Friday, January 28, 2011

Sandhill Cranes: An Ancient Lineage

Greater Sandhill Cranes in early light
(Photos by Narca)

Sandhill Cranes are a huge draw at Bosque del Apache National Wildlife Refuge in New Mexico, and the inspiration for their annual Festival of the Cranes, now in its 24th year. When you rise early, before dawn breaks, and venture out to the gatherings of cranes, where they sleep during the long winter night along the margins of wetlands, you may hear their primeval, haunting rattle, long before the light reveals the masses of the great birds.

Joy in the Morning (Mixed media by Narca)

And primeval they are: a 9-to-10-million-year-old crane skeleton found in Nebraska is identical to that of the modern Sandhill Crane's, making it the oldest known bird species still surviving! Biologists argue about how many subspecies of Sandhill Cranes there are, either five or six. Three of those are non-migratory, living year-round in their strongholds in Cuba, Mississippi and Florida. The others (Greaters, Lessers and––some say––Canadians) migrate each year between northern breeding grounds and more southerly wintering grounds, such as Bosque del Apache. Here at Bosque, the Greater Sandhills predominate, with a sprinkling of Lessers mixed in.

Lesser Sandhill Cranes have shorter legs and bills.

Why are Lesser Sandhill Cranes smaller? They are actually a great illustration of "Allen's rule," which states that warm-blooded animals from colder climates usually have shorter limbs than their equivalents in warmer climates. And indeed, Lessers nest in the High Arctic, at the highest latitudes of any of the Sandhill Crane subspecies, and their bills and legs are noticeably shorter than those of other Sandhills.

As the early sun slants across the bosques (or woodlands) of the Rio Grande, we notice an odd pairing of cranes. A young Lesser Sandhill (about 3 feet tall) is staying right next to an adult Greater Sandhill (over 4 feet tall). Their motions mirror each other's, first as they walk, and then in preflight posture with their necks craned. When they finally fly, they fly together, just the two of them.

A Greater and a Lesser Sandhill Crane keeping company

Rod Drewien, our friend and crane specialist, suspects that this young Lesser was a member of a family group that was disrupted by hunting in a state to the north of New Mexico. The immature bird became lost, and winged its way to Bosque del Apache, where it appears to have found a kindred spirit in this adult Greater.

So in the case of our Odd Couple, I'm wondering whether a pair bond is actually forming, and if it is, where would this odd couple nest? In the High Arctic with the other Lessers? Or perhaps with other Greaters somewhere like Gray's Lake in eastern Idaho? Talk about a basically dysfunctional marriage!

Sandhill Crane Pas de Deux

Rod tells me that some day I have to visit the Lesser Sandhill Cranes' primary staging area along the Platte River in Nebraska, where 80% of the world population of Sandhill Cranes (as many as 800,000) amasses in March along a 75-mile stretch of river, in an immense roil of wings and dancing. Here they gather, eager to push north to their nesting grounds, but compelled to wait until winter releases its grip on their breeding territories. Okay... a month and a half from now... I'm ready!

If you are ready, too, a good place to go is Audubon's Rowe Sanctuary near Kearney, Nebraska. Or, if you enjoy exploring with a guide and like-minded companions, both Naturalist Journeys and WINGS offer an annual jaunt to the Platte River to witness the staging of the cranes.

Sandhill Cranes cover about 300 miles in a day of flying!

Friday, January 21, 2011

A Snow Goose Named 5-1V

Each year we witness grand tides of migratory life. Cranes rattle overhead; geese wing south from their breeding grounds; tiny warblers rain into coastal brush after battling a headwind on their way north across the Gulf of Mexico. And it is possible through banding programs to follow individuals, to learn in detail their migratory routes.

