Tag Archives: ring-billed gull (Larus delawarensis)

Moments

Transient and fleeting.  A part of history as soon as they become the present.  Sometimes only captured by the mind’s eye and quickly faded into dim memories.

A Spotted cucumber beetle (Diabrotica undecimpunctata) on a common dandelion (Taraxacum officinale) (2010_03_14_051351)

Spotted cucumber beetle (Diabrotica undecimpunctata) on common dandelion (Taraxacum officinale)

A great blue heron (Ardea herodias) standing in the shallows (2009_07_26_027929)

Great blue heron (Ardea herodias)

A twinflagged jumping spider (Anasaitis canosa) hiding on an outside electrical socket (2009_04_26_016720)

Twinflagged jumping spider (Anasaitis canosa)

A ring-billed gull (Larus delawarensis) in flight  (2009_11_26_041016)

Ring-billed gull (Larus delawarensis)

A blue-ringed dancer (Argia sedula) perched on a blade of grass (2009_07_07_026225)

Blue-ringed dancer (Argia sedula)

A barn spider (Neoscona crucifera) hanging in the center of her web (2009_10_10_031194)

Barn spider (Neoscona crucifera)

A swift setwing (Dythemis velox) perched on a stem (2009_07_06_026092)

Swift setwing (Dythemis velox)

A few of my favorite things #5

Birds in the water.  Beauty can be found in any environment, yes, but water has such dynamic personality.  And its ability to reflect that which resides above it makes it all the more majestic as a backdrop, an in situ mirror that adds more than a touch of real or abstract flavor.

Yet my fascination runs deeper than the water.  I believe it has something to do with creatures with wings who soar on the wind that in turn spend so much time in the water, so much so that evolution has granted them webbed feet, spatulate bills, long legs and liquid-straining pouches.  What a marvelous dichotomy…

Snowy egret (Egretta thula) wading in the shallows (2009_09_27_029522)

Snowy egret (Egretta thula)

American coot (Fulica americana) swimming by me (2010_03_06_050437)

American coot (Fulica americana)

Pied-billed grebe (Podilymbus podiceps) swimming away from me (2009_11_01_036416)

Pied-billed grebe (Podilymbus podiceps)

Ring-billed gull (Larus delawarensis) swimming by me (2010_03_06_050489)

Ring-billed gull (Larus delawarensis)

American white pelican (Pelecanus erythrorhynchos) swimming toward me (2009_10_25_033970)

American white pelican (Pelecanus erythrorhynchos)

Male lesser scaup (Aythya affinis) floating in the water (2010_03_06_050444)

Lesser scaup (Aythya affinis)

Great blue heron (Ardea herodias) wading into a creek (2009_09_05_028695)

Great blue heron (Ardea herodias)

— — — — — — — — — —

On a related note: The only nesters at the rookery at present are great egrets (Ardea alba).  But the time is now for the multitude of other bird species to arrive at this marvel that rests in the heart of the city.  The second major species has already made an appearance: anhingas (a.k.a. water turkey or snakebird; Anhinga anhinga).  I can’t wait to share this magic with you.  What a spectacle, what a mystery, and what a gift!

Farewells – Part 1

The mockingbirds sing and display, their aerial ballets worthy of the finest stages across the globe and their diverse songs reminiscent of the finest works of Mozart.  The first purple martin arrived yesterday, a vanguard leading the way for many others to follow, and soon they will fill the days with profound beauty.  The merlin waded into the crystal river and began its long swim northward, putting behind it this cold season in the south and setting its eyes on love to be found in another place and at another time.  The mourning doves pour upon the sunrise their woeful dirge until my eyes water at the sadness of the sound, yet to them it is not sad but joyous, a plaintive call that seeks to warm the heart of another.

Even as more snow is forecast next week, nature prepares her children for the season that is to come.  An eclectic celebration of dance and music.  The building of nests and the starting of families.  The putting on of fine colors and patterns, the best dress available, the finest suit.  And her migrating offspring begin their journeys.  While many will leave, many more will arrive.  Yet it is the farewells which cut us deeply, not the hellos.

So in honor of the endings that now beset us and the beginnings they foretell, I offer this brief series in celebration of the lives with whom I’ve shared a brief moment this winter, the faces that will now pass into memory as new faces take their place.  And because I believe no life is complete without reading it, I will include the divine words of Kahlil Gibran’s The Prophet alongside the beauty of that which even now passes into history.

Farewell to you and the youth I have spent with you.

Yellow-rumped warbler (a.k.a. myrtle warbler or Audubon’s warbler; Dendroica coronata) perched in a bush (2010_02_06_049418)

It was but yesterday we met in a dream.

Cedar waxwing (Bombycilla cedrorum) perched on a branch (2010_02_06_049331)

You have sung to me in my aloneness, and I of your longings have built a tower in the sky.

Brown creeper (Certhia americana) climbing the side of a tree (2010_02_07_049537)

But now our sleep has fled and our dream is over, and it is no longer dawn.

