KHALE a ku vuriwa leswaku xinyenyana lexi vuriwaka arctic tern xi kota ku haha mpfhuka wo ringana 35 200 wa tikhilomitara ku suka laha xi tshamaka kona ku ya eAntarctica ni ku va xi tlhelela endzhaku. Hambiswiritano, mindzavisiso ya sweswinyana yi kume leswaku swinyenyana leswi swi haha mpfhuka wo tlula wolowo.

Xitirhisiwa lexitsongo lexi vuriwaka geolocator, lexi kotaka ku pima mpfhuka loko swinyenyana swi haha, xi bohiwe emilengeni ya swinyenyana swo hlaya. Xitirhisiwa lexi, lexi vevukaka swinene hi xiringaniso xi kume leswaku swinyenyana swin’wana swi hahe mpfhuka lowu endlaka 90 000 wa tikhilomitara loko swi rhurha ni ku tlhelela endzhaku, ku nga mpfhuka lowu ku nga riki na xiharhi lexi nga kotaka ku wu famba. Xinyenyana xin’wana xi hahe tikhilomitara ta kwalomu ka 96 000. Ha yini mpfhuka lowu xinyenyana lexi xi wu hahaka wu tlhele wu kambisisiwa?

Loko swinyenyana leswi swi rhurhela endhawini yin’wana a swi nambi swi kongoma kona. Xifaniso lexi nga laha hehla xi kombisa ndlela leyi swi haheke ha yona. Hikokwalaho ka yini swi endla tano? Swi landzelela moya laha wu belaka kona leswaku wu swi pfuna ku haha.

Loko swi fa swi ri ni malembe ya kwalomu ka 30, swi va swi hahe mpfhuka wo tlula 2.4 wa timiliyoni ta tikhilomitara. Ku nga mpfhuka lowu ringanaka ni ku ya en’wetini u tlhela u vuya kanharhu kumbe ka mune. Mulavisisi un’wana u te: “Leswi swa hlamarisa swinene ku va xinyenyana lexi tikaka tigiramu ta kwalomu ka 100 xi kotaka ku haha mpfhuka wo leha swonghasi.” Buku leyi nge Life on Earth: A Natural History yi vula leswaku tanihi leswi loko swinyenyana leswi swi ri en’walungu ni loko swi ri edzongeni ku vaka ku ri ximumu, sweswo swi vula leswaku “hi swona swivumbiwa leswi vonaka dyambu ku tlula swivumbiwa hinkwaswo.”