Archive for March, 2006
From Wikipedia, the free encyclopedia
Description
The birds called Swiftlets or Cave Swiftlets are contained within the four genera of Aerodramus, Hydrochous, Schoutedenapus and Collocalia. They form the Collocaliini tribe within Apodidae. The group contains around thirty species mostly confined to southern Asia and south Pacific islands and north eastern Australia all within the tropical and subtropical regions. They are in many respects typical members of the Apodidae having narrow wings for fast flight, with a wide gape and small reduced beak surrounded by bristles for catching insects in flight. What distinguishes many (but not all species) from other Swifts and indeed almost all other birds (see Oilbird) is their ability to use a simple but effective form of echolocation to navigate in total darkness through the chasms and shafts of the caves they utilize for night time roosting and breeding
Nest as delicacy
One fact that these birds (only a few species within the genus) are possibly more renowned for, is the use of their nests for making bird’s nest soup (燕窩 pinyin Yan4 Wo1) in Chinese cuisine. During the breeding season, all the species’ salivary glands expand to produce the special sticky saliva for binding twigs and other detritus together for building the nest, which is a shallow cup stuck to the cave wall. Only a few species are suitable, and it is those species whose nests are made purely or almost purely of saliva that are harvested and most prized. The nests are harvested, at some risk to the collector, from high up on cave walls, with collectors standing on tall bamboo scaffolding (sometimes hundreds of feet tall and centuries old - with obvious repairs). There is some concern that over-harvesting is causing several species to become scarce. Bird nest merchants in southeast Asia (including Vietnam, Indonesia, Thailand etc.) have started to raise and breed the swiftlets in house-like structures. They build the shelters to attract wild swiftlets to build nests in them. The wrong kind of nests are then destroyed along with the eggs inside. Over time, the selection process only leaves behind a colony of swiftlets that produce the right kind of nest for the trade. “House nests” are priced much lower than the “cave nests” due to the level of risks involved in the harvesting process.
When cooked, the birds’ nests have a gelatinous texture. In Asian cuisine they are considered very good for the health. Some consumers of bird nest soup have noticed significant improvement in appetite. However, some others noticed excessive secretion of gastric acid that may cause acid reflux symptoms.
Food
Guano (dung) from both the Swiftlets and the many bats that inhabit the caves supports a huge array of specialized animals that feed on the dung. There are yet other creatures that have evolved to feed on these dung eaters as well as the bats and the swiftlets themselves including among others, snakes that can climb the sheer walls to snatch a passing meal and huge carnivorous crickets that prey on chicks and bat pups.
This ecosystem is totally self sustaining, the only link being the birds and the bats that bring the nutrients into the caves in the first place.
Species
• Genus Hydrochous
◦ Waterfall Swift, Hydrochous gigas
• Genus Collocalia
◦ Glossy Swiftlet, Collocalia esculenta
◦ Cave Swiftlet, Collocalia linchi
◦ Pygmy Swiftlet, Collocalia troglodytes
• Genus Aerodramus
◦ Seychelles Swiftlet, Aerodramus elaphrus
◦ Mascarene Swiftlet, Aerodramus francicus
◦ Indian Swiftlet, Aerodramus unicolor
◦ Philippine Swiftlet, Aerodramus mearnsi
◦ Moluccan Swiftlet, Aerodramus infuscatus
◦ Mountain Swiftlet, Aerodramus hirundinaceus
◦ White-rumped Swiftlet, Aerodramus spodiopygius
◦ Australian Swiftlet, Aerodramus terraereginae
◦ Himalayan Swiftlet, Aerodramus brevirostris
◦ Indochinese Swiftlet, Aerodramus rogersi
◦ Volcano Swiftlet, Aerodramus vulcanorum
◦ Whitehead’s Swiftlet, Aerodramus whiteheadi
◦ Bare-legged Swiftlet, Aerodramus nuditarsus
◦ Mayr’s Swiftlet, Aerodramus orientalis
◦ Palawan Swiftlet, Aerodramus palawanensis
◦ Mossy-nest Swiftlet, Aerodramus salangana
◦ Uniform Swiftlet, Aerodramus vanikorensis
◦ Palau Swiftlet, Aerodramus pelewensis
◦ Guam Swiftlet, Aerodramus bartschi
◦ Caroline Islands Swiftlet, Aerodramus inquietus
◦ Atiu Swiftlet, Aerodramus sawtelli
◦ Polynesian Swiftlet, Aerodramus leucophaeus
◦ Marquesan Swiftlet, Aerodramus ocistus
◦ Black-nest Swiftlet, Aerodramus maximus
◦ Edible-nest Swiftlet, Aerodramus fuciphagus
◦ German’s Swiftlet, Aerodramus germani
◦ Papuan Swiftlet, Aerodramus papuensis
• Genus Achoutedenapus
◦ Scarce Swift, Schoutedenapus myoptilus
◦ Schouteden’s Swift, Schoutedenapus schoutedeni
March 22nd, 2006
sfgate.com
Sarah Rooney, Chronicle Foreign Service
Muk Island, Thailand — High in the caves of Thailand’s idyllic southern islands lies an unlikely treasure that people are willing to kill for — the nest of a sparrowlike bird called the swiftlet.
About a half-dozen companies, which have been granted concessions by local governments to gather swiftlet nests for the lucrative bird’s nest soup market,
are protecting their fiefdoms with private armies that shoot at “unauthorized” visitors. They also bribe authorities to look the other way, charge tourist operators protection money and keep locals suspected of being poachers from their traditional fishing grounds on the coast of the scenic Andaman Sea.
These concessionaires are so secretive about their operations on about 140 cave-ridden limestone islands that few Thai officials have any idea what they are up to or are willing to provide much information.
“The bird’s nest companies are big and influential,” said a bureaucrat from the tax revenue department in Bangkok who spoke off the record. “We can’t give out information (about their activities) to just anyone.”
But it is no secret that swiftlet colonies are being depleted to supply Chinese restaurants with edible nests from glutinous globs of dried bird saliva that are cooked in a broth. The soup is popular because it is believed to help growth, skin complexion and sex drive, prevent lung disease and stave off aging.
When a swiftlet’s cup-shaped nest is taken before it can lay eggs, the bird is forced to build another one. In the caves, collectors shimmy up bamboo poles lashed together with liana vines. Death and injury from falls are not uncommon.
The climbers typically take two nests from each bird, allowing the bird to rear its young in a third so the population can regenerate. But high demand has increasingly caused gatherers to take that nest as well, and baby birds are sometimes thrown away.
A local source familiar with the bird’s nest industry said there are only one-third as many nests as there were a decade ago, and the swiftlets have abandoned many caves.
