Some new neighbors moved in a few weeks ago.  And they are very friendly neighbors.  In fact, their motto seems to be “su casa es mi casa.”  These neighbors are showing a surprising degree of interest in our house!

     You guessed it.  Our new neighbors are birds.  Phoebes.  I so often see them flitting about near our windows, swooping up under the eaves of the house, and emerging from our three-sided tool shed.

    Phoebes, apparently, are known for living in close proximity to humans.  Unlike shyer birds, phoebes build their nests on the ledges of buildings, under steps, and under the eaves of houses.  Phoebes are not at all distressed by human activity nearby.  In fact, I read of one phoebe pair that built their nest on the underside of a railroad bridge.  There they raised their young, unconcerned about the trains that roared over them every day!    Ornithologists say that the phoebe is one bird whose numbers have  increased, rather than decreased, along with rising human numbers and humans’ geographical expansion.  More people mean more buildings.  And more buildings, it seems, mean more potential nest sites.

     Phoebes are not colorful birds.  They have a dark head and a dark back and tail feathers.  The breast is white, with smudgy grey on the upper part.  The cutest thing about the phoebe, I think, is its tail, which seems made to move.  When a phoebe arrives at its perch, the tail gets activated– flipping, dipping, and quivering.  The ph0ebe is easy to recognize by its raspy-sounding call.  It says its name.  

     Phoebes are flycatchers, a large family of birds that eat insects by darting out from a perch and catching them in mid-air.  During the winter, phoebes may supplement their diet with berries.  

     While I have mostly enjoyed observing the habits of our new neighbors, I have to admit they have also been annoying.   One of the phoebes began to hang out around a couple of the windows of our house, just below a small balcony.  The bird would hover, then scrabble its feet against one of the windows.  After a few moments, the bird would then move to the adjacent screen, and press against it,  clutching the screen with its feet and facing in, tail feathers spread wide, for balance, I assume.  Then the routine would resume:  hover; scrabble; cling.  

     Well, it didn’t take long for the windows and screens to become streaked and dotted with globs of white.  I wasn’t happy to have to wash the windows and scrub the screens.  But once I covered the outside of the windows and screens with newspaper, the phoebe left them alone.

     I assumed the bird had been interested in building a nest in the balcony eaves, and that it interpreted its reflection in the window below as a rival that must be driven away.  While I would love to have a nest of baby birds so close by, I wasn’t willing to put up with filthy windows.  The birds would just have to find another spot for their nest.  

     And it seems they have.  Even as I sit here writing, I have been hearing bird feet scrabbling against a sliding glass door and on our basement windows.  Uh-oh.  I am not looking forward to washing these larger windows and taping newspapers onto them.  But I am also hoping the phoebes will build their cup-shaped nest in a near enough place that I’ll be able to observe the little ones.–April Moore

     

 

 

My husband Andy has been urging me to write a piece about the differences between ravens and crows.  That seemed like a good idea to me, since the extent of my knowledge was merely a vague “ravens are bigger.”

First of all, ravens are crows, but crows are not ravens.  The Common Raven and the American Crow are members of the corvidae family.  Magpies and jays are also corvids.

A raven is typically the size of a hawk, while the smaller crow is about the size of a pigeon.  And the two birds differ in shape as well as size.  The raven’s tail ends in a triangular point, while the tip of the crow’s tail is more-or-less straight across, perhaps a little rounded.  The raven has a flatter head than the crow.  And their beaks are different.  Experts explain that the crow’s beak is sharper and shorter than the raven’s, that the upper part of the raven’s beak is more curved than that of the crow.   Even so, the two birds’  beaks look practically the same to me, and I would not use their beaks to try to tell them apart.

An easier-to-detect difference, I think, is the shaggy ‘ruff’ of feathers around the raven’s neck, different from the smooth feathers surrounding the crow’s neck.

