Solitary Eagle’s Nest Discovered in Belize:Part 2

August 13, 2012 by  
Filed under Features

To travel horizontally, a static soaring bird must descend and subsequently ascend using convective currents as an elevator, often in a slow cyclic pattern. The bird will enter a rising column of air at the bottom, ascend to the upper limits of the thermal, and then set its wings in a shallow, descending glide slope to move a linear distance. When the bird exhausts the momentum of its descent or nears the ground, it must intersect the bottom of another thermal to gain height and repeat the process. A bird that travels in this manner may have to work many thermals in succession in order to travel great distances across the landscape. Thus, soaring birds are keenly aware of the location, timing and prospect of air currents in their home territories; they will often use the same geological features or localities known to produce such currents and exploit them as “aerial highways”.

Two primary air currents used by the male Solitary Eagle–one an updraft and the other a downdraft–straddled the Orange-breasted Falcon hack site on opposite sides. The hack site was positioned on a peninsular, highland ridge, directly overlooking an unnamed river at the height of 2,000+ vertical feet, not far from Thousand Foot Falls, a popular tourist attraction. The eagle would ascend from the north, often carrying prey, soar directly over the hack site, and then descend the opposite side to the south in order to intersect another thermal further down the river valley. This initial descent, so near to the observation blind, gave one the impression that the eagle was “landing” in the forest directly below the hack site. Such a conclusion would be a mistake and is precisely the reason this particular Solitary Eagle’s nest went undiscovered for nearly a decade. Previous raptor biologists had erroneously searched for the nest in the forested slopes of this southern drop zone.

Only a person who could correctly interpret the eagle’s flight patterns would be able to ascertain a final descending glide into a nest. When a soaring bird is truly landing, it will stiffly set its wings, rotate the feet forward, angle the head and body toward the intended perch and glide in a fast, direct fashion. It will not ascend lazily into the air again. Once the general landing area of the food-carrying male eagle was defined, it was a simple matter of setting up surveillance points along its route of travel to pinpoint the nest location. The Peregrine Fund attendants manned three observation points that intercepted the eagle’s trajectory for four days before locating the actual nest tree.

The male Solitary Eagle was first seen at the hack site on 7 June 2011, the day the attendants arrived to prepare the hack tower for the Orange-breasted Falcon release. Regular sightings occurred at the hack site every two- three days thereafter between 1000 and 1500 hours, when wind and thermal activity was at its peak. After two weeks of continuous observation, surveillance points were marked along the eagle’s known flight path by 27 June 2011, and sightings began to occur daily, as the attendants drew closer and closer to the nest. Roni Martinez was invited by the author at that time to assist in the search–after the general nest location and flight path were known–to help the hack site attendants monitor surveillance points with an “extra set of eyes”. As a native conservation officer, Roni was also needed to negotiate passage through a military weapons training area adjacent to the suspected nest site, as it was decidedly foolish for American foreigners to be caught trespassing across this dangerous, and possibly restricted, zone without permission.

Continued in Part 3

Article contributed by Stacia A. Novy

Photo: The Peregrine Fund Crew

Caption: The “Solitary Eagle Search Team” employed by The Peregrine Fund,
Boise, Idaho

Solitary Eagle’s Nest Discovered in Belize:Part 3

August 13, 2012 by  
Filed under Features

On the morning of discovery, Stacia, Matt, Audrey and Roni hiked across the military exercise area, northwest of Baldy Beacon, to access a new observation point that was closest to the predicted nest location. Roni brought along a spotting scope, while Stacia draped a trusted, high-powered 10 X 50 Swarovski binocular about her neck. The Peregrine Fund owned a Zeiss spotting scope, but theirs was needed for observations back at the Orange-breasted Falcon release site, which Camille and Jon were scheduled to manage that day. Therefore, Roni had to bring his own scope for use in the field, as the attendants’ scope was not available. The three hack site attendants indicated the hillside of greatest interest to Roni: a thickly forested slope that had shown the greatest amount of eagle activity while under observation and, thus, most likely to contain the nest. Roni scanned the slope with the spotting scope and just happened to see the male Solitary Eagle swoop in carrying a yellow snake at that precise moment. Roni later exclaimed that he “never would have seen the eagle against the dark backdrop of trees if the snake hadn’t been so brightly colored”.

