The birdy breeding cycle 2020 – 4: growing into adult plumage

As mentioned in a previous blog, when young birds are ready to leave the nest, they don’t necessarily look like their parents. Many of the altricial birds (ready to move about and forage on their own) may resemble fluffy versions of the adults, as is the case with these hooded merganser ducklings (Lophodytes cucullatus) following their mother.

The brown-headed nuthatch babies (Sitta pusilla) look very much like their parents. Sharp-eyed observers might notice that the tops of their heads are not as brown as those of their parents.

The Eastern meadowlark juveniles (Sturnella magna) resemble their parents but lack the bright yellow and black coloring on the throat and breast.

 

The difference between adult and juvenile downy woodpeckers (Picoides pubescens) is subtle. The female woodpecker has no coloring on the top of her head, which is simply bedecked with the white and black feathers that cover the rest of her body.

The male woodpecker has a red patch on the back of his head.

The immature woodpecker has a red patch on top if the head and this is lost as the bird reaches adulthood.

The Northern mockingbird youngling (Mimus polyglottos) resembles mom and dad quite a bit except for some spotty streaking on the chest.

In other species, the babies start out looking quite different from their parents. Spots characterize many members of the thrush family, with birds like wood thrushes (Hylocichla mustelina) and hermit thrushes (Catharus guttatus) retaining the spots in adulthood.

   

The Eastern bluebirds (Sialia sialis) and American robins (Turdus migratorius), on the other hand, are only strongly speckled as immature birds, losing their spots as they mature.

In some cases, the birds undergo color changes. Male summer tanagers (Piranga rubra) start out yellow-orange with their reddish coloring appearing in patches until they finally achieve their very bright adult red hue. Some of the immature birds are really quite beautiful with their mottled colors.

 

   

The male blue grosbeaks (Passerina caerulea) start out brown and gradually achieve their dark blue feathers with some reddish/brown wing accents.

 

 

Among the birds that undergo a major change are the European starlings (Sturnis vulgaris). The young birds start out with dullish brown or gray hues with some streaking. Eventually, they begin to develop some spotting and then ultimately achieve the beautiful adult summer glossy feathering with green and purple hues mixed in.

 

 

The females of the Eastern towhee species (Pipilo erythrophthalmus) have a brown back above a white breast with reddish sides, while the males have black backs.

The young developing towhees keep you guessing as to their sex since they undergo quite a lot of color changes as they develop. They do have the white in their tails, which helps you identify them as to species.

 

  And then we come to the hawks and owls. It is not unusual for the young raptors to look nothing at all like their parents. The red-shouldered hawks (Buteo lineatus) start out looking like fluffy and then becoming gradually kind of scruffy looking.

     

As they get a little older and leave the nest, they start to resemble their parents more but have more streaking on the breast. As they near adulthood, they look much more like mom and dad.

 

And we end with an example of another raptor. There is a real difference between the baby great horned owl (Bubo virginianus) and its parent as you can see. Many birds are impressed by the adults but ooh and aah over the nestlings. It must be the combination of those big eyes and fluffy feathers that take away attention from the already formidable claws!

               

Next up – a foray into the world of amphibians and reptiles!

The Northern mockingbird boundary dance

In between searching the web and bird guides for plant and other IDs for my (long-time coming, I know!) next Costa Rica blogs, I’ve taken time for nature walks so that I can continue to see lovely wildlife and plants here in my home area. A recent discovery came up unexpectedly when I was with a couple friends looking for migrating warblers at a local lake.

Previously, I’ve written about how Northern mockingbirds (Mimus polyglottos) engage in wing-flashing behavior, which scientists continue to study in an effort to pinpoint its various functions. I’ve seen the wing-flashing every year since I began watching the mockingbirds, but a few days ago I saw a pair of mockers exhibiting a different type of behavior that was very interesting to watch. (If you click on a photo, you can see it larger.)

The two birds landed on a section of parking lot and proceeded to face off against one another.

They slowly drew closer.

Then they stretched to stand very erect.

 

They confronted each other face to face.

 A little hop by one or the other followed. A shifting from side to side ensued.

Occasionally, they flew up with flapping wings to confront one another in the air (I tried to video this but obviously don’t know yet how to take proper videos with my new camera). According to research, they might actually have an airborne physical tussle but that didn’t really happen with this pair.

So why do the mockingbirds do this? These displays are called boundary dances, where male birds go to the edge of the territory they claim to ensure that another male does not encroach on their domain.

After several confrontations, this pair eventually decided that they had made their point. It has been reported that they stop when one dominates but these males seemed evenly matched. Or perhaps they were not feeling very aggressive. Each one flew off and presumably they settled in to patrol the areas that they had claimed as their own. It was nice that there was a peaceful end to the show of masculine bravado!

Going out in nature is such a delight – you never know when you will discover something new (at least to yourself!)

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.

 

Surprise gifts from Mother Nature in 2018 – part 1: birds

On the last day of January 2019, I thought it would still be ok to post a couple blogs on some surprises I encountered the past year. Almost always when I go out on nature walks, I encounter something new – a species of wildlife or plant that I have not seen before or an interaction between species not previously observed. So, I wanted to share a few of those delightful surprises from 2018. In this blog, I focus on birds; in the next part, other kinds of wildlife will be featured.

As I mentioned in a previous blog, my own front yard was the scene of my biggest surprise last year when a snowstorm brought feeder visitors whom I had never seen before and who rarely come to the state where I live. The evening grosbeaks were just stunning.

 

They were not the only grosbeaks who treated me with their beauty, however. I’ve had rose-breasted grosbeaks (Pheucticus ludovicianus) visit the feeders before, but they still always elicit my appreciation with their bright colors.

