciurus carolinensis), as well as many smaller birds like Renee, one of the banded Carolina wrens (Thryothorus ludovicianus) living in my yard.

     

But to see a large cuckoo sprawled on the branches was unexpected and I feared that it had an injured wing after escaping from a hawk attack. I took a few quick photos. Then I approached to get a better look — the bird tried to flutter away but didn’t get far.

I ran inside to get a box and the phone number of a local wildlife rehabilitator. I left a message and managed to get the bird in the box, to which it protested vigorously. When I closed the top, it calmed down and then the rehabilitator returned my call stating that perhaps it was a fledgling – I said it looked like the wing was injured so she asked me to take a photo of it.

When she saw my point-and-shoot camera photo, she said it wasn’t clear whether it was a juvenile or not and asked me to photograph the beak. Young birds have a yellow or bright “lining” where the beak meets the face. This area is called the gape flange and in most birds, the color disappears as they age and the beak becomes firmer.

      

With a slightly better photo of the bird’s head and beak, the rehabilitator informed me that this was indeed a young bird. She also told me that the bird probably was feigning a wing injury to get the parents to come back more quickly with food! On her recommendation, I put the bird back on a stump by the makeshift lattice.

I knew about killdeer adults pretending to have a broken wing and dragging it on the ground to lead predators away from a nesting area. The yellow-billed cuckoo adults will also do this distraction display.

But I had not heard of fledglings engaging in this ruse. The rehabilitator said she had known of crow fledglings that kept this up a couple days, although she didn’t realize cuckoos would do this as she doesn’t get many calls about this species. But, she commented, “birds aren’t stupid; a free meal is a free meal.”

I kept checking on the bird and it stayed on the stump quite a while. Then it hopped down into the leaf litter and made its way over to some large rocks under a cedar tree with low-hanging branches. First, the cuckoo just hung out on the rock. And all this time, it kept that wing stretched out.

Then the bird lunged upward to get onto the branch. At this point, I seriously wondered whether it wasn’t injured after all, perhaps having fallen out of the nest and hurting its wing when it landed. It got a purchase on the limb and continued to keep its wing out. Then it fell off the branch.

       

After a short rest on the rock, the fledgling jumped up on to the branch again and stayed there. I went inside and returned periodically to check on him/her. About 3.5 hours from time I first saw him/her, the bird was still resting on the branch with the wing out. S/he was no longer wary when I came to look but viewed me calmly.

About 30 minutes later, I went back outside for another check and found the bird on the branch, but now with its wings both folded in towards its body. I was really glad that it appeared to be ok and hoped the parents would come for it. I had heard them calling earlier in the afternoon but never saw them approach the offspring, though this may have happened when I went inside for brief periods. And when I finally looked at the first photos I had shot in quick succession, I saw a couple where the bird had drawn in both wings to hop about, only to stretch out its wing later again.

 

When it was almost time for me to leave for a theater engagement with a friend, I went back out to check one more time and discovered my cuckoo friend was gone. I examined the cedar tree to see if it was further up, as well as the trees and ground all around, and could find no sign of him/her. I hoped that s/he finally decided to give up the display and just flew to a better place. I did check the area the next two days but did not see the bird again.

Then, this morning, a distressing finding started off my day. When I went outside, a neighbor boy was staring at the ground in front of my street-side willow oak. When I got there, the cuckoo lay dead at the street edge. He said he had seen the bird yesterday sitting on the road “with a broken wing”. I wish I had seen it – I don’t know if the bird had really been injured after all, was feigning an injury and then fell prey to a neighbor’s cat (which is what I think happened as its underside looked like it might have been in a cat’s mouth), or if something else occurred. In any event, it was such a sad discovery.

I buried the cuckoo while regretting how short its life was. I’m glad I don’t let my cats roam about anymore and I wish neighbors would also keep their felines inside, even though I know that birds might fall prey to a hawk or die because of a disease. But I wish I’d been able to help this beautiful young bird. My emotions tell me the cuckoos won’t return but my mind says they won’t avoid the yard because they lost an offspring. Time will tell.

