The badger is chubby but strong, with short legs, a long body and endearingly goofy gait. It has become a cultural icon to children who grew up reading “The Wind in the Willows,” or more recently, “Harry Potter,” in which the badger is the symbol of the Hufflepuffs. Once tortured by dogs in a blood sport called badger baiting, it is now a protected species in Britain.
But the beloved creatures also carry bovine tuberculosis, a disease that has killed hundreds of thousands of cows across Britain since at least the 1970s. For that reason, the omnivorous mustelids have been targeted in bloody culls to control the disease’s spread.
In some instances the effort worked; in others, it didn’t. All along, Britons who love badgers have questioned the effectiveness and necessity of the culls.
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In a new study, researchers simulated different badger-culling scenarios, and discovered that culling can help reduce the spread of wildlife disease. But to work, the efforts must fall within a “Goldilocks zone,” wherein the number of animals killed, the ground covered and the duration of the cull all must be just right. The study’s results, published in Journal of the Royal Society Interface on Tuesday, help explain some of the mystery over the varied effectiveness of the culls, which has driven decades of dispute in Britain. The results also provide a framework for understanding culling efforts to stop the spread of wildlife diseases in other animals, and suggest that on-the-ground realities often make a successful cull unattainable.
Although the bacterium that causes bovine tuberculosis typically spreads from cow to cow, badgers, which also fall sick from it, are thought to play a role when uninfected cows come into contact with infected badgers or their waste. As British farms faced the spread of bovine tuberculosis, various strategies were tried to control the disease: vaccination, testing, fencing and culling cattle, and culling badgers.
Not all culls are created equal, says Naomi Fox, a quantitative ecologist at Scotland’s Rural College, Edinburgh, and an author on the study. They are deemed effective when the target population is significantly reduced, and reduced uniformly across all sites, at just the right time and for an extended period.
Miss any of these details, however, and the disease can spread even more than it would have if nothing had been done. That outcome is called a perturbation effect, and is related to how these animals congregate.
Culling disrupts badger social structures, creating a vacuum that draws in badgers from neighboring areas to fill vacancies in culled zones. They move into the open spots because there is little dispute over territory, as well as more food and potential mates. This dynamic increases contact between infected and susceptible badgers, and creates more places with disease, at least temporarily.
“Our results help to explain what’s happened in real life,” said Dr. Fox. “Sometimes culling can lead to a decrease in disease levels, sometimes it can lead to an increase in disease levels, and sometimes it can lead to a decrease in one area and an increase next door.”
The team’s simulations and findings also may be applicable to other situations in which dense populations of animals have been culled to control the spread of disease — such as the culling of possums in New Zealand or white-tailed deer in Minnesota, which reduced tuberculosis, whereas culling red foxes in Europe and vampire bats in Peru did not stop rabies.
