Native Landscaping in Urban Areas Can Help Native Birds

Iturria: Science Daily

ScienceDaily (Aug. 22, 2012)A recent study of residential landscape types and native bird communities in Phoenix, Ariz., led by a University of Massachusetts Amherst urban ecologist suggests that yards mimicking native vegetation and wildlands offer birds "mini refuges," helping to offset the loss of biodiversity in cities and supporting birds better than traditional grass lawns and non-native plantings.

Residential yards mimicking nearby native vegetation and wildlands offer birds “mini refuges.” (Credit: UMass Amherst)
The study, led by Susannah Lerman with her advisor Paige Warren at UMass Amherst, and Hilary Gan and Eyal Shochat at Arizona State University, is one of the first to use quantitative measures and a systematic approach, with 24-hour video monitoring, to assess and compare foraging behavior of common backyard birds in yards in Phoenix, at the northern edge of the Sonoran Desert. It appears in the current issue of PLOS ONE.
It is also one of the first to conduct experiments to compare different types of a single urban landscape form (residential yards), Lerman says. Overall, the study found that desert-like, "xeric" yards had a more even bird community and superior habitat compared to moist, or "mesic," grass lawns in the Phoenix area.
She explains, "We already know that bird communities differ and there are more desert birds found in the desert-type yard. With this study, we're starting to look at how different yards function, whether birds behave differently by yard type. We do that using behavioral indicators, specifically foraging, as a way to assess the bird's perception of habitat quality between the two yard designs."
Lerman and colleagues conducted the experiment in 20 residential yards at least 1.8 miles (3 km) apart, making it unlikely that the same birds would visit more than one study yard. Half of the yards were xeric, or desert-like, while the other 10 were mesic, with exotic green lawns. Homeowners removed bird feeders before and during the 24-hour experimental data collection period during February and April 2010.
The researchers set up feeding stations (seed trays) in each yard to simulate resource patches like those used by wild birds. Plastic trays had 0.70 ounce (20 g.) of millet seed mixed into six lbs. (3 kg) of sand, and were left out on a low stool for 24 hours. Later, Lerman and colleagues removed the trays, sifted out and weighed uneaten seed to the nearest 0.01 gram. This represents the giving-up densities (GUD) or amount of seed remaining, which quantifies the foraging decision and quitting point for the last species visiting a seed tray. Trays were videotaped for the entire 24-hour experiment.
This experiment assumes that an animal behaving optimally will quit foraging a seed tray when its energy gains equal the "costs" of foraging, Lerman explains. Costs include predation risk, cost of digestion and missed opportunities to find food elsewhere. As time spent foraging a seed tray increases, so do costs associated with foraging. When a bird first arrives at the tray, seeds are easy to find, but this gets harder as it is depleted. Each bird makes a decision about whether to spend time searching in the tray or to move on to a new patch in the yard. The "giving up" point will be different for different species and in different environmental conditions. Birds visiting seed trays in yards with more natural food available will quit a tray sooner compared to birds in resource-poor yards.
Since the method only measures the foraging decisions for the last species visiting the seed tray, the researchers devised a mathematical model for estimating the foraging decisions for all visiting species. Using the videotapes, they counted every peck by every bird for each tray to calculate the relationship between the number of pecks and grams of seed consumed (the GUD) for each seed tray. This was the GUD-peck ratio for the last species visiting the seed tray.
They then estimated the seed consumption (GUD) for all other species visiting the seed tray based on the number of pecks per tray when each species quit. "We know how many pecks each species had and can put that number into the model and calculate the number of grams at that point," Lerman explains. This greatly enhances the GUD method by expanding the ability to assess foraging decisions for all species visiting trays.
In all, 14 species visited the trays, 11 of which visited both yard types. Abert's towhee, curve-billed thrasher (species unique to the Sonoran desert), house finch and house sparrow were the most widespread tray visitors.
In this study, the researchers found that birds foraging in mesic yards depleted the seed trays to a lower level (had lower GUDs) compared to birds foraging in xeric yards. Further, species that visited trays in both yard designs consumed more seed from trays placed in mesic yards, indicating lower habitat quality compared to the xeric yards. Similarly, foragers in the desert-like yards quit the seed trays earlier due to greater abundance of alternative food resources in those yards, spending more time foraging in the natural yard and less at the seed tray.
Lerman says that by videotaping the trays, counting pecks and measuring giving-up points by species, this work also advanced the GUD method, allowing researchers to disentangle some of the effects of bird community composition and density of competitors, and how these factors affect foraging decisions between two different landscape designs. Results continue to build evidence that native landscaping can help to mitigate the impacts of urbanization on common songbirds, she says.

Rock Sparrows React to Infidelity by Singing Louder

Iturria: Science Daily

ScienceDaily (Aug. 23, 2012)Rock sparrows indicate their age and their reproductive success with their songs and react to infidelity with a higher song volume.