 

 

 

Outwitting the starlings during Winter Storm Helena

white-tailed-deer-i77a4029-maria-de-bruyn-resSo this past weekend, our part of North Carolina dealt with Winter Storm Helena, which brought us 83 straight hours of below-freezing temperatures (e.g., -9C/15F but we had lower) and a need to bundle up really well if venturing outside. (It also brought me a realization that winter storms are being named like hurricanes.) The first morning, when I went out to fill the bird feeders, I didn’t put on gloves or a cap and dealt with hypothermia symptoms when I finally went inside. I had on triple layers after that! The deer had their fur puffed up and seemed to be coping well.

The frigid air made me feel very sorry for the wildlife, although living outdoors is, of course, what they do and what they have evolved to accommodate. (I did hear today, however, of some birds and small animals that were found frozen to death!) With the snow covering the ground, it turned out the birds were more than happy to visit the feeders and piles of food I had strewn on the snow for the ground feeders.

yellow-rumped-warbler-i77a4305-maria-de-bruyn-res

Not only did I have many types of birds coming round, but also record numbers of them. Some birds, like the yellow-rumped warblers (Setophaga coronata, above), usually tend to visit on their own and are not happy with their species mates in the vicinity but during these days, I had four of them alighting near feeders at a time. The same was true for the colorful pine warblers (Setophaga pinus) although they didn’t come close to each other.

yellow-rumped-warbler-i77a3138-maria-de-bruyn-res

pine-warbler-i77a2441-maria-de-bruyn-res

The Carolina wrens (Thryothorus ludovicianus) and Carolina chickadees (Poecile carolinensis) don’t seem to have too many problems with sharing space and visited the feeders in the same way they always do – quick flights to and fro from nearby tree and shrub branches.

carolina-wren-i77a3873-maria-de-bruyn-res   carolina-chickadee-i77a2710-maria-de-bruyn-res

brown-thrasher-i77a4236-maria-de-bruyn-res

 

Most of the birds were fairly content to be in close proximity to one another during the snow days. The brown thrashers (Toxostoma rufum) did get very cross with one another, however, when they came too close to one another and chased their rivals away.

Sometimes a bird would go off and rummage in the snow, like this blue jay (Cyanocitta cristata).

 

blue-jay-i77a2776-maria-de-bruyn-res blue-jay-i77a2770-maria-de-bruyn-res

european-starling-i77a2674-maria-de-bruyn-resThe biggest challenge for me was keeping the suet and meal worms in supply, mainly because the European starlings (Sturnus vulgaris) show up in large groups and gulp down food at a speedy pace. The other birds nibble but the starlings seem to inhale food as if they have vacuum cleaners in their throats. They can get grumpy with one another and don’t mind landing atop each other to get a foothold on the feeder.

brown-thrasher-i77a3641-maria-de-bruyn-resI was pleased that the other species of birds are learning to cope with them, no longer being intimidated to fly away when these greedy avians arrive. However, they may get displaced from a feeder just because the bulky starlings take up so much room and never wait their turn to get a spot. The larger birds, like the thrashers and red-bellied woodpeckers, may express their displeasure to the starlings while trying to hold their ground. Other people report common grackles (Quiscalus quiscula) as feeder dominant birds but they are well behaved at my house.

common-grackle-i77a3068-maria-de-bruyn-res

suet-i77a3541-maria-de-bruyn-res

So, what was I going to do? Some of my feeders are set in a flower garden and I had left the dried stalks of sage, butterfly bush and scarlet mallow standing. They don’t look pretty but the birds love sitting on them near the feeders as they digest a bite before getting another. So I began smearing suet on the stalks, which are not sturdy enough to hold the starlings.