“When the resources are of such high value, the temptation is to take as much as you can get hold of,” said Charli Evans, representative in Thailand for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), an international group that monitors commerce in endangered species.
Many people interviewed for this story were afraid to speak on the record. A resident of the town of Puhuket who has spoken out against a nest company’s violent tactics has moved his residence four times because of death threats. “It is a dark business,” he said.
The Chinese began eating bird’s nest soup about 1,500 years ago. Today, millions of nests are sent to Chinese communities around the world. Hong Kong is the world’s largest market, followed by the United States, mainland China and Taiwan.
Some call it “white gold,” because a kilo (2.2 pounds) sells for almost $2, 000. A bowl of bird’s nest soup at a good Hong Kong restaurant can go for as much as $60. Thailand exports about 19,800 pounds annually, which generates $23.8 million in taxes.
A push by CITES to protect swiftlets has failed, mostly because of opposition by southeast Asian countries where so much money is at stake.
In Thailand’s southern Trang province, a company called Satun Trang Bird’s Nest recently obtained a five-year concession on swiftlet nests. Fishermen on Muk say company speedboats have chased them away and armed men have shot at them if they sailed too close to company operations. In the early 1990s, clashes between licensed collectors and locals who poached on nest concession areas resulted in the deaths of 29 villagers in a nearby area called Pattalung,
according to the Bangkok Post.
“I was standing at the head of my boat looking for schools of fish,” said San Khang-Nam, who, along with his son and nephew, was recently wounded by guards shooting at them when their boat approached company operations. “I didn’t have any idea what had happened (until) I felt the heat of the blood running down my leg.”
Daraeb Meun-Phakdee, an elderly resident who has fished on Muk since childhood, says the island has become too dangerous. “I can’t even feed my family anymore,” he said.
Area fishermen have filed police reports after each attack, but their complaints typically have been ignored. Fear of trigger-happy security guards is so great that a Muk fisherman recently sailed into a typhoon rather than risk waiting out the storm near a concession area. His boat sank, and he drowned. His daughter clung to a piece of Styrofoam and managed to drag her father’s body ashore.
Apichit Angsutrangkul, who runs Satun Trang Bird’s Nest, did not return calls seeking comment.
Until 1997, the bird’s nest industry was governed by a 61-year-old law. Then new legislation decentralized control, giving local governments the power to grant five-year concessions to the highest bidder in exchange for tax payments of $252 per kilo collected. This new system is riddled with corruption, most observers agree.
The companies avoid paying higher taxes by reporting fewer kilos. “If they get 600 kilos, they report 200. I should know. I used to count them,” said a former manager of Satun Trang Bird’s Nest, who asked to remain anonymous.
A committee headed by the local governor is supposed to oversee the tax collection. “There are no real checks,” said Issama-el Bensaard, a committee member and industry critic. “The checks take place in hotel restaurants over red wine and meals hosted by Satun Trang Bird’s Nest. They even serve us bird’s nest.”
Ironically, many islands are part of national parks and should be protected by the Royal Forestry Department. Yet concessionaires often have refused access to forestry officials.
“We are not getting the full cooperation of the companies,” said Schwann Tunhikorn, director of the Royal Forestry Department’s Wildlife Conservation Department.
But Somsak Kittidhrakul, president of P.P. Cabana, owner of the nation’s largest bird’s nest concession of almost 100 islands, says he is taking the necessary precautions to preserve the swiftlet.
“To conserve the bird population is the first tenet of our business,” he said. “We wouldn’t kill our own livelihood now, would we?”
March 21st, 2006
by Jennifer Dick
uoguelph.ca/research/news
One of the oldest Chinese delicacies – a bird’s nest that’s made from the saliva of the male swiftlet, and sells upwards for $4,000 per pound – has food experts around the world swooning for a taste of what’s called the “food of the emperor,” or the “caviar of the East.”
Only the male swiftlet, a small swallow native to Southeast Asia, can make the tiny crescent-shaped nests once each year before mating. The nest’s small size (it weighs only a few grams), combined with the hazards undertaken by nest harvesters, explain the high cost.
But as with any high-priced commodity, knock-offs are inevitable. And with upscale restaurant prices hovering around $80 per serving of a dish of “bird’s nest soup,” diners want to make sure they’re getting the real McCoy.
Enter Discovery Channel. When it found the red or “blood” coloured nests fetching a premium at least three times greater than white nests – and saw the potential for the unscrupulous adulteration of the white nests, to turn them red — they asked University of Guelph food scientist Dr. Massimo Marcone to step in for some analysis.
The Discovery Channel also wondered if there was a nutritional difference causing the price discrepancy.
It turns out there isn’t.
“Value is a relative term,” says Marcone. “Chemically, there isn’t enough of a difference between the nests to justify the price difference. But this is the so-called emperor’s food, and the red nests are rarer. When someone offers this nest to a person, they offer their heart, their very best – in that sense maybe the value is worth more than we even estimate.”
North America is the second largest market in the world for bird’s nests, largely because of the traditional medicine market. Each year over 17 million nests are collected in Indonesia and its neighbouring countries for export, and demand seems to be increasing. This leaves many wondering about the effects of this trend on the swiflet populations, especially regarding harvesting procedures.
“There are regulations about harvesting – they are supposed to occur once the fledglings have gone but because of the high price the harvesters receive for the nests, many don’t follow the rules,” says Marcone. “For some it’s a choice between conservation and putting food on the table.”
The Chinese bird’s nest market is also a threat to the people who harvest the nests. Nest harvesting is difficult and dangerous. It involves cave wall climbing and there’s a high risk of getting caught in flooded caves.
Work is being done to improve the conservation efforts for these birds. Some groups have developed barn-like structures so swiftlets can raise their young in safety. Harvesting is done when the fledglings have matured and left the nests. Marcone says creating such an industry could be a source of income for local people as well as meet the demands of the bird nest export market.
But back to nutrition. Marcone has studied the differences in the coloured nests’ compositions, and he says they’re comprised mainly of protein and carbohydrates. Contrary to the belief that the “blood” nests are made from blood, they’re simply rarer, and the nutrient composition varies only slightly form the white nests.
And as for the dishonest harvesters who try to dye the nests red to fetch a higher price, there’s no fooling Marcone.
“The nests that are genuinely red are permanently so,” he says. “If it leeches too much red, it’s dye.”
March 21st, 2006
NorthJersey.com
– Peter J. Sampson
A spring ritual is getting under way as the itinerant tree swallow returns to nest in the Meadowlands from its winter sojourn along the Gulf Coast and points as far away as Costa Rica.
