Raptor feast

Nothing attracts raptors, especially scavengers like vultures and Caracaras, like free food.  Within just a few minutes of spreading a banquet of frozen chicken on the ground in front of our blind at Laguna Seca near Edinburg, Texas, the Turkey Vultures and Black Vultures began circling overhead, and a couple of Caracaras made swooping passes over the carcasses.  Finally, they decided to test the meat.

Adult and juvenile Caracara

An adult (left) and juvenile Caracara were the first ones to sample the banquet.

Using their feet to hold the meet, Caracaras grab chunks of flesh or skin and tug on it until it rips free.  They might immediately swallow big chunks but often fly off to a safer location where they can eat without competition from other birds.

Juvenile Caracara flying off with a meal

Juvenile Caracara flying off with a meal

Turkey Vultures

Turkey Vultures were more timid about approaching the meat.  They usually wait until Caracaras have opened up the carcass before they start to feed.

Harris Hawk

A Harris Hawk took a look at the Caracara feeding frenzy and decided to join in.

Harris Hawk and juvenile Caracara

The Harris Hawk warned off an encroaching young Caracara several times, smacking it with its wings or threatening with its beak.

Juvenile White-tailed Hawk

A juvenile White-tailed Hawk landed on the feast table but must not have liked what it saw and took off. It’s a much larger bird and could have dominated the other species there for a free meal.

Black Vulture vs Turkey Vulture vs Caracara

Even though Black Vultures are larger than both Turkey Vultures and Caracaras, they didn’t try to dominate either of the other species. Two Black Vultures instead fed on the fringes of the crowd.

Competition for food inevitably leads to some conflicts between individuals.  Exactly what determines who gets to eat what and when may be influenced by the number of individuals of a particular species present, their size, age, and/or temperament.

In this mixed group of raptors species, the smaller Caracaras clearly had the edge, probably because of their numbers, although age didn’t seem to matter, with those aggressive juveniles badgering the adults for food.  Both Vultures species were lower on the pecking order, despite their larger size, and took a backseat to both the Harris Hawk and the Caracaras.  However, they stuck around to clean up the scraps after others had left the feeding area.

Caracara

After two hours of intense feeding, there was nothing left but tiny scraps for the mammalian scavengers to clean up.

Setting up the pose

If there is one thing I’ve learned from the Alan Murphy workshop in Alamo, Texas, it’s to make sure you have the right set up before you bring birds in to photograph.  Providing the right food is just the final step.

Altamira Oriole

An Altamira Oriole landed exactly where it was supposed to, on a bare portion of the mesquite, next to the grape.

First, find suitable staging perches from which the bird will fly a short distance to the food.  That ensures that you will get some good flight shots out and/or back.

Golden-fronted Woodpecker

A Golden-fronted Woodpecker popped his head up on the side of the stump feeder which had been decorated with flowers and greenery.

Second, decorate the source of the food so it doesn’t look like a feeder.  Alan gets quite creative with his decorations so that the colors blend well with both the background and add some splashes of color to the photo.

Great Kiskadee

A Great Kiskadee landed exactly where we had pre-focused, on the brightly colored berries that contrast nicely with the green leaves of the citrus orchard behind it.

Make sure the feeder set up has a nice backdrop 30-50 feet away, so that you will get a smooth background with a telephoto shot.  Then, of course, you have to have a place to sit with your camera on a tripod that is at the same level as the feeder and the staging perch, so you are not shooting down on the birds.  Blinds are ideal, although a little chilly for us to sit in during the winter in Minnesota.  Raising the feeder perch and staging perch to window height works too.

And voila, wonderful photos that hardly need editing!  In fact, the only editing I did on these photos was some very minor cropping.

Who’s the boss?

With limited resources (one feeder) for a highly desirable food (lard-peanut butter mix), there is bound to be a lot of competition and aggression at the feeder among the resident birds.  After a number of inter-species face-offs, and a few beakings, it was apparent that the Golden-fronted Woodpeckers were top dog, or big boss, or head honcho, as illustrated below.

Golden -fronted Woodpecker vs Red-winged blackbird

Golden -fronted Woodpecker vs Red-winged blackbird

Golden -fronted Woodpecker vs Great Kiskadee

Golden -fronted Woodpecker vs Great Kiskadee–no room on the feeder for the Kiskadee

Golden -fronted Woodpecker vs Green Jay

Golden -fronted Woodpecker vs Green Jay. The Jay landed, Woody turned his head and threatened with his beak, and the Jay crouched submissively.

What happens when two Woodpeckers confront each other?

Golden -fronted Woodpeckers

Female Golden -fronted Woodpeckers face off.

