A recent study by evolutionary biologist Tom Flower of the University of Cape Town in South Africa has revealed that the African fork-tailed drongo mimics alarm calls of other species as part of its food gathering strategy. Wildlife observers in Africa have noted that the drongo is an accomplished thief, but it was thought that it was using its own alarm call to falsely alert other birds and meerkats that a predator was nearby, thereby causing them to drop their meal, which the drongo would swoop in and claim. It is estimated that the drongo steals more than twenty percent of its daily food. But the lengthy study carried out by Flower in the Kuruman River Reserve, located in the Kalahari Desert, yielded some astounding insight into the drongo’s ability to perfectly mimic a variety of bird and mammal species for its own advantage.
In the wild, birds and mammals often pay attention to other species in their environment when it comes to sounding the alarm. An extra pair of eyes and ears can be handy when it comes to safety. But as researchers have discovered, the drongo can’t be trusted. Perched high up in a tree a drongo watches with keen interest as meerkats forage, and when one of them catches something, an insect or lizard, the drongo sounds its own alarm call, anticipating that the meerkat will drop its prey and head for cover. However, the foraging meerkats are likely to ignore the drongo after it has used its own alarm call a few times. Undaunted, the drongo will switch to the alarm call of another bird species, often with successful results.
During the study, Flower and his colleagues tracked and recorded the calls of 42 drongos as they attempted to steal food from the same target. It was noted that of the 151 recorded incidents, the drongos switched to a different alarm call a total of 74 times. After giving its own alarm call without success, a drongo may give the alarm call of its target, which general proved successful.
Flower notes that he doubts the birds have ‘theory of mind’ – the ability to understand that another being has different beliefs and intentions – which is currently only attributable to humans. It’s more likely that they are responding to feedback, or have an ability to grasp cause and effect, and use this to their advantage. Nonetheless, this is another example of the keen intelligence of the feathered creatures that share our planet.
Best known for the spectacular courtship display put on by the males of the species, peafowl originate in Asia and belong to the genus Pavo of the Phasianidae (pheasant) family. While the term “peacock” is often used to describe the entire species, irrespective of sex, “peacock” is the correct term for the male in the species, with the female being referred to as a “peahen” and their offspring are known as “pea chicks”. The name for a group of peafowl – pride or ostentation – is very descriptive and this colorful bird has long been associated with high social standing and royalty, particularly in Asian cultures. It also features in Hindu mythology as the mount of the god of war, Karthikeya.
The species of peafowl are the Indian Peafowl (Pavo cristatus), the Green Peafowl (Pavo muticus) and Congo Peafowl (Afropavo congensis). The Indian Peafowl is found in South Asia and is the national bird of India. The male of the species has a brilliantly blue colored body and head, which is topped by a fan-like crest of feathers. Its most prominent feature is its long train of upper-tail covert feathers covered in colorful, iridescent spots resembling eyes. During courtship, this breathtakingly beautiful tail is spread out into a fan and quivered by the male in an attempt to attract a mate. The female of the species has a duller brown plumage with its neck being a greenish color. Although they can fly and often roost in tall trees, Indian Peafowl are usually found on the ground, where they forage for berries, grains and other plant material, with lizards, snakes and small rodents also being on the menu.
While Indian Peafowl are considered to be of “Least Concern” by the IUCN, the Green Peafowl is listed as “Endangered”. Found in the tropical and subtropical forests of Southeast Asia, the Green Peafowl is a target of predators such as Leopards, Tigers, Jungle Cats and humans. Hunting and a loss of habitat has resulted in numbers of these beautiful birds dwindling to the extent that they are now considered to be endangered. The males and females of Green Peacocks are relatively similar in appearance, with the male’s upper tail coverts being longer than the female during breeding season. After breeding season the male molts, resulting in the appearance of the two sexes being even more similar.
Found in the Congo Basin, the Congo Peacock looks like a cross between a peafowl and a guineafowl, with the male’s feathers being a deep blue, tinged with green and violet, while the female is brown with shiny green feathers over its back. Due to habitat loss and hunting, the Congo Peacock has the IUCN status of “Vulnerable”.
This celebration of the Marbled Godwit offers the opportunity to explore the spectacular Redwood Coast and observe a host of bird species and wildlife. The program includes, lectures, workshops, field trips and boat excursions with experienced and well-informed local guides. For more information on this popular event, which is celebrating its 20th anniversary, visit godwitdays.org
Dates: 15-21 April 2015
Country: United States
The American Kestrel (Falco sparverius) is the smallest member of the family Falconidae in North America. The American Kestrel can be identified by two distinct black streaks on each side of the head that contrast with the white throat and cheeks, and by a blue-gray patch encircling a rufous-colored spot on the top of the head. The males have a prominent rufous coloration on the back and tail. The Southeastern American Kestrel (F.s. paulus), which is one of two subspecies that occurs in the United States, is a local resident of Louisiana. It is approximately the size of a robin, and the female is larger than the male. The Southeastern American Kestrel (SAK) is often seen during the winter months in Louisiana perched on telephone lines located along fields and pastures.