With the swallows’ impending arrival, the staff at New Jersey Meadowlands Commission have begun installing the first of 500 new nesting boxes built by area Boy and Girl Scouts, Brownie troops and other volunteers.
The small, metallic-blue bird prefers to nest in the cavities of dead trees, but this species has taken to its man-made digs.
“Sometimes you’ll see the tree swallows following our conservationists out and they’ll fly right into the boxes once they put them up in the marshes,” said spokesman Nancy Benecki. “They’ve adapted really well to living in these structures and they provide a little bit of natural insect repellant, too. They like to feed on mosquitoes.”
Kirk Weber, an educator with the Meadowlands Environmental Center, and Gabrielle Bennett-Meany, outreach naturalist, braved stiff winds this week as they replaced old nest boxes in the marshes at Richard W. DeKorte Park in Lyndhurst.
Along with the requisite degree of isolation, the waterfront houses offer breathtaking views of the Manhattan skyline and easy access to the major roadways in the area.
March 20th, 2006
From The Star
earthisland.org/borneo/news
Over-exploitation of edible birds’ nest in the Mulu National Park may inflict irreparable damage to the ecosystem in the world heritage site. Royal Mulu Resort manager January Kohli said exploiting the nests in the park would only serve to upset the natural biochemistry of the unique cave systems in the world-renowned destination.
“The greater issue of concern must be the impact to the environment due to these excessive birds’ nest collection.
“The potential damage to the environment in Mulu outweighs the benefits of collecting the birds’ nest,'’ she said when interviewed.
Kohli was asked to comment on recent reports of illegal harvesting of birds’ nest by certain groups in the Mulu Caves.
The state Tourism Ministry and National Parks and Wildlife Department are investigating claims that outsiders may be involved.
Kohli said the authorities must also consider if the birds’ nest collection industry would harm the image of Mulu.
“Mulu has already been declared a world heritage site. This image needs to be preserved. Exploiting the natural resources will create a bad image among tourists,'’ she said.
Birds’ nest collection is a lucrative business in the state, but the activities are licensed. Collectors who are issued permits by the department are only allowed to harvest limited amount of the birds’ nest.
Demands by restaurants and families for birds’ nest usually surge during festive seasons because of its supposedly health-enhancing qualities.
March 17th, 2006
Brian Handwerk
for National Geographic News
For male barn swallows on the make, success is all about keeping their feathers in trim.
The birds attract mates by the color intensity of their feathers—a signal of their desirability. A new study suggests that if males’ appearances change for the better, females are less likely to cheat.
“[Appearances] are also important for establishing sneaky pair bonds behind your mate’s back,” said biologist Rebecca Safran, who led the Cornell University study. “Upkeep and maintenance are just as important as the first impression.”
Between two successive breeding bouts, Safran and her colleagues turned birds from duds to studs by improving their plumage color with nontoxic inks.
Birds whose feathery mojo was enhanced sired more offspring than those whose plumage remained the same. Improved males also sired more than they had in their first breeding season with the same female.
“It’s interesting that birds should be doing such constant evaluation,” said Olivia Judson, an evolutionary biologist at Imperial College in London. “Now a male has to not only get territory, build a nest, and seduce somebody—he’s also got to keep her.
Choosy But Not Promiscuous
Safran’s team used DNA tests to determine how many young birds in a nest were actually fathered by their mother’s mate, both before and after his plumage was manipulated.
Researchers studied established pairs, allowing them to eliminate other possible factors, like age or territory, from the mate-choosing process.
“We can say with great certainty that feather color affects female preference for particular males and that changes in the signal have really important consequences in terms of whose offspring you’re caring for,” Safran said.
Female barn swallows (Hirundo rustica) made their sexual assessments repeatedly and in a short period of time—on the fly, as it were.
Judson cautions that the term “promiscuous” doesn’t adequately describe the barn swallow’s sexual behavior.
“We tend to think of promiscuous as meaning indiscriminate, but that doesn’t have to be the case,” she said.
“It’s possible for an animal to be choosy while still having lots of sexual partners if the encounter rate with potential partners is very large. If I reject 90 percent of 1,000 suitors, that still leaves me 100 partners—even though I’ve been choosy.”
Those males whose color stayed the same between breeding bouts remained paired with the same female. However, they did end up fathering fewer of their mate’s offspring.
“In some cases males are willing to stick around and care for a nest of young, none of whom are theirs. That’s interesting because it’s a genetic dead end for them,” she said.
It’s not known whether males can tell if they are caring for their own offspring or not.
Monogamy Myths
Selective cheating isn’t limited to barn swallows. Judson noted that about 90 percent of bird species were once thought to be monogamous and only 10 percent not monogamous. Now scientists believe that those numbers are reversed.
“It’s interesting how incredibly common this phenomenon of cheating is in most socially monogamous systems that we study—including humans,” Safran added.
Scientists aren’t sure exactly what certain traits, like a swallow’s plumage color, convey to potential mates. Do they suggest that the male will be a good father, that he has good genes, or that he’ll be good at defending a territory? The answer is likely a combination of these or other factors.
“Darwin’s dilemma in looking at the evolution of traits is why so many seem to hinder survival,” Safran said. “How to explain antlers and peacock tails that seem to attract predators and hinder escape?
“The more we learn it seems that these signals are really important for another dimension of survival—survival of the genes through attracting mates and having as many offspring as possible.”
For birds, the potential benefits of such promiscuity must outweigh the potential risks.
Judson hypothesizes that jackdaws, crow-like birds that are monogamous despite many opportunities to cheat, remain faithful because they have little to gain from hanky-panky.
“It’s very hard to raise any jackdaw chicks at all,” she said. “So any time spent doing anything other than raising jackdaw chicks screws up the process completely.”
For others, like female barn swallows, there are likely unrecognized benefits that outweigh potential costs, like diseases or the risk that a male will withdraw care for offspring. Scientists are still working to understand what those benefits are.
Meanwhile, for males, it’s important to keep up appearances.
“Female promiscuity creates a problem for the male,” Judson explained. “Biologists [once] thought that a male should try to seduce as many females as he could. But that may not be beneficial if his primary mate cuckolds him as soon as he starts to look seedy and worn out.”
