Diet of key predators responsible for livestock conflict in Namaqualand, South Africa

Jansen, Corle (2016-03)

Thesis (MSc)--Stellenbosch University, 2016.

Thesis

ENGLISH ABSTRACT: Human-wildlife conflict (HWC) occurs in areas where humans and wildlife occupy the same area or compete for the same resources. Although some carnivores are responsible for incidental attacks on humans, predation on livestock is an increasingly common form of HWC. Understanding the ecology of these predators outside the confines of protected areas could provide insight into decreasing conflict and ensuring the persistence of these animals in non-protected areas. I analysed the diet of leopard (Panthera pardus), caracal (Caracal caracal) and black-backed jackal (Canis mesomelas) in Namaqualand, Northern Cape, South Africa, an area where HWC is commonly reported. Scats were collected for each predator in both protected areas (Namaqua National Park) and surrounding, non-protected farmlands (810 km²). Eight caracals were also collared to analyse caracal diet from GPS-cluster data. The diet of the three predators was assessed across both land classifications (protected vs. non-protected). Prey availability was determined by means of camera and small mammal traps and compared between the two land classifications. The relative abundance index (RAI) was used to determine the abundance of prey species on the two contrasting land classifications and whether prey abundance and availability influenced the feeding ecology of leopard, caracal and jackal in Namaqualand. All three predators relied on the most abundant and easy to catch prey species, reflecting opportunistic feeding behaviour. In the protected national park, where livestock was absent, all three predators selected for natural prey items. These findings coincided with previous studies on leopard, caracal and black-backed jackal in South Africa. A shift in leopard diet was observed on farmlands, as livestock replaced small-to medium-sized ungulates in scats. For black-backed jackals, steenbok (Raphicerus campestris) contributed >20% to the total biomass consumed in protected areas while on farmlands sheep (Ovis aries) contributed > 20% and steenbok only < 5%. These findings in scat are mirrored in ungulate surveys; steenbok was the most abundant small-to medium-sized ungulate in the national park and sheep were the most abundant prey on farmlands. Caracal preferred hyrax (Procavia capensis) and lagomorpha as prey, while predation on livestock occurred in low frequencies (scat analysis, 6.9%), making caracal the predator which depended the least on livestock. Land-use also had very little effect on caracal diet. When analysing caracal diet by means of kill site analysis, sheep contributed the bulk to the total biomass consumed (59.5%). However, GPS cluster analysis is inherently biased towards the overestimation of larger bodied prey items and excludes smaller prey items (< 1 kg) which contributed > 25% to the total biomass consumed according to scat analysis. Predation of livestock by these three predators was not significant in relation to livestock availability on farmlands, especially for caracal. Due to the opportunistic feeding behaviour of these predators it was more likely that livestock was an alternative prey source. A suitable natural prey base on farmlands would decrease livestock losses, especially where leopards depredate on stock. Leopards are the last remaining large predator in this area and the loss of these large felids could be detrimental to the healthy functioning of the ecosystem. If increased vigilance is practiced during the lambing period, lambs could survive to past their vulnerable size when they fall victim to jackals. Improved livestock husbandry methods, implementation of guarding animals and herders and various other holistic methods could decrease livestock losses in Namaqualand.

AFRIKAANSE OPSOMMING: Konflik tussen mense en diere kom gewoonlik voor in areas waar wilde diere en mense dieselfde area beset en vir soortgelyke hulpbronne kompeteer. Deur die ekologie van roofdiere kwesbaar vir hierdie konflik buite beskermde gebiede te bestudeer, kan baie insigte verkry word oor hoe om konflik te vermy en te verminder. Verder kan dit verseker dat sulke predatore nie verlore gaan buite formeel beskermde areas nie. Hierdie studie het die dieet van luiperd, rooikat en rooijakkals in Namakwaland, Noord-Kaap, Suid-Afrika geanaliseer. Mismonsters van die drie predatore is versamel in die Namakwa Nasionale Park en omliggende veeplase (810 km²). Agt rooikatte was ook voorsien met radio-nekbande om rooikat dieët verder te ontleed. Die dieet van die drie predatore is geanaliseer en vergelyk tussen beide die nasionale park en die omliggende plase. Die beskibaarheid van prooi op altwee grondgebruike is ook ontleed deur gebruik te maak van kameras in die veld en klein-soogdier lokvalle. ‘n Relatiewe volopheids-indeks (RVI) is gebruik om te bepaal of die beskibaarheid en getalle van prooi die dieet van luiperd, rooikat en rooijakkals beïnvloed in Namakwaland. Al drie van die predatore het opportunistiese voergedrag getoon. Die dieet was verder grootliks afhanklik van die volopheid van maklik-bekombare prooi. Vorige studies van luiperd-, rooikat- en rooijakkals-dieet stem ooreen met die resultate verkry van die mismonsters versamel in die nasionale park. ‘n Verskuiwing in luiperddieet is op kleinveeplase waargeneem waar vee essensieël die rol van kleiner bok-soorte vervang. ‘n Soortgelyke tendens is waargeneem in jakkalsdieet. Steenbok, wat > 20% bygedra het tot die algehele biomassa gevreet deur jakkals in die nasionale park, is effektief vervang deur skaap, wat > 20% bygedra het tot biomassa op aanliggende plase, waar steenbok slegs > 4%. Steenbok was ook die volopste van die kleiner bok-soorte in die nasionale park, met skaap die volopste prooi item op die plase. Rooikat het dassie en lagomorpha (hase en konyne) verkies in beide die nasionale park en die aanliggende plase. Rooikat het selde gevoed op vee; op 6.9% die laagste van al die predatore in die studie. Rooikat-dieet is ook ontleed van karkasse wat opgespoor is deur middel van GPS-kluster besoeke. Die data verkry bewys dat skaap ‘n beduidende deel van die algehele biomasssa gevreet deur rooikat bydra. Hierdie metode het egter alle prooi kleiner as 1 kg, wat meer as 25% bygedra het tot die algehele biomassa gevreet deur rooikat, uitgesluit. Luiperd was die hoofpredatoor van boerbokke in die droeë seisoen. Volgens die beskikbaarheid van vee was die predasie deur hierdie drie predatore op vee nie beduidend nie. Omdat hierdie predatore so ‘n aanpasbare patroon volg, in terme van hul dieet, is dit meer waarskynlik dat luiperd, jakkals en meer so rooikat vee gevang het as alternatiewe prooi. As daar op plase ‘n voldoende, natuurlike prooi-basis beskikbaar is sal vee verlieste moontlik verminder, veral verlieste as gevolg van luiperd predasie. Luiperds is die laaste oorblywende groot karnivore in hierdie area en die moontlike verlies van hierdie diere sal groot nagevolge hê vir die algehele funksionering van Namakwaland as ‘n gesonde, interaktiewe ekosisteem. As daar meer waaksaamheid uitgeoefen word in tye wanneer ooie lam, kan lammers grootliks ongehinderd groei tot op ‘n punt waar jakkalse hulle nie meer sal teiken nie. Uiteindelik kan dit lei tot ‘n wen-wen situasie vir beide die ekosisteem se gesonde funksionering en produksie. ‘n Toename in vee-bestuur metodes, soos die gebruik van herders in die veld, vee waghonde en ander holistiese metodes kan vee verlieste in Namakwaland effektief verminder.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98722
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