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Archive for the ‘Vertebrates’ Category

OCTOBER 21, 2021

Don’t underestimate rabbits: These powerful pests threaten more native wildlife than cats or foxes

by Pat Taggart, Brian Cooke, The Conversation

Don't underestimate rabbits: these powerful pests threaten more native wildlife than cats or foxes
Rabbits eventually built up a tolerance to biocontrols. Credit: Shutterstock

In inland Australia, rabbits have taken a severe toll on native wildlife since they were introduced in 1859. They may be small, but today rabbits are a key threat to 322 species of Australia’s at-risk plants and animals—more than twice the number of species threatened by cats or foxes.https://e8facf95f2a45a2fd1e278c392de6377.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.html

For example, research shows even just one rabbit in two hectares of land can solely destroy every regenerating sheoak seedling. Rabbits are also responsible for the historic declines of the iconic southern hairy-nosed wombat and red kangaroo.

Our latest research looked at the conservation benefits following the introduction of three separate biocontrols used to manage rabbits in Australia over the 20th Century—all three were stunningly successful and resulted in enormous benefits to conservation.

But today, rabbits are commonly ignored or underestimated, and aren’t given appropriate attention in conservation compared to introduced predators like cats and foxes. This needs to change.

Why rabbits are such a serious problem

Simply put, rabbits are a major problem for Australian ecosystems because they destroy huge numbers of critical regenerating seedlings over more than half the continent.

Rabbits can prevent the long-term regeneration of trees and shrubs by continually eating young seedlings. This keeps ecosystems from ever reaching their natural, pre-rabbit forms. This has immense flow-on effects for the availability of food for plant-eating animals, for insect abundance, shelter and predation.

In some ecosystems, rabbits have prevented the regeneration of plant communities for 130 years, resulting in shrub populations of only old, scattered individuals. These prolonged impacts may undermine the long-term success of conservation programs to reintroduce mammals to the wild.https://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-0536483524803400&output=html&h=280&slotname=5350699939&adk=2071891895&adf=780081655&pi=t.ma~as.5350699939&w=540&fwrn=4&fwrnh=100&lmt=1634968622&rafmt=1&psa=1&format=540×280&url=https%3A%2F%2Fphys.org%2Fnews%2F2021-10-dont-underestimate-rabbits-powerful-pests.html&flash=0&fwr=0&rpe=1&resp_fmts=3&wgl=1&uach=WyJXaW5kb3dzIiwiMTAuMC4wIiwieDg2IiwiIiwiOTUuMC4xMDIwLjMwIixbXSxudWxsLG51bGwsIjY0Il0.&dt=1634968622468&bpp=9&bdt=270&idt=150&shv=r20211020&mjsv=m202110200101&ptt=9&saldr=aa&abxe=1&cookie=ID%3D895ac2cb13223d7c-224f137c58cb0056%3AT%3D1628474727%3AS%3DALNI_Mbcifc_L6AwwVQop1sOsaLGpFy88g&correlator=1365095016994&frm=20&pv=2&ga_vid=575682118.1628474640&ga_sid=1634968623&ga_hid=210059594&ga_fc=1&u_tz=-300&u_his=1&u_h=864&u_w=1536&u_ah=824&u_aw=1536&u_cd=24&adx=326&ady=2217&biw=1381&bih=685&scr_x=0&scr_y=0&eid=31063260%2C31062524&oid=2&pvsid=2957186773193720&pem=278&wsm=1&ref=http%3A%2F%2Fwww.bcpc.org%2F&eae=0&fc=896&brdim=0%2C0%2C0%2C0%2C1536%2C0%2C1536%2C824%2C1396%2C685&vis=1&rsz=%7C%7CpeEbr%7C&abl=CS&pfx=0&fu=128&bc=31&ifi=1&uci=a!1&btvi=1&fsb=1&xpc=0yB8cvZkXQ&p=https%3A//phys.org&dtd=168

Things are particularly dire in arid Australia where, in drought years, rabbits can eat a high proportion of the vegetation that grows, leaving little food for native animals. Arid vegetation is slow growing and doesn’t regenerate often as rainfall is infrequent. This means rabbits can have a severe toll on wildlife by swiftly eating young trees and shrubs soon after they emerge from the ground.

Rabbits eat a high proportion of regenerating vegetation even when their population is at nearly undetectable levels. For example, it took the complete eradication of rabbits from the semi-arid TGB Osborn reserve in South Australia, before most tree and shrub species could regenerate.

Rabbits also spread weeds, cause soil erosion and reduce the ability of soil to absorb moisture and support vegetation growth.

If you control prey, you control predators

When restoring ecosystems, particularly in arid Australia, it’s common for land managers to heavily focus on managing predators such as cats and foxes, while ignoring rabbits. While predator management is important, neglecting rabbit control may mean Australia’s unique fauna is still destined to decline.

Cats and foxes eat a lot of rabbits in arid Australia and can limit their populations when rabbit numbers are low. A common argument against rabbit control is that cats and foxes will turn to eating native species in the absence of rabbits. But this argument is unfounded.