However, the scope had so narrow an angle of view that the position of any tree on such a distant hillside could not be determined. All Roni could see was the tree, and the tree was so far away that it could not be seen with the naked eye. Roni wrung his hands and nervously paced back and forth in the field, shouting, “Don’t touch the scope! Nobody touch the scope!” Even the slightest tilt of the lens would have offset the view and the marked tree would have been lost in a fuzzy sea of green. So, the author performed an old falconry trick: she calmly placed her wide-angled binocular on top of the telescope lens barrel to view the nest tree with all the distinctive landmarks around it. With those features in mind, the author was able to lead Matt and Roni through the rough, forested terrain until they got close enough to see the actual nest.

This same method works with trained falconry birds as they will tighten their body conformation and fixate their eyes on quarry before launching an attack, most likely to triangulate a position. Before the hunting hawk flies off the fist, the falconer can place a binocular on the bird’s head to see what it is looking at. Since birds-of-prey possess binocular vision–as do humans and manufactured optics–the technique works. It is commonly used throughout the falconry community both in North America and abroad. Audrey remained behind at the final observation point, but watched the three others progress to the nest tree through the spotting scope. When the nest was finally found, the good news was radioed back to Jon and Camille, as they were a part of the original “Peregrine Fund Solitary Eagle Search Team”, but could not participate on the day of discovery.

As The Peregrine Fund/World Center for Birds of Prey was the first organization to document the presence of Solitary Eagles in the region so long ago, it seems a fitting conclusion that subsequent employees of that same organization confirmed the first breeding record for the country of Belize 22 years later. Following on the heels of this phenomenal find, the South American and North American classification committees of the American Ornithologists’ Union recently agreed to subsume the Solitary Eagle’s old genus Harpyhaliaetus, into the genus Buteogallus. Recent DNA studies have confirmed that the Solitary Eagle is so closely related to the Common Black Hawk (Buteogallus anthracinus) and Great Black Hawk (Buteogallus urubitinga) that reclassification is warranted.

Editor’s Note: This is not the first time the author has located a rare raptor. In 1996, while working for The Peregrine Fund on an Aplomado Falcon repatriation project in Laguna Atascosa National Wildlife Refuge (NWR) in Texas, she discovered a Collared Forest-Falcon (Micrastur semitorquatus). It was the first record of that tropical species for Laguna Atascosa NWR and was documented in their archives.

Article contributed by Stacia A. Novy

Photo Title: Peregrine Fund Vehicle
Caption: “The author returns after a successful day of searching for the
Solitary Eagle’s nest”

Birding Along the Great Rift Valley Flyway in Israel

July 31, 2012 by  
Filed under Features

Located at the point where three continents meet, Israel has reported sightings of more than 500 species of birds, many of which stop-over during their migration between Europe/Western Asia to Africa along the Great Rift Valley flyway. So, a recent announcement by the Israeli government that it will be investing NIS 37 million (US$10 million) in developing a network of centers along the migration route is welcome news for birding enthusiasts. Three existing bird watching centers are to be upgraded – Kfar Rupin, Eilat and Ma’agan – with four new centers planned for Ein Gedi, Hatzeva, Lotan and Sde Boker, as per the proposal put together by the Society for the Protection of Nature in Israel (SPNI) and Tel Aviv University. The project, which will include a web-accessible computerized bird monitoring database, aims to attract up to 100,000 bird watchers to the region annually, while raising environmental awareness and promoting education and research.

An estimated 500 million birds stop-over in Israel during their autumn and spring migrations, between mid-March and mid-May and November to December. The area of Galilee, with its kibbutz farms and fishponds located on the banks of the Jordan River, hosts migratory birds that take a rest period of several days before completing the last stretch of their trip which spans three continents and covers thousands of kilometers. During this time bird watchers can expect to see vast flocks of pelicans, storks (up to 85 percent of the world’s stork population) and other birds setting up temporary rest-stops.

The Hula Valley Nature Reserve is one of the country’s most famous birding sites and well worth visiting if you plan to go birding in Israel. The reserve, which is listed by BBC Wildlife magazine as one of the world’s most important wildlife observation sites, has an interesting history. In the 1950s most of the lake was drained to make way for farming, with devastating results on the ecosystem and endemic plant and animal life. In 1994, in an effort to restore the balance, part of the lake was re-flooded and soon attracted birds again. Today the reserve is home to tens of thousands of aquatic birds representing more than 200 species and welcomes birders with an informative visitors’ center and a floating bridge with blinds from which birds can be viewed. Hula Nature Reserve stands as testimony to nature’s ability to recover when given the opportunity to do so.