The two birds clearly behave differently during flight.  While the raven mostly soars silently, the crow flaps its wings and calls again and again.  And upon landing, the crow flicks its wings and tail feathers, while the raven simply sets its feet down, ‘calmly,’ without excess movement.

Ravens and crows can be fairly easily distinguished by their sound.  The raven sounds like this:   the raven\’s call The crow sounds like this:  sound of a crow The raven’s call is deeper and throatier than the crow’s call, which can be described as louder and harsher.

The crow and raven often share habitat, but each has its own preferences.  Ravens prefer a more natural environment and can be found in forests, deserts, and tundra, usually at higher altitudes.  Crows are found throughout America’s lowlands, especially in agricultural areas.  And crows do extremely well in urban areas.  I even read (Rare Encounters with Ordinary Birds by Lyanda Lynn Haupt) of two crows spotted near a garbage can in a McDonald’s parking lot;  they were dipping fries in honey mustard sauce and then eating them!

Another difference, not noticeable to the observer, is lifespan.  A raven typically lives about 30 years, while a crow lives only about eight years.

Another difference between the two corvids, it seems to me, is image.  Crows are commonplace, everyday birds, while ravens have an air of the exotic.  The term ‘raven-black hair’ sounds beautifully vivid;  ’crow-black hair’ wouldn’t be the same.

And in Edgar Allan Poe’s beloved poem “The Raven,” the following verse is just a sample of the dark, foreboding mystery associated with the raven perched above the writer’s chamber door:

`Prophet!’ said I, `thing of evil! – prophet still, if bird or devil!
By that Heaven that bends above us – by that God we both adore -
Tell this soul with sorrow laden if, within the distant Aidenn,
It shall clasp a sainted maiden whom the angels named Lenore -
Clasp a rare and radiant maiden, whom the angels named Lenore?’
Quoth the raven, `Nevermore.’

–April Moore

On a very cold, snowy walk one recent morning, I wondered where the birds were.

Just the day before, I’d seen all the usual suspects–chickadees, titmice, nuthatches, and juncoes.  They’d eaten from the feeder, flitted in and out of  bushes, and hopped about on the ground.  But this day was much colder, and they were  nowhere to be seen.  Except for an occasional crow.

I assumed these little birds were keeping warm somewhere, taking the day off from their usual foraging.  But where were they?

And were they going without food?  I had to wonder–if  birds must eat voraciously every day in order to maintain their body weight, did the day’s extreme cold mean they had to sacrifice nourishment in order to keep warm?

And while I didn’t know the answers to my questions, I was not worried.   Birds have been navigating harsh winter weather for a very long time.  Still, I was curious. Where do birds go on the coldest days?

So I decided to do a little research.

I learned, not surprisingly, that small birds are more vulnerable to cold than large ones. Hence, the spotting of crows on that cold day, but not little guys.  Because of small birds’ proportionally larger surface area compared to their heat-generating core, keeping warm is more challenging for them.

Fortunately, small birds have many strategies for keeping warm on the coldest winter days. They do what they do on winter nights.  Chickadees, titmice, nuthatches, and woodpeckers, for example, gather together in a tight space, like a cavity in a tree, the dense branches of an evergreen tree, an old nest, a chimney, a birdhouse, or even in the space between a building and close-growing bushes.  In such close quarters, birds huddle together and share body heat.

Packing into a small space with their fellows is not the only tool small birds have for staying warm. Chickadees, for instance, can significantly slow their metabolism, so that their bodies burn fewer calories.  Their body temperature can drop by as much as 14 degrees F during very cold spells! Many birds can even control the temperature of their legs and feet separately from the rest of their body!  By constricting the flow of blood to their extremities, birds can maintain more heat in their core.

Feathers also play a key role in small birds’ winter survival.  Their oily surface is insulating, and some species even grow additional feathers during the fall to add greater warmth in winter.