March 16th, 2006
findarticles.com/p/articles
by Chaplin, Susan B, Cervenka, Mora L, Mickelson, Alison C
ABSTRACT.-We continuously recorded temperatures of the nest cup (T^sub n^) and air (T^sub a^) just outside the nest box throughout development of Tree Swallow (Tachycineta bicolor) chicks in east-central Minnesota. Brood size was manipulated (three or six chicks per nest) to study the effect of number of chicks in the nest on its thermal environment. From day 0 to day 4, T^sub n^ paralleled T^sub a^, approximately 2-7 deg C higher, with nocturnal T^sub n^ maintained at 24 deg C and daytime T^sub n^ maintained at 26 deg C. From day 6 to day 12, T^sub n^ was relatively constant throughout the day, maintained at 32 deg C (day) and 29 deg C (night). The T^sub n^ became increasingly independent of T^sub a^, as determined by regression analysis of T^sub n^ versus T^sub a^ with age. Nocturnal T^sub n^ of larger clutches (six chicks) was -2 deg C warmer than smaller clutches (three chicks), and T^sub n^ of larger clutches exhibited greater independence from T^sub a^ at day 10 than in smaller clutches. The occurrence of nest homeothermy at day 10 in six-chick nests correlates with near-maximal body mass of chicks and completion of feather insulation. Small (three-chick) clutches showed greater dependence of T^sub n^ on T^sub a^ at 10-12 days of age than large (six-chick) clutches; we propose that development of thermoregulatory capacity may have proceeded more slowly in chicks from those nests.
RESUMEN.-Registramos continuamente la temperatura de la copa del nido (T^sub n^) y del aire (T^sub a^) inmediatamente exterior a la caja de nidificaci6n durante el periodo de desarrollo de polluelos de Tachycineta bicolor en el centro-este de Minnesota. Manipulamos el tamaho de la nidada (tres o seis poIluelos por nido) para estudiar el efecto del ndmero de polluelos en el nido sobre el ambiente termico de este. Desde el dia 1 al dia 4, T^sub n^ fluctuo en forma paralela con T^sub a^, pero fue aproximadamente 2-7 deg C mayor; la T^sub n^ nocturna se mantuvo a 24 deg C mientras que la diaria a 26 deg C. Desde el dfa 6 hasta el dfa 12, T^sub n^ fue relativamente constante a traves del dia, manteni6ndose a 32 deg C durante el dfa y a 29 deg C durante la noche.
Mediante un analisis de regresion de T^sub n^ versus T^sub a^ determinamos que la independencia entre T^sub n^ y T^sub a^ fue incrementando con el tiempo. La T^sub n^ nocturna de las nidadas grandes (seis polluelos) fue -2 deg C mas alta que la de las nidadas pequenas (tres polluelos), y al decimo dia la T^sub n^ de las nidadas grandes presento una mayor independencia de la T^sub a^ que la de las nidadas pequenas. La presencia de homeotermia en el decimo dia de los nidos con seis polluelos se correlacion6 con la masa corporal maxima de los polluelos y con la finalizaci6n del aislamiento por plumas. Con 1012 dias de edad, T^sub n^ mostro una mayor dependencia de la T^sub a^ en las nidadas pequenas (tres polluelos) que en las nidadas grandes (seis polluelos). Proponemos que el desarrollo de la capacidad termoregulatoria podria haber procedido mas lentamente en polluelos de nidadas mas pequenas.
Tree Swallows (Tachycineta bicolor) begin breeding in April in Minnesota and the first young hatch approximately 1 June, when air temperatures at night may range from 5-15 deg C. On cool days and during inclement weather, average daytime air temperatures at that latitude may only be 15-20 deg C, posing significant risk of cooling to newly hatched chicks without an attendant brooding parent. Perhaps because of the risk of hypothermia associated with early breeding at northern latitudes, Tree Swallows line their cavity nests of dry grass with feathers (Robertson et al. 1992). The importance of that feather insulation was documented by Lombardo et al. (1995), who found that Tree Swallow chicks from nests with artificially reduced feather insulation had lower growth rates and were smaller and less mature at day 12 (approximately two-thirds of the nestling period).
Few measurements of nest thermal environment during posthatch chick development have been reported. Calder (1971) recorded temperatures of artificial eggs inserted into two Calliope Hummingbird (Stellula calliope) nests by continuous recording during incubation, brooding of young chicks, and late postnatal development. However, most studies have focused on nest or egg temperatures during laying and incubation periods (Haftorn 1978, Cooper and Afton 1981, Zann and Rossetto 1991, Smith and Montgomerie 1992, Flint and Maccluskie 1995, Wilson and Verbeek 1995). This study reports results of continuous recording of nest cup and air temperature (at the surface of the nest box) throughout Tree Swallow nestling development and as a function of clutch size. On the basis of the premise that nest temperature is critical to nestling development, several questions have been investigated with these data. (1) How is nest temperature influenced by the ambient environment (air temperature, variation in air temperature, or time of day)? (2) Does the number of chicks in the nest affect the thermal environment of the nest during development? (3) How is nest temperature influenced by growth and maturation of chicks-that is, does the pattern of nest temperature change daily during the nestling period, specifically with changes in nestling biomass and development of endothermy?
Methods.-Tree Swallows were studied at the Twin Cities Army Ammunition Plant, New Brighton, Minnesota, from 1995 through 1997. Over 400 bluebird (Sialia sialis) nest boxes had been installed on the 2,400 acre site during the previous six years. Pairs of nests in close proximity and with similar hatch dates were selected for continuous temperature monitoring. Clutch size was reduced to three young in one nest, and was held at six in the other. Data loggers (Model ML-1, Mini-Mitter Co., Bend, Oregon) were installed in six pairs of nests to record air and nest temperatures throughout chick development.
Prior to their installation in nest boxes, probes for the data loggers were calibrated in a water bath against a reference thermometer over a temperature range of 20-40 deg C, were programmed to log temperatures 10 times an hour throughout the day, and synchronized with real time. Response time of the external nest probe was
To evaluate the effect of air temperatures on nest temperature throughout development, mean nest and air temperatures were computed for two periods only for each nest: 0000-0400 CST (a stable period of nocturnal air temperature) and 0600-1200 (representing daytime air temperatures that had the greatest daily variation). Daytime and evening data (12000000) were not used in this analysis because loggers were often in direct sun during part of that time and did not provide accurate air temperature measurement. Mean nest and air temperatures of the two selected periods and their coefficients of variation (CV) were used in a repeated measures ANOVA, in which the effect of clutch size, time of day, and age on nest temperature (T^sub n^) or coefficient of variation of nest temperature (CVT^sub n^) were analyzed. Because of a highly significant correlation of air temperature and nest temperature (P
Acknowledgments.-This study was conducted at the Twin Cities Army Ammunition Plant (TCAAP), New Brighton, Minnesota, with the permission of the U.S. Army and Alliant Technology. We are grateful to Craig Andreson for establishment and maintenance of the bluebird boxes on the TCAAP property.
