Izikhova—Ziklanyelwe Ukuphila Ebusuku

CISHE izikhova zikuyo yonke indawo. Zitholakala kunoma yiliphi izwekazi ngaphandle kwaseAntarctica. Ziyehlukana ngobukhulu kusukela kwezingangomzwilili kuya kwezingangokhozi. Izikhova ezincane kakhulu yielf nepygmy; ezinkulu kakhudlwana izikhova ezingangokhozi zaseEurasia, izikhova ezinkulu ezimpunga, izikhova ezinkulu ezinezimpondo, nezikhova ezinhle ngokumangalisayo ezimhlophe njengeqhwa zaseNyakatho Melika. Kunezinhlobo ezingu-140 ezisakazeke kabanzi ezindaweni zokuhlala ezihlukahlukene njengezindawo ezinotshani obuningi, ezinkangala, ezingwadule, emaxhaphozini, emahlathini aminyene, emahlathini emvula, nasemathafeni angenamithi asearctic. Ukudla ezikudlayo kuhlukahlukene njengezindawo ezihlala kuzo: imisundu, izinambuzane, amaselesele, izilwane eziququdayo, izinyoni ezincane, nezinhlanzi.

UMnu. Sikhova ubonakala ehlakaniphe kakhulu, ngekhanda lakhe elikhulu, amehlo amakhulu ayindilinga asawolintshi noma aphuzi, womabili abheke phambili futhi abuka eseziyingelezini ezimisé okwamasoso ezenziwe izimpaphe. Akumangalisi ukuthi ubizwa ngokuthi isikhova esidala esihlakaniphile. Okunye okunikeza umqondo wokuthi sihlakaniphile amehlo amakhulu abheka ngokugqolozela okungagudluki nokungaguquki. Nokho, lokho kugqolozela okungaguquki, akungenxa yanoma yimaphi amandla ajulile okuzindla—amehlo aso asezingoxweni ezivimbela ukugingqika noma ukuyaluza kwawo. Noma kunjalo, kusukela emandulo isikhova sasibhekwa njengesihlakaniphile—sasiyinyoni engcwele kaPallas Athene, unkulunkulukazi wokuhlakanipha wamaGreki.

Akuzona zonke ezibonisa imfanelo enjalo yokuhlakanipha. Isikhova esincane ielf asihlabi umxhwele kangako njengesikhova esikhulu esinezimpondo, ngokufanayo nesikhova esihlala emgodini. Izikhova ezingamaelf zihlala ezindaweni eziwugwadule futhi zingena emigodini eyenziwe yiziqophamithi esala emithini emikhulu imisaguaro. Nakuba ziyizinyoni ezincane kangako zinamaphimbo amakhulu, futhi lapho iduna nensikazi zicula kanye kanye—uma ungakubiza ngokucula—kuzwakala njengokukliwula nokunswininiza kwemidlwane yezinja.

Izikhova ezihlala emgodini zihlala emigodini yezilwanyana zasenkangala (prairie dogs) yaseMelika noma yezingwejeje futhi kaningi zibonakala zigxumagxuma ezindundumeni zenhlabathi noma ziqhwakele ezigxotsheni zothango. Amaphuphu asongelwa esemigodini yawo abanga umsindo wokwethuka ofana nomsindo wokuxwayisa owenziwa yinyoka okuthiwa yirattlesnake. Uvimba ukungena kwezivakashi ezingafuneki.

Abaningi bacabanga ukuthi izikhova aziboni kahle emini. Bacabanga nokuthi izikhova zibona kangcono ebumnyameni. Kodwa banephutha kukho kokubili. Izikhova zibona kahle kakhulu. Emini, zibona kahle kakhulu. Ebusuku azinankinga futhi. Izikhova ezihamba ebusuku—futhi eziningi zinjalo—zinamaretina agcwele kakhulu izinzwa ezamukela ukukhanya ezenza zikwazi ukubona ekukhanyeni okuluvindi kakhulu. Endaweni ezungezile enjalo amehlo azo aqoqa ukukhanya okuluvindi izikhathi eziphindwe kayikhulu kunanoma kwenza awethu. Kodwa ebumnyameni obuphelele, nazo futhi zingase zingaboni lutho. Omunye umcwaningi wasakaza amagundane afile phansi endlini emnyama ngokuphelele futhi wafaka izikhova kuyo. Lezozikhova azitholanga nelilodwa igundane.