Snow and Ross's Geese join Sandhill Cranes in stubble 
at Bosque del Apache NWR (Photos by Narca)

One of the real pleasures of a winter trip to Bosque del Apache National Wildlife Refuge is the opportunity to contribute to what is known of the wanderings of Snow and Ross's Geese, by recording the numbers and letters written on any neck collars that we may be lucky enough to see. Banders use particular colors of neck collars for each major nesting colony.

The geese have traditional breeding grounds: Snows wintering at the Bosque are usually from the Western Arctic or Central Canadian Arctic region. Big colonies nest at Prudhoe Bay, Banks Island and Queen Maud Bay. Ross's Geese traditionally have nested in the Queen Maud Gulf region, with a more recently established nesting colony around the McConnell River in western Hudson Bay.

This map shows the main seasonal ranges of Lesser Snow Geese and Ross's Geese in the western Central Flyway. It is based on a map in an article, "Status of Lesser Snow Geese and Ross's Geese wintering in the Interior Highlands of Mexico," by Rod Drewien, Alberto Lafon Terrazas, John Taylor, Manuel Ochoa Barraza and Ruth Shea, published in the Wildlife Society Bulletin in 2003.

As we scan the masses of white geese with our scope, we find on Snow Geese the black-writing-on-yellow collars of geese banded at Queen Maud Bay and the white-writing-on-black collars of geese from Banks Island. Waterfowl biologist Rod Drewien tells us that on very rare occasions, he finds at Bosque the red collars of birds banded on Wrangel Island. Those are becoming very scarce, since the Russians have stopped their banding program, so only the older birds still wear the red collar of Wrangel.

Snow Goose 5-1V allows me to take a distant photo through the scope. After some research, Rod tells me that 5-1V is a female banded in the year 2000 at Queen Maud Bay. In subsequent years, she has been reported up and down the flyway, and this is the second year that Rod has seen her here at Bosque del Apache.

Banding studies have revealed that families from the multiple nesting colonies of Snow and Ross's Geese head south, then mix with families from other colonies on the wintering grounds. The young geese form their pair bonds on the wintering grounds, and the young male then accompanies the young female back to her natal colony to start a family of their own. A constant, strong genetic mixing is the result of this pairing strategy.

So the next time you are enjoying the spectacle of a blizzard of white geese, watch for neck collars! If you are able to read the numbers and letters, make a note, and report it to wildlife refuge personnel. You'll be helping to map the wanderings of a bird like 5-1V!

Dawn at Bosque del Apache

Wednesday, January 12, 2011

A Daze of Ducks

Our party of friends––Tony Donaldson, photographer Bill Mullins, Alan and I––had the opportunity at Bosque del Apache National Wildlife Refuge to join Rod Drewien and refuge personnel, including head biologist John Vradenburg, for a morning of duck banding.

Banding programs allow biologists to track the movements of some individuals, to know their nesting and wintering grounds, to learn whether they are healthy and feeding well, to answer questions that are important to a refuge's management. Banding studies can answer questions that bear on the health of an entire population of birds.

500 ducks in a cannon net! (Photos by Narca)

This particular banding project started before dawn, when refuge staff baited a levee to attract the ducks, then fired off a cannon net to capture them. We arrived as the biologists, along with a group of students from Arizona State University, were wading in the icy water and quickly retrieving ducks from the net, in an effort to prevent any from drowning. They had caught far more ducks than expected, with perhaps as many as 500 in the single net! Some of those escaped, but by the end of the morning, 432 had been banded.

Rod is ready to open the cage for the next ducks to come.

Ducks retrieved from the net are put into plastic pens to await processing. 

Too many ducks were caught to fit into the plastic pens, so the others were put into bags in the back of a pickup truck.

Jail break!

Other methods are often employed to trap ducks, including night-lighting to capture individuals and swim-in traps. Old-time waterfowl banders will generally employ cannon nets over dry land, not water, although no doubt the refuge staff had their reasons for handling it the way they did. The method they used certainly was effective at catching large numbers! 