A male rock sparrow: His song reveals a lot about his qualities as a potential mate, so females will be listening carefully to his performance. A team of researchers from the Max Planck Institute for Ornithology in Seewiesen and the University of Copenhagen have discovered that the tempo, the pitch, and the amplitude of song reflect male reproductive success. (Credit: Henrik Brumm/MPI for Ornithology)
The song of male songbirds is multifaceted and has two main functions: to repel rivals and to attract mates. Females often pay attention to certain features within a song, such as the presence of special syllables, to assess the quality of the singing male. A team of researchers from the Max Planck Institute for Ornithology in Seewiesen and the University of Copenhagen has now found that the tempo, the pitch, and the amplitude of song reflect male reproductive success in rock sparrows. Surprisingly, the more successful and older males sang their songs with a higher pitch and a slower tempo than yearling males. However, older males lost paternity more often in their own nest but could more than compensate this by a larger number of extra-pair young, resulting in the highest reproductive success. Cuckolded males regardless of whether they were young or old, sang louder -- perhaps as a response to the absence of their unfaithful mate.
Female birds often have a hard job to do in order to assess the quality of a prospective mate. Many males literally dress up their feathers to impress females. For songbirds, it is apparently easier as they are able to modify their songs in a sensational manner. However, the question remains as to which song trait a female should pay particular attention -- should she perhaps monitor the number of all song syllables a male is able produce? For species with large song repertoires this would take quite long. Therefore females are better off to listen to special features within male song, such as the so-called "sexy syllables" in the songs of canaries. This means, the more a certain song trait a male is able to sing, the higher its quality, and the female can look forward to healthy and strong offspring. This also might hold true for the trait song amplitude, as in some species loud song is more attractive than silent song.
An international team of researchers headed by Henrik Brumm from the Max Planck Institute for Ornithology in Seewiesen apparently has now found the opposite scenario in a population of rock sparrows in the French Alps. The researchers recorded the songs of male rock sparrows in two subsequent breeding seasons with a special emphasis on the amplitude. The conditions in the field make measurements of amplitude relatively difficult, making it a rather neglected topic in behavioural research. The birds were nesting exclusively in wooden nestboxes that were attached to utility poles and which they also used as singing posts. In this way the researchers were able to attach the microphones to the pole in a defined distance to the singing bird, which is essential for a reliable determination of the sound pressure level. Additionally, the researchers conducted a paternity analysis by means of the microsatellite method.
Rock sparrows sing a very simple song that consists of only one element that is repeated several times to form a song bout. This is in clear contrast to other birds such as the nightingale, which has a huge repertoire of different song types. Surprisingly, the researchers found that those birds that were singing at a lower rate and a higher pitch sired a larger number of extra-pair young in other nests. Successful males, which were mostly older, could be distinguished from their younger, yearling rivals by their slower song tempo. Older males had a higher status and probably they did not need to advertise it by their song.
In contrast, one-year old males were not able to compensate for the lower attractiveness by a higher song rate and a lower pitch. Moreover, those males that sang louder were more likely to lose paternity in their own nest; but again there were age-dependent differences: Older males had a higher loss of paternity in their own nest and sang at higher amplitudes compared to their younger rivals. "The high amplitude song of males that lost paternity is not a quality characteristic but rather the desperate attempt to tighten the pair bond to the unfaithful partner," says Erwin Nemeth, first author of the study. The older males were able to compensate their paternity loss in their own nest by gaining more extra-pair young, whereas there is nothing else for the younger yearling males but to wait for better times in the next year.

Two New Owl Species Discovered in the Philippines

Iturria: Science daily

ScienceDaily (Aug. 17, 2012) Two new species of owls have been discovered in the Philippines, and a Michigan State University researcher played a key role in confirming their existence.

Two new species of owls have been discovered in the Philippines, and an MSU researcher played a key role in confirming their existence. (Top left: Cebu Hawk owl. Bottom right: Camiguin Hawk owl.) (Credit: Courtesy of Oriental Bird Club: original painting by John Gale)

The discovery, which is featured in the current issue of Forktail, the Journal of Asian Ornithology, took years to confirm, but it was well worth the effort, said the paper's lead author Pam Rasmussen, MSU assistant professor of zoology and assistant curator of mammalogy and ornithology at the MSU Museum.
"More than 15 years ago, we realized that new subspecies of Ninox hawk-owls existed in the Philippines," she said. "But it wasn't until last year that we obtained enough recordings that we could confirm that they were not just subspecies, but two new species of owls."
Announcing the finding of a single bird is rare enough. But the discovery of two new bird species in a single paper is so rare that Rasmussen and the other researchers couldn't recall the last time it happened.
The first owl, the Camiguin Hawk-owl, is found only on the small island of Camiguin Sur, close to northern Mindanao. Despite being so close geographically to related owls on Mindanao, it has quite different physical characteristics and voice. At night, it gives a long solo song that builds in intensity, with a distinctive low growling tone. Pairs of owls give short barking duets that start with a growl. They also are the only owls to have blue-gray eyes.
The second new discovery was the Cebu Hawk-owl. This bird was thought to be extinct, as the forests of Cebu have almost all been lost due to deforestation. But it had never been considered a distinct form. Study of its structure and vocalizations confirmed that it was a new species. In fact, it was the unique calling or vocalizations of both owls that confirmed that the new classifications were warranted.
"The owls don't learn their songs, which are genetically programmed in their DNA and are used to attract mates or defend their territory; so if they're very different, they must be new species," Rasmussen said. "When we first heard the songs of both owls, we were amazed because they were so distinctly different that we realized they were new species."
The owls have avoided recognition as distinct species for so long because the group shows complex variation in appearance that had been poorly studied, and their songs were unknown. Both islands are off the beaten path for ornithologists and birders, who usually visit the larger islands that host more bird species.
Sound recordings of both new owl species and those from other islands are available free on AVoCet.
Since the discovery process is both tedious and time consuming, it took a team of scientists and contributors to confirm the owls' existence. The team included individuals from BirdLife International, the Oriental Bird Club, Philippines Biodiversity Conservation Foundation Inc. and Birdtour Asia. Additional support was provided by National Geographic.


Sleep deprived birds have more chicks

Sleep deprived birds have more chicks

For pectoral sandpipers, losing sleep means gaining offspring

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Sleep deprived birds appear to have greater mating success, according to a study conducted in Alaska.
By analysing sleep patterns and testing the paternity of chicks, a team of researchers from Germany and Switzerland have found that male individuals that sleep less, sire the most offspring.
This is at odds with the assumption that sleep loss retards the ability to perform complex tasks.
The research is published in Science.
Out all night The birds studied were pectoral sandpipers (Calidris melanotos), which engage in long migrations between the Southern and Northern hemispheres.
In May and June, the shorebirds mate and nest on the barren tundra of Alaska, when the area experiences almost 24 hours of sunlight.
During fieldwork near Barrow, director of the Avian Sleep Group at the Max Planck Institute for Ornithology and leader of the study, Prof Bart Kempenaers noticed a peculiar behaviour.
"He discovered that these male pectoral sandpipers were being incredibly active throughout the 24-hour period," co-author Dr Niels Rattenborg told BBC News.
"We used a variety of methods to gain insight into what was actually going on up there. What were these sandpipers doing? We put transmitters on their back that could measure when they were moving. So we could record patterns throughout 24 hours, over a period of several weeks," Dr Rattenborg said.
By analysing these data, along with brain activity recordings, the team found that some male pectoral sandpipers were extremely active during the whole day, whereas others were engaging with fewer females, choosing instead to sleep.
You snooze, you lose Dr Rattenborg and his colleagues then tested the paternity of the young that were laid on the site.
"We collected every egg on the study site, incubated them, hatched them and then got DNA from each of the chicks, so we could tell how many chicks a given male sired. Then we returned the chicks to the mothers out in the field," Dr Rattenborg said.
This paternal data proved that the individuals that were the most active - up to 95% of 24 hours - sired the most young, despite having hardly slept over a period of weeks.
Tags Male and female pectoral sandpipers were equipped with tags to monitor their activity
The behaviour may be linked to the mating strategy employed by the birds, as pectoral sandpipers are "polygynous", meaning males mate with many females during periods of intense competition, whereas other species of sandpipers concentrate their efforts on a single female.
"We also observed that the monogamous species of sandpipers nesting in exactly the same area had periods of inactivity during the dimmest part of the 24 hour period. So they seemed to be sleeping, where some of the male pectoral sandpipers are engaging in almost constant activity," said Dr Rattenborg.
The findings were a surprise to the team, especially as the sleep deprived males seemed to suffer no ill-effects, returning to the breeding site the following year.
"There's an extensive body of research looking at the effects that sleep loss has on performance in a variety of types of animals. Pretty much across the board these studies showed that even losing a relatively small amount of sleep, just a couple of hours a night, has adverse effects on our ability to perform waking functions," explained Dr Rattenborg.
Yet this appeared not to faze the "super-active" pectoral sandpipers with the individuals developing "adaptive" sleep loss being more successful, from an evolutionary point of view, even after migrating vast distances from the Southern hemisphere.