A mated pair of northern pintails (Anas acuta) swimming in the bay (2010_01_24_048844)

The noontide is upon us and our half waking has turned to fuller day, and we must part.

Song sparrow (Melospiza melodia) perched in winter reeds (2010_01_12_048009)

If in the twilight of memory we should meet once more, we shall speak again together and you shall sing to me a deeper song.

Ring-billed gull (Larus delawarensis) standing on a submerged log (2009_12_20_045591)

And if our hands should meet in another dream we shall build another tower in the sky.

— — — — — — — — — —

For those looking to fill your weekend not with farewells but with hellos, I turn your attention to these delectable blog carnivals.

Friday Ark #283: Steve ushers critters aboard the ark throughout the weekend, so visit now and visit often.  Through Sunday you will find a growing collection of marvels both great and small.

I and the Birds #119: The Cult of Birds: I cannot recommend enough that you visit Laura’s edition of this bird carnival.  She is someone I look up to as a writer, a naturalist, a feeler of emotions.  Her edition of this celebration of all things winged is the preeminent presentation that should not be missed.

An Inordinate Fondness #1 – Inaugural Issue: A man for whom I have developed a sincere admiration and great fondness, Ted MacRae offers up the inaugural edition of a carnival celebrating the largest group of animals on the planet: beetles.  His passion manifests clearly in this festival, and he sets the bar high for future versions that no doubt will struggle to meet this standard.

Photos:

[1] Juvenile yellow-rumped warbler (a.k.a. myrtle warbler or Audubon’s warbler; Dendroica coronata)

[2] Subadult cedar waxwing (Bombycilla cedrorum)

[3] Brown creeper (Certhia americana)

[4] Mated pair of northern pintails (Anas acuta)

[5] Song sparrow (Melospiza melodia)

[6] Ring-billed gull (Larus delawarensis)

The chase

A Forster’s tern (Sterna forsteri) preparing to dive for a meal.

A Forster's tern (Sterna forsteri) preparing to dive for fish (2009_11_01_036573)

Said tern after catching said meal.

A Forster's tern (Sterna forsteri) after capturing a fish (2009_11_01_036611)

Said tern realizing a ring-billed gull (Larus delawarensis) wants to take said meal.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036617)

Said gull chasing said tern.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036621)

And chasing.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036631)

And chasing.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036633)

Until a second tern sees said meal.

Two Forster's terns (Sterna forsteri) in flight (2009_11_01_036640)

And chases.

One Forster's tern (Sterna forsteri) chasing another (2009_11_01_036641)

And chases.

One Forster's tern (Sterna forsteri) chasing another (2009_11_01_036644)

Until said gull outmaneuvers said second tern and gets back into said chase.

A Forster's tern (Sterna forsteri) and ring-billed gull (Larus delawarensis) chasing another Forster's tern (Sterna forsteri) (2009_11_01_036646)

And chases.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036652)

And chases.

A Forster's tern (Sterna forsteri) being chased by a ring-billed gull (Larus delawarensis) (2009_11_01_036656)

Until said tern makes good its escape by outmaneuvering said gull.

A Forster's tern (Sterna forsteri) flying away with a fish (2009_11_01_036668)

At which point said tern vanishes into the distance to enjoy said meal.

Frozen

In December 1983, White Rock Lake froze from shore to shore with ice thick enough that a person could walk across the 1,100 acre body without getting their feet wet.  But 1983 was an exception.  This is Dallas—Texas, by golly!—and though we have our freezes and our ice storms and our snow storms, usually our winters are an eclectic mix of arctic incursions coupled with subtropical comfort.  In essence, today’s parka and gloves are quickly replaced by tomorrow’s t-shirt and shorts.

The last several weeks have offered a wee bit of a twist on that normalcy.  Progressively cooler temperatures beginning in December ushered in a start to the New Year defined by real, honest-to-goodness cold weather, something that rarely happens here.  And several days below freezing after a prolonged “cool” spell meant seeing a rarity in these parts.

Dallas's White Rock Lake with a massive ice floe filling Sunset Bay (2010_01_10_047953)

Down here in the South we think of ice sheets as being measured in puddles and ponds, in small pools of water that cool off quickly and freeze in the short time that temperatures allow.  Yet standing on the shore of the lake yesterday, I looked out over a true ice floe, a sheet of ice at least 100 acres/40 hectares in size.  The whole of Sunset Bay, including the creeks that come together in the confluence, had frozen over, and in some places they had frozen solid.

Ring-billed gulls standing on an ice floe in Dallas's White Rock Lake (2010_01_10_047876)

The interesting thing about fresh water is that it reaches maximum density at 39° F/4° C.  If the water temperature is above or below that, the liquid’s density lessens and it becomes lighter.  That means none of the water in the lake can fall below 39° F/4° C until all the water hits that temperature.  That’s because water cooled to maximum density becomes heavier than the warmer water beneath it, so it sinks and forces warmer water to the surface.  This trading places continues until the entire body of water has the same density.  Then and only then can the water temperature fall below that threshold.

