First Robin

On Monday evening, when I popped out to get a log for the fire, I thought I heard a robin churr. However, a quick look around didn’t reveal any robins. On Tuesday morning, I heard the call again and set out to find the source. Sure enough, there he was, high up in a tree. The first robin of spring! He chose a beautiful, blue-skied, sunny day for his first appearance. Another first to check off as the new season slowly takes hold.

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Happy Birthday, Dear Carl!

Carolus Linnaeus, that is. Strictly speaking, that should be Happy Belated Birthday, as his birthdate is May 23, 1707. The 300th anniversary of his birth was celebrated in 2007. What an amazing man. Darwin gets lots of credit for the whole Origin of Species thing, even though Alfred Russel Wallace had come to similar conclusions contemporaneously. I think I prefer Linnaeus as a hero. He brought order to the study of natural science.

Taxonomy, or systematics, is the science of classifying organisms. The system that was developed by the great Swedish botanist Linnaeus is still used today. It is a hierarchical system that ranks every organism, both plant and animal and even the neither here nor theres, in a series of categories. You may be familiar with King Phillip Comes Over For Good Soup, or some similar mnemonic. The phrase reminds schoolchildren and more than a few adults of the hierarchy: Kingdom, phylum, class, order, family, genus and species.

Somehow, I missed this in school and came to it late in life when I developed an interest in birds. Birds belong to the kingdom Animalia; the phylum Chordata (animals with vertebrae, or a backbone); and class Aves (this class refers exclusively to birds). There are about 2 dozen orders of birds. Names of orders end in “iformes”. The largest order is Passeriformes, the perching birds, which include more than half of the world’s approximately 10,000 species. Other orders are referred to as non-passerines. Examples of other orders are Piciformes (woodpeckers); Columbiformes (pigeons and doves); and Anseriformes (ducks and geese).

Each order is divided into families. There are many families in Passeriformes. Examples are Corvidae (crows and jays) and Turdidae (thrushes). Bird guides are generally set up in a standard layout of orders and families. The layout reflects the evolutionary age of the orders and species. The orders thought to have evolved first are at the beginning of guides. The more recently-evolved birds, the passerines, are presented after all the other orders.

Each family is divided into genera, which include very similar species. Each species has a latinized name made up of the genus combined with a specific name to distinguish it from other members of its genus. A shared genus name indicates that two species are closely related. Scientific names are traditionally italicized. Because the Linnean system features a two-part scientific name it is commonly referred to as binomial nomenclature. Here is how the American Robin (Turdus migratorius), above, photographed recently in my garden, would be classified:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Turdidae
Genus: Turdus
Species: migratorius

The Canada geese (Branta canadensis) that I photographed last winter would be classified as follows:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Branta
Species: canadensis

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The Big Reveal

Once the trees drop their leaves, the nurseries that cradled the year’s bounty of baby birds are suddenly revealed. It’s amazing how well-concealed nests are during the summer. Of course, if you pay close attention to the actions of birds, and know where to look, it is possible to find their nests while they are active. However, I have been content to let the birds live their lives in my yard without my scrutinizing of their comings and goings to closely. Consequently, I have daily walked right past nests without knowing they were present until the fall.

Many American Robins (Turdus migratorius) build their nests close to our house in trees and hedges bordering the lawn and driveway. Robin nests are among the easiest nests to identify in the fall. Robins construct very sturdy nests, weaving grasses into a cup and plastering the walls with mud. They are the only builders of cup-shaped nest to employ mud in this fashion, so dried-mud is a pretty sure sign that you are looking at a robin’s nest. The nest pictured at the top of the post was built in a hawthorn tree. The nests above and below are further examples of robin architecture.

The robin who built the nest below included some twine in the construction.

This nest, located in a Amur Maple tree, features a strip of torn plastic. The mud isn’t conspicuous, but I got out the ladder and climbed up to take a closer look. Sure enough, the mud rim can readily be observed. For more on robin nests, see Robin’s Egg Blues.

Another readily-identifiable nest to be found in the bare tree branches is that of the Baltimore Oriole (Icterus galbula). Orioles weave a hanging basket that is typically secured at the rim or edges to a drooping branch. It is woven with various plant fibres and lined with fine grass, hair or plant down. The nests often hang in branches over roads, an adaptation, perhaps, of an instinct to build the nest over flowing water. The nests quickly become weather-worn once the trees lose their leaves.

Many nests are difficult to identify once their occupants have departed. Here is a nest with a scenic situation over water. It may have been built by an Eastern Kingbird (Tyrannus tyrannus). Kingbirds like to nest on a horizontal tree limb, about halfway between the tree trunk and its canopy. About 25 % of the time, the nest is located over water. Kingbirds build a bulky, untidy nest using weed stems, grass, plant down and rootlets.

The nest below is likely that of an American Goldfinch (Carduelis tristis). Goldfinches prefer to build their tightly-woven nest in a branch fork. Caterpillar webbing and spider silk is often used to bind the outer rim of the nest.

The builder of this large nest, over a foot across and high up in a larch tree, remains a mystery.

Not all the nest-builders were birds. This nest, possible belonging to Bald-faced Hornets (Dolichovespula maculata), has already started to disintegrate.

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Baby Robin

It’s baby bird season. Throughout the nature blogosphere, posts on baby birds are popping up. Here’s a great post over at The Marvelous in Nature about chickadee fledglings. And how about these cuties? Baby field sparrows. Over at A Passion for Nature, Winterwoman is showing off little house wrens. Not being as intrepid a birder as Seabrooke or Jennifer, I let the baby bird find me. When I walked into the kitchen, there was a young robin sitting on the windowsill. It was probably newly out of the nest, and still being cared for by its parents. My windowsill wasn’t the best place for it to be sitting. I was concerned about a parent running into the window. However, I did enjoy getting a good look at the youngster. I love the speckled breasts of baby robins. It’s when the species looks its most thrush-like, I think. I wasn’t the only one who found the baby of interest. Moey, left, and Tonka were quick to notice the new arrival. I shooed them away from the window, and when I came back a little later, the little robin was gone. I hope he found a better spot to perch.