Cats and foxes may turn from rabbits to native species in the immediate short-term. But, research has also shown fewer rabbits ultimately lead to declines in cat and fox numbers, as the cats and foxes are starved of their major food source.

Regrowth could be seen from space

An effective way to deal with rabbits is to release biocontrol agents—natural enemies of rabbits, such as viruses or parasites. Our research reviewed the effects of rolling out three different biocontrols last century:

  • myxomatosis (an infectious rabbit disease), released in 1950
  • European rabbit fleas (as a vector of myxomatosis), released in 1968
  • rabbit haemorrhagic disease, released in 1995.

Each lead to unprecedented reductions in the number of rabbits across Australia.

Despite the minor interest in conservation at the time, the spread of myxomatosis led to widespread regeneration in sheoaks for over five years, before rabbit numbers built back up. Red kangaroo populations increased so much that landholders were suddenly “involved in a shooting war with hordes of kangaroos invading their properties“, according to a newspaper report at the time.

Following the introduction of the European rabbit flea, native grasses became prolific along the Mount Lofty Ranges, South Australia. Similarly, southern hairy-nosed wombats and swamp wallabies expanded their ranges.

By the time rabbit haemorrhagic disease was introduced in 1995, interest in conservation and the environment had grown and conservation benefits were better recorded.

Native vegetation regenerated over enormous spans of land, including native pine, needle bush, umbrella wattle, witchetty bush and twin-leaved emu bush. This regeneration was so significant across large parts of the Simpson and Strzelecki Deserts, it could be seen from space.

Red kangaroos became two to three times more abundant, and multiple species of desert rodent and a small marsupial carnivore (dusky hopping mouse, spinifex hopping mouse, plains rat, crest-tailed mulgara) all expanded their ranges.

But each time, after 10 to 20 years, the biocontrols stop working so well, as rabbits eventually built up a tolerance to the diseases.

So what should we do today?

Today, there are an estimated 150–200 million rabbits in Australia, we need to be on the front foot to manage this crisis. This means researchers should continually develop new biocontrols—which are clearly astonishingly successful.

But this isn’t the only solution. The use of biocontrols must be integrated with conventional rabbit management techniques, including destroying warrens (burrow networks) and harbors (above-ground rabbit shelters), baiting, fumigation, shooting or trapping.

Land managers have a major part to play in restoring Australia’s arid ecosystems, too. Land managers are required by law to control invasive pests such as rabbits, and this must occur humanely using approved and recognized methods.

They, and researchers, must take rabbit management seriously and give it equal, if not more, attention than feral cats and foxes. It all starts with a greater awareness of the problem, so we stop underestimating these small, but powerful, pests.


Explore furtherA numbers game—killing rabbits to conserve native mammals


Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Benefits to Using Barn Owls for Rodent Control

Barn owls are big, beautiful biocontrol.By Stacie Clary -October 7, 20210485

Like any biocontrol option, barn owls won’t drive pest populations to zero and may need to be augmented with rodenticides occasionally (all photos courtesy Ryan Bourbour.)

Barn owls are rodent-killing machines,” said Sara Kross, a lecturer at Columbia University, “They are natural predators of gophers and voles, which can be really horrible pests for agriculture.”

For farmers, ranchers and/or land managers facing serious rodent problems, encouraging native barn owls to nest on their land can provide effective, ongoing biocontrol. The Western Sustainable Agriculture Research and Education (SARE) program has funded multiple research projects, such as one by Kross, looking at how to incorporate barn owls into a broader integrated pest management system. From this research, the program has developed a four-page “How To Guide” with tips for welcoming in barn owls to provide rodent control.

The Research

Barn owls are effective biocontrol against rodents, but like any biocontrol option, they won’t drive pest populations to zero and may need to be augmented with rodenticides occasionally.

Kross’ study looked at the frequency and level owls on farms are being exposed to rodenticides through analysis of their pellets, droppings and blood. The team looked for the effects of that rodenticide exposure on the owls.

One farm where the team has been conducting its research is Matchbook Wine Company’s vineyards in the Dunnigan Hills north of Sacramento.

“My family’s been growing wine grapes here since the 1970s, and controlling rodents is a big part of our integrated pest management program,” said Matchbook’s Greg Giguiere.

“We have 40 owl boxes on the farm. The rodent control is what we’re after, and it’s part of having an integrated system of biodiversity and biological controls to complement the chemical options we have for controlling these types of things.”

Another aspect of the project is tracking where the owls hunt. For that, adults were fitted with little GPS backpacks that recorded their movements for up to two weeks at a time before the backpacks were transferred to a different bird to record more data.

“Barn owls are an excellent study species because they come back to sleep in these boxes during the day, so we can safely recapture them,” says Ryan Bourbour, a Ph.D. student at UC Davis who is tracking the owls.

The study data is helping growers place barn owl boxes in the locations that will do them the most good and place rodenticide bait stations in the periods and places that cause the owls the least harm.