LITERATURE CITED
BLEM, C. R., AND L. B. BLEM. 1994. Composition and microclimate of Prothonotary Warbler nests. Auk 111:197-200.
BROWN, C. R. 1994. Nest microclimate, egg temperature, egg water loss, and eggshell conductance in Cape Weavers, Ploceus capensis. Ostrich 65:2631.
CALDER, W A. 1971. Temperature relationships and the nesting of the Calliope Hummingbird. Condor 73:314-321.
COOPER, J. A., AND A. D. AFTON. 1981. A multiple sensor system for monitoring avian nesting behavior. Wilson Bulletin 93:325-333.
DESTEVEN, D. 1980. Clutch size, breeding success, and parental survival in the Tree Swallow (Iridoprocne bicolor). Evolution 34:278-291.
DUNN, E. H. 1979. Age of effective homeothermy in nestling Tree Swallows according to brood size. Wilson Bulletin 91:455-457.
FLINT, P. L., AND IVI. C. MACCLUSKIE. 1995. A device for simultaneously measuring nest attendance and nest temperature in waterfowl. Journal of Field Ornithology 66:515-521.
HAFTORN, S. 1978. Egg laying and regulation of egg temperature during incubation in the Goldcrest (Regulus regulus). Ornis Scandinavica 9:2-21.
LOMBARDO, M. P., R. M. BOSMAN, C. A. FARO, S. G. HOUTTEMAN, AND T. S. KLUISZA. 1995. Effect of feathers as nest insulation on incubation behavior and reproductive performance of Tree Swallows (Tachycineta bicolor). Auk 112:973-981.
MARSH, R. L. 1980. Development of thermoregulation in nestling Tree Swallows. Condor 82:46-63. O’CONNOR, R. J. 1984. The Growth and Development of Birds. J. Wiley and Sons, New York.
March 15th, 2006
forestry.gov.uk/newsrele.ns
Thankful county foresters were glad to forego firing up their new ‘green’ flue for fear of frying their feathered friends.
The Forestry Commission team were about to ignite their new environmentally friendly heating system when an eagle-eyed ornithologist called a dramatic halt.
RSBP volunteer Juliette Buttler was on duty at the foresters’ Fineshade base, near Corby, welcoming visitors to the Rockingham Forest Red Kite centre.
But when her binoculars went in the direction of the new boiler room she glimpsed a flash of steel blue streaking in through a gap in the roof.
Closer investigation revealed a family of swallows had set up home in the rafters near the hot-house chimney stack.
Forest ranger Cheryl Joyce, said: “We were relieved that Juliette spotted the birds just in time.
“Had we fired up the boiler as we planned the chicks would almost certainly have been lost.
“Now we’ve stopped all testing until the baby swallows have fledged and flown the nest.”
Miss Joyce said that steps would be taken to ensure that no more creatures could wander into danger.
She said that from now their new boiler’s mission would be to protect wildlife.
Once the high-performance system is turned on it will generate sufficient energy to supply the entire Fineshade complex.
However, its burners run on nothing but coppice timber taken from the Forestry Commission’s own woodlands.
As the new crop of fuel grows the plants will absorb more carbon dioxide from the air, and fix it in their cells, than the boiler gives off generating heat.
And as the new willow and hazel plantations develop they will also provide precious habitats for a huge range of wildlife, including butterflies and dormice.
March 14th, 2006
warintek.progressio.or.id/peternakan/walet
I. UMUM
1.1. Sejarah Singkat
Burung Walet merupakan burung pemakan serangga yang bersifat aerial dan suka meluncur. Burung ini berwarna gelap, terbangnya cepat dengan ukuran tubuh sedang/kecil, dan memiliki sayap berbentuk sabit yang sempit dan runcing, kakinya sangat kecil begitu juga paruhnya dan jenis burung ini tidak pernah hinggap di pohon.
Burung walet mempunyai kebiasaan berdiam di gua-gua atau rumah-rumah yang cukup lembab, remang-remang sampai gelap dan menggunakan langit-langit untuk menempelkan sarang sebagai tempat beristirahat dan berbiak.
1.2. Sentra Peternakan
Sentra Peternakan burung puyuh banyak terdapat di Sumatera, Jawa Barat, Jawa Timur dan Jawa Tengah
1.3. Jenis
Klasifikasi burung walet adalah sebagai berikut:
Superorder : Apomorphae
Order : Apodiformes
Family : Apodidae
Sub Family : Apodenae
Tribes : Collacaliini
Genera : Collacalia
Species : Collacaliafuciphaga
1.4. Manfaat
Hasil dari peternakan walet ini adalah sarangnya yang terbuat dari air liurnya (saliva). Sarang walet ini selain mempunyai harga yang tinggi, juga dapat bermanfaat bagi dunia kesehatan. Sarang walet berguna untuk menyembuhkan paru-paru, panas dalam, melancarkan peredaran darah dan penambah tenaga.
II. PERSYARATAN LOKASI
Persyaratan lingkungan lokasi kandang adalah:
a) Dataran rendah dengan ketinggian maksimum 1000 m dpl.
b) Daerah yang jauh dari jangkauan pengaruh kemajuan teknologi dan perkembangan masyarakat.
c) Daerah yang jauh dari gangguan burung-burung buas pemakan daging.
d) Persawahan, padang rumput, hutan-hutan terbuka, pantai, danau, sungai, rawa-rawa merupakan daerah yang paling tepat.
III. PEDOMAN TEKNIS BUDIDAYA
3.1. Penyiapan Sarana dan Peralatan
a Suhu, Kelembaban dan Penerangan
Gedung untuk kandang walet harus memiliki suhu, kelembaban dan penerangan yang mirip dengan gua-gua alami. Suhu gua alami berkisar antara 24-26 derajat C dan kelembaban ± 80-95 %.
Pengaturan kondisi suhu dan kelembaban dilakukan dengan:
1 Melapisi plafon dengan sekam setebal 20 cm
2 Membuat saluran-saluran air atau kolam dalam gedung.
3 Menggunakan ventilasi dari pipa bentuk “L” yang berjaraknya 5 m satu lubang, berdiameter 4 cm.
4 Menutup rapat pintu, jendela dan lubang yang tidak terpakai.
5 Pada lubang keluar masuk diberi penangkal sinar yang berbentuk corong dari goni atau kain berwarna hitam sehingga keadaan dalam gedung akan lebih gelap. Suasana gelap lebih disenangi walet.
b Bentuk dan Konstruksi Gedung
Umumnya, rumah walet seperti bangunan gedung besar, luasnya bervariasi dari 10×15 m2 sampai 10×20 m2. Makin tinggi wuwungan (bubungan) dan semakin besar jarak antara wuwungan dan plafon, makin baik rumah walet dan lebih disukai burung walet. Rumah tidak boleh tertutup oleh pepohonan tinggi.
