Ijenali:Ibhayoloji yamanzi acocekileyo, i-64 (6), iphepha 1183-1195.
Iintlobo (Intaka):Irhanisi lembotyi (Anser fabalis), Irhanisi elingaphantsi elimhlophe elingaphambili (Anser erythropus)
Inkcazo:
Isantya esikhawulezileyo sokutshintsha kwemekobume eyenziwe ngumntu sibangela umngeni omkhulu kwizilwanyana zasendle. Ukukwazi kwezilwanyana zasendle ukuziqhelanisa notshintsho lwemo engqongileyo kuneziphumo ezibalulekileyo ekomeleleni kwazo, ukusinda kunye nokuzala. Ukuguquguquka kokuziphatha, ukulungiswa ngokukhawuleza kokuziphatha ekuphenduleni ukuguquguquka kokusingqongileyo, kunokubaluleka ngokukodwa ekujonganeni notshintsho lwe-anthropogenic. Eyona njongo iphambili yolu phononongo ibikukulinganisa impendulo yeentlobo ezimbini zerhanisi zasebusika (irhanisi lembotyi Anser fabalis kunye nerhanisi elinomphambili ongaphantsi omhlophe iAnser erythropus) kwimeko yendawo yokuhlala embi kwinqanaba labemi ngokufunda indlela yokuziphatha ngokutya. Ukongeza, siye savavanya ukuba iplastikhi yokuziphatha inokutshintsha i-trophic niche. Sibonise indlela yokuziphatha ngokutya kwaye sabala uluhlu lwasekhaya lwemihla ngemihla (HR) lwamarhanisi sisebenzisa idatha yokujonga inkqubo yokubeka indawo yehlabathi. Sibale iindawo ezisemgangathweni zeellipse ukulinganisa ububanzi beniche sisebenzisa i-δ13C kunye ne-δ15N ixabiso lerhanisi ngalinye. Sidibanise iplastiki yokuziphatha kunye nomgangatho wendawo yokuhlala usebenzisa i-ANCOVA (uhlalutyo lwe-covariance) imodeli. Siphinde savavanya ulungelelwaniso phakathi kweendawo eziqhelekileyo ze-ellipse kunye ne-HR usebenzisa imodeli ye-ANCOVA. Sifumene iiyantlukwano ezibalulekileyo kwindlela amarhanisi aziphatha ngayo ngokutya phakathi kweminyaka kwindawo yawo yokutya yemihla ngemihla, umgama wokuhamba kunye nesantya, kunye ne-engile yokujika. Ngokukodwa, iintaka zandisa indawo yazo yokutya ukuze zanelise imfuno yazo yemihla ngemihla yokufumana amandla ngenxa yeemeko ezingezizo. Babhabha ngakumbi kwaye bahamba imigama ekhawulezayo nemide yonke imihla. Kwirhanisi elisemngciphekweni wokuphela elingaphantsi elimhlophe, zonke iindlela zokuziphatha zayanyaniswa nomgangatho wendawo yokuhlala. Kwirhanisi lembotyi, yi-HR kuphela kunye ne-engile yokujika ehambelana nomgangatho wendawo yokuhlala. Iintaka, ngakumbi irhanisi elingaphantsi mhlophe ngaphambili, linokuba nendawo ephezulu phantsi kweemeko ezimbi. Iziphumo zethu zibonisa ukuba amarhanisi asebusika abonise umgangatho ophezulu wokuziphatha kweplastiki. Nangona kunjalo, ukuziphatha okusebenzayo kokutya phantsi kwemeko yeendawo zokuhlala engalunganga akuzange kukhokelele kwi-trophic niche ebanzi. Ubukho bendawo yokuhlala bunokuba noxanduva kwiimpendulo ezahlukeneyo zokufuna i-HR kunye ne-isotopic niche kutshintsho oluye lwenziwa ngumntu. Ke ngoko, ukugcinwa kweenkqubo zendalo zamanzi ngexesha elibalulekileyo (okt Septemba–Novemba) ukuqinisekisa ukuba ukutya okusemgangathweni kuyafumaneka kusembindini wekamva lamarhanisi akwi-East Asian-Australasian Flyway.
USHICILELO LUFUMANEKA KWI-:
https://doi.org/10.1111/fwb.13294