Each method has its pros and cons. One problem with using a net over water is that ducks can become soaked and be unable to fly until they dry off, cormorant-style. Getting that wet is stressful, and the drying ducks are temporarily vulnerable to predators like Coyotes.

A Northern Pintail's wings are temporarily too wet to fly.

Northern Pintail can, however, be wilier than Coyotes. Rod told us of his colleague working with nesting ducks in the prairie pothole region of North Dakota, who watched a Coyote trotting along with a female pintail in his mouth. The Coyote dug a hole and cached his prey, completely burying the duck. Soon after the Coyote left, the dirt started to move, and one bright eye peeked out and looked around. The pintail hen then emerged from the dirt and flew away! She had been playing dead.

A handsome drake Northern Pintail, ready for release

Most of the captured ducks were Northern Pintails, with a number of Green-winged Teal and a handful of Mallards, including this hybrid male Mallard x Mexican Duck. Hybrids of this mix are more often encountered here at the northern edge of the Mexican Duck's range than they are farther south in the bootheel of New Mexico, where green-headed Mallards only rarely breed.

A hybrid Mexican Duck x Mallard shows a gloss of green on his head.

Mexican Ducks are officially considered a subspecies of Mallard, probably based in large part on political ramifications. Hunting programs would be impacted if Mexican Ducks were given full species status, because they would have to be treated as endangered. See Richard Webster's assessment of the issue at

Rod bands a Northern Pintail drake

Rod is an old hand at banding ducks, geese and cranes. He much prefers to do it sitting in a chair, but the staff at Bosque didn't get that fancy in their set-up.

Here's a method of holding a band that is hard to do with songbird bands!

And what questions were answered by this day's banding? 

To start with, refuge biologists saw that a few of the ducks were loaded with parasitic worms. The weight of many was lighter than expected, raising some concern about nutrition. But other questions will only be answered down the road, as band returns trickle in, or as birds return in future winters and are recaptured. For example, banding studies can clarify whether the problems in a declining bird population are occurring on the breeding grounds, on the wintering grounds, or in migration. Banders are a patient breed, and the questions that banding studies may eventually answer can't always be anticipated. 

Tuesday, January 11, 2011

A Bitter Day

We have just finished another winter stay in the bunkhouse at the headquarters of Bosque del Apache National Wildlife Refuge, courtesy of the refuge manager Tom Melanson and our good friend Rod Drewien, who goes each year to count geese for the refuge. This year's trip was made profoundly bittersweet by the juxtaposition of excellent days afield with the tragedy in Tucson, where our Congresswoman Gabrielle Giffords was shot by a young, unbalanced idiot, and remains in intensive care. She is, bar none, my favorite elected official currently in office, because of the grace, intelligence and deep caring she has brought to her work on local issues affecting us here in the Chiricahua Mountains.

Much will be written about Gabby Giffords in the days to come, and much will be written about the distinguished federal judge, John Roll, who died that day, and the young girl brimming with potential whose life was cut so short. I didn't know most of the victims, but I can say a little about Gabe Zimmerman, Giffords' young aide, who has come to the Portal community several times, sent by Gabby to meet with us on Forest Service-related issues, and to speak at our local Heritage Days festival in Rodeo on the issue of immigration reform.

Gabe Zimmerman struck all of us who dealt with him as a bright light flaming in a world that badly needs light. He was the sort of intelligent young person whose potential shines brilliantly, someone you want to watch, to see what he does with his life. All of us who had worked with him are deeply mourning his loss.

In this fractious world, people too often subvert their own intelligence and judgment, and identify atavistically with tribal allegiances (Republican/Democrat/Tea Party). That kind of angry identification doesn't allow for real discourse to develop on complex, subtle, and vitally important issues. It doesn't allow for solutions to problems to emerge.

We really need voices like those of Gabe Zimmerman and Gabrielle Giffords. There is no way of knowing the true dimensions of what we have lost––of what the world has lost.

Sunset on a bitter day, January 8, 2011
(Photo by Narca)