Tembok gedung dibuat dari dinding berplester sedangkan bagian luar dari campuran semen. Bagian dalam tembok sebaiknya dibuat dari campuran pasir, kapur dan semen dengan perbandingan 3:2:1 yang sangat baik untuk mengendalikan suhu dan kelembaban udara. Untuk mengurangi bau semen dapat disirami air setiap hari.
Kerangka atap dan sekat tempat melekatnya sarang-sarang dibuat dari kayu-kayu yang kuat, tua dan tahan lama, awet, tidak mudah dimakan rengat. Atapnya terbuat dari genting.
Gedung walet perlu dilengkapi dengan roving room sebagai tempat berputar-putar dan resting room sebagai tempat untuk beristirahat dan bersarang. Lubang tempat keluar masuk burung berukuran 20×20 atau 20×35 cm2 dibuat di bagian atas. Jumlah lubang tergantung pada kebutuhan dan kondisi gedung. Letaknya lubang jangan menghadap ke timur dan dinding lubang dicat hitam.
3.2. Pembibitan
Umumnya para peternak burung walet melakukan dengan tidak sengaja. Banyaknya burung walet yang mengitari bangunan rumah dimanfaatkan oleh para peternak tersebut. Untuk memancing burung agar lebih banyak lagi, pemilik rumah menyiapkan tape recorder yang berisi rekaman suara burung Walet. Ada juga yang melakukan penumpukan jerami yang menghasilkan serangga-serangga kecil sebagai bahan makanan burung walet.
3.2.1. Pemilihan Bibit dan Calon Induk
Sebagai induk walet dipilih burung sriti yang diusahakan agar mau bersarang di dalam gedung baru. Cara untuk memancing burung sriti agar masuk dalam gedung baru tersebut dengan menggunakan kaset rekaman dari wuara walet atau sriti. Pemutaran ini dilakukan pada jam 16.00-18.00, yaitu waktu burung kembali mencari makan.
3.2.2. Perawatan Bibit dan Calon Induk
Di dalam usaha budidaya walet, perlu disiapkan telur walet untuk ditetaskan pada sarang burung sriti. Telur dapat diperoleh dari pemilik gedung walet yang sedang melakukan “panen cara buang telur”. Panen ini dilaksanakan setelah burung walet membuat sarang dan bertelur dua butir. Telur walet diambil dan dibuang kemudian sarangnya diambil. Telur yang dibuang dalam panen ini dapat dimanfaatkan untuk memperbanyak populasi burung walet dengan menetaskannya di dalam sarang sriti.
a Memilih Telur Walet
Telur yang dipanen terdiri dari 3 macam warna, yaitu :
b Merah muda, telur yang baru keluar dari kloaka induk berumur 0-5 hari.
1 Putih kemerahan, berumur 6-10 hari.
2 Putih pekat kehitaman, mendekati waktu menetas berumur 10-15 hari.
Telur walet berbentuk bulat panjang, ukuran 2,014×1,353 cm dengan berat 1,97 gram. Ciri telur yang baik harus kelihatan segar dan tidak boleh menginap kecuali dalam mesin tetas. Telur tetas yang baik mempunyai kantung udara yang relatif kecil. Stabil dan tidak bergeser dari tempatnya. Letak kuning telur harus ada ditengah dan tidak bergerak-gerak, tidak ditemukan bintik darah. Penentuan kualitas telur di atas dilakukan dengan peneropongan.
c Membawa Telur Walet
Telur yang didapat dari tempat yang jaraknya dekat dapat berupa telur yang masih muda atau setengah tua. Sedangkan telur dari jarak jauh, sebaiknya berupa telur yang sudah mendekati menetas.
Telur disusun dalam spon yang berlubang dengan diameter 1 cm. Spon dimasukkan ke dalam keranjang plastik berlubang kemudian ditutup. Guncangan kendaraan dan AC yang terlalu dingin dapat mengakibatkan telur mati. Telur muda memiliki angka kematian hampir 80% sedangkan telur tua lebih rendah.
d Penetasan Telur Walet
1 Cara menetaskan telur walet pada sarang sriti.
Pada saat musim bertelur burung sriti tiba, telur sriti diganti dengan telur walet. Pengambilan telur harus dengan sendok plastik atau kertas tisue untuk menghindari kerusakan dan pencemaran telur yang dapat menyebabkan burung sriti tidak mau mengeraminya. Penggantian telur dilakukan pada siang hari saat burung sriti keluar gedung mencari makan.
Selanjutnya telur-telur walet tersebut akan dierami oleh burung sriti dan setelah menetas akan diasuh sampai burung walet dapat terbang serta mencari makan.
2 Menetaskan telur walet pada mesin penetas
Suhu mesin penetas sekitar 400 C dengan kelembaban 70%. Untuk memperoleh kelembaban tersebut dilakukan dengan menempatkan piring atau cawan berisi air di bagian bawah rak telur. Diusahakan agar air didalam cawan tersebut tidak habis.
Telur-telur dimasukan ke dalam rak telur secara merata atau mendata dan jangan tumpang tindih. Dua kali sehari posisi telur-telur dibalik dengan hati-hati untuk menghindari kerusakan embrio. Di hari ketiga dilakukan peneropongan telur. Telur-telur yang kosong dan yang embrionya mati dibuang. Embrio mati tandanya dapat terlihat pada bagian tengah telur terdapat lingkaran darah yang gelap. Sedangkan telur yang embrionya hidup akan terlihat seperti sarang laba-laba. Pembalikan telur dilakukan sampai hari ke-12.
Selama penetasan mesin tidak boleh dibuka kecuali untuk keperluan pembalikan atau mengisi cawan pengatur kelembaban. Setelah 13-15 hari telur akan menetas.
3.3. Pemeliharaan
3.3.1. Perawatan Ternak
Anak burung walet yang baru menetas tidak berbulu dan sangat lemah. Anak walet yang belum mampu makan sendir perlu disuapi dengan telur semut (kroto segar) tiga kali sehari. Selama 2-3 hari anak walet ini masih memerlukan pemanasan yang stabil dan intensif sehingga tidak perlu dikeluarkan dari mesin tetas. Setelah itu, temperatur boleh diturunkan 1-2 derajat/hari dengan cara membuka lubang udara mesin.