Studies Shed Light On Why Species Stay or Go in Response to Climate Change

Iturria: Science Daily

Studies Shed Light On Why Species Stay or Go in Response to Climate Change

ScienceDaily (Aug. 17, 2012)Two new studies by scientists at UC Berkeley provide a clearer picture of why some species move in response to climate change, and where they go.

The Ash-throated Flycatcher, a low-elevation species, shifted its range downslope in response to climate change, researchers found. (Credit: Morgan Tingley photo)
One study, published online Aug. 6, in the journal Global Change Biology, finds that changes in precipitation have been underappreciated as a factor in driving bird species out of their normal range. In the other study, published August 15 in the journal Proceedings of the Royal Society B, researchers found a sharp decrease in range for the Belding's ground squirrel, but noted some surprising areas where the species found refuge.
The two studies exemplify the type of research being explored through the Berkeley Initiative in Global Change Biology, or BiGCB, an ambitious effort to better understand and predict how plants and animals will respond to changing environmental conditions by studying how they have responded to earlier periods of climate change.
The first study's findings challenge the conventional reliance on temperature as the only climate-related force impacting where species live. The authors noted that as many as 25 percent of species have shifted in directions that were not predicted in response to temperature changes, yet few attempts have been made to investigate this.
"Our results redefine the fundamental model of how species should respond to future climate change," said study lead author Morgan Tingley, who began the research as a graduate student in UC Berkeley's Department of Environmental Science, Policy and Management. "We find that precipitation changes can have a major, opposing influence to temperature in a species' range shift. Climate change may actually be tearing communities of organisms apart."
The findings are based upon data gathered from the Grinnell Resurvey Project, which retraces the steps of Joseph Grinnell, founder of the UC Berkeley Museum of Vertebrate Zoology, in his surveys of Sierra Nevada wildlife from the early 1900s. The resurvey project, which began in 2003, was led by Craig Moritz, former UC Berkeley professor of integrative biology, and his colleagues at the Museum of Vertebrate Zoology.
For the bird study, the researchers included 99 species in 77 historic survey sites in Lassen Volcanic, Yosemite and Sequoia national parks, as well as in several national forests. In the century that has passed since the original Grinnell survey, summer and winter temperatures have increased an average of 1-2 degrees Celsius in the Sierra Nevada. Yosemite experienced the most warming -- with average temperatures increasing by 3 degrees Celsius -- while parts of Lassen actually got cooler and much wetter.
Among the bird species that moved upslope are the Savannah Sparrow, which shifted upward by 2,503 meters, and other meadow species such as the Red-winged Blackbird and Western Meadowlark. The ones that shifted their range downslope include both low-elevation species like the Ash-throated Flycatcher and Western Scrub-Jay, and high-elevation species like the Cassin's Finch and Red-breasted Nuthatch.
"Temperature did not explain the majority of these shifts," said Tingley, who is now a postdoctoral researcher at Princeton University's Program in Science, Technology and Environmental Policy. "Only when we included precipitation as an explanatory variable did our models adequately explain the movement patterns we observed."
The researchers found that while rising temperatures tended to push birds to cooler regions upslope, increased precipitation, which is more common at higher elevations, pulled them downslope.
"We believe many species may feel this divergent pressure from temperature and precipitation, and in the end, only one wins," said Tingley.
Notably, more than half of the bird species in each of the three study regions did not shift their range despite pressures from climate change. "Moving is a sign of adaptation, which is good from a conservation standpoint," said Tingley. "More worrisome are the species that have not shifted. How are they adapting? Are they moving, but we just can't detect it? Or are they slowly declining as environmental conditions gradually become less ideal where they live?"
The answers are complex, as illustrated by the second UC Berkeley paper about range changes for a species of squirrel found in the mountains of the western United States.
In that paper, researchers again used information obtained from the Grinnell Resurvey Project. Through visual observations and trapping surveys conducted throughout the mountains of California, they discovered that the Belding's ground squirrel had disappeared from 42 percent of the sites where they were recorded in the early 1900s. Extinctions were particularly common at sites with high average winter temperatures and large increases in precipitation over the last century.
"We were surprised to see such a dramatic decline in this species, which is well-known to Sierran hikers and was thought to be fairly common," said study lead author Toni Lyn Morelli, a former National Science Foundation postdoctoral researcher who was based at UC Berkeley. "In fact, the rate of decline is much greater than that seen in the same region for the pika, a small mountain-dwelling cousin of the rabbit that has become the poster child for the effects of climate warming in the contiguous United States."
Morelli added that the squirrels are thriving in areas that have been modified by humans. For example, irrigated Mono Lake County Park serves as an artificial oasis that sustains squirrel populations despite otherwise hot and dry conditions in eastern California.
"As predictions indicate that the range of the Belding's ground squirrel could disappear out of California by the end of the century, these areas might be particularly important for this and other climate-impacted species," said Morelli, who is now a technical advisor for the U.S. Forest Service's International Programs in the Democratic Republic of Congo.
Although the Belding's ground squirrel is widespread, the rapid decline in its distribution is of concern because it is an important source of food for raptors and carnivores. However, the paper suggests that even when climate change causes large range declines, some species can persist in human-modified areas.
"Taken together, these two studies indicate that many species have been responding to recent climate change, yet the complexities of a species' ecological needs and their responses to habitat modification by humans can result in unanticipated responses," said Steven Beissinger, professor at UC Berkeley's Department of Environmental Science, Policy and Management and the senior author on both studies. "This makes it very challenging for scientists to project how species will respond to future climate change."
Funding from the National Science Foundation, National Park Service, and California Landscape Conservation Cooperative helped support this research.

