Grand Junction Audubon Society birders

Follow local birders in pursuit of their life lists. For more visit audubongv.org.

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SWARMING ANTS: THE HORROR (THE ECSTASY!)

By Nic.Korte
Thursday, April 28, 2016

My wife, Mary, is almost perfect. But, there is one characteristic I would change. Her reactions to unpleasant events seem the same to me whether she believes my habit of birding while driving is about to cause a head-on or whether she’s realized we have run out of an ingredient she needed for cooking dinner.

So it was a couple of weeks ago when I heard her exclaim with horror in the small cabin we were renting in southern Costa Rica. She was preparing dinner. “She's cut or burned herself badly,” I thought. I ran to the room. No. It was ants! The two pañuelos we had selected for breakfast at the local panaderia were literally black with tiny ants. The sack containing a whole-grain bread, difficult-to-find here, had also been breached. The pañuelos were history. A heavily-covered poppy seed roll was never so black. We brushed off the bread and re-wrapped it. The ants were unpleasant, but not a catastrophe.

The next morning we went birding at the nearby Las Cruces Biological Station—part of the Organization for Tropical Studies (http://www.ots.ac.cr). This has been one of our favorite places to visit (http://www.gjsentinel.com/blogs/birds_and_more/entry/green-mansions). We were going birding, but what we really wanted to find were swarming ants! So why didn't we stay home and watch our baked goods?

Eciton burchellii are popularly known as army ants. Peaceful Costa Rica loves to point out that such ants are the only army in their country. It is true that they are a swarming army of sorts, but it is not true, as has been shown in old movies, that they eat everything in their path including humans.

Army ants live a nomadic life. They form armies of half a million ants that march from temporary nests or ‘bivouacs.’ For about three weeks, they march out and return to the same camp until the larvae hatch. Then for two weeks, the army moves to a new location every night. Finally, the larvae pupate and the horde selects another three-week bivouac.

(Army ants on the march.)

These ants forage as an army spreading out over the jungle floor, crawling up limbs and tree trunks, and hunting under every leaf. Insects of every kind flee frantically, and that’s what brings the antbirds. (Read more about the ecological importance of army ants at:
http://phenomena.nationalgeographic.com/2010/11/30/an-entire-world-follows-the-march-of-the-army-ants/)

Found mostly in the lowland tropics, there is a large group of birds with “ant-“in their names: antbirds, antshrikes, antpittas, antthrushes, and more. While not all of these depend on army ants, some are obligate ant followers, meaning they forage not on the army ants themselves, but on the insects fleeing the army ants. When a large group of birds is attending foraging army ants, the event is called an antswarm. A good antswarm can have more than a dozen bird species with multiple individuals of each type. It is a feeding frenzy with usually-shy birds landing almost at your feet.

Most of the antbirds, particularly those that forage with army ants, are shy, and very difficult to see. Many have habits more like forest rodents, keeping quiet and close to the ground. All of them need large areas of mature forest. Despite more than twenty previous trips to the tropics, whether due to bad luck, being with too many other birders such that the birds were frightened, or being in the wrong location, I had never watched an antswarm. I still had never seen two of Costa Rica’s antswarm obligates, and had only fleeting glimpses of others. I wanted to see the new birds. I wanted long and satisfying views of the others. I wanted to experience this phenomenon that I had read and heard about for so many years.

We did find two small antswarms at the Las Cruces Biological Station. I saw the two birds I had never seen before, but I wasn't satisfied. There were not enough species or individuals. The birds were still shy, and sort of dropped in and out. “Is that all there is?” I wondered.

Two weeks later, at a more remote location, I finally realized my dream of encountering a king sized, fully-raucous, wildly-entertaining antswarm. I heard the feeding call of a Bicolored Antbird. I looked about and saw army ants all over the trail. I found a nice vantage point next to a tree and waited. I didn't wait long. Soon an Ocellated Antbird appeared, and then another.