And that is very attractive to Giguiere.

“A big part of farming is being connected to the land,” he said. “So, a lot of what we do goes to that. I’ve been very interested in reducing chemical inputs into our system and moving away from a monoculture and having more biodiversity. So, it’s a very exciting program and we’re definitely on board and moving forward, and want to do even more habitats for hawks and other predators.”

Providing barn owls with artificial nest boxes on your farm and ranch helps them because natural nest sites are often a limiting factor for barn owl populations.

Are Barn Owls Right for Your Operation?

Barn owls can help keep rodent populations under control and deter rodent damage to fields, irrigation lines and equipment. As night-hunters, they’re effective at controlling mice, gophers and voles. Their boxes can also serve as hunting platforms for day-hunters like hawks, kestrels and eagles, which can help control and deter ground squirrel populations. In addition, there’s often great satisfaction knowing you’re hosting and helping these gorgeous natural predators.

If you have a serious rodent problem in your fields, barn owls can help. Providing barn owls with artificial nest boxes on your farm and ranch helps them because natural nest sites are often a limiting factor for barn owl populations.

During the mating and nesting season, barn owls are looking for a safe place to raise their young and a lot of rodents to feed them. If you already have the rodents, you just need to add owl boxes to house the barn owls.

For even better rodent control, also install raptor perches when you install barn owl boxes. Mount a wooden cross brace to a 10- to 15-foot-high pole. Hawks and kestrels will use them while hunting during the day, and barn owls use them at night.

Developed from this research, Western SARE’s free How-To Guide (western.sare.org/resources/welcome-in-barn-owls-to-provide-rodent-control/) takes you through decision-making, provides tips on how to provide nest boxes and describes how to site and maintain the boxes as well as how to determine if they are working.
Western SARE has developed multiple research-based How-To Guides for farmers and ranchers that can be downloaded for free at western.sare.org/learning-and-resources/how-to-quick-guides/.

For farmers, ranchers and/or land managers facing serious rodent problems, encouraging native barn owls to nest on their land can provide effective, ongoing biocontrol.

Read Full Post »

Benefits to Using Barn Owls for Rodent Control

Barn owls are big, beautiful biocontrol.By Stacie Clary -October 7, 20210338

Like any biocontrol option, barn owls won’t drive pest populations to zero and may need to be augmented with rodenticides occasionally (all photos courtesy Ryan Bourbour.)

Barn owls are rodent-killing machines,” said Sara Kross, a lecturer at Columbia University, “They are natural predators of gophers and voles, which can be really horrible pests for agriculture.”

For farmers, ranchers and/or land managers facing serious rodent problems, encouraging native barn owls to nest on their land can provide effective, ongoing biocontrol. The Western Sustainable Agriculture Research and Education (SARE) program has funded multiple research projects, such as one by Kross, looking at how to incorporate barn owls into a broader integrated pest management system. From this research, the program has developed a four-page “How To Guide” with tips for welcoming in barn owls to provide rodent control.

The Research

Barn owls are effective biocontrol against rodents, but like any biocontrol option, they won’t drive pest populations to zero and may need to be augmented with rodenticides occasionally.

Kross’ study looked at the frequency and level owls on farms are being exposed to rodenticides through analysis of their pellets, droppings and blood. The team looked for the effects of that rodenticide exposure on the owls.

One farm where the team has been conducting its research is Matchbook Wine Company’s vineyards in the Dunnigan Hills north of Sacramento.

“My family’s been growing wine grapes here since the 1970s, and controlling rodents is a big part of our integrated pest management program,” said Matchbook’s Greg Giguiere.

“We have 40 owl boxes on the farm. The rodent control is what we’re after, and it’s part of having an integrated system of biodiversity and biological controls to complement the chemical options we have for controlling these types of things.”

Another aspect of the project is tracking where the owls hunt. For that, adults were fitted with little GPS backpacks that recorded their movements for up to two weeks at a time before the backpacks were transferred to a different bird to record more data.

“Barn owls are an excellent study species because they come back to sleep in these boxes during the day, so we can safely recapture them,” says Ryan Bourbour, a Ph.D. student at UC Davis who is tracking the owls.

The study data is helping growers place barn owl boxes in the locations that will do them the most good and place rodenticide bait stations in the periods and places that cause the owls the least harm.

And that is very attractive to Giguiere.

“A big part of farming is being connected to the land,” he said. “So, a lot of what we do goes to that. I’ve been very interested in reducing chemical inputs into our system and moving away from a monoculture and having more biodiversity. So, it’s a very exciting program and we’re definitely on board and moving forward, and want to do even more habitats for hawks and other predators.”

Providing barn owls with artificial nest boxes on your farm and ranch helps them because natural nest sites are often a limiting factor for barn owl populations.

Are Barn Owls Right for Your Operation?