And birds use their feathers in ways that increase the warmth they provide.  For example, many birds fluff out their feathers, creating tiny air pockets that hold warm air close to the body, like a down jacket.  On sunny days, birds turn their back to the sun and spread their wings and tail, maximizing the feathered surface area that receives the sun’s rays.  And birds crouch, covering–and warming–their feet and legs with their feathers.

Many birds fatten themselves up for the winter, building fat reserves by gorging during the fall.  During extreme cold, a last-ditch mechanism–that we share with birds–may kick in–shivering. Shivering occurs when the metabolic rate is elevated, generating more body heat.  But shivering is only a short-term solution, since it uses up a great many calories.

And I learned that, indeed, many birds do go without food on the coldest days.  Apparently, the energy little birds would expend in foraging on such cold days exceeds the energy they would derive from the food itself.  So, even though their nutritional needs are greater in colder weather, on the coldest days it makes sense for them to hunker down until the temperature rises.–April Moore

One of the many wonderful things about a family reunion at the beach last week was watching ghost crabs on the sand.

These pale, sand-colored crustaceans, common along the U.S. east coast, blend in perfectly with their beach home.  They even appear translucent, which may explain their spooky-sounding name.

It was a delight to walk along the beach and spot these little fellows, scuttling sideways, this way and that, along the sand.  Often I would watch a crab perched motionless at the edge of the opening to its burrow.  And before I could make a move for my camera, the crab had disappeared down the hole, out of sight.

Sometimes I noticed sand flying out from a burrow entrance.  Below, an unseen ghost crab was industriously making improvements to the shaft or chamber that made up its home.  Now, some burrows sported a neat little pyramid of sand beside the entrance, while other burrow entrances were surrounded by messy-looking little collections of sand.

Well, I had to learn more about these ghost crabs, so I did a little research.

Apparently, the orderly pyramids of sand denote a reproductively mature male’s burrow.  The carelessly tossed sand indicates the home of a female or a young individual.  Scientists speculate that females use the neat pyramids to find potential mates.

The burrow is an important part of a ghost crab’s life.  In summer the burrow is a cool retreat from the hot sun, and during the winter it serves as shelter from the cold.  In fact, a ghost crab may hibernate in its burrow for up to six weeks during the coldest part of the winter.

The ocean is also important to the ghost crab.  The crab makes nocturnal trips down to the water line to wet its gills, which must be kept moist for breathing.  And the female ghost crab releases her eggs into the ocean, where they develop into marine larvae.

A true sea creature, the ghost crab won’t drown if submerged.  It is protected by its air-tight exoskeleton, which also prevents water loss from internal tissues.

While ghost crabs are sea creatures, they spend much more of their time on the shore, where they scavenge for food.  And they are not picky eaters.  They’ll eat just about any plant or animal material that washes up onto the shore.  Mature ghost crabs do most of their scavenging at night, while the younger ones can be seen scurrying along the sand’s surface during the day as well.

And do these crabs scurry!  The fastest crustacean on the planet, the ghost crab can reach a speed of 10 mph!  Of its 10 legs, two (the largest) are used for feeding and digging a burrow.  The other eight legs–slender and pointed at the end–are for movement.  For a walking pace, the crab uses all four pairs of legs.  To speed up, the crab lifts one pair of legs off the ground.  And to speed up even more, the crab shifts into ‘high’ gear by pulling up all but two legs.   Then it runs across the sand!

Ghost crabs live as long as three years.  And like other arthropods, they molt.  Inside the hard, external skeleton, the crab’s body grows, encased in a new, soft skeleton within the rigid outer skeleton.  After awhile, the tight, outer skeleton cracks, and the crab squeezes out.  While the new skeleton is still soft, the crab enlarges it to gain some growing room  (like buying shoes a size too large in order to grow into them).  Once the new skeleton has hardened, the crab resumes foraging on the beach.

At maturity, a ghost crab is about two inches wide.–April Moore

The other day I had to stare, as an inchworm made its way along the railing of our deck.