(Ocellated Antbird by Pat O'Donnell. Check out Pat's blog to plan your Costa Rica trip: http://birdingcraft.com/wordpress/)

Next a Ruddy Woodcreeper dove in, snatched a large insect, and clung to a nearby stem. Next came two more Ruddy Woodcreepers, two more kinds of antbirds, and three more species of Woodcreepers. Eventually I tallied 12 bird species. I watched the spectacle for more than an hour. I have been fortunate to have had many noteworthy wildlife experiences. This one was as good as any!

My wife and I make a good pair. We both have emotional reactions to ants!

This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to audubongv@gmail.com. [To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

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WHERE’S THE DOWN? WHERE’S THE HAIR?

By Nic.Korte
Thursday, April 14, 2016

If you are familiar with Downy and Hairy Woodpeckers, you know their plumage is similar enough to cause identification problems. But, I will get back to that. What about their names? Birds can be “downy,” I guess, but “hairy?” Surely, I can find out from the internet.

I found this: “The Hairy Woodpecker's name is derived from the long, filamentous white or whitish feathers in the middle of its back.” And this: “This woodpecker looks a little hairy due to small feathers on its legs, head and over the upper mandible. That is why it is called a Hairy Woodpecker.”

For the Downy, I found this story: “One day a very large white & black woodpecker was looking for the perfect tree to start his noisy pecking. He wasn’t looking where he was going and flew right into some lady’s washer. The lady hadn’t noticed and she started the washer. While the woodpecker was in the washer he shrunk. Then he was put into the dryer. The lady used Downy fabric softener. So, when the woodpecker emerged, he was as soft as a baby. That is how the Downy Woodpecker got its name.”  

Well, that can’t be right. I suppose I should go with the Cornell University website “All About Birds,” which says the Downy was named because of the soft white feathers on its lower back.” That seems reasonable because it is consistent with the naming of the Hairy.

My yard is occasionally visited by a Downy Woodpecker. It will be attracted to my suet feeder or will poke about looking for insects amidst the bark on my apricot tree. The only time I have had a Hairy Woodpecker was when a dying peach tree had a large branch clearly infested with some large burrowing grubs. For days, a Hairy Woodpecker showed up every morning and feasted.

Because the Downy is a more of a yard bird and more commonly seen, the results of the Colorado Breeding Bird Atlas surprised me. Rich Levad, one of the best birders ever known in Colorado, and a huge contributor to the Atlas, asked me, “Which do you think was found breeding in more locations in Colorado, the Downy Woodpecker or the Hairy Woodpecker.” I realized the only reason for him to ask the question was if the answer was unexpected. Yes, the Hairy Woodpecker breeds in more Colorado locations than the seemingly more familiar Downy.

(Here is a Downy with a white grub in her small bill)

Here’s something more interesting. Despite their resemblance, Downy and Hairy woodpeckers are not closely related. As one source notes, their “outward similarity is a spectacular example of convergent evolution.” Convergent evolution means the two species have analogous characteristics that have similar form and function. These characteristics, however, were not present in their last common ancestor. No one knows why the two species evolved to appear so alike; but it is relevant that they eat foods of different sizes and do not compete with each other ecologically.

(This Hairy Woodpecker has two insects in her bill.)

Now, telling them apart! You would think that would be easy. Hairy Woodpeckers are the size of a Robin, Downy Woodpeckers are the size of a House Sparrow. If they are nearby, identification is easy. Hairy Woodpeckers have a much larger bill, nearly the same length as the bird's head. Downy Woodpeckers have a small, chisel-like bill. Nonetheless, I’m not the only experienced birder to be fooled when trying to identify a woodpecker working high in a tree when size is difficult to distinguish. That is a good time to consider the marvel of evolution. They look so alike, but are, yet, so different.

This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to audubongv@gmail.com. [To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]

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HERO WORSHIP AND THE AMERICAN ROBIN

By Nic.Korte
Wednesday, March 30, 2016

One of my heroes was Alexander F. Skutch. He was a pioneer tropical ornithologist who traveled through much of South and Central America in the 1930s and 40s. He eventually settled in Costa Rica. He lived on a small farm and nature preserve until his death in 2004--a few days before his 100th birthday. One of many things that impressed me about his writings is that although he was surrounded by some of the most interesting exotic species in the world, he never tired of studying and appreciating the commonplace.