Barn owls can help keep rodent populations under control and deter rodent damage to fields, irrigation lines and equipment. As night-hunters, they’re effective at controlling mice, gophers and voles. Their boxes can also serve as hunting platforms for day-hunters like hawks, kestrels and eagles, which can help control and deter ground squirrel populations. In addition, there’s often great satisfaction knowing you’re hosting and helping these gorgeous natural predators.

If you have a serious rodent problem in your fields, barn owls can help. Providing barn owls with artificial nest boxes on your farm and ranch helps them because natural nest sites are often a limiting factor for barn owl populations.

During the mating and nesting season, barn owls are looking for a safe place to raise their young and a lot of rodents to feed them. If you already have the rodents, you just need to add owl boxes to house the barn owls.

For even better rodent control, also install raptor perches when you install barn owl boxes. Mount a wooden cross brace to a 10- to 15-foot-high pole. Hawks and kestrels will use them while hunting during the day, and barn owls use them at night.

Developed from this research, Western SARE’s free How-To Guide (western.sare.org/resources/welcome-in-barn-owls-to-provide-rodent-control/) takes you through decision-making, provides tips on how to provide nest boxes and describes how to site and maintain the boxes as well as how to determine if they are working.
Western SARE has developed multiple research-based How-To Guides for farmers and ranchers that can be downloaded for free at western.sare.org/learning-and-resources/how-to-quick-guides/.

For farmers, ranchers and/or land managers facing serious rodent problems, encouraging native barn owls to nest on their land can provide effective, ongoing biocontrol.

Read Full Post »

Laikipia village where farmers sleep in farms to deter jumbos

By CLEMENT MASOMBO | March 26th 2021 at 00:00:00 GMT +0300

Joyce Mukami from Nginyii village in Laikipia East is lucky that elephants did not destroy her crop of tomatoes. [Kibata Kihu, Standard]

The nightly routine of residents of Nginyii village in Umande ward, Laikipia County, has been upended by the invasion of elephants that descend from the nearby Lolldaiga Hills in search of food.

Locals have to brave the cold as they stand guard over their crops of tomatoes, carrots, French beans and other horticultural produce that prove irresistible to the jumbos, which destroy all fences or hedges erected to stop them from eating to their fill.

Rose Wairimu, 75, knows only too well the health issues she’s exposing herself to in the biting cold, but guarding the farms is a communal activity in which everyone is expected to pull their weight.

“They should just come and take away their animals. Since January, these jumbos only failed to invade our farms for one week. That’s the only time we enjoyed our sleep,” Wairimu said.

Despite the night vigils, Wairimu is counting heavy losses after the elephants invaded her tomato farm and laid waste to her crop. Her neighbour, Alex Ngare, did not fare any better after his crop of French beans was destroyed.

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hindu business

TN’s hill banana plantations wilt under elephant, viral attacks

A bunch of Hill banana grown in Dindigul, Tamil Nadu

Animal menace, inadequate insurance cover have resulted in shrinking acreage of the fruit

Kochi, April 20

Rampaging wild elephants coupled with Bunchy Top Banana (BTB) disease have hit Hill Banana growers in the Dindigul district of Tamil Nadu.

Found only in the Palani Hills of Dindigul, hill banana — locally called ‘Virupakshi’ — is a highly remunerative crop that can be harvested in 18-36 months .

This specific variety has a commercial importance and it caters only to Chennai market with a sales of around 50,000 fruits per day in the price range of 60-80/kg, said TVSN Veera Arasu, Secretary of the Tamil Nadu Hill Banana Growers Federation.

However, wild elephants straying into the fields in search of food and water have wrought havoc in several areas, causing financial loss to farmers.

The hill banana crop is the livelihood of farmers in 29 villages in the region.

But without any adequate insurance protection available, farmers are starved of funds to start the next crop.

“I have lost around 40 lakh in the last season due to the damage caused by wild elephants in my farm. Majority of the farmers here are scared to come back to banana cultivation,” he said.

Acreage down

Arasu, who was in Kochi recently to attend the farmers conclave organised by the Kerala Farmers Federation, told BusinessLine that the banana acreage has also come down to 3,000 acres compared to 16,000 acres five years back.

The threat of damage discourages new entrants to take up banana cultivation.

“To control the elephant menace, we have an assurance from the authorities to set up trenches and solar fencing for crop protection,” he said.

“We have successfully controlled BTB disease in the early 2000 with the help of Tamil Nadu Agriculture University. As the virus started attacking the plants again, we have approached the National Research Centre for Banana, Tiruchi, along with TNAU for remedial measures”, he said.

Highly remunerative

Among all the plantation crops, hill banana is the only crop which provides a weekly income to farmers, whereas remuneration from all other crops was on annual basis.

The Federation has been successful in obtaining GI certification for Virupakshi and Sirumalai — the two varieties of Hill Banana — a favourite fruit during the British period.

The famous Panchamritham in Palani Temple is made out of Virupakshi banana, the pulp of which is the main ingredient, he added.