Lacking all but two or three pairs of legs at the very front and about the same number at the very back, the inchworm’s method of locomotion is quite different from that of its fellow caterpillars, who seem to glide along on scores of  rapidly moving legs.

No, the inchworm does not glide; it inches.  First, the front stretches out.  Then the back is brought forward to meet the front, with the body in between looped upward.  The inchworm then stretches out again as the front is propelled forward.  Loop and flatten.  Repeat again and again.

Watching this entertaining process, I found myself wondering what evolutionary niche was filled or what advantage gained by the development of caterpillars with legs only at each end.  So I did a little research.

I didn’t find the answer to my question, but I did learn some interesting things about inchworms.  I learned that they are the larval stage of geometer moths.  The term ‘geometer’ refers to the way the caterpillar appears to ‘measure the earth’ as it moves.  And of the 35,000 species of geometer moth, about 14,000 are native to North America.

Unlike other types of caterpillars, inchworms are generally hairless.  Most are green, grey, or brown.  As soon as the inchworm hatches from its egg on the underside of a leaf in spring, it begins eating.  Inchworms typically eat leaves, although some species also eat lichen, flowers, or pollen.

After about a month of continuous feeding, the inchworm makes its way to the ground.  In early summer, the inchworm burrows into the soil and pupates.  It makes a cocoon of silk and soil near the earth’s surface.  The moth emerges in November and lays its eggs in the winter.

The inchworm has a great defense against predators–its resemblance to a twig.  This resemblance is heightened by little appendages that look like tree buds.  When disturbed, the inchworm often stands erect on its prolegs (back legs), further enhancing its twiglike look!–April Moore

As regular visitors to The Earth Connection well know, I am deeply concerned about global warming.  In fact, I would venture to say it’s the most serious problem humanity has had to face.  And if only we were facing it!  But tragically for our children and grandchildren, we are doing next to nothing.

In this short video, my husband Andy Schmookler, Democratic candidate for Congress, speaks strongly and eloquently on the subject.  I hope you’ll click this link Andy Schmookler on global warming and take a look.

The video was made by Chris Graham of the Augusta (VA) Free Press.–April Moore

     As I was held in the thrall of Costa Rica’s fascinating birds during our recent visit to that country, I got into reading what I could find about these amazing creatures with exotic crests, giant beaks, and extravagant appendages at the end of already-long tails.    

      I learned that many of these neotropical (the tropics of the western hemisphere) birds differ from their North American cousins in some interesting ways.

     The heart of the differences between birds of the north and those of Central America is that “neotropical birds do things slowly, much more slowly than their North American counterparts,” explains ornithologist Alexander Skutch.  For example, neotropical birds tend to have a much slower metabolic rate than do northern birds.  Probably related to the difference in metabolic rate, neotropical birds tend to live much longer than North American birds, on the order of two to three times longer.    

     In keeping with a slower life, the typical Central American bird’s first breeding is later than that of a typical North American bird.  And the ‘slower’ birds of Costa Rica incubate their eggs longer and care for their chicks longer than do most birds of North America.

      So what are the reasons for these differences between ’our’ birds of the north and those of Costa Rica? 

     The main reason for the differences appears to be climate.  The more ‘speeded up’ lives of North American birds helps them to survive in an environment where food is not abundant all year and where harsh winters force birds to work to stay warm.  A rapid metabolic rate generates needed body heat.

     The breeding differences also make sense in the different climates.  In the north, getting an early start on breeding increases the number of offspring a bird will likely produce in its lifetime.  And that’s important, since the lifespan of many North American birds is so short, only two or three years for many common species.  Likewise, a shorter incubation period and an earlier fledging for offspring, gets more birds ‘out there’ sooner.  A higher number of individuals strengthens the species as a whole against a harsher climate and frequent food scarcity. 