Lapho Izindlebe Ziphenduka Amehlo

Nokho, lapho kufakwa isikhova esivamile, (ikhasi 15) endlini emnyama ngokuphelele enamahlamvu phansi namagundane aphilayo ekhwashana kuwo, sawabamba onke. Ezinye izikhova ezihamba ebusuku zazingasenza lesisenzo esifanayo, kodwa ngokuqinisekile isikhova esivamile sichwepheshile kulokhu. Ebumnyameni obuphelele izindlebe zaso ziphenduka amehlo aso. Izikhova ezivamile zinenzwa yokuzwa ukuthi umsindo uvela ngakuphi enembe ukwedlula noma eyasiphi isilwane sasezweni esiye sacwaningwa.

Lapho sifuna ukuzwa umsindo omncane kakhulu, siphendulela indlebe yethu ngalapho uvela ngakhona futhi singabeka isandla ngemuva kwendlebe yethu ukuze siqoqe amaza omsindo futhi siwaqondise ezimbotsheni zezindlebe zethu. Ubuso besikhova esivamile buklanyelwe ukuba lokhu bukwenze ngokuzenzekelayo, futhi imisindo emincane ngokweqile engezwakali kithi sona siyizwa kalula. IScience Year 1983 yeWorld Book iyachaza: “Ukuzwela kakhulu emsindweni kwesikhova esivamile kubangelwa ikakhulukazi imfanelo yokuqoqa umsindo yokusahwanqa okusebusweni—unqenqema lwezinsiba eziqinile, eziminyene ezenza umfanekiso osanhliziyo ozungeze ubuso. . . . Njengesandla esibekwe ngemva kwendlebe, ububanzi balolunqenqema buqoqa umsindo buwuqondise ezimbotsheni zezindlebe.”

Umklamo wokuzwa awugcini nje ngehwanqa lesikhova esivamile. Kunesinye ‘isandla esikhangezile’ esiqondisa umsindo embotsheni yendlebe. IScience Year 1983 iyasichaza: “Isivadlwana esibomvana esingasembotsheni yendlebe yesikhova esivamile sinokwakheka okufana negwagwa lomuntu. Izinsiba ezingaphandle kwalesivadlwana nezisehwanqeni ngemuva kwendlebe zisebenza njengezandla ezikhangezile ukuze zethele umsindo ezindlebeni.”

Nokho, lesivadlwana asisona nje esinye ‘isandla esikhangezile’ esiqinisa amandla okuqoqa umsindo kwehwanqa elisebusweni. Lesivadlwana, sihambisana nehwanqa, siklanywe ngokukhethekile ukuze sengeze isici esisha ngokuphelele ekhonweni lesikhova esivamile lokuzwa lapho umsindo uvela ngakhona. Izimbobo zezindlebe ezisogebhezini lwekhanda lesikhova esivamile ziqondene, okungukuthi, imbobo engakwesokudla imalungana ngokuthé ngqo nengakwesobunxele ekhanda. Nokho, ukwakheka kwangaphandle kwezindlebe akuqondene. Kokubili isivadlwana sendlebe sangakwesokudla nembobo ephumela ngaphandle kungaphansana futhi kubheke phezulu, kuyilapho isivadlwana sendlebe yangakwesobunxele nembobo ephumela ngaphandle kungaphezudlwana futhi kubheke phansi. Ngakho-ke, indlebe yangakwesokudla, nesivadlwana sayo nembobo kukhongezele phezulu, izwela kakhulu emisindweni evela ngenhla, kuyilapho indlebe yangakwesobunxele, nesivadlwana sayo nembobo kukhongozele phansi, izwela kakhulu emisindweni evela ngezansi. Uma umsindo uqine kakhudlwana endlebeni engakwesokudla, isikhova siyazi ukuthi umthombo wawo ungenhla; uma uqine kakhudlwana endlebeni engakwesobunxele, umthombo ungezansi.

Ngokufanayo, uma umthombo womsindo ungasemaceleni kakhudlwana kunangenhla futhi uzwakale endlebeni yangakwesokudla kuqala kunengakwesobunxele, ngokushesha uqondakala njengovela ngakwesokudla; uma uzwakale kuqala endlebeni engakwesobunxele, uqondakala njengovela ngakwesobunxele. Ikhanda lesikhova lincane, ngakho umehluko phakathi kwesikhathi sokufika komsindo kwenye indlebe uma kuqhathaniswa nenye mncane, ulinganiswa ngamamicrosecond (imicrosecond liyingxenye eyodwa kweziyisigidi zomzuzwana). Ukusabela kwesikhova ngalapho umsindo uvela ngakhona kuyashesha—kuphakathi nengxenye eyodwa kweziyikhulu zomzuzwana, ubuso besikhova buphendukela ngakulowomthombo. Ikhono laso lokuhlunga ngokuphazima kweso lezinkomba ezenzeka ngezingxenye zemizuzwana libaluleke kakhulu ekutholeni ngokuthé ngqo umthombo womsindo.