Skutch also made a great study of and wrote several books on belief systems from all over the world. “What was their essence”? he wondered. “What did they have in common”? From these studies and his experience, he reported that appreciation and co-operation were the most important attributes in one’s approach to life.

I am reminded of Skutch’s appreciation of the commonplace when I think of our familiar Robins. I have lots of favorite birds, but this time of year my choice is the American Robin as it is officially known. I love hearing them sing as they stake out their territories in our yards and announce the arrival of spring.

Sadly, I have heard folks be dismissive of Robins simply because of their abundance. Don’t take them for granted! What are the other most abundant birds around town? Eurasian Starlings. House Sparrows. Eurasian Collared Doves. Mourning Doves. Except for the latter, the others are non-natives, and the former two, in particular, are known as much for their ability to persecute and out-compete our native species as for any endearing habits they might have. One native bird they haven’t beaten up on is the Robin.

Although the American Robin is a native, its name is a misnomer. Homesick European settlers thought it resembled the Eurasian Robin which is from an altogether different family. I would name our Robin a Rufous-breasted Thrush. Six other thrushes are widespread in the United States, but unless you are a birder, you may not have heard of the others. Although several have beautiful songs, they are drably-colored and tend to be skulkers. They avoid humans and hide in thick vegetation. Our Robin, however, is an outlier—a disrupter in the thrush family. Robins will hunt worms and insects in your yard even while you mow it—or play fetch with the dog. Indeed, I often tend to think of Robins as pets—especially when they hop on the deck and drink from the dog’s dish.

I noted some years ago that Robins are year-around residents in our part of the US (http://www.gjsentinel.com/blogs/birds_and_more/entry/when-the-red-red-robinnot). But, they aren’t year-around singers and nesters. That’s what happens now. Now is the time to celebrate spring and the return of Robins to our yards.

This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to audubongv@gmail.com. [To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

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BIRDING THE BAY OF PIGS

By Nic.Korte
Wednesday, March 16, 2016

The crosses along the road were a sad reminder of past events. They were dedicated to Cubans killed during the US-supported invasion of Cuba known in our country as the Bay of Pigs, but elsewhere as the Invasion of Playa Girón.
(Photo by Tim Henson)

The failed invasion occurred in April 1961. Fifty-five years later, birders are invading. The village of Playa Larga was our base for exploring the nearby Zapata Swamp—the largest protected area in the Caribbean.

But, why go birding in Cuba?

Because it is an island!  Renowned biologist E.O. Wilson and his collaborator Robert MacArthur tested a theory of species equilibrium on a tiny island in the Florida Keys. All insect species were eradicated and they observed the re-population by new species. A book describing this experiment, The Theory of Island Biogeography, became a standard ecology text explaining how many species will populate islands of a certain size, and why many are endemics—that is, found nowhere else in the world.

While the exact number can be debated—if Hawaii (home to many island-endemics) is eliminated--the number of bird species found only in the United States during their entire life span is 16. The number found in Cuba and nowhere else is 24-- down from 26 because two are already extinct. The number of Cuban endemics may rise as more genetic testing is performed, but it may also fall because most of the 24 remaining endemics are rated endangered or vulnerable because of their small populations and dwindling habitat.

Besides, the “Cuba-only” birds, 21 others found on Cuba are found only in the West Indies—often on only one or two other islands. Some of these are also endangered.
One endemic we saw frequently was the Cuban Trojan or tocororo—a local name based on its call. Fortunately, this beautiful bird, unlike many trogons found in Central and South America, is adaptable, and has a stable population.

(Cuba's National Bird, the Cuban Trogan, photo by Tim Henson)

Why Cuba now?

Restrictions for travel by US citizens are still in place. Travel in a group and under a special license is required. The pretense is that the group is doing a Natural History Survey or engaging in some sort of educational or social outreach. What is driving birders, however, is the sense of "before it is too late.” There is fear that Western investment and too many visitors will overrun the limited habitat. For example, two major birding magazines recently published articles about birding on Cuba.