 

In late October, an osprey (Pandion haliaetus) made me stop for a photo as the other birds of its species had already gone south for the winter. The bird was perched on a branch extended over a pond and had to unfortunately contend with a persistent crow that was harassing it. After some time, the sea eagle finally took off with the crow in pursuit – it seemed that the osprey might have injured its wing and perhaps that accounted for a delayed departure to warmer climes.

  

Although the pursuit photos are not high-quality, you can see a gap in the osprey’s wing and perhaps it was waiting for healing before it undertook a very long journey.

 

On another day, I was near a wetland when an unexpected visitor flew onto a branch above me. Green herons (Butorides virescens) usually keep their distance from me; I regretted that it was overcast and the lighting was not wonderful for my close-up portrait of this colorful immature bird.

 

A more muted bird, but lovely nonetheless, is the Northern mockingbird (Mimus polyglottus). When I saw this individual in late December, I was thinking that it must be difficult for them to find food as the vegetation shrivels and insects are in hiding. At that moment, the bird dropped to the ground and was foraging – coming up with a bug to prove that they still could find sustenance in the cold temperatures!

  

The mockingbirds are often solitary except for breeding season. Some people complain that they are aggressive towards other birds at their feeders but those in my yard are not that way at all. They share space at feeders and don’t chase anyone else away. When it is mating and nesting time, however, they can become quite territorial and are very protective of their nests. This seasonal “grumpiness” was brought home to me one day along a country road when I witnessed a pair of mockingbirds driving a third bird – rival? Intruder? – away from their roosting spot.

When large flocks of gulls and double-crested cormorants (Phalacrocorax auratus) visited a small local lake because of a shad die-off, I had the chance to watch them for a while. One day, it was interesting to observe how one cormorant wanted to jump up on a floating platform, but another bird didn’t want him/her there. They faced off with open beaks – the bird wanting to get out of the water won.

 

 

It’s always interesting to me to watch birds as they forage for sustenance. When I think of woodpeckers, my thoughts immediately turn to nuts and insects, which I think of as their staple diets. So it was a surprise to me to see this red-bellied woodpecker (Melanerpes carolinus) dining at length one day on nice ripe persimmons – a bird with a sweet tooth!

 

 

 

Well, I probably shouldn’t say “sweet tooth” but “sweet tongue”. Woodpeckers don’t have teeth but they have exceptionally long tongues that can be wrapped around their brains inside their skulls when not being used to extract insects and other food morsels from crevices.

Another bird that has a long tongue is the great blue heron (Ardea herodius). One day, I came across this bird on its favorite roosting log obviously trying to dislodge something that had gotten stuck – or perhaps something that tasted foul. I hadn’t really seen the species’ tongue before, so the bird gave me some good views.

  

The effort of shaking its head also led it to protect its eye with the nictating membrane.

Because tufted titmice (Baeolophus bicolor) visit my bird feeders daily to get nuts and, to a lesser extent, seeds, I associate them completely with that type of diet. It was that assumption that made me do a double-take when I spotted a titmouse on a walk with a long spaghetti-like object dangling from its beak. It didn’t seem like a grass stalk so when I lifted my camera to look through the zoom lens, I discovered it had a worm snake (Carphophis amoenus amoenus) in its beak – a finding that really did astound me.

 

As I took photos, the bird finally flew further away and unfortunately dropped the reptile when it came close to a creek. I felt a bit guilty, thinking I might have disturbed its meal but after waiting about 5 minutes, the bird suddenly flew up with the snake back in its beak! It obviously really wanted to hang on to that prize!

 

And now on to part 2 of my 2018 surprises – some more reptiles and amphibians, bugs and mammals!

The birds and the beautyberry – a great match

Not long after moving into my current home, I began looking for plants that would provide color as well as food for the birds and pollinators in my yard. Although I was not aware at that time of the rationale for avoiding exotics and preferring native plants, I did make some good choices, including an American beautyberry (Callicarpa americana L.) which is also called a French mulberry.

This shrub can grow about 5-7 feet high and about that size wide as well. The flowers are tiny and a pale lilac color, circling the stem like a corona.

They eventually turn into green berries that slowly turn in color, starting out in shades of pink and lilac and eventually gaining a beautiful deep purple shade as they ripen.

People can eat the berries, which are apparently very sweet. I haven’t tried them; they do cause stomach cramps for some people if more than a few are eaten. They are a popular food for wildlife, however. White-tailed deer like both the berries and leaves; raccoons and opossums eat them, too. It is the birds that really get the most fruit from my bushes, including Northern cardinals, Eastern towhees and gray catbirds. The birds kindly transported some seeds to a spot next to my back porch, so I now have a large bush there as well.

When the berries began ripening at the end of August, the cardinals began dining on them first. They were quickly followed by house finches (Haemorhous mexicanus) who began visiting the shrubs daily. The female house finch stayed on the bush far from the house.

 

 

The male house finches were bolder and fed on the berries right under the kitchen window. It has been a pleasure to watch them.

 

 

 

 

           

   

The Northern mockingbirds (Mimus polyglottos) are a bit more reluctant to feed when they see me looking at them from a few feet away. Even with the window closed, they are shy but I finally got one to sample some berries while I watched.

The leaves of the beautyberry have been used as an insect repellent in folk remedies; laboratory studies have shown that a chemical compound in the plant will stave off mosquitoes.

I haven’t pruned my beautyberries much but it seems that the plant will bear more fruit the next year if this is done. I do think I will transplant some young ones to other parts of the yard this fall, however, as this plant – along with the purple pokeweed (Phytolacca decandra) – is a real wildlife crowd pleaser.