     Not only do neotropical birds start breeding later, incubate longer, and care for their young longer than do birds in northern climes, but they also tend to lay fewer eggs per clutch than their northern cousins, typically just one or two.  Scientists explain that predation of eggs is a bigger problem in southern climes than in North America.  An egg in a nest in Costa Rica is far more vulnerable to snakes and to a variety of mammals than are eggs in a nest in North America.  But by laying just a single egg, or two at the most, Central American birds lose fewer eggs to predation.  Many Central American birds ’make up’ for the small number of eggs per clutch by breeding several times a year, unlike northern birds, who are limited by climate in the number of clutches they can produce in a year.

     Another difference between Central and North American birds I found interesting is that far more Central American species engage in ‘lek’ breeding than do northern birds.  Lek breeding is when the males of a species gather in a particular area for the purpose of a competitive mating display.  Females visit the ‘arena’ and choose a mate from among the displaying males.  After mating, the male and female are done with each other.  The male plays no role in nest building, in helping the female during incubation, nor in caring for the young.  The reason lek breeding is much more prevalent in the neotropics than in North America, scientists say, is that food is so much more easily available in the warmer climate that the female does not need the male’s help the way northern female birds do, to help ensure their young’s survival.–April Moore

a chestnut mandibled toucan

 

a mot-mot

 

 

 

 

 

 

 

 

 

 

     Winter is the time when I get to see a lot of titmice.  (And you gotta love that plural!)  With leaves gone from the trees, and the insects and spiders these birds like to eat unavailable, titmice keep our two feeders hopping.

     As I watch the action at the window feeder from our living room couch, I feel a great fondness for these hardy little birds.  They are unassuming in appearance, except for their jaunty crest, and they strike me as hard workers.  Over and over again, they drop from a branch of the saucer magnolia tree, onto the feeder’s rim, pluck out a sunflower seed with their beak, and flutter back to the tree.  Holding the seed in place with their feet, they pound away at it with their beak until it breaks open, and they can eat it.  Then they go through the same process again.  And again and again.

     Not only does winter bring titmice to the feeders, but it also evokes different sounds from these little birds.  Their sweet, whistling calls of  spring are replaced by squawking, scolding sounds.  In fact, several times lately, when I stopped near the feeder to watch them, all the action was, instead, up in the trees.  Several titmice squawked angrily and fluttered about.  It took me a little while to realize they were carrying on about me!  I imagine my nearness to the feeder made them feel unsafe to jump down for a seed, and they wanted me to go away!  Never mind that I’m the one who keeps the feeder filled with food!

     I decided I would like to know more about these feathered neighbors of ours, so I did a little research.  And I love this description I found on the Cornell Lab of Ornithology’s website:  ”The large, black eyes, small, round bill, and brushy crest give these birds a quiet but eager expression that matches the way they flit through canopies, hang from twig ends, and drop in to bird feeders.”  The ‘quiet but eager expression’ part is apt.  Perhaps this attitude of theirs is part of what I find so appealing about the little fellows. 

     I learned that the titmouse has a very wide range.  It can be found year-round throughout the eastern states and the midwest.  And its range is expanding northward, perhaps due to climate change and maybe also to increased winter feeding.  The titmouse lives in deciduous and mixed-deciduous forests and in residential areas where there are tall trees and dense canopy.

     The tall trees and canopy provide food for titmice during the summer, when they also store nuts and seeds in crevices along the bark of trees for eating later.   Titmice also forage on the ground, and in winter they can be seen on tree trunks and at feeders.  

     Late February through April is breeding season for the titmouse.  Males and females are monogamous for a single breeding season.  The female chooses for her nest a very deep cavity (about 8-11 inches), typically in a rotted tree.   Over the course of about four days, she builds the nest.  First comes the foundation of dried leaves, moss, and strips of bark.  Then she adds the insulation–down, fur, and hair.  Female titmice have actually been observed yanking hair from live mammals for their nest, including from the arms and heads of humans! 