Setelah berumur ± 10 hari saat bulu-bulu sudah tumbuh anak walet dipindahkan ke dalam kotak khusus. Kotak ini dilengkapi dengan alat pemanas yang diletakan ditengah atau pojok kotak.
Setelah berumur 43 hari, anak-anak walet yang sudah siap terbang dibawa ke gedung pada malam hari, kemudian dletakan dalam rak untuk pelepasan. Tinggi rak minimal 2 m dari lantai. Dengan ketinggian ini, anak waket akan dapat terbang pada keesokan harinya dan mengikuti cara terbang walet dewasa.
3.3.2. Sumber Pakan
Burung walet merupakan burung liar yang mencari makan sendiri. Makanannya adalah serangga-serangga kecil yang ada di daerah pesawahan, tanah terbuka, hutan dan pantai/perairan. Untuk mendapatkan sarang walet yang memuaskan, pengelola rumah walet harus menyediakan makanan tambahan terutama untuk musim kemarau. Beberapa cara untuk mengasilkan serangga adalah:
a) menanam tanaman dengan tumpang sari.
b) budidaya serangga yaitu kutu gaplek dan nyamuk.
c) membuat kolam dipekarangan rumah walet.
d) menumpuk buah-buah busuk di pekarangan rumah.
3.3.3. Pemeliharaan Kandang
Apabila gedung sudah lama dihuni oleh walet, kotoran yang menumpuk di lantai harus dibersihkan. Kotoran ini tidak dibuang tetapi dimasukan dalam karung dan disimpan di gedung.
3.4. Hama dan Penyakit
a Tikus
Hama ini memakan telur, anak burung walet bahkan sarangnya. Tikus mendatangkan suara gaduh dan kotoran serta air kencingnya dapat menyebabkan suhu yang tidak nyaman. Cara pencegahan tikus dengan menutup semua lubang, tidak menimbun barang bekas dan kayu-kayu yang akan digunakan untuk sarang tikus.
b Semut
Semut api dan semut gatal memakan anak walet dan mengganggu burung walet yang sedang bertelur. Cara pemberantasan dengan memberi umpan agar semut-semut yang ada di luar sarang mengerumuninya. Setelah itu semut disiram dengan air panas.
c Kecoa
Binatang ini memakan sarang burung sehingga tubuhnya cacat, kecil dan tidak sempurna. Cara pemberantasan dengan menyemprot insektisida, menjaga kebersihan dan membuang barang yang tidak diperlukan dibuang agar tidak menjadi tempat persembunyian.
d Cicak dan Tokek
Binatang ini memakan telur dan sarang walet. Tokek dapat memakan anak burung walet. Kotorannya dapat mencemari raungan dan suhu yang ditimbulkan mengganggu ketenangan burung walet. Cara pemberantasan dengan diusir, ditangkap sedangkan penanggulangan dengan membuat saluran air di sekitar pagar untuk penghalang, tembok bagian luar dibuat licin dan dicat dan lubang-lubang yang tidak digunakan ditutup.
3.5. Panen
Sarang burung walet dapat diambil atau dipanen apabila keadaannya sudah memungkinkan untuk dipetik. Untuk melakukan pemetikan perlu cara dan ketentuan tertentu agar hasil yang diperoleh bisa memenuhi mutu sarang walet yang baik. Jika terjadi kesalahan dalam menanen akan berakibat fatal bagi gedung dan burung walet itu sendiri. Ada kemungkinan burung walet merasa tergangggu dan pindah tempat. Untuk mencegah kemungkinan tersebut, para pemilik gedung perlu mengetahui teknik atau pola dan waktu pemanenan.
Pola panen sarang burung dapat dilakukan oleh pengelola gedung walet dengan beberapa cara, yaitu:
a Panen rampasan
Cara ini dilaksanakan setelah sarang siap dipakai untuk bertelur, tetapi pasangan walet itu belum sempat bertelur. Cara ini mempunyai keuntungan yaitu jarak waktu panen cepat, kualitas sarang burung bagus dan total produksi sarang burung pertahun lebih banyak. Kelemahan cara ini tidak baik dalam pelestaraian burung walrt karena tidak ada peremajaan. Kondisinya lemah karena dipicu untuk terus menerus membuat sarang sehingga tidak ada waktu istirahat. Kualitas sarangnya pun merosot menjadi kecil dan tipis karena produksi air liur tidak mampu mengimbangi pemacuan waktu untuk membuat sarang dan bertelur.
b Panen Buang Telur
Cara ini dilaksanankan setelah burung membuat sarang dan bertelur dua butir. Telur diambil dan dibuang kemudian sarangnya diambil. Pola ini mempunyai keuntungan yaitu dalam setahun dapat dilakukan panen hingga 4 kali dan mutu sarang yang dihasilkan pun baik karena sempurna dan tebal. Adapun kelemahannya yakni, tidak ada kesempatan bagi walet untuk menetaskan telurnya.
c Panen Penetasan
Pada pola ini sarang dapat dipanen ketika anak-anak walet menetas dan sudah bisa terbang. Kelemahan pola ini, mutu sarang rendah karena sudah mulai rusak dan dicemari oleh kotorannya. Sedangkan keuntungannya adalah burung walet dapat berkembang biak dengan tenang dan aman sehingga polulasi burung dapat meningkat.
Adapun waktu panen adalah:
a Panen 4 kali setahun
Panen ini dilakukan apabila walet sudah kerasan dengan rumah yang dihuni dan telah padat populasinya. Cara yang dipakai yaitu panen pertama dilakukan dengan pola panen rampasan. Sedangkan untuk panen selanjutnya dengan pola buang telur.
b Panen 3 kali setahun
Frekuensi panen ini sangat baik untuk gedung walet yang sudah berjalan dan masih memerlukan penambahan populasi. Cara yang dipakai yaitu, panen tetasan untuk panen pertama dan selanjutnya dengan pola rampasan dan buang telur.
c Panen 2 kali setahun
Cara panen ini dilakukan pada awal pengelolaan, karena tujuannya untuk memperbanyak populasi burung walet.
3.6. Pascapanen
Setelah hasil panen walet dikumpulkan dalu dilakukan pembersihan dan penyortiran dari hasil yang didapat. Hasil panen dibersihkan dari kotoran-kotoran yang menempel yang kemudian dilakukan pemisahan antara sarang walet yang bersih dengan yang kotor.