 

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Daily News Blog

Predatory Birds Can Successfully Replace Pesticide Use in Agriculture

(Beyond Pesticides, March 8, 2018) Simple approaches that increase populations of vertebrate predators, like bats and falcons on farms, can reduce pesticide use, increase on-farm productivity, and conserve wildlife, according to a literature review published by researchers at Michigan State University in the journal Agriculture, Ecosystems and Environment.  The review encompasses 48 studies published over the last 150 years on the effect of human interventions to enhance natural ecosystem services. Results point not only to new methods to improve on-farm pest management, but also potential ways to engage farmers and citizen scientists in implementing these win-win strategies.

Researchers looked at a number of methods tested in the scientific literature that would increase on-farm populations of vertebrate pest predators. Broadly, discrete approaches such as installing structures like nest boxes, perches, and artificial roosts were investigated alongside more wide-ranging systems aimed at altering habitat and increasing landscape complexity. The latter includes methods such as installing field borders, increasing tree cover, reintroducing native species, and eliminating invasives.

The more discrete approaches provided a simpler, more accessible, and less expensive method of pest management when compared to approaches that require more wide-ranging landscape changes, though the benefits of those activities were not negligible. Nest boxes were found to successfully increase the abundance of predator species. Populations of western bluebirds increased by a factor of 10 when nest boxes were installed as part of a study on California vineyards, and vineyards without the nest boxes saw significantly higher pest levels when compared to those with bluebird boxes. In Europe, apple orchards that installed nest boxes for the native great tit bird saw 50% less pest damage than orchards that did not install the structures. Likewise, the installation of artificial bat roosts around Spanish rice fields led to significant declines in major moth pests over a 10 year period. When perches were installed around Australian soybean fields, raptors and other predatory birds caused a statistically significant decline in mouse populations.

The creation of field borders – strips of non-crop flowers and plants – did represent a successful method of improving populations of vertebrate pest predators. Studies reviewed found that bird abundance around these strips grew as the distance between cropland and forested areas increased, indicating potentially significant benefits of this practice for otherwise monotypic row crop farms.

In considering research on the addition of tree cover, studies have found mixed results. While some work indicates higher populations of various birds on farms of shade-grown coffee, other show species richness to be greater in sun-grown fields. That being said, studies generally indicate that increasing tree cover is likely to improve vertebrate pest control services.

Reintroducing native species can be a multifaceted, costly undertaking, and as a result of misperceptions about large carnivores, is more successful when the species is smaller, well-known, and non-threatening for people and farmers. A case study following the introduction of the New Zealand falcon into region known for its grape production found that the predators reduced fruit loss from pest bird species.

Both structural and landscape-level strategies can interact with one another. In one example, nest boxes installed to promote kestrel populations in Michigan were displaced by the widespread and invasive European starling. Although the solution to this problem is as simple as removing the nests, it indicates broader efforts may be necessary to maintain discrete approaches.

In sum, these methods provide a myriad of benefits. The economic value of vertebrate predators in reducing pests is significant. Bats alone contribute millions of dollars in pest-controlling ecosystem services – one study reviewed found that the loss of bats in Indonesian cacao fields would decrease yields by over 700 lb per hectare, a loss of $730 per year per hectare. The falcons reintroduced to New Zealand grape fields saved farmers there between $234 and $326 as a result of decreased pest bird consumption of fruit. In addition to monetary benefits, structures like nest boxes help conserve species by enhancing local populations, as occurred with the reintroduction of kestrels in Michigan.

Critically, these strategies help replace the over $15.2 billion American farmers spent purchasing pesticides in 2016. However, as researchers indicate, the true cost of pesticide use, through the poisoning of humans and animals, the displacement of pest predators, and contamination of our environment may increase that number by over $10 billion.

This review provides sound evidence in favor of farmers implementing simple, environmentally sustainable pest management methods. Researchers note the need to further investigate ways to engage farmers and citizens to participate in these activities, potentially through social networks, games such as the Ebird mobile app, and other tools. “Now that we’ve bundled these studies, we really need to set a research agenda to quantify best practices and make the results accessible to key stakeholders, such as farmers and environmentalists,” said lead author of the study Catherine Lindell, PhD to the National Science Foundation.

For more information on the benefits of not only vertebrate predators, but a wide range of wildlife species in reducing pesticide use, see Beyond Pesticides’ Wildlife Program page.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.

Source: National Science Foundation, Agriculture, Ecosystems and Environment

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Reuters

December 6, 2017

Rats join mosquitoes as targets for ‘gene drive’ pest control

LONDON (Reuters) – Rodents have joined mosquitoes in the cross-hairs of scientists working on a next-generation genetic technology known as “gene drive” to control pests.

FILE PHOTO: A rat eats pieces of bread thrown by tourists near the Pont-Neuf bridge over the river Seine in Paris, France, August 1, 2017. REUTERS/Christian Hartmann/File Photo

Researchers in Scotland said on Tuesday they had developed two different ways to disrupt female fertility in rats and mice, building on a similar approach that has already been tested in the lab to eliminate malaria-carrying mosquitoes.