Speaking of baby birds, here’s the latest on the boreal forest bird nursery. The Save Our Boreal Birds petition, with 60,000 signatures, was presented to the federal government on June 15th by MP Linda Duncan. May it help to preserve a future for many more baby birds.

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Mom’s the Word

I’ve been in horse stables where Barn Swallows (Hirundo rustica) were nesting above the horses’ heads, barely out of arms-reach of people coming and going and everyone got on fine. The several pairs of swallows nesting in the barn here, however, are upset whenever I enter the barn, even though they are far overhead on the roof rafters. They seem to feel they should have the barn to themselves and set up a cacophony of distressed chittering when I arrive.

Meanwhile, just down the field the Tree Swallows (Tachycineta bicolor) are carrying nesting materials to their box.

When I was walking past this small pine tree, putting hay out for the horses’ breakfast, I noticed a dark shape near the trunk of the tree. A closer look revealed this female American Robin (Turdus migratorius) sitting on her nest.

Robins are numerous around here. When I was walking along the river, I noticed another mother robin, incubating her eggs.

Robins usually sit tight. That is, even when disturbed by a person close at hand, they stick to their nest and stay still. One season when Birdgirl was working on a nest monitoring study, she came across one robin who wouldn’t budge until she was actually putting her fingers in the nest to check for eggs. Now that’s a dedicated mom. In contrast to robins, Common Grackles (Quiscalus quiscula) are quite easily disturbed. When I walked past a small spruce tree, a grackle made a hasty exit and I knew to look for a nest. Here it is!

The mother retreated to the top of a nearby tree and complained loudly about my presence from the safety of her high perch. With both robins and grackles, the female incubates the eggs, keeping the eggs warm with her body. In order to warm the eggs efficiently, the female develops a brood patch, an area of skin on the belly that loses its feathers toward the end of the egg-laying period. Most birds shed the feathers automatically, though geese and ducks pluck the feathers and add the to the nest. The brood patch also develops extra blood vessels to bring hot blood close to the surface of the skin. When birds return to the nest after a break to resume incubating, they make settling-in movements while they position the brood patch so it is in contact with the eggs. In species where the male also incubates, males may also develop a brood patch. The feathers gradually grow back in after brooding is done.

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A New Nesting Season Begins

Back in March, while there was still snow on the ground, I noticed a nest high up in the hoophouse on a bit of old machinery. It had been deserted last summer before the four eggs had hatched. I removed the nest to photograph it and didn’t replace it. Today, I walked into the hoophouse, looking for a shovel and glanced up. The nest was back! A pair of robins (Turdus migratorius) have replaced the nest in exactly the same spot. I hope they are successful in fledging a family from the new nest.

Meanwhile, out in the old barn, a half a dozen old nests on the roof rafters are evidence of Barn Swallows past. This week, Barn Swallows (Hirundo rustica) returned and when I entered the barn a few days ago, I was greeted by their disapproving chatter. Like robins, Barn Swallows use mud in the construction of their nest, but plaster the cup-like structure to a wall or beam in a sheltered location. The above view, looking up at one of the nests on the roof rafters, reveals the occupants forded tail! Swallow flight is swift and acrobatic, and they were difficult to capture with the camera as they flitted in and out of the barn, but here is one resting on a beam near the barn entrance.

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Here he is!

First Robin

Here he is, the first robin (Turdus migratorius) to be spotted on our lawn this spring. Welcome!

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Robin’s Egg Blues

One of the nice things about the trees losing their leaves in the winter is the way that the activity of the bird community is revealed.
Nests hidden in the summer suddenly become conspicuous. There are quite a few nests to be seen in the trees around here, including the Baltimore Oriole’s nest (Icterus galbula) pictured above. There are also some nests in unexpected places, such as this nest I noticed in the hoophouse. Can you see it?

The hoophouse was once one of three that were used by a former owner as part of a nursery operation. The last owners of the property had 2 of the houses removed and allowed the third to deteriorate, its equipment unmaintained, and it was full of junk and garbage when we first viewed it. The wood for the garden monster is stored in here now. I noticed that high up on an old bit of machinery, there was a nest.

I climbed up to take a closer look at the nest. It was clearly that of an American Robin (Turdus migratorius), readily identifiable by the mud cementing the structure. Robins and swallows are the main employers of mud in nest construction, and the cup-like shape points to the former as the builder of this nest. When I reached my fingers over the edge of the nest, I could feel that there were still eggs in the nest. I removed it from its perch for closer inspection.

Obviously, something disrupted the robin parents after their eggs were laid. It could have been simply that someone closed the door to the hoophouse, cutting off their access. Four lovely eggs remain, sadly, never to hatch.

Normally, the female robin would incubate the eggs for 12 to 14 days. Like the young of most songbirds, robin hatchlings have closed eyes, are naked, and require feeding by their parents. Such hatchlings are termed altricial. These babies are very different from the hatchlings of birds like ducks and geese, who have open eyes and down when they hatch and are able to leave the nest within 24 hours of hatching. Those hatchlings are termed precocial.

The baby robins would have grown quickly. In just over 2 weeks, they would have been close to the size of their parents, would be fully-feathered, and ready to leave the nest and fly. The fledglings would continue to be fed and cared for by the male until they could manage on their own. Meanwhile, Mom would begin to incubate a second clutch of eggs. Robins raise 2 or 3 broods, or families, each summer.

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