IV. ANALISIS EKONOMI BUDIDAYA PETERNAKAN
4.1 Analisis Usaha Budidaya
Perkiraan analisis budidaya burung walet di daerah Jawa Barat tahun 1999:
a Modal tetap
- Gedung
- Renovasi gedung
- Perlengkapan
Jumlah modal tetap
Biaya penyusutan/bulan : Rp. 23.500.000,-:60 bln ( 5 th)
b Modal Kerja
1 Biaya Pengadaan
- Telur Walet 500 butir @ Rp. 5.000,-
- Transportasi
- Makan
2 Biaya Kerja
- Pelihara kandang/bln@ Rp. 5000,- x 3 bln
- Panen
Jumlah biaya 1x produksi:Rp. 650.000,-+Rp. 35.000,-
c Jumlah modal yang dibutuhkan pada awal Produksi
- Modal tetap
- Modal kerja 1x Produksi
Jumlah modal
d Kapasitas produksi untuk 5 tahun 1 kali produksi :
- sarang burung walet menghasilkan 1 kg
- sarang burung sriti menghasilkan 15 kg
- untuk 1 tahun, 4 kali produksi, menghasilkan :
a sarang burung walet 4 kg
b sarang burung sriti 60 kg
- untuk 5 tahun, 20 kali produksi, menghasilkan :
a sarang burung walet 20 kg
b sarang burung sriti 300 kg
e Biaya produksi
- Biaya tetap per bulan : Rp. 23.500.000,-:60 bulan
- Biaya tidak tetap
Total Biaya Produksi per bulan
- Biaya produksi: Jumlah produksiRp.1.076.667:16 kg (untuk walet dan sriti) = Rp. 67.292,-
f Penjualan
a sarang burung walet 1 kg
b sarang burung sriti 15 kg
Untuk 1 kali produksi
- Untuk 5 tahun
a sarang burung walet 20 kg
b sarang burung sriti 300 kg
Jumlah penjualan
g Break Even Point
1 Pendapatan selama 5 Tahun
2 Biaya produksi selama 5 th Rp. 1.076.667 x 60 bln
3 Keuntungan selama 5 tahun
4 Keuntungan bersih per produksi 335.400.000 : 60 bln
5 BEP
h Tingkat Pengembalian Modal
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
Rp.
13.000.000,-
10.000.000,-
500.000,-
23.500.000,-
391.667,-
500.000,-
100.000,-
50.000,-
15.000,-
20.000,-
685.000,-
13.500.000,-
685.000,-
14.185.000,-
391.667,-
685.000,-
1.076.667,-
17.000.000,-
3.000.000,-
20.000.000,-
340.000.000,-
60.000.000,-
400.000.000,-
400.000.000,-
64.600.000,-
335.400.000,-
5.590.000,-
232.919
3 bulan (1 x produksi)
4.2. Gambaran Peluang Agribisnis
Sarang burung walet merupakan komoditi ekspor yang bernilai tinggi. Kebutuhan akan sarang burung walet di pasar internasional sangat besar dan masih kekurangan persediaan. Hal ini disebabkan oleh masih kurang banyaknya budidaya burung walet. Selain itu juga produksi sarang walet yang telah ada merupakan produksi dari sarang-sarang alami. Budidaya sarang burung walet sangat menjanjikan bila dikelola dengan baik dan intensif.
V. REFERENSI
5.1. Daftar Pustaka
a) Chantler, P. & G. Driessens. Swift : A guide to the Swift an Treeswift of the World. Pica Press, the Banks. East Sussex, 1995.
b) Mackinnon, John. Panduan Lapangan Pengenalan Burung-Burung di Jawa dan Bali. Yogyakarta: Gadjah Mada University Press, 1994.
c) Nazaruddin & A. Widodo. Sukses Merumahkan Walet. Cet. 2. Jakarta : Penebar Swadaya, 1998.
d) Tim Penulis PS. Budidaya dan Bisnis Sarang Walet. Cet. 4. Jakarta : Penebar Swadaya, 1994.
March 13th, 2006
Florida Today
BY MARIA SONNENBERG
Nature volunteer makes homes for purple martins
Human parents can learn a tip or two from purple martins.
The little insect eaters are good providers, zealously guarding their brood on nests high above the ground.
When the fledglings reach maturity, however, the martins enforce a tough-love approach, relentlessly pushing their heirs away and into a life of their own.
The youngsters must set up their own digs, making for a purple martin housing market as hot as Brevard’s human equivalent.
Merritt Island National Wildlife Refuge volunteer and nature tour leader Chuck Blakey hopes more homeowners will join him in becoming landlords for these elegant members of the swallow family.
Blakey became interested in the gregarious little birds seven years ago and since has gained such expertise into their housing requirements that when Animal Planet network was looking for a purple martin guru to appear on its “Backyard Habitat” program, Blakey’s name popped up.
“Backyard Habitat” demonstrates how anyone can provide a natural living space for animals regardless of where they live.
For the television show, Blakey used his experience as a purple martin housing manager to help a Mims family create inviting nesting sites for the birds.
Blakey is landlord to 32 nests that produce an average of 80 to 100 fledglings a year. And his bird condos look nothing like the rows of avian condos that most people associate with purple martins.
Many of those cute little houses high above the ground are no good, he said. And, “a lot of those little apartments are too small,” Blakey said.
Go with gourds instead, he suggests.
“The birds love them,” Blakey said.
Gourds, natural or plastic, hung from a 20-foot telescoping pole are better for the birds in more than one way.
“It makes it more difficult for the owls to predate on the babies,” he said.
The relative privacy of the gourds also keeps tabs on mite infestation, another significant source of fledgling mortality.
Blakey’s gourds are indeed popular. The “scouts” — actually experienced parents that return to established nests — are already in his Titusville backyard this year, signaling the start of another nesting season.
Blakey has purposefully kept the nests in his property at 32, a number he feels is manageable for him.
“If landlording becomes work, you have too many nests,” he said.
He keeps the gourds at least 40 feet from human dwellings or any big trees to discourage most predators.
Rat snakes are kept at bay by predator guards.
Every five days during the season, Blakey lowers the poles that hold six gourds each and inspects nests for dampness and mites, counting the number of eggs and chicks and recording the data for reporting to the Purple Martin Conservation Association’s Project Martin Watch.
When he finds excessive mites, he will carefully remove the chicks and place them in five-gallon plastic bucket using surgical gloves, toss out the infected nesting material, clean the gourd inside and out with rubbing alcohol and wipe the inside thoroughly with paper towels before rebuilding the nest and replacing the chicks.
The parent birds readily accept the clean nests.
According to Blakey, the cost and effort is minimal and well worth the opportunity to make a home for the little birds before they migrate to South America later in the year.
“We also set aside time for sitting in our screen room and watching for their return from foraging each afternoon and listening to their social hour each morning,” he said. “When they leave in the summer, we really miss them.”
March 10th, 2006
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