Bird Louse Study Shows How Evolution Sometimes Repeats Itself

Iturria: Science Daily

ScienceDaily (Aug. 16, 2012)Birds of a feather flock together and -- according to a new analysis -- so do their lice.

Barred owl. (Credit: © Feng Yu / Fotolia)
A study of the genetic heritage of avian feather lice indicates that their louse ancestors first colonized a particular group of birds (ducks or songbirds, for example) and then "radiated" to different habitats on those birds -- to the wings or heads, for instance, where they evolved into different species. This finding surprised the researchers because wing lice from many types of birds look more similar to one another than they do to head or body lice living on the same birds.

The study appears in the journal BMC Biology. (Watch a video about the research.http://www.youtube.com/watch?v=FRTqiOL65og)
Wing lice are long and narrow and insert themselves between the feather barbs of a bird's wings. This allows them to avoid being crushed or removed by a bird when it preens, said Kevin Johnson, a University of Illinois ornithologist with the state Natural History Survey. Johnson conducted the new analysis with Vincent Smith, of the Natural History Museum in London, and Illinois graduate student Scott Shreve.
"If you were just guessing at their ancestry based on external traits, you would think the wing lice on different birds were more closely related to one another than they were to head or body lice on the same bird," Johnson said. "But that's just not the case."
Each type of louse is adapted to life on a particular part of the body. Head lice are rounder than wing lice, for example, and have triangular, grooved heads. The groove helps them cling to a single feather barb so their bird host can't scratch them off.
Body lice are plump and will burrow into the downy feathers or drop from feather to feather to avoid being preened. And the lice known as generalists, which range all over the bird, have their own method of escaping preening: They run.
"The similarities between the lice living in specific habitats on the bodies of birds are really striking," Johnson said. "But it appears that those similarities are the result of what we call 'convergent evolution': The lice independently arrived at the same, or similar, solutions to common ecological problems. This occurred only after they had colonized a particular type of bird."
In the new analysis, Johnson and his colleagues drew up two family trees of feather lice. The first tree grouped the lice according to physical traits; the second mapped their genetic relationships.
The two trees looked significantly different from one another, Johnson said. The genetic tree showed that different types of feather lice living on the same type of bird were often closely related, whereas lice that had evolved to survive on specific bird parts, such as the wing, were only distantly related across bird groups, he said.
The history of feather lice turns out to be a very robust example of convergent evolution, Johnson said.
"Here we see how evolution repeats itself on different bird types," he said. "The lice are converging on similar solutions to the problem of survival in different microhabitats on the bird."
The Illinois Natural History Survey is a division of the Prairie Research Institute.


El Supremo ratifica al inventario SEO/Birdlife para designar zonas de protección para aves

Iturria: Europa Press

El Tribunal Supremo

Ratifican al inventario SEO/Birdlife para designar zonas de protección para aves

Carraca, Ave, Pájaro
   El Tribunal Supremo ha ratificado en una sentencia el valor del inventario de áreas importantes para la conservación de las aves (IBA) de SEO/BirdLife, al considerarlo como la base de la designación de las Zonas de Especial Protección para las Aves (ZEPA) de la Red Natura 2000.  
   Una anterior sentencia del año 2004 condenaba a España por infringir la Directiva Aves al no haber designado como ZEPA suficientes espacios, tanto en número como en superficie, según el inventario publicado por SEO/BirdLife en 1998.
   Sin embargo, la sentencia ahora publicada asemeja aquel caso con el presentado en el recurso actual en el que el recurrente no considera el citado inventario como válido para la designación de las ZEPA. Ante esta situación, la sentencia vuelve a reiterar que ante la ausencia de pruebas científicas contrarias los espacios que figuran en el inventario deben ser los territorios a considerar para su designación como ZEPA.
   Esta decisión ha sido tomada por el Tribunal Supremo debido a un recurso contencioso-administrativo primero y de casación después interpuesto contra el acuerdo del Gobierno de Canarias por el que se aprobó en 2006 la propuesta de nuevas áreas para su designación como ZEPA en Canarias. Así, esta comunidad autónoma, que contaba con 28 ZEPA y una superficie de 210.696 hectáreas, paso en 2006 con la aprobación de la nueva propuesta a tener 43 ZEPA y una superficie total de 277.309 hectáreas.
   "El inventario de IBA de SEO/BirdLife, basado en criterios ornitológicos y científicos, contiene la información más documentada y precisa para la definición de los espacios idóneos para la conservación, supervivencia, migración y reproducción de las especies de determinadas aves", ha señalado la organización en un comunicado.

Birds Do Better in 'Agroforests' Than On Farms

Iturria: Science Daily

ScienceDaily (Aug. 6, 2012) — Compared with open farmland, wooded "shade" plantations that produce coffee and chocolate promote greater bird diversity, although a new University of Utah study says forests remain the best habitat for tropical birds.