The yellow-rumped warblers and chickadees were pleased, as was my faithful ruby-crowned kinglet (Regulus calendula) and the Carolina chickadee.

yellow-rumped-warbler-i77a3913-maria-de-bruyn-res  carolina-chickadee-i77a4283-maria-de-bruyn-res

ruby-crowned-kinglet-i77a4167-maria-de-bruyn-res

To my surprise, even the larger Northern mockingbird (Mimus polyglottos) and brown thrashers discovered and sampled the suet-laden stalks.

northern-mockingbird-i77a3629-maria-de-bruyn-res   brown-thrasher-i77a3607-maria-de-bruyn-res

Following advice from the Bird Sleuth program, I had stuffed the bluebird and nuthatch boxes with pine needles and wool in case the birds wanted to shelter there overnight. I don’t know if any of them did, but the brown-headed nuthatches (Sitta pusilla) were again checking out their preferred nest box, so perhaps they did roost there overnight.

brown-headed-nuthatch-i77a3959-maria-de-bruyn-res    brown-headed-nuthatch-i77a4183-maria-de-bruyn-res

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I was filling the heated bird bath daily, too, as it became a popular drinking fountain.

The thrill of the wintery snow days for me was a new yard visitor, a gorgeous fox sparrow (Passerella iliaca). I have never had one here before so it was a wonderful surprise and discovery. (I’m still hoping that a red-breasted nuthatch will turn up, too.)

 

 

fox-sparrow-i77a4347-maria-de-bruyn  fox-sparrow-i77a4348-maria-de-bruyn-res

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The birds “missing” from the storm gathering were the hawks. I’ve had a Cooper’s hawk  (Accipiter cooperii) visiting for years, but recently discovered that a sharp-shinned hawk (Accipiter striatus) is also taking birds from my yard. As they look quite similar, the sharpie may have been coming around for some time and I just never realized it. They were both here in the last couple weeks, but neither one made an appearance during the storm.

coopers-hawk-i77a1341-maria-de-bruyn-res   sharp-shinned-hawk-i77a8520-maria-de-bruyn-res

Our two neighborhood white-tailed does (Odocoileus virginianus) and their three offspring came by, obviously finding my yard a peaceful and safe space to rest.

white-tailed-deer-i77a4432-maria-de-bruyn-res   white-tailed-deer-i77a4431-maria-de-bruyn-res

So I’ll end with some “beauty shots” from the snow days as the snow and ice are now melting. In two days’ time, we are supposed to be having temperatures of 68F/20C or higher! And then we can wait out the rest of January as well as February and March to see if we get any more winter storms.

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White-throated sparrow (Zonotrichia albicollis)

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     house-finch-i77a2852-maria-de-bruyn-res

Chipping sparrow (Spizella passerina)        House finch (Haemorhous mexicanus)

dark-eyed-junco-i77a2590-maria-de-bruyn-res  downy-woodpecker-i77a2810-maria-de-bruyn-res

Dark-eyed junco (Junco hyemalis)          Downy woodpecker (Dryobates pubescens)

eastern-towhee-i77a4111-maria-de-bruyn-res    northern-cardinal-i77a3099-maria-de-bruyn-res

Eastern towhee (Pipilo erythrophthalmus)      Northern cardinal (Cardinalis cardinalis)

blue-jay-i77a2858-maria-de-bruyn-res     eastern-bluebird-i77a2285-maria-de-bruyn-res

Blue jay                                                       Eastern bluebird (Sialia sialis)

red-bellied-woodpecker-i77a4047-maria-de-bruyn-res       ruby-crowned-kinglet-i77a4263-maria-de-bruyn-res

Red-bellied woodpecker (Melanerpes carolinus)     Ruby-crowned kinglet

northern-mockingbird-i77a2714-maria-de-bruyn-res   pine-warbler-i77a2657-maria-de-bruyn-res

Northern mockingbird                                              Pine warbler