Golden -fronted Woodpeckers

Birds in flight

I’m currently in Alamo, Texas attending a bird photography workshop run by Alan Murphy, and learning how to set up for taking photos of small birds in flight. Today’s challenge — learn how to pre-focus the camera in the place you expect the birds to be. Sometimes it worked, but most of the time, I captured an empty perch.

Great Kiskadee vs Red-winged Blackbird

Great Kiskadee vs Red-winged Blackbird

Green Jays

Green Jays

Golden-fronted Woodpecker vs Cardinal

Golden-fronted Woodpecker vs Cardinal

Golden-fronted Woodpecker

Golden-fronted Woodpecker vs Blackbird

at the mouth of the Rio Grande

Running an almost 2000 mile course from south-central Colorado to the beaches of Brownsville, Texas, the mighty Rio Grande river trickles into the Gulf of Mexico, much of its volume removed as irrigation water along its path.

The mouth of the Rio Grande near Brownsville, Texas

At the mouth of the Rio Grande, a thin slice of river on the far side of the sandbar separates Mexico and the U.S.

Brown Pelicans

Fish were so plentiful near the shore, the Brown Pelicans scooped them up while floating in ankle deep water.

Brown Pelicans

Brown Pelicans

Brown Pelicans

Great Egrets, Great Blue Herons, and an assortment of gulls and terns tried to cash in on the feast as well.

Royal Tern

South Texas beauties

The Rio Grande valley of south Texas is a birding mecca where Northern temperate migrants meet neotropical species to form colorful mixtures of old friends and new at various birding centers along the borderland with Mexico. With almost 500 bird species recorded here, this is a place you come to increase the number of birds on your life list, or just to be awed by the beauty of these southern birds.  A few examples of some neotropical birds that only make it as far north as the RioGrande valley region in the US.:

Couch's kingbird

Birds perched on power lines are always interesting…this one is Couch’s Kingbird, a species so similar to the widespread Tropical Kingbird they can only be told apart by their song.  Couch’s Kingbird has a far more restricted range along the eastern Mexican coast–and parts of the RioGrande Valley.

Couch's Kingbird

It’s hard to miss their brilliant yellow color in the drab olive green vegetation here.

Green Jay

The Green Jay could have been called the Blue hooded Jay, because that is one of its most dramatic featureS.  The species has an unusual distribution, in which the Mexican population is separated from that in northern South America by 1500 miles.

Green Jay

Like other jays, these are quite social, visiting feeding stations in family groups.  One year old birds stay with their parents and help defend the breeding territory and feed new chicks.  After those chicks fledge, the teen-agers get booted out.

Altamira Oriole

Unlike other orioles, both male and female Altamira Orioles have black bibs and beaks, with striking black and white wings that contrast with a brilliant deep yellow-orange head and body.

Altamira Oriole

This is the largest oriole species in the U.S., although it barely makes it into the country with its very limited Rio Grande valley distribution.  In Mexico, an Altamira oriole female weaves a two-foot long hanging nest in which she raises her young.

Great Kiskadee

Great Kiskadee flycatchers are numerous in their Central and South American range, but occur only in a narrow strip of the Rio Grande valley in the U.S.  They are noisy squawkers, calling out their name –kiss-ka-dee!, as they “hunt like a flycatcher, fish like a kingfisher, and forage like a Jay” (Cornell Lab quote).

Parrots in paradise

Four species of parrots come to roost each evening in Oliveira Park in Brownsville, Texas. Groups of 30-40 birds fly in, perch on bare branches or wires, calling continuously, and flitting from place to place before settling down.  Bird watchers and photographers congregate to admire the spectacle, and it is impressive!

Parrots in Brownsville, Texas

They time their fly-in so the light is just fading after sunset, making photography doubly challenging.

Parrots in Brownsville, Texas

Noisy chattering from a line-up of parrots on power lines…

Parrots in Brownsville, Texas

A lot of jostling for position among bare branches of mesquite trees…these are the red-crowned parrots, probably the most common species in this assemblage.

Red-lored parrot, Brownsville, Texas

A Red-lored parrot, with a red and yellow face, the next most common species in the large group.

Yellow-headed parrot, Brownsville, Texas

Yellow-headed parrots were far less common than the other two.  This shot looks like it was taken in mid-day, but the lightened exposure was actually taken at 6:30, long after sunset, with a little illumination from the lights over the soccer field.

White-fronted Amazon parrots also made an appearance, though it was too dark for me to photograph them.  Lilac-crowned Amazon parrots have also been seen in this mixed flock.

Why are so many parrots fond of this park in Brownsville, Texas?  Perhaps because there is a lot of fruit and produce grown here in the fertile Rio Grande valley, and the park trees make excellent cover for an overnight stay.  Some birds may be wild birds from points south in Mexico, but others are probably escaped pets that have since gone feral.