The orange-billed nightingale-thrush is an insect-eating bird that lives on Costa Rican “shade” coffee plantations. A new University of Utah study indicates that, compared with open farmland, wooded “agroforests” like shade coffee and cacao plantations promote bird diversity and also the “ecosystem services” birds provide to human society, including insect control, spreading seeds and pollinating crops. (Credit: Çağan Şekercioğlu, University of Utah)
The findings suggest that as open farmland replaces forests and "agroforests" -- where crops are grown under trees -- reduced number of bird species and shifts in the populations of various types of birds may hurt "ecosystem services" that birds provide to people, such as eating insect pests, spreading seeds and pollinating crops.
"We found that agroforests are better overall for bird biodiversity in the tropics than open farms," says study author Çağan H. Şekercioğlu (pronounced Cha-awn Shay-care-gee-oh-loo), an assistant professor of biology at the University of Utah.
"This doesn't mean people should farm in intact forests," the ornithologist adds. "But if you have the option of having agroforest versus open farmland, that is better for biodiversity, with shade coffee and shade cacao [the source of cocoa and chocolate] being the prime examples."
Şekercioğlu's new study, funded by the University of Utah, is being published this month in the Journal of Ornithology. He will present the findings on Aug. 9, at the Ecological Society of America's annual meeting in Portland, Ore.
If consumers wish to support bird diversity and agroforests, "a good way is by choosing certified, bird-friendly, shade coffee or shade chocolate," he says. While such coffee or chocolate often cost more because they are more labor-intensive to produce, the certification "is usually better for the farmers' income as well."
He adds: "There are trustworthy environmental organizations that certify shade coffee," including the Smithsonian Institution, the Rainforest Alliance and the Rainforest Action Network.
Other crops grown in shade include cardamom, which is a spice, and yerba mate, which is steeped in hot water to make a beverage popular in South America.
Study Focuses on Birds of Forests, Farms or Both
An agroforest "is a type of farm where the crops are grown under trees at a reasonable density," Şekercioğlu says. "Often, it's not like forest-forest -- it feels more like a open park," although in Ethiopia "commercial coffee is grown under full-on forests in its original native habitat."
Şekercioğlu conducted the study in two steps. First, "I used my world bird database that has information on all the 10,000-plus bird species of the world," he says. "I sorted birds based on habitat choices and compared species that prefer forests to those that prefer agricultural areas and others that prefer both forests and agricultural areas."
Next, he reviewed about 40 previously published studies that examined bird communities in forests, agroforests and open agricultural areas.
"The global analysis of all the birds species mostly agrees with the findings of detailed local bird studies," Şekercioğlu says.
The study focused 6,093 tropical bird species, including migratory birds, in which their top three habitat choices (out of 14 possible habitats) included forests, farms or both, with the latter described as agroforest birds. So the study found 4,574 bird species that include forest but not farms in their top three habitats, 303 species that include farms but not forests in their top three habitat choices, and 1,216 agroforest species tha include both forests and farms among their top three habitats.
The findings suggest, but don't prove, that conversion of forest to farmland may reduce ecosystem services, which are services birds provide to people.
"As you go to more and more open agriculture, you lose some bird groups that provide important ecosystem services like insect control [insect eaters], seed dispersal [fruit eaters] and pollination [nectar eaters], while you get higher numbers of granivores [seed and grain eaters] that actually can be crop pests," Şekercioğlu says. Specifically:
-- Insectivores or insect-eating birds do best in forests -- especially those that live near the ground in the understory, the layer of plants below the tree canopy and above the ground cover. But small and medium insect-eating birds, especially migrant and canopy species, do well in agroforests. The number of insect-eating species declines on open farms, where they help control pests.
-- Frugivores or fruit-eating birds, especially larger ones, "do best in forest because they have more habitat and more food, and the large ones often are hunted outside forests in agricultural settings. Overall, frugivores -- especially smaller ones -- do OK in agroforests, but the number of fruit-eating species decline significantly on open farms." Frugivores help spread the seeds of the fruits they eat.
-- Nectarivores or nectar-eating birds help pollinate many plants. They "tend to increase in agroforests compared with forests. A lot of nectar-eating birds obviously like flowers, and many plants flower when there's some light. When you have extensive forest its often pretty shady so not many things are in flower at any given time." The nectar eaters are less common on open farms.
-- Omnivores, which are birds that eat many things, "tend to do better in agroforests and especially on open farms" than in forests, because their diet is so generalized instead of specialized in certain foods.
- Granivores, or grain- and seed-eating birds are "the only group that significantly increases in open agricultural areas. A lot of the seeds they eat are grass seeds, but also from crops. Some of these seed-eating bird species are major agricultural pests, and that's another reason for encouraging agroforests. In completely open agricultural systems, you have more seed-eating birds that can cause significant crop losses."
While the study found fewer species on farms than in agroforests, and fewer on agroforests than in forests, Şekercioğlu says it doesn't answer a key question: "Does the decline in the number species translate into a decline in individuals providing a given ecosystem service?" If so, farms and agroforests have lost birds that provide important insect-control, pollination and seed-dispersal services.
"It is possible you may lose a lot of species, but some of the remaining species increase in number and compensate and for the decline in ecosystem services by the lost species," he adds. "It's one of the biggest questions in ecology."
The Trend toward Sun Coffee
Noting that the study found forests have more tropical bird species than agroforests, which in turn have more bird species that open farms, Şekercioğlu says: "A lot of threatened species globally are found only in forests, and most of them disappear from agroforests and open agricultural areas."
He says many migratory birds that breed in the United States are in decline -- even though the nation has a law to protect them -- and not just because of U.S. environmental problems, "but due to problems in their wintering grounds in Latin America, such as loss of habitat and intensification of agriculture."
"Coffee was originally a mid- to high-elevation African forest understory plant," he adds. "For centuries in Ethiopia and parts of Central and South America, coffee has been grown as an understory plant with shade traditionally provided by native trees."
But fungi can be a problem in humid shade coffee plantations, and growers have come up with varieties that grow well in the sun with less fungus and bigger yields, so in recent decades, there has been a trend toward converting Central and South American shade-coffee forests to open farms, Şekercioğlu says.
"As tropical forest is converted to increasingly open types of agriculture, hundreds of endangered bird species are being lost," he says. "Tropical forest is the only refuge for thousands of bird species and hundreds of endangered bird species. Although agroforest is better than open farmland, at the end of the day intact tropical forest is the only suitable habitat for thousands of bird species."