     Once her nest is complete, the female lays an egg each day for 5-6 days.  Incubation begins after the second to the last egg has been laid, and before beginning to incubate her eggs, the female spends the night perched on the rim of her nest.  The young fledge in about 18 days, and some might remain with their parents during the first winter, even staying on to help raise the next year’s brood!

     I had to find out about the name ‘titmouse.’  It is believed to be a combination of the old English term for ‘bird’–’mase,’ and ‘tit,’ meaning something small.  There you have it!–April Moore

 

a titmouse at our window feeder

 

    

 

     Biological evolution fascinates me.  I find it truly wondrous that life began where there was no life and evolved over millions and millions of years into the astonishingly complex web of life that exists today.

     Because I love learning about evolution, I am reading THE SONG OF THE DODO:  ISLAND BIOGEOGRAPHY IN AN AGE OF EXTINCTION by David Quammen.  In an effort to understand the implications of the ‘islands’ that human activity is creating on our continents, Quammen explores the ways in which life evolves differently on islands than it does on large mainlands.  We humans are turning once vast stretches of wilderness into small, isolated chunks, with our roads, pipelines, shopping centers, and subdivisions.  By better understanding the ways of evolution on islands, Quammen believes we can better understand why diversity declines on isolated ’islands’ of wilderness.  

     Despite the book’s sobering premise, it reads like a novel.  Quammen, an award-winning science writer, tells us so interestingly why some kinds of creatures abound on islands, while others are rare or non-existent there.  He writes with humor and a great sense of ‘Wow!’  And you don’t have to be a scientist–or even particularly science-oriented–to love this book.

     I would like to share here a short passage from THE SONG OF THE DODO that explains why mammals are found only in small numbers, if at all, on islands.–April Moore

     “If I haven’t said much about mammals in this discussion of island colonization, it’s because there is not much to say.  Mammals don’t travel as well as most other vertebrates.  Their dispersal ability across salt water is generally low.  They are burdened with urgent physiological needs and blessed with only modest endurance.  Starvation and drought can kill them quickly.  So can drowning.  If they do manage to make a crossing, their prospects of establishment are still poor.  Since they reproduce sexually, give birth to live young, and suckle those young, they don’t enjoy the same adaptive advantages as many plants, insects, and reptiles.  An adult mammal needs a mate;  an infant mammal needs a mother.  All these factors reduce their chances of colonization.  Rarely a species of mammal does reach an island and establish itself, but more commonly an island remains empty of mammalian fauna despite the passage of eons.  As reptiles and ferns and pigeons tend to be disproportionately present on islands, mammals tend to be disproportionately absent.”–David Quammen, THE SONG OF THE DODO

 

     I just learned a little bit about an amazing fish called the gobiid.  What I read about the little ‘goby’ in David Brooks’ s book THE SOCIAL ANIMAL was so incredible, I went online to learn more.  To my disappointment, however, I found very little basic information about this little fish.  But I will share below what David Brooks had to say about the gobiid:

     “This is a little fish that lives in shallow water.  At low tide, its habitat is reduced to little pools and puddles.  Yet the gobiid fish jump with great accuracy over rocks and dry ridges from pool to pool.  How do they do it?  They can’t scope out the dry patches before they jump, or see where the next pool is.  If you put a little gobiid fish in an unfamiliar habitat, it won’t jump at all.

     “What happens is that during high tide the gobiid fish wander around absorbing the landscape and storing maps in their heads.  Then when the tide is low, they have a mental map of the landscape, and they unconsciously know what ridges will be dry at low tide and what hollows will be full of water.”–David Brooks, THE SOCIAL ANIMAL

     I find it amazing that such a tiny fish (some gobiids are no longer than 4 centimeters) can do such complex mental processing.  We humans assume that our large brains are so much more capable than the smaller brains of so many other animals.  We so often underestimate the complex abilities possessed by many small animals, abilities we humans can barely imagine.–April Moore

a gobiid fish