So-called gene drives push engineered genes through multiple generations by over-riding normal biological processes, so that all offspring carry two copies. Usually, animals would receive one copy of a gene from the mother and one from the father.

The technique is extremely powerful but also controversial, since such genetically engineered organisms could have an irreversible impact on the ecosystem.

Concerns about the proliferation of mutant species have led some to call for a gene drive ban, but Bruce Whitelaw of the University of Edinburgh’s Roslin Institute believes that would be short sighted.

“A moratorium would prevent the research which is required for us to understand if and how this can be used in an advantageous way for our society,” he told reporters in London.

“We need to have an understanding of what gene drive can do and how it can be controlled so that decisions are based on knowledge rather than fear.”

A key appeal of a gene drive is its durable effect on pests, whether they are disease-carrying insects or crop-eating rodents. And since relatively small numbers of animals would need to be released initially, it is likely to be quite cheap.

It also offers a humane way to eliminate unwanted populations of sentient mammals like rats, which are typically killed with poison and traps.

Still, researchers agree more work is needed on the risks and potential unintended consequences of release of such animals.

Whitelaw and his colleagues, who published details of their rodent work in the journal Trends in Biotechnology, hope as a next step to build self-limiting gene drives that would burn out after a certain number of generations.

If their approach is successful, the gene drives could potentially be applied to help control a range of other non-insect pest species, such as rabbits, mink and cane toads.

 Currently, an older approach called “sterile insect technology” is being used in some areas to fight mosquitoes. Intrexon’s Oxitec unit has already deployed its sterile male mosquitoes, whose offspring die when young, in Brazil. But because Oxitec’s mosquitoes last only one generation, a vast number must be released to swamp their wild counterparts.

 

Existing approaches to fighting pests, particularly mosquitoes, have so far shown mixed success, with insecticide resistance increasing in many parts of the world and drugmakers struggling to develop good vaccines against complex diseases such as dengue.

Reporting by Ben Hirschler; Editing by Mark Potter

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Western Farm Press

  • Rodents cause millions of dollars in damages to field crops, stored grain and farm equipment each year. In addition, they are the major carrier for more than 60 diseases that are transmissible to humans, companion animals, and livestock.
  • “Rodents pose one of the most serious threats to food production worldwide, but indiscriminately removing rodents from ecosystems is not always the best management option.”

Rodents cause millions of dollars in damages to field crops, stored grain and farm equipment each year. In addition, they are the major carrier for more than 60 diseases that are transmissible to humans, companion animals, and livestock.

In the new book titled, “Agricultural Production,” by Nova Science Publishers, Inc., Felix C. Wager (editor), researchers from the USDA and the International Rice Research Institute (IRRI) present a review of the latest information on rodent damage management as it relates to worldwide agricultural production. The review can be found here.

“Rodents pose one of the most serious threats to food production worldwide, but indiscriminately removing rodents from ecosystems is not always the best management option,” states Dr. Gary Witmer, lead author and research wildlife biologist at the USDA-APHIS National Wildlife Research Center. “Sustainable agriculture attempts to ensure the profitability of farms while preserving and protecting the environment upon which they depend.”

Traditional approaches to rodent population and damage management have relied on direct reduction of populations using rodenticide baits or rodent traps and modifying the habitat to be less suitable for rodents. Recently, the use of an ecologically-based rodent management system (EBRM) that is tailored to the rodent species, agricultural system, and local habitat is gaining more support from researchers and agricultural specialists.

“The key to the EBRM is to reduce important resources needed by rodents, such as food and nesting sites at critical times of the year through habitat modification,” notes co-author Dr. Grant Singleton from the IRRI. “The emphasis is on a lower reliance on rodenticides and more community-wide habitat management approaches.”

Witmer and Singleton note the EBRM approach may still involve the use of lethal methods, such as rodenticides, and research is critical to finding new rodenticides as well as make existing rodenticides more effective and less hazardous to non-target animals and the environment.

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http://irri.org/rice-today/flying-heroes-of-ecuador-s-rice-fields

IRRI

Written by Imelda Felix, Finbarr Horgan, and Alex Stuart.

Bird IRRI

Apple snails (Pomacea spp.) have been a problem for Asian rice farmers for decades. First introduced in the late 1980s to Taiwan and the Philippines, these snails have now spread to most countries in Southeast Asia, as well as East Asia, such as Japan and Korea, where they are among the most damaging pests of rice and other aquatic crops. Recently, established populations of apple snails were found close to major rice-growing regions in Pakistan. India, and Bangladesh. While a few other Asian countries are still free of apple snails, what can these countries expect should the snails someday arrive?

Events in Ecuador might give some clues. In 2005, rice damaged by apple snails was first noticed in Ecuador. Since then, and particularly after severe flooding in 2008, the snail has spread to most of Ecuador’s major rice-growing regions. Losses to the rice sector from apple snails in 2013 alone were estimated at over US$56 million. However, Ecuadorean rice farmers have one big advantage in dealing with apple snails over their Asian counterparts—the snail kite (Rostrhamus sociabilis), a predatory bird that specializes in eating snails.