Njengoba kubonisiwe ngaphambili, cishe amehlo esikhova awanyakazi. Nokho, lokhu akulona iphutha lomklamo. Intamo yesikhova igobeka kalula kangangoba ezinye izikhova zikwazi ukuphendula izintamo zazo amadegree angu-270, yenze ukuba sibuke ngisho nangemva kwaso ngokuqondile. Ngaphezu kwalokho, ukuthi amehlo awanyakazi kuyisici esiwusizo. Kusho ukuthi noma nini lapho isikhova sizwa umsindo futhi siphendulele intamo yaso ngasemthonjeni wawo, amehlo aso ngokuzenzekelayo asuke ebheke ngalapho. Umthombo womsindo siwubona engxenyeni eyodwa kweziyikhulu zomzuzwana emva kokuba siwuzwile.

Izimpiko Eziklanyelwe Ukungabangi Umsindo

Izinsiba zezinyoni eziningi zibanga umsindo njengoba zintweza emoyeni zindiza. Akunjalo ngezinsiba zesikhova; ziklanywe ngokukhethekile ukuba zingabangi umsindo. Zithambile futhi zintofontofo, zizwakala njengevelvet esandleni, ngakho umoya awubangi msindo njengoba udlula phezu kwazo. Izinsiba zokundiza aziqondile futhi azilukhuni emachosheni azo njengezezinyoni eziningi, ezenza umsindo ontwezayo njengoba zibhenguza emoyeni zindiza. Amagatsha ezinsiba zesikhova awalingani ngobude, eshiya amachopho athambile ayephuzelayo angenzi msindo njengoba ephephetheka emoyeni.

Nokho, lokhu kuzinikela ekuthuleni izikhova ziyakuyeka lapho zihileleka enkulumweni yezikhova—ukukhala, ukutshiyoza, ukunswininiza, ukushayanisa imilomo nokushayanisa izimpiko lapho zindiza. Abanye abacwaningi babhekisela kulemisindo njengezingoma zezikhova, futhi ezindlebeni zezikhova eminye yalemisindo ingezwakala njengokucula, ngoba inayo ingxenye eyifezayo ekuxhumaneni kokuqomisana phakathi kwemibhangqwana.

Izikhova ziyigugu ekulawuleni izinambuzane nezilwane eziququdayo. Isikhova esivamile ikakhulukazi sicatshangelwa njengomngane womlimi, siqeda amagundane namabunzi emasimini akhe nezinye izinambuzane ezikhathazayo ezidla izilimo zakhe. Kwezinye izindawo izikhova zikhuthazwa “ngeminyango yezikhova” ekhethekile ukuze zingene ngokukhululekile ezakhiweni zasemapulazini. EMalaysia, abalimi bemithi yeoil-palm babekela izikhova ezivamile amabhokisi okuzalela—futhi lokho akuwona umusa nje. Umbhangqwana ohlala lapho ukhokha intela, ngokuqeda amagundane afinyelela ku-3 000 ngonyaka abengase adle izitshalo zomlimi. Futhi izikhova ezivamile zenezela ubuhle. Ziphakathi kwezinyoni ezinhle kunazo zonke, zisakazeke nomhlaba wonke, futhi zinobuso obumise okwenhliziyo obuhlaba umxhwele kakhulu kuyo yonke imvelo.

Uma ucabanga ngamehlo amakhulu aphuzi aqoqa nokukhanya okuncane kakhulu, amadlebe abamba nomsinjwana ohoshozayo ovela noma kuluphi uhlangothi, nezinsiba zokundiza ezishelela buthule emoyeni, kumelwe umangale ngalezozikhova ezihamba ebusuku ezidaliwe futhi zikuklanyelwe kahle ukuphila kwasebusuku.

[Izithombe ekhasini 16, 17]

Ngakwesobunxele ngenhla: Isikhova esikhulu esinezimpondo nomntwana

[Umthombo]

page 16 left, Robert Campbell; page 16 right, John N. Dean

Kwesokudla: Isikhova esihlala emgodini

[Umthombo]

Paul A. Berquist

Kude ngakwesokudla: Isikhova ielf

[Umthombo]

Paul A. Berquist

[Isithombe ekhasini 15]

Photos: page 15, Paul A. Berquist