In Britain, managers are working on more elaborate solutions to control the spread of bovine tuberculosis. But for now, achieving the study’s Goldilocks zone is unlikely, in part because protections limit the number of badgers that can be culled.
It often is difficult to gain access to badger habitats, too. And as political parties argue over whether to oppose or support badger culls, relying on short-term evidence of culls’ effectiveness may hurt the case for longer-term culls.
“It’s all well and good saying in policy that you need to remove 70 percent of the population,” said Dr. Fox. “But to actually implement that is quite difficult, and to implement it uniformly is difficult.”B:
北京pk10赛车手机直播开奖结果【【番】【外】【之】【国】【内】【赛】】 （【很】【久】【没】【更】【新】【了】，【把】【前】【面】【的】【剧】【情】【忘】【了】emmm【就】【写】【写】【国】【内】【赛】，【故】【纵】【带】【着】【新】【人】【们】【打】【职】【业】【赛】） “【第】【六】【局】，TG【天】【宫】【超】【玩】【会】【获】【胜】！【至】【此】，【开】【启】【第】【七】【局】——【自】【由】【选】【择】【局】！” “【这】【次】【的】【总】【冠】【军】，【是】【势】【不】【可】【挡】【的】TG？【还】【是】【赛】【场】【常】【胜】【将】【军】WD？【我】【们】【拭】【目】【以】【待】！” “【蒙】【羊】【酸】【酸】【乳】【独】【家】
【白】【小】【升】【在】【内】【的】【四】【十】【五】【位】【商】【人】【在】【华】【京】【逗】【留】【了】【两】【日】，【这】【期】【间】，【受】【到】【各】【方】【领】【导】【接】【见】，【同】【时】【也】【在】【做】【一】【些】【出】【行】【上】【的】【准】【备】。 【侯】【允】【成】【给】【众】【人】【发】【了】【一】【份】【行】【程】【安】【排】，【所】【到】【国】【家】、【所】【到】【城】【市】，【还】【有】【要】【参】【观】【的】【华】【夏】【企】【业】【名】【单】【尽】【数】【在】【列】。 【各】【国】【各】【地】【区】【要】【邀】【请】【他】【们】【参】【观】【的】【当】【地】【企】【业】，【因】【为】【目】【前】【尚】【且】【没】【有】【百】【分】【百】【确】【定】，【所】【以】【会】【在】【商】【团】【到】【访】【之】【后】【再】
【虽】【然】【有】【朱】【由】【检】【的】【穿】【越】【乱】【入】，【但】【朱】【由】【检】【还】【是】【笃】【定】【历】【史】【上】【的】【宁】【远】【兵】【变】【仍】【然】【会】【不】【可】【避】【免】【的】【发】【生】。 【据】【史】【料】【记】【载】，【崇】【祯】【元】【年】【七】【月】【二】【十】【五】【日】，【宁】【远】【发】【生】【兵】【变】，【哗】【变】【首】【先】【是】【由】【从】【四】【川】、【湖】【广】【调】【来】【的】【部】【队】【发】【起】【的】，【以】【杨】【正】【朝】、【张】【思】【顺】【等】【为】【首】。 【他】【们】【先】【秘】【密】【串】【联】，【再】【集】【中】【到】【广】【武】【营】，【会】【盟】【歃】【血】，【率】【先】【兵】【变】。【接】【着】，【事】【态】【不】【断】【扩】【大】，【影】
【时】【光】【正】【好】，【微】【风】【不】【噪】。 【对】【于】【这】【个】【结】【尾】，【其】【实】【我】【很】【早】【之】【前】【就】【有】【了】【预】【想】，【尤】【其】【是】【关】【于】【众】【女】【的】【安】【排】，【我】【知】【道】，【有】【很】【多】【兄】【弟】【姐】【妹】【希】【望】【女】【主】【不】【要】【那】【么】【多】，【因】【而】，【一】【开】【始】【我】【是】【打】【算】【采】【取】【开】【放】【式】【结】【局】。 【但】【是】，【经】【历】【了】【这】【么】【多】【事】【情】，【我】【实】【在】【是】【不】【太】【忍】【心】【不】【给】【众】【女】【一】【个】【安】【排】，【因】【而】，【便】【是】【一】【笔】【带】【过】，【盛】【世】【大】【婚】，【我】【觉】【得】，【依】【旧】【是】【是】【远】北京pk10赛车手机直播开奖结果【会】【议】【开】【到】【现】【在】，【也】【就】【说】【明】【了】【一】【件】【事】【情】，【那】【就】【是】【从】【目】【前】【的】【情】【况】【来】【看】，【一】【切】【都】【是】【顺】【利】【进】【行】【的】。 【而】【这】【个】【时】【候】，【叶】【顺】【心】【里】【也】【在】【想】【着】，【这】【场】【游】【戏】，【是】【不】【是】【该】【到】【了】【结】【束】【的】【时】【候】【了】。【从】【目】【前】【的】【情】【况】【来】【看】，【伽】【马】【人】【已】【经】【找】【到】【了】【能】【够】【回】【去】【的】【办】【法】【了】，【这】【是】【其】【一】，【其】【二】【呢】，【他】【们】【的】【船】【长】，【也】【就】【是】【领】【袖】【级】【别】【的】【人】【物】，【也】【已】【然】【出】【现】【了】，【证】【明】【他】【们】
【子】【言】【和】【坤】【鹏】【的】【眼】【里】【都】【有】【一】【种】【惊】【讶】【的】【表】【情】，【子】【言】【可】【能】【想】【的】【是】，【她】【从】【来】【都】【没】【有】【看】【过】【子】【豪】【哥】【哥】【做】【过】【饭】，【他】【不】【知】【道】【这】【个】【人】【其】【实】【不】【是】【子】【豪】，【而】【是】【一】【个】【和】【子】【豪】【长】【得】【和】【一】【模】【一】【样】【的】【人】。 【而】【鲲】【鹏】【更】【感】【觉】【惊】【讶】，【那】【就】【是】【自】【己】【的】【恩】【人】，【这】【个】【武】【艺】【高】【强】【的】【男】【子】，【竟】【然】【会】【做】【饭】，【在】【古】【代】【男】【子】【会】【做】【饭】【可】【是】【个】【惊】【天】【地】，【动】【鬼】【神】【的】【事】【情】【啊】。 【陆】【晨】【的】
【显】【而】【易】【见】，【古】【一】【即】【将】【被】【死】【亡】【女】【神】【召】【唤】，【奥】【丁】【即】【将】【死】【去】【的】【这】【段】【时】【间】【是】【地】【球】【乃】【至】【九】【界】【防】【御】【力】【最】【为】【空】【虚】【的】【一】【段】【时】【间】。 【两】【位】【强】【者】【用】【尽】【全】【力】【拖】【延】【那】【一】【天】【到】【来】【的】【本】【意】【是】【想】【给】【予】【他】【们】【的】【传】【承】【者】【更】【多】【的】【时】【间】，【从】【而】【使】【得】【阿】【斯】【嘉】【德】【以】【及】【地】【球】【不】【至】【于】【空】【门】【大】【开】。 【可】【惜】【的】【是】，【无】【论】【是】【斯】【特】【兰】【奇】【还】【是】【索】【尔】【到】【现】【在】【别】【说】【是】【成】【为】【地】【球】【以】【及】【阿】【斯】【嘉】