We finally gave up our observations when the sky looked like this….

Full moon

 

Heron haven

South-eastern Texas, and South Padre Island, in particular are a haven for egrets and herons.  Five species of them just in one nature area.  There were so many little fish in the pools, the five species could forage almost side by side.

South padre island herons

Great white egret, snowy egret, and great blue heron fishing in a small back water.

Reddish Egret

Standing just a few feet away, a Reddish Egret, feeling drowsy after a big meal.

Tri-colored heron

On the other side of the boardwalk, a Tri-colored heron fishes for minnows.

Fish food for herons

Fish food for herons in the shallow waters surrounding the mangroves

South Padre Island birding and nature center boardwalk

A boardwalk through the mangroves that surround Laguna Madre gives viewers numerous opportunities to photograph wildlife.

Great blue heron

The wildlife is so used to people on the boardwalk, we can get some really close-up views–like the head of a Great blue heron.

Wind surfers on Laguna Madre

There are others enjoying the Laguna Madre waters besides the birds.

 

Why don’t trees freeze solid in the winter?

A bright, sunny day in mid-winter in the northern U.S. makes it look like a good time for a walk in the backyard — but, one step out the door and I know it won’t be fun at all. The air temperature is -7 F, and there is a stiff wind blowing.  This makes for a very short walk, snap a couple of photos, retreat indoors again.  Why bother?  Because I got to wondering how trees manage these sub-freezing conditions.  Obviously, standing still in this kind of weather would be lethal for any warm-blooded creature, so how can trees withstand freezing solid for six months of the year?  Or do they?

oak-tree-in-snow-

And what happens on warm sunny days when half of the tree is subjected to bright sunlight while the other side remains in the dark?  Is there freeze and thaw going on?

The short answer is that they don’t actually “freeze solid”, because the same changing light (decreased photoperiod) and fluctuating temperature conditions in the fall that bring on that wonderful display of fall color also induce physiological changes in plants called “cold hardening” that prevent freezing.

snowfall

The strikingly white bark of birch trees serves a useful purpose in the winter by reflecting a lot of the sun’s radiation on bright, sunny days, and thus preventing the unequal heating of the exposed and unexposed sides of the tree.

Photoperiod and temperature signals in the fall cause plant cell membranes to become more permeable and flexible.  Sugars produced by the leaves move down to storage in the roots, and water follows the sugar movement, so cellular contents become much more concentrated.  So concentrated in fact, that they lower the threshold for freezing dramatically, to -30 F or more.  In addition, cells produce protective cryoproteins that act like potent antifreeze agents.   Residual water trapped between cells may freeze, but the now shrunken and flexible cells remain uninjured, and ready to restart their metabolic engines when spring weather thaws the ground, the roots take up water from the soil, and the sap rises in the plants’ fluid transport vessels (xylem and phloem).

basking-squirrel-

Rough textured bark also serves a useful purpose, beyond providing a foot-hold for the squirrels. It can’t serve as an insulative blanket like a warm coat of feathers or fur does, but corrugations of bark absorb the radiant heat of winter sun, expanding and contracting in heat and cold, without affecting the underlying layers that might crack with exposure to the sun.

In effect, trees and other plants that survive the sub-freezing conditions of northern winters are in a static state of super-cooled dormancy, still liquid and viable, although metabolically quiescent.  Waiting…

A splash of color

Needing some color to brighten up the dull winter shades of gray here, I stopped by the Como Park Conservatory in St. Paul.  Now if only this amazing collection of orchids and other blooms was attached to my house…

Como Park Conservatory sunken garden

A variety of poinsettias are planted in the sunken garden room during the holiday season.

Como Park Conservatory

A few fish nibble at the toes of the statue at one end of the long reflecting pool.

como-conservatory-orchid

A variety of orchids bloom along winding paths through the other rooms of the Conservatory.

Some orchids flower only once or twice a year, so they must make the most of the time the flowers are viable to insure that they get pollinated.  They entice their pollinators to visit with a variety of traps and lures: some plants use fragrances or nectar to attract insects; others use color and nectar to attract birds; still others mimic female insects that males seek to mate with.  Some species coat the landing pad with wax that causes insect visitors to fall into a watery pool formed by one petal; the only way out of the pool is, of course, to squeeze through an opening at one end of the pool where the pollinia (pollen sacs) are then deposited on the insect’s back.  Such clever strategies!

The end result is a huge variety of shapes, colors, and colorful designs that delight the human eye as well as the potential pollinators.

como-conservatory-orchid

como-conservatory-orchid

como-conservatory-orchid

como-conservatory-orchid

como-conservatory-orchid