One morning, I asked our tour leader how many other birding groups he thought might be in the area. He said he'd be surprised if there were others. We arrived at our planned location only to be confronted with two large buses and two larger groups of birders. We had hoped to see the endangered Zapata Wren. Possibly less than 1000 still survive. With more than 50 birders and three guides trying to call one; is it any wonder none of us saw a Zapata Wren? Lack of infrastructure and lack of enforcement of existing law, rather than resorts and condos may be more likely to doom Cuba’s remaining fragile species. Indeed, our local guide thought major resort developments on the Western model would not happen because Cuba’s leaders have clung to their original paradigm and not used their power to enrich themselves.  Whatever one may think of the Cuban socioeconomic model, it is a good thing that money can't buy influence.

The people we met were delightful. Our food was tasty and plentiful. A five-inch piece of thick spiny lobster tail anyone? How about a plateful of fresh shrimp? 

However the future plays out, I hope there will be room for Fernandina’s Flicker. Perhaps only 600 individuals remain in isolated populations. We were lucky, two of them gave us a great view for many minutes. 

(Fernandina's Flicker, photo by Tim Henson)

[Populations of all Cuban endemics are believed to be decreasing. Other species in jeopardy include: Giant Kingbird (population possibly as low as 250, we saw two), Blue-headed Quail Dove (population possibly no more than 1000, we saw none), Zapata Sparrow (population possibly no more than 1000, we saw none).]

This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to audubongv@gmail.com. [To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

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DOWNTOWN’S DEADLY KILLERS

By Nic.Korte
Sunday, February 28, 2016

My friend and I drove up 8th street early that morning. There on top of the tower was the killer. Not only had he killed, he was ripping the now lifeless body to shreds.
We were watching a Peregrine Falcon devour what appeared to be a Rock Pigeon. The pigeon probably had no chance. Peregrines can reach 200 mph when in one of their power dives, called a stoop.

That we see Peregrines at all is one of the Conservation movement's greatest success stories. The widespread use of organochlorine pesticides, such as DDT, had caused thinning of the eggshells of Peregrines and other birds at the top of the food chain. This led to a widespread disappearance of Peregrines and to their listing as an endangered species. Once use of organochlorine pesticides was regulated, Peregrine Falcons, and other species (e.g. Bald Eagle, Brown Pelican) whose populations had plummeted, began to recover.

In recent years, it has become fashionable for some to portray Rachel Carson, author of Silent Spring, as a mass murderer because mosquitos continue to kill, and organochlorines are seldom used against them. This characterization of Carson is unfair and misleading. Her book was written, for example, before DNA was discovered. There was no EPA. There was no Resource Conservation and Recovery Act, no Superfund, no Toxic Substances Control Act, etc. Carson reacted to what was essentially fumigation. Clouds of DDT were doused on people and wildlife. She saw for herself an incident where fish died immediately after a large, indiscriminate application. Her overall warning was accurate.

Current naysayers also forget that DDT use had already been discontinued in some locations where it had formerly been effective, because the local mosquito population had developed resistance rendering applications ineffectual. Carson also did not call for DDT to be banned. “It is not my contention that chemical insecticides should never be used,” she wrote. “I do contend that we have put poisonous and biologically potent chemicals indiscriminately into the hands of persons largely or wholly ignorant of their potential for harm... I contend, furthermore, that we have allowed these chemicals to be used with little or no advance investigation of their effects on soil, water, wildlife, or man himself.” She was right. And, indeed, DDT is still used, but in focused, careful applications, an approach that if used in the beginning, would have obviated the need for her book.

Grand Junction’s local Rock Pigeons may wish Rachel Carson had never written Silent Spring, but the rest of us can enjoy the resurgence of the fastest bird in the world. The last time I looked, there were a pair of falcons. (Check out the tower at 8th and Main.) As with many birds-of-prey, the female is slightly larger. Hopefully, they will nest on one of our downtown buildings and there will always be generations of Peregrines to keep the Rock Pigeons in check.

This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to audubongv@gmail.com. [To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

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