Warblers Ward off Imposters

April 19, 2011 by  
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Cuckoos have never been very popular amongst other birds species. They are known to be lazy parents and have become sophisticated in their methods of camouflaging their own eggs to look like those of other species, so that they are able to introduce their own eggs into the nest and have the other birds raise their chicks. But host birds are beginning to wise up to the counterfeit eggs being laid in their nests and have developed their own skills to fight off imposter eggs.

Studies conducted at the University of Cambridge, led by Claire Spottiswoode, revealed that host birds, especially warblers, have become more vigilant in regard to recognizing imposter eggs. Most birds use one of two methods. They either teach themselves to be able to recognize the imposter eggs purely by sight, or they have taught themselves to change the coloring of their own eggs, making it more difficult for the cuckoo to copy. During the research studies, scientists placed the eggs in the nests of bird species that were closely related to warblers. It seemed to show that the red-faced cisticola was quite apt in noticing an imposter egg purely by sight, while the tawny-flanked prinia was not very confident in noticing a difference. In its defense, the prinia is able to lay a rainbow color of eggs, complete with variable patterns, which deter cuckoos from the challenge of laying eggs in their nests. In addition they are able to recognize the imposter egg due to their defenses and eject the eggs immediately. The rattling cisticola is no longer the target of the cuckoo, as it has been able to use both defenses, that of recognition and color changing of eggs, to establish which of the eggs are imposters.

Researcher Dr. Martin Stevens expressed his findings of the outcome of the studies, saying: “Our experiments have shown that these different strategies are equally successful as defenses against the cuckoo finch. Moreover, one species that has done a bit of both – the rattling cisticola – appears to have beaten the cuckoo finch with this dual strategy, since it is no longer parasitized. The arms race between the cuckoo finch and its host emphasizes how interactions between species can be remarkably sophisticated especially in tropical regions such as Africa, giving us beautiful examples of evolution and adaptation.”

Bird watching in Thailand

May 5, 2009 by  
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Many bird watching enthusiasts have already discovered the magnificent opportunities that wait in Thailand. With almost a thousand bird species, Thailand is a treasure trove of birding experiences that can be enjoyed in various provinces around the country. Tourist operators also specialize in bird watching excursions, offering daily hikes and even week long hiking packages, through some of the most breathtaking landscapes in Thailand. Bird watching here, is a unique and unforgettable experience.

Some of the more popular bird watching sites include Khok Kham, the Khao Kieo Wildlife Sanctuary, Kaeng Krachan National Park, Doi Chiangdao Wildlife Sanctuary, Khao Pra-Bang Kam Wildlife Sanctuary, Chiangsaen and the Koh Similan National Park. Although there are various bird species that overlap in all the provinces, some bird species prefer specific provinces according to landscape and food supply.

In the Samutsakhon Province for instance, the habitat is blanketed in fish ponds, swamps, mangroves and mudflats, luring species such as the Nordmann’s Greenshank, Streaked Weaver, Malaysian Plover, Ruddy-Breasted Crake, Pheasant-Tailed Jacana and the Asian Dowitcher to this region. Birds such as the Large Hawk Cuckoo, Asian Golden-Weaver, Forest Wagtail and Black Blaza prefer the woodlands and rice fields of the Nakhonpratom Province, while Grey Peacock Pheasants, Blue-bearded Bee-eaters, Violet Cuckoo, Green Magpie and White-hooded Babbler feel at home in the forests, by water streams and waterfalls located in the Petchburi Province.

Some of the larger national parks have a variety of habitats within their borders, having a larger variety of birds in one area. The Khao Yai National Park, in North-Eastern Thailand, gives visitors the opportunity to see birds such as the Siamese Fireback, Mountain Hawk Eagle, Scaly-breasted Partridge, Coral Billed Ground Cuckoo and many more. Other breathtaking species to be seen in Thailand include the Black-backed Forktail, Chestnut-flanked White-eye, Long-tailed Minivet, Collered Owlet, Hume’s Pheasant, White-bellied Redstart, Stripe-breasted Woodpecker, Sapphired Flycather and the Crested Tree Swift. In general, many national parks have more than two hundred different species of bird living and breeding within the park, giving visitors the experience of a lifetime. To see truly amazing bird life, Thailand is the perfect bird watching destination.

Common Cuckoo (Cuculus canorus)

February 9, 2009 by  
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The Common Cuckoo (Cuculus canorus) is a medium-sized bird that averages between 32 to 37 centimeters in length. The males have solid gray coloring over their heads, neck and wings. Their bellies are white with gray to black stripes, dark gray tail feathers and black eyes. Bills are pointed and black of color. The female Cuckoo resembles the males, but with morphed brown coloring. The Common Cuckoo is a migratory bird and is seen across Europe, including Britain, as well as Japan and China, and migrates to Africa during the winter months. It adapts easily to live in cultivated areas, on the edges of dense forests, open country, marshes and coastal areas.

The Cuckoo has a wingspan of approximately 71 to 76 centimeters and has an extremely distinctive low flight. They fly with rapid ing beats and are very swift in flight. Their flight pattern bears a resemblance to that of raptors, with the exception that the Cuckoo has much weaker strokes and does not glide after a series of beats.

The preferred food of the Common Cuckoo includes a diet of hairy caterpillars, larvae and insects. Not being too fussy, they will also eat beetles, crickets and dragonflies, and have in some instances also been seen eating eggs and songbird nestlings. The female Cuckoo is not the best parent, to say the least. They are not interested in parenthood at all. She can lay in the region of eight to twenty five eggs, and the eggs can vary in color. Sometimes the eggs are brown with markings of lilac, gray, black and red-brown. At times eggs can be green, blue or red, with markings. This enables the Cuckoo to secretly lay an egg in another nest. Not all of the Cuckoo species find host parents for their eggs. The Common Cuckoo will find a species with similar eggs to her own and when the host parents are not in sight, she will lay her eggs amongst the eggs already in the nest. The host parents, not realizing anything is amiss, will complete the 11 to 13 day incubation period and rear the chicks until they are ready to fledge the nest. The female Cuckoo will never return or revisit her chick. Most of the time, the Common Cuckoo chick will be bigger in size than host parents, putting strain on the parents to feed the intruder.

Although the Common Cuckoo is a very wide-spread species and difficult to monitor, it is believed to be plentiful and is not threatened by extinction.

Common Bird Numbers Declining

September 23, 2008 by  
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Previously birds such as the cuckoo, turtle dove and nightingale were thought to be amongst the world’s most common bird species. However it seems that even these birds are now at risk, with each of these species suffering massive slumps in their overall population numbers during the past half century.

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The Bane of Brood Parasites

December 17, 2007 by  
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When we hear the word “parasites”, most of us would assume it is referring to an organism that feeds off another. In brood parasites, in the avian world, it works a little differently. To put in laymen’s terms, it is when one bird species lays their eggs in a different species‘ nest, so that the parasite species do not have to take care of their young. Over the years, host bird species became wise to the brood parasites, but as a parasite does not give up that easily, the brood parasites have come up with various devious plans to fool the hosts.

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