Prohibida la caza en la totalidad del monte Ulia

Iturria: Ugatza


Prohibida la caza en la totalidad del monte Ulia

La caza acaba de ser abolida en la totalidad del Monte Ulia. Los grupos ecologistas, conservacionistas, montañeros…, gipuzkoanos, y en particular los donostiarras (Eguzki, Itsas Enara, Club Vasco de Camping, Haritzalde, Amigos de Ulia, y Ugatza), estamos de enhorabuena, este año no emitiremos una nota de prensa sobre el particular, ya no hace falta. Años de lucha y gestiones en defensa de ese espacio natural han dado este feliz resultado, que desde Ugatza consideramos un primer e importante paso en la conservación de este espacio periurbano.
Desde el año 1989 buena parte del término municipal de Donostia-San Sebastián se encuentra declarada como zona de seguridad para el ejercicio de la caza, declaración realizada a propuesta del Ayuntamiento donostiarra y con el objetivo de establecer un cinturón de seguridad alrededor de Donostia-San Sebastián, garantizando la adecuada seguridad de las personas y de sus bienes. Mediante esta declaración se prohibió el ejercicio la caza en todas sus modalidades en dicha zona, con la excepción de la caza en puesto fijo autorizado, durante el período migratorio. En esta excepción a la prohibición general de la caza, se incluía el monte Ulia, desde el cuarto domingo de setiembre al cuarto domingo de noviembre, con un horario restringido los sábados, domingos y festivos hasta las diez de la mañana.
El 30 de octubre de 2009 la Junta de Portavoces del Ayuntamiento de Donostia-San Sebastián aprobó una declaración institucional, en la que se acordaba demandar a la Diputación Foral de Gipuzkoa que adoptase las medidas necesarias para decretar la prohibición de la actividad cinegética en la totalidad del monte Ulia.
Por su parte, el Ayuntamiento de Pasaia, en pleno celebrado el 26 de octubre de 2011, acordó también solicitar a la Diputación Foral de Gipuzkoa la prohibición de la caza en los terrenos del municipio en el monte Ulia.
Asimismo, las Juntas Generales de Gipuzkoa, en sendas resoluciones (74/2009 y 90/2010), instaron al Departamento de Desarrollo del Medio Rural a realizar una revisión de la Zona de Seguridad de Donostia-San Sebastián, teniendo en cuenta el futuro proyecto de parque en Ulia, aplicando criterios racionales de gestión, compatibilizando usos y primando criterios de seguridad.
La Diputación Foral de Gipuzkoa ha considerado, por fin!, atender la petición y proceder a la modificación de los límites y de las condiciones de la zona de seguridad de parte del término municipal de Donostia-San Sebastián.
La modificación consiste en la ampliación de los límites al municipio de Pasaia en Ulia y a la eliminación de los puestos de caza en dicho monte.


Birds That Live With Varying Weather Sing More Versatile Songs

Iturria: ScienceDaily:

ScienceDaily (Aug. 3, 2012) A new study of North American songbirds reveals that birds that live with fluctuating weather are more flexible singers.

Northern oriole. Researchers analyzed song recordings from more than 400 male birds spanning 44 species of North American songbirds -- a data set that included orioles, blackbirds, warblers, sparrows, cardinals, finches, chickadees and thrushes. (Credit: © Richard L. Carlson / Fotolia)
    Mixing it up helps birds ensure that their songs are heard no matter what the habitat, say researchers at Australian National University and the National Evolutionary Synthesis Center.
    To test the idea, the researchers analyzed song recordings from more than 400 male birds spanning 44 species of North American songbirds -- a data set that included orioles, blackbirds, warblers, sparrows, cardinals, finches, chickadees and thrushes.
    They used computer software to convert each sound recording -- a medley of whistles, warbles, cheeps, chirps, trills and twitters -- into a spectrogram, or sound graph. Like a musical score, the complex pattern of lines and streaks in a spectrogram enable scientists to see and visually analyze each snippet of sound.
    For each bird in their data set, they measured song characteristics such as length, highest and lowest notes, number of notes, and the spacing between them.
    When they combined this data with temperature and precipitation records and other information such as habitat and latitude, they found a surprising pattern -- males that experience more dramatic seasonal swings between wet and dry sing more variable songs.
    "They may sing certain notes really low, or really high, or they may adjust the loudness or tempo," said co-author Clinton Francis of the National Evolutionary Synthesis Center.
    The Pyrrhuloxia or desert cardinal from the American southwest and northern Mexico and Lawrence's goldfinch from California are two examples.
    In addition to variation in weather across the seasons, the researchers also looked at geographic variation and found a similar pattern. Namely, species that experience more extreme differences in precipitation from one location to the next across their range sing more complex tunes. House finches and plumbeous vireos are two examples, Francis said.
    Why might this be?
    "Precipitation is closely related to how densely vegetated the habitat is," said co-author Iliana Medina of Australian National University. Changing vegetation means changing acoustic conditions.
    "Sound transmits differently through different vegetation types," Francis explained. "Often when birds arrive at their breeding grounds in the spring, for example, there are hardly any leaves on the trees. Over the course of just a couple of weeks, the sound transmission changes drastically as the leaves come in."
    "Birds that have more flexibility in their songs may be better able to cope with the different acoustic environments they experience throughout the year," Medina added.
    A separate team reported similar links between environment and birdsong in mockingbirds in 2009, but this is the first study to show that the pattern holds up across dozens of species.
    Interestingly, Francis and Medina found that species with striking color differences between males and females also sing more variable songs, which means that environmental variation isn't the only factor, the researchers say.


    Cuckoo Tricks to Beat the Neighborhood Watch


    ScienceDaily (Aug. 2, 2012)To minimise the chance of being recognised and thus attacked by the birds they are trying to parasitize, female cuckoos have evolved different guises. The new research, funded by the Natural Environment Research Council, was published August 3, in the journal Science.

    Common Cuckoo in flight, Cuculus canorus. (Credit: © FLORIAN ANDRONACHE / Fotolia)
    The common cuckoo (Cuculus canorus) lays its eggs in the nests of other birds. On hatching, the young cuckoo ejects the host's eggs and chicks from the nest, so the hosts end up raising a cuckoo chick rather than a brood of their own. To fight back, reed warblers (a common host across Europe) have a first line of defence: they attack, or 'mob', the female cuckoo, which reduces the chance that their nest is parasitized.
    Some female common cuckoos are grey and hawk-like, and previous research has shown that their resemblance to hawks reduces host bird attack. However, other females are bright rufous (brownish-red). The presence of alternate colour morphs in the same species is rare in birds, but frequent among the females of parasitic cuckoo species. The new research shows that this is another cuckoo trick: cuckoos combat reed warbler mobbing by coming in different guises.
    Cuckoos are secretive. To widen their source of information about local cuckoo activity, reed warblers eavesdrop on the mobbing behaviour of their neighbours. In the study, the researchers manipulated local frequencies of the more common grey colour cuckoo and the less common (in the United Kingdom) rufous colour cuckoo by placing models of the birds at neighbouring nests. They then recorded how the experience of watching neighbours mob changed reed warbler responses back at their own nest.
    They found that reed warblers increased their mobbing, but only to the cuckoo morph that their neighbours had mobbed. Therefore, as one cuckoo morph increases in frequency, local host populations will become alerted specifically to that morph. This means the alternate morph will be more likely to slip past host defences and lay undetected. This is the first time that 'social learning' has been documented in the evolution of mimicry as well as the evolution of different observable characteristics -- such as colour -- in the same species (called polymorphism).
    Dr Rose Thorogood, of the University of Cambridge and co-author on the paper, said: "When mimetic disguises become less effective, evolving a polymorphism can be a successful trick. Our research shows that individuals assess disguises not only from personal experience, but also by observing others. However, because their learning is so specific, this social learning then selects for alternative cuckoo disguises and the arms race continues."
    Professor Nick Davies, of the University of Cambridge and co-author on the paper, added: "It's well known that cuckoos have evolved various egg types which mimic those of their hosts in order to combat rejection. This research shows that cuckoos have also evolved alternate female morphs to sneak through the hosts' defences. This explains why many species which use mimicry, such as the cuckoo, evolve different guises."