Flying pest control

The snail kite’s natural range extends from Florida in the United States to subtropical region in Argentina, a region that is also the native habitat of several apple snail species, including the most invasive species: the golden apple snail. West of the Andes, snail kites are largely restricted to mangrove swamps and river estuaries in southern Ecuador, where they likely feed on less invasive snails such as the spike-topped snail.

Prior to the recent apple snail invasion of Ecuador, snail kites were a threatened species. Their population had declined dramatically because of habitat loss and the overuse of agrochemicals. Moreover, farmers often hunted and killed the birds, believing that they damaged livestock. In recent years, as the apple snails have continued to spread, snail kites have become a common feature of the Ecuadorean rice landscape and a welcome sight for farmers. Groups of these birds can be regularly seen perched over rice fields watching for snails, communicating with one another through haunting, rolling caws, or swooping down to catch the snails before gracefully flying off with their prey.

But are snail kites enough to control the snails? We found out that the snail kites first respond to high snail densities by building up their own populations. This means that the snail kites require ample food and suitable habitat for hunting and nesting. Thus, for some time, as the apple snails spread, they escaped the predatory snail kites.

During this time, snail densities peaked, and had terrible effects. A visit to any newly snail-invaded region is a lesson in an ecosystem out of balance: hundreds of bright pink egg masses, containing millions of eggs, can be seen on wooden posts or the trunks of trees near infested ponds and paddy fields. Large patches of rice fields, where the water is deepest, become denuded of rice and other aquatic weeds. Snails, the size of small apples, chew through any remaining green vegetation and decomposing matter at the water’s edges.

Desperate chemical measures

Agrocalidad, Ecuador’s agricultural extension service, has been working with farmers to control snail damage to rice. Experience in Asia had shown that delayed transplanting of rice plants, careful control of water depth, and other cultural control methods could help reduce snail damage. Agrocalidad has shared these methods with tens of thousands of farmers through workshops, talks, theater, videos, posters, and handbooks. However, although Agrocalidad discourages the use of highly toxic insecticides, farmers overwhelmingly used these chemicals, particularly endosulfan, to kill the snails. This reduced snail densities but at high environmental and health costs. Worst of all, farmers noted that the chemicals were also killing their greatest allies—the predatory snail kites. In 2011, the government of Ecuador banned the use of endosulfan, and promoted the use of a more selective molluscicide, methaldehyde—for which the effects on snail kites are still unknown.

Overall, 2013 seems to have seen a decline in snail numbers in some affected areas, particularly in fields at higher elevations. However, a large part of Ecuador’s rice is produced during the dry summer months (June-December) in vegas. Vegas are natural wetlands that are completely flooded for 6 months of the year. In June-July, the water recedes, and farmers track the water levels and plant their rice in a sequential manner in areas of shallow water. This results in an attractive rice landscape with rice of different stages in natural patterns (a system called arroz escalonado or stepped rice). Apple snails in vega systems have remained at very high densities and continue to damage rice significantly. Furthermore, these habitats are highly vulnerable to agrochemicals because they are the natural habitat for a diversity of amphibians, fish, birds, and other fauna and flora.

For scientists, the events in Ecuador are an opportunity to better understand how snails invade rice and how predators and prey interact with each other. Continued monitoring of the situation will highly benefit both scientists and farmers, and could help predict future effects and help design management options as apple snails continue to invade new areas.

Above all, the tremendous negative impact of the invasive apple snail on the Ecuadorean rice sector, despite the presence of a key predator, should encourage snail-free rice-producing countries to be vigilant against possible infestation by tightening quarantine regulations and banning the trade and import of exotic snails. The best way by far to avoid apple snail damage is to ensure that these voracious snails are not introduced to any new regions, where, without natural predators such as snail kites, losses to the rice sector could be even more severe than those experienced in Ecuador.

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NEWSWISE

http://www.newswise.com/articles/view/618448/?sc=swtn

Columbia Engineering computer scientists launch electronic field guide to North American birds

Released: 5/28/2014 9:05 AM EDT
Source Newsroom: Columbia University School of Engineering and Applied Science