Ring-billed gulls on an ice floe in Dallas's White Rock Lake (2010_01_10_047888)

Lake water mixes in this fashion until all the water is at or near freezing.  It’s at that point when ice can form on the surface.  That requires an extended period of time with freezing air temperatures, and it requires sufficient time with cold air for the water to reach maximum density in the first place.  The whole process can speed up or slow down depending on the surface area (the amount of water being cooled by the freezing air) and the depth (the amount of water that has to be mixed before the entire lake reaches maximum density and can continue cooling).

Ice on the shore of White Rock Lake in Dallas (2010_01_10_047902)

The first part to freeze generally is along the shore where water is shallow and held relatively still through contact with the land.  This kind of ice is called shorefast ice (or border ice).  It’s the most common ice seen on any body of water.  Once shorefast ice forms, it begins expanding away from land along the surface of the water.  This floating ice sheet is called a floe.

Ice and ice formations on the shore of White Rock Lake in Dallas (2010_01_10_047890)

Wind also impacts freezing since water in motion is much more difficult to freeze than is standing water.  Also, water in motion causes friction, and friction causes heat.  Even before shorefast ice forms, strong winds can create waves.  Waves create spray.  If the air is below freezing, that spray becomes supercooled like freezing rain (liquid water with a temperature below freezing).  And what happens when supercooled water hits something?  It immediately turns to ice.  As in the above image, wave spray that freezes on the shore can create dazzling, otherworldly designs.  This kind of formation is called an ice foot (or ice rampart) when it remains attached to both the ground and the floating ice.

Ring-billed gulls standing on an ice floe in Dallas's White Rock Lake (2010_01_10_047886)

As our temperatures increased, the fast ice (ice that stays where it formed) began to crack, and one massive floe broke apart into a few separate floes.  The lane of open water in the above photo is called a lead, a place where floes move apart.  And that separated floe the gulls are standing on?  That’s called an ice cake.  It’s still attached to the shore where the water froze all the way to the bottom at least ten paces out (where the water freezes all the way to the bottom, it’s called anchor ice).

Ice formations on the shore of a frozen lake (2010_01_10_047904)

That photo shows an interesting detail.  There’s a gap of about six inches/15 centimeters between the frozen lake surface and the ice formations on all southern shores.  The lake didn’t freeze until it became still (hence the floe is perfectly smooth).  The gap between the two stems from the aggressive onshore waves.  Everything above the wave height froze while everything in the waves remained liquid, at least until the winds calmed.

Aquatic plants frozen in place by ice (2010_01_10_047932)

The effect became most evident on aquatic plants.  Significant ice formed atop the stems, but then the lake froze well below that ice layer.  It created a bizarre scene where plants were frozen at both ends but left bare in the middle.  It’s as if the wave spray ice floats in the air above the lake ice.

Onshore ice formations draped over shoreline plants at White Rock Lake in Dallas (2010_01_10_047926)

In places the ice looked more like hot wax poured over the earth and allowed to cool into bizarre shapes and patterns.  Where plants or other obstructions captured the spray, quickly formed ice created a barrier upon which other ice formed but beyond which the water didn’t travel.  Whole walls of ice stood between the lake and the ground beyond, in places the demarcation drawing sharp dichotomies between the cold and the barren.

Waves frozen into ice near the shore of White Rock Lake in Dallas (2010_01_10_047912)

And finally one of the more fascinating structures.  Everything facing north froze from the wave spray.  Anything that could catch water became a magnet for ice, hence plants and rocks and the ground itself developed thick coatings.  But this photo shows a perfectly formed echo of the waves themselves.  As water splashed against the barrier, it did what you’d expect it to do: it exploded into the air, curved over itself and fell back into the lake.  Only in this case it began freezing on contact.  Eventually the ice developed spires that showed how the water splashed rhythmically in the same place, each time sending a spray into the air, each time adding a bit more ice to the frozen reflection that now stands.  There’s no support for this structure save the ice itself and where it’s grounded on the rocks below.

— — — — — — — — — —

It’s important to note that I’ve oversimplified what’s required to freeze the surface of a lake.  Many different conditions play a part.  For example, the process of crystallization (turning liquid water into ice) actually generates heat.  In order for a lake surface to freeze, both air and water must be cold enough to overcome that seemingly counterintuitive effect.  Ground temperature, subsurface water movement, wind, pressure, humidity and many other items play a part.

As for the wildlife, all the inlets, bays and creeks are frozen.  This is especially problematic for wading birds like herons and egrets, not to mention dabbling ducks like mallards.  (Diving ducks are having fewer problems since plenty of open water exists in the middle of the lake, though the depths there prohibit dabblers from feeding normally.)  Cormorants and pelicans have curtailed their near-shore fishing and have been forced to eat and sleep in deeper water.  Smaller birds like warblers and sparrows struggle to find open water from which to drink.  Mammals that don’t hibernate likewise are having difficulty finding open water.  However, temperatures are moderating quickly and the ice is already breaking apart.  Nevertheless, as yesterday’s duck image showed, a good deal of damage has already been done.