    Extinction Risk Factors for New Zealand Birds Today Differ from Those of the Past


    ScienceDaily (Aug. 2, 2012)What makes some species more prone to extinction? A new study of nearly 300 species of New Zealand birds -- from pre-human times to the present -- reveals that the keys to survival today differ from those of the past.

    Taupo Bay, New Zealand. What makes some species more prone to extinction? A new study of nearly 300 species of New Zealand birds -- from pre-human times to the present -- reveals that the keys to survival today differ from those of the past. (Credit: © Cloudia Newland / Fotolia)
    The results are important in light of the growing number of studies that try to predict which species could be lost in the future based on what kinds of species are considered most threatened today, said lead author Lindell Bromham of Australian National University.
    In the roughly 700 years since humans arrived in the remote islands that make up New Zealand, more than one out of four of New Zealand's native bird species have been wiped out.
    Gone are birds such as the massive Haast's eagle, which weighed up to 33 pounds (15kg), and the giant moa, a flightless bird that stood up to ten feet (3m) tall.
    Many species were hunted to extinction. Others were eaten by the animals humans brought with them -- such as cats, rats and weasels -- or pushed off their land as humans cleared and burned forests to make way for farms and pastures.
    In a new study, a team of researchers examined whether biological traits such as body size might help scientists predict which species were likely to perish, and whether those risk factors held up over time.
    To find out, they analyzed extinction patterns for New Zealand's native birds across four time periods in New Zealand's history, from pre-human times to the present. The data set included 274 species of living and extinct birds, such as ducks, penguins, geese, gulls, pigeons, parakeets and wrens.
    The researchers looked for the biological traits that best predicted extinction risk in each time period. After accounting for similarities among closely related species, the researchers found that the traits that make some species more vulnerable today differ from what made species more prone to extinction in the past.
    When the researchers compared the last 700 years of human occupation to pre-human times, for example, they found that flightless species such as moa and rails have been consistently hard-hit -- presumably because species that can't fly make easy snacks.
    "There was no difference in extinction risk between flightless and flighted species until humans arrived," said co-author Robert Lanfear, currently a visiting researcher at the U.S. National Evolutionary Synthesis Center.
    Other risk factors for extinction changed with each new wave of human settlement.
    In the period after Polynesians appeared until Europeans arrived in the 1820s, for example, bigger species were more likely to die out. According to one study the extinct giant moa -- a group of ostrich-like birds that weighed up to 600 pounds (270 kg) -- was hunted to extinction within less than one hundred years.
    The researchers were surprised to find that after Europeans arrived, size was no longer a factor. Instead, species having males and females of different color were the hardest hit -- possibly because those species were prized for museum collections.
    Today, species that nest on the ground and lay only a few eggs at a time are considered most threatened, including the iconic kiwi, and a giant flightless parrot called the kakapo -- two birds found only in New Zealand.
    Why do the extinction risk factors for New Zealand birds living today differ from those of the past? Size, for example, was only associated with extinction risk in the period after Polynesians arrived but before European settlement.
    "It could be that that's when birds were most heavily hunted for food," Bromham said. "Or it might be that all the largest birds went extinct soon after human arrival, so now there are no longer enough large species to spot the raised extinction risk!"
    "If extinction has already caused the loss of a susceptible trait, then this trait may no longer be relevant to surviving species even though it is still the original cause of past extinctions. This is known as an 'extinction-filter'," explained co-author Phillip Cassey of the University of Adelaide in Australia.
    For studies of extinction risk, the results mean we should proceed with caution when analyzing different time periods. "We can't guarantee that the patterns we detect in contemporary extinction risk are the same as those that have caused extinctions in the past, or will be the ones that are most important in the future," Bromham said.

    Amazing Deep Diving by Imperial Cormorant Bird


    ScienceDaily (July 31, 2012) — A team of researchers from the Wildlife Conservation Society (WCS) and the National Research Council of Argentina recently fitted a South American sea bird called an imperial cormorant with a small camera, then watched stunned as it became "superbird" -- diving 150 feet underwater in 40 seconds, feeding on the ocean floor for 80 seconds where it eventually caught a snakelike fish, before returning to the surface 40 seconds later.

    Imperial cormorants from Punta León in Argentina. (Credit: Wildlife Conservation Society)
    This is the first time researchers have been able to watch first-hand the amazing feeding techniques of these fascinating birds, which occur off the coast of Argentina.
    The footage shows the cormorant briefly on the surface before diving for the bottom. The camera is attached to the bird's back, so the view is of its head as it pumps its feet to swim deeper. When it finally reaches the ocean floor, it explores a vast area searching for food. It eventually finds an elongated fish, which it brings to the surface to eat.
    The footage came from Punta León in Patagonia, Argentina, a coastal protected area supporting more than 3.500 pairs of imperial cormorants. A WCS scientific team, led by Dr. Flavio Quintana, has been studying the cormorants' feeding behavior for the past ten years. The team was joined by Dr. Carlos Zavalaga along with Ken Yoda from the University of Nogoya, Japan to fit the camera on the bird.
    The WCS team has tracked more than 400 cormorants along the Patagonian Coast of Argentina using cutting edge technological tools such as multi-channel archival tags and high resolution GPS-loggers. This information will help identify priority feeding areas to help design new protected areas and to understand environmental conditions that affect cormorant populations.
    Video: http://www.youtube.com/watch?v=jZ4QAWKgBu4&feature=youtu.be


    La democracia de las corporaciones y la incineradora

    Iturria: Diagonal periódico


    La democracia de las corporaciones y la incineradora

    La autora, urbanista, explica los intereses del lobby de la venta de energía en la puesta en marcha del proyecto de la incineradora de basuras para Gipuzkoa.