Is it a Crow or a Raven? New Birdsnap App Will Tell You!
Newswise — New York, NY—May 27, 2014—Researchers at Columbia Engineering, led by Computer Science Professor Peter Belhumeur, have taken bird-watching to a new level. Using computer vision and machine learning techniques, they have developed Birdsnap, a new iPhone app that is an electronic field guide featuring 500 of the most common North American bird species. The free app, which enables users to identify bird species through uploaded photos, accompanies a visually beautiful, comprehensive website that includes some 50,000 images. Birdsnap, which also features birdcalls for each species, offers users numerous ways to organize species—alphabetically, by their relationship in the Tree of Life, and by the frequency with which they are sighted at a particular place and season. The researchers, who collaborated with colleagues at the University of Maryland, are presenting their work at the IEEE Conference on Computer Vision and Pattern Recognition in Columbus, OH, June 24 to 27.
“Our goal is to use computer vision and artificial intelligence to create a digital field guide that will help people learn to recognize birds,” says Belhumeur, who launched Leafsnap, a similar electronic field guide for trees, with colleagues two years ago. “We’ve been able to take an incredible collection of data—thousands of photos of birds—and use technology to organize the data in a useful and fun way.”
Belhumeur and his colleague, Computer Science Professor David Jacobs of the University of Maryland, realized that many of the techniques they have developed for face recognition, in work spanning more than a decade, could also be applied to automatic species identification. State-of-the-art face recognition algorithms rely on methods that find correspondences between comparable parts of different faces, so that, for example, a nose is compared to a nose, and an eye to an eye. Birdsnap works the same way, detecting the parts of a bird so that it can examine the visual similarity of its comparable parts (each species is labeled through the location of 17 parts). It automatically discovers visually similar species and makes visual suggestions for how they can be distinguished.
“Categorization is one of the fundamental problems of computer vision,” says Thomas Berg, a Columbia Engineering computer science PhD candidate who works closely with Belhumeur. “Recently, there’s been a lot of progress in fine-grained visual categorization, the recognition of—and distinguishing between—categories that look very similar. What’s really exciting about Birdsnap is that not only does it do well at identifying species, but it can also identify which parts of the bird the algorithm uses to identify each species. Birdsnap then automatically annotates images of the bird to show these distinctive parts—birders call them ‘field marks’—so the user can learn what to look for.”
The team designed what they call “part-based one-vs-one features,” or POOFs, each of which classifies birds of just two species, based on a small part of the body of the bird. The system builds hundreds of POOFs for each pair of species, each based on a different part of the bird, and chooses the parts used by the most accurate POOFs as field marks. Birdsnap also uses POOFs for identification of uploaded images.
The team also took advantage of the fact that modern cameras, especially those on phones, embed the date and location in their images and used that information to improve classification accuracy. Not only did they come up with a fully automatic method to teach users how to identify visually similar species, but they also designed a system that can pinpoint which birds are arriving, departing, or migrating. “You can ID birds in the U.S. wherever you are at any time of year,” Berg notes.
The Leafsnap app, which involved costly time and resources spent in collecting and photographing thousands of leaves, took almost 10 years to develop and now has more than a million users. Belhumeur got Birdsnap going in about six months, thanks to the proliferation of online data sources and advances in computer vision and mobile computing. Photos were downloaded from the Internet, with species labels confirmed by workers on Amazon Mechanical Turk, who also labeled the parts. Descriptions were sourced through Wikipedia. The maps were based on data from eBird, a joint venture of Cornell University’s Lab of Ornithology and the National Audubon Society, and BirdLife, an international network of conservation groups.
Belhumeur hopes next to work with Columbia Engineering colleagues on adding the ability to recognize bird songs, bringing audio and visual recognition together. He also wants to create “smart” binoculars that use this artificial intelligence technology to identify and tag species within the field of view.
“Biological domains—whether trees, dogs, or birds—where taxonomy dictates a clear set of subcategories, are wonderfully well-suited to the problem of fine-grained visual categorization,” Belhumeur observes. “With all the advances in computer vision and information collection, it’s an exciting time to be immersed in visual recognition and big data.”
This research was funded by the National Science Foundation, the Gordon and Betty Moore Foundation, and the Office of Naval Research.

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Image

Yorke Peninsula farmer Mark Schilling runs the Cunliffe bait station.

Cheap mouse bait killing off plague
ABC Rural Lauren Waldhuter

http://www.abc.net.au/news/2014-05-21/yorke-peninsula-dead-mice/5468110

Mouse bait mixing stations are helping Yorke Peninsula farmers in South Australia control mice numbers.

At the start of the season, farmers were planting grain crops in paddocks that had been inundated with mice.

The mice can eat the seeds farmers sow, as well as newly-germinated crops.

Grain growers have spent tens of thousands of dollars on bait to try to kill off the mice and keep their crops safe.

Now new baiting stations, where poison and grain are mixed together on the farm, are making that process cheaper.

Maitland farmer Dylan Schultz has spent a lot of time spreading bait in his paddocks.

“We’ve baited some paddocks three times,” he said.

“They only need to eat one (poisoned) grain. One grain is lethal to a mouse.

“But it’s been shown that a mouse can actually eat 20 grains before they die.

“That’s why it’s important to be able to put out more bait per hectare.”

Cunliffe farmer Mark Schilling has a mouse bait mixing station on his farm.

The station is a shed, where the process of mixing poison and grain can take place.

The stations have to be approved by a number of regulatory bodies before they can go ahead.

Mr Schilling says it would have been better if the stations had been opened earlier, but it’s a relief the cheaper bait is finally available.

“If you came and saw me a month ago, there were mice everywhere. They’ve quietened right down now.

“It’s a combination of the season having broken and we’ve been baiting pretty heavily, as we now have access to cheap bait.”

 

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