The resident SAK is often confused during the winter with the migratory subspecies F.s. sparverius, although the resident species is smaller. The mean body mass of the SAK is approximately 22 percent lower in males and 26 percent lower in females, as compared to the migratory subspecies. It is very difficult to distinguish the two subspecies in the field. F.s. sparverius may look chunkier, but it takes someone who has spent long hours in the field watching kestrels to determine the difference between the two subspecies.
SAKs form strong pair bonds that tend to remain permanent. Displaying high site fidelity, pairs often remain on or near their nesting territories. SAK territories can range in size from 300 to 700 acres. In Louisiana, the SAK prefers open, park-like pine forest and open areas with scattered mature trees, which are needed for perch and nest sites. It is important that forest stands do not have a dense understory. The SAK prefers the same type of habitat preferred by the endangered Red-cockaded Woodpecker (RCW).
The SAK begins breeding courtship in late winter. The courtship includes aerial displays in which the male performs dives and a flutter-glide to advertise to the female. The SAK nests in cavities located in snags or living trees, usually excavated by woodpeckers. The Pileated Woodpecker often plays on important role in creating cavities suitable for nesting SAKs by enlarging the cavities of smaller woodpecker species. The SAK will also use nest boxes, when they are placed in suitable habitat. On Fort Polk, we usually find our first eggs in early April, and a full clutch usually consists of four to five eggs. The incubation period lasts 29 to 30 days. The young will fledge around the age of 30 days. The adults and young will forage together until dispersal, which occurs in the fall.
The SAK hunts from a perch, on the wing, and hovering. It is a generalized predator, feedings on rodents, insects, reptiles, amphibians, and small birds. The favorite food items on Fort Polk are lizards, including anoles, fence lizards, and skinks.
The U.S. Fish and Wildlife Service formerly considered the SAK a candidate subspecies for listing as threatened or endangered. It is no longer being considered a candidate for listing, but is considered a species of concern. The SAK is listed as threatened in Florida by the state’s game and fish commission. The SAK is a nonmigratory resident of the gulf coast states, now very rare over much of its former range. Current range includes east Texas, Florida, Louisiana, and the southern portions of the states of Mississippi, Alabama, South Carolina, and Georgia. The ranges of the two subspecies overlap during the winter.
Habitat loss is the main factor in the population decline of SAK in parts of its range. Industrial forest lands provide open areas important for the SAK, but they do not provide mature trees for nests sites. When the timber matures, the timber stand is usually too dense to be suitable for the SAK. Lack of prescribed fire is also detrimental to the SAK, because it prefers open, park-like forest stands kept open by regular prescribed burning. Prescribed burning and placing nest boxes in suitable habitat are the quick and feasible ways to improve SAK habitat.
Contributed by: Kenneth Moore
Also by Kenneth Moore: Southeastern Kestrel Management on Fort Polk
The Hollywood film The Big Year presents what seems to be an exaggeration of the extremes birding enthusiasts will go to in boosting their number of sightings, particularly of rare birds, with camaraderie turning to cut-throat competition in the blink of an eye, or the twitch of a feathered tail. But the reality is that competitive birding, referred to as “twitching”, has reportedly become an obsession with some birders as they attempt to beat rivals at adding birds to their list. While this activity is very popular in the United States, according to those in the know, British twitchers are among the fiercest competitors in the world.
There are various definitions of “twitching” and descriptions of “twitchers”, but in general it refers to birding enthusiasts who are prepared to stop whatever they are doing immediately to follow up on reports of birds not yet on their list of sightings, or that they have not yet ticked off their list of birds they hope to see. The verb “twitching” is thought to be a reference to the nervous anticipation, stress and anxiety experienced by a birder in pursuit of his/her hobby which often includes traveling long distances and overcoming physical and other obstacles, with the single-minded goal of getting to see (or hear) an elusive bird. There are also varying rules as to when a twitcher can tick a bird off a list, with some saying that hearing the bird is enough and others insisting the seeing the bird should be the rule. Either way, twitchers are not required to provide photographic evidence of their sightings, so the system relies on honor among twitchers.
As with most serious hobbies, twitching has its own vocabulary, and when a twitcher fails to sight the bird he rushed off to see, he considers himself to have “dipped out”, and if his competitors managed to see the bird, he is likely to feel “gripped off”. Some twitchers have compiled a “life list” of birds they hope to see in their lifetime, while others set goals for a season, or specific time period such as 24-hours, which increases the competitive spirit.
Modern technology has aided twitchers immensely as information on rare bird sightings can be sent out immediately, with updates alerting twitchers to the bird’s whereabouts as they are en route to view it. Based in Norwich in the United Kingdom, Rare Bird Alert has been operating since 1991, with a team of experienced birders making information available to birders fifteen hours a day, every day of the year. Similar organizations exist in other countries where birders take their hobby seriously.