    Martes 31 de julio de 2012.  Número 179
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    ZABALGARBI. Imagen de esta incineradora en Bizakia. (Foto: Jesús Villaseca)
    El papel del sector público en materia de toma de decisiones políticas se ha orientado hacia nuevas formas de “gobernabilidad más allá del Estado”. La lógica de este modelo se basa en la actuación del poder público como agente definidor de estrategias, objetivos y actuaciones urbanísticas y el sector empresarial como contribuyente del capital inversor.
    Así se va estableciendo lo que desde Análisis de Regímenes Urbanos (URA) se llama “formación de preferencias”. La existencia de unos agentes –principalmente vinculados a diferentes sectores económicos– y recursos determinados –capital inversor, experiencia previa en determinado tipo de estrategias de desarrollo– favorece la decisión de orientarse hacia objetivos concretos. En este contexto, desde las esferas de decisión, la colaboración público-privada está más “engrasada” y reporta mutuas satisfacciones y compensaciones, conformándose de esta manera un “poder sistémico”. En cambio, este poder llega al convencimiento de que la participación pública no sólo no es positiva para el desarrollo, sino que entorpece la eficacia a la que ha llegado la colaboración público- privada. Se afirma que la concertación y la construcción de consensos con los colectivos y agentes sociales tienen más “costes de oportunidad” para los gobiernos institucionales. Así, la participación ciudadana y las propuestas de grupos de la sociedad civil se enmarcan en el ámbito de lo “no factible”.
    Un ejemplo de este modelo de gobernanza institucional se está dando en la esfera de la gestión de servicios y recursos públicos básicos: sanidad, gestión del agua, etc. así como en la de los Residuos Sólidos Urbanos (RSU). Por ley (Ley 7/1985 de Bases de Régimen Local) recae en los ayuntamientos la competencia/responsabilidad de la gestión de los RSU, que engloba tanto la recogida como el tratamiento posterior. La reciente Ley de Residuos (Ley 22/2011) en su artículo 12, relativo a la distribución de competencias en esta materia, dice que corresponde a las entidades locales la recogida, transporte y tratamiento de los RSU. De ese texto se deduce que el modelo será en primer término descentralizado, desde cada ayuntamiento, y que en su caso podrán adoptar formas consorciadas de gestión común, pero siempre desde el ámbito de decisión de la autonomía local. Entonces, ¿cómo es posible que se plantee una solución centralizada como es una incineradora para toda Gipuzkoa como se hizo desde la Diputación Foral en la legislatura anterior?
    Esta planta se dedica a la “valorización energética” de la basura. Esto significa que por un lado factura a los ayuntamientos por “tratar su basura” a precios que se aprueban en el Consejo de Administración de Zabalgarbi, y por otro lado, y en aplicación del RD 661/2007 que regula la actividad de producción de energía eléctrica en régimen especial, como productora de “energía renovable” es beneficiaria de una serie de primas e incentivos, además de subvenciones directas y bonificaciones fiscales.
    El antecedente de esta planta, la bizkaína Zabalgarbi, llegó a facturar 68 millones de euros en 2011, con un beneficio neto declarado de tres millones. Así, la incineradora es un negocio doble y, tras la valorización energética, que consiste en una combustión asistida mediante inyección de gas, como una planta de ciclo combinado, se generan hasta 682 Gw/hora, el equivalente al consumo doméstico del 30% de los hogares de Bizkaia, según datos de la Diputación Foral de Bizakia.
    Pero esta producción no se distribuye entre esos hogares, sino que se vende a las compañías distribuidoras por todos conocidas y su tarifación engrosa las cuentas de Zabalgarbi y la de sus socios (60% capital privado). O sea, tú ciudadano pagas para que “traten” tu basura, y eso que a ti te cobran como residuo, en la planta incineradora se convierte en materia de combustión para producir energía que se vierte a la red general y que acabas pagando en tu factura a la compañía eléctrica, y además, al ser de régimen especial, pasa a engrosar el denominado déficit tarifario.
    Exportadora de energía
    Euskadi es un territorio importador de energía bruta y exportador de energía procesada, a través de la refinería de Petronor en Somorrostro y la enorme potencia instalada de plantas de producción de “ciclo combinado” de combustión de gas: Bahía de Bizkaia-Zierbana (Iberdrola- EVE-Repsol-BP) y Boroa- Amorebieta (Sener-General Electric- ACS). La “industria energética” en Euskadi destina un excedente para la exportación del 65,6% de la producción total, con una facturación de 15.000 millones. Esto supone un balance de huella ecológica entre facturación económica/contaminantes atmosféricos de 25.500 toneladas de CO2 excedentarias.
    En conclusión: el lobby energético en Euskadi, aparte de la política energética, también lidera la política de gestión de residuos, tanto RSU como industriales, hacia su “valorización” energética, dando un vuelco a la jerarquía de prioridades marcadas por la normativa tanto europea como interna (reducción-reutilización- reciclaje-revalorización, por ese orden), generando un gran negocio de servicio (recogida y tratamiento de residuos) y energético (producción de energía eléctrica mediante combustión).
    Como resultado, el lobby energético (15.000 millones de euros de facturación anual) presiona a los partidos políticos para que la política sobre residuos se encamine hacia la incineración, éstos se justifican en los beneficios de autoabastecimiento energético que conllevaría ese método, pero que en Euskadi no deberían tener eco mediático, puesto que, en primer lugar, la dependencia energética principalmente es de hidrocarburos para el consumo del sector industrial (45%) y de transporte (33%), y no tanto de consumo eléctrico, que representa el 21% del total, y en que las renovables, a pesar de que la solar está muy poco desarrollada en comparación con Alemania, por ejemplo, ya abastecen una tercera parte del consumo.
    El Ente Vasco de la Energía (EVE) es una agencia pública dependiente del Gobierno Vasco que actúa como facilitador institucional y participa en el accionariado de las plantas de tratamiento de residuos, condicionando la política pública en la materia hacia esa “solución”. El antecedente de la estrategia tomada para la incineradora de Guipuzkoa es un proceso muy similar al que ya se dio en Bizkaia en la década anterior: la incineradora Zabalgarbi. La planta de incineración de RSU de Bizkaia se construyó en 2001, en el término municipal de Bilbao, con un presupuesto de 154 millones de euros. Para acometer esta infraestructura se constituyó una sociedad mercantil denominada Zabalgarbi, que en la actualidad cuenta con los siguientes socios: FCC (30%), Sener (30%), Diputación Foral de Bizkaia (20%), Ente Vasco de la Energia (10%), Kutxabank (5%) y Mancomunidad de la Margen Izquierda (5%). En origen el Ministerio de Industria participaba con el 10% de las acciones, que en el año 2008 fueron adquiridas a partes iguales por los socios mayoritarios (FCC y Sener).
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