Mynahs as Pet Birds

May 22, 2012 by  
Filed under Pet Birds

Mynah’s make fascinating pets and are the best mimics in the world of birds. Categorized amongst the softbills, these playful birds require special care, especially when it comes to diet. It is also important to note that they are very active birds and require a lot of space. If you think a mynah is the bird for you, then read on.

It is important that you obtain your mynah bird from a reputable domestic mynah breeder, so as to avoid supporting wildlife smugglers, who are responsible for the deaths of vast numbers of birds captured in the wild. Because mynahs can, and should, only be obtained through domestic breeders, it may be a challenge to obtain one; however, there are a number of online resources that will assist you in locating a good breeder.

The most popular pet mynah species are the Greater Indian Hill mynah and the Java Hill mynah. Java Hill mynah’s are the larger of the two and are notable for having a clearer, more human-like voice. On the other-hand Greater Indian Hill mynahs are known to be easier to handle. Mynah’s do well on their own, but a pair is also acceptable. They tend to make more noise when there are two, and do better in an outdoor aviary.

It is advisable to house your mynah in a large cage with a few perches made of natural branches, as they do not climb but only fly and hop. A cage with a grated floor is best as it allows for easy cleaning of the newspaper lined catch tray. A shelf and a nest box will make your mynah feel right at home. The mynah’s cage should be put in a busy part of the home as they are gregarious and enjoy company. Avoid drafty spots and direct sunlight. Include a bathing dish in the cage, along with a water bottle or dish. Be sure to keep both sources of water clean. Supply your very active bird with toys such as mirrors, bells, swings, bottle caps, paper and so forth. Be careful of rope toys as these may catch the tongue of your mynah.

Mynah’s require a specialized diet as hemochromatosis is common. This is a disease that causes too much iron to collect in the bird’s liver, resulting in the bird being poisoned. As such, the mynah must be fed a low iron diet, preferably softbill food that has been formulated to meet their needs. Avoid things such as parrot food, red meat, acidic fruits, seeds and live foods. Recommended fruits to accompany the pelleted diet include apple, banana, melon and grapes, with the seeds removed. Keep the food dishes clean and the cage free of uneaten food items that may spoil. You may wish to give your mynah distilled water if you are concerned about the iron content in your water.

While there are number of considerations to take into account before bringing a pet mynah into your home, if you do decide to do so you will find it a truly rewarding experience.

Feathers, Fashion and Conservation

May 8, 2012 by  
Filed under Features

Chosen in 1953 as the symbol of the National Audubon Society in the United States, the Great Egret (Ardea Alba) represents an inspiring conservation success story. Had it not been for the dedicated efforts of bird-lovers, this majestic bird would have been hunted to extinction – all in the name of fashion. In the 19th century, the snowy white plumage of the Great Egret made the bird a target for hunters who were supplying the fashion industry in North America. Records indicate that their populations plummeted by up to 95 percent before action was taken to prevent their extinction. Today, they are protected by legislation in the United States and are among the birds listed under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA). The Great Egret’s conservation status is now listed as ‘Least Concern’ on the IUCN Red List.

This elegant long-legged, startlingly white bird with its S-shaped neck is found throughout North and South America, as well as in many other parts of the world. They are typically found near both fresh and salt water as they feed in wetlands, tidal flats, streams and ponds. They stand still for long periods of time waiting for their prey to come to them, whereupon they snap it up and swallow it whole. Although they primarily feed on fish, they will also eat amphibians, mice and reptiles. These monogamous birds nest in trees near water, where both parents take responsibility for incubating and raising their young.

Feathers have long been used by humans as a fashion statement, features of traditional dress or in tribal customs. While examining the remains of a Neanderthal dwelling in the Fumane Cave in the region of Verona, Northern Italy, paleontologists discovered more than 600 bones of birds dating back some 44,000 years, neatly laid out in layers. Thorough examination of the bones revealed that they belonged to twenty-two species of birds, with clear evidence that the feathers had been cut off in a manner that would preserve them intact. While it may be easy to conclude that they had killed the birds as a food source, research reveals that the birds from which the remiges (flight feathers) had been cut, were poor food sources, and considering that feathered arrows had not yet been invented, it was concluded that the feathers had been used for decorative purposes. It’s a sobering thought that when killing or maiming birds simply for the purpose of using their feathers, humans today are displaying behavior in keeping with our Neanderthal ancestors.

Bird-lovers who want to make a positive contribution to the conservation of our feathered friends should contact their local Audubon Society.

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