Feeding and spatial ecology of brown hyaena (hyaena brunnea) in the presence of a vulture restaurant on Mogale’s Gate Biodiversity Centre, Gauteng province, South Africa

Abstract

Initial studies of brown hyaena occurred mainly in relatively large and arid systems, such as in the Namib Desert, the Kalahari region of southern Africa and savanna regions of Botswana and northern South Africa. In recent years studies on this species have focused on smaller areas, and in different habitats and land use types. My study investigated the feeding and spatial ecology of brown hyaena in the presence of a long-standing supplementary feeding site (vulture restaurant) on the Mogale's Gate Biodiversity Centre, a small (3060 ha) protected area in the Gauteng province of South Africa. Vulture restaurants have, for decades, been used globally to facilitate conservation by increasing survival and reproduction in local vulture populations. As little is known about the potential impact of vulture restaurants on other scavengers the main objective of my study was to ascertain how the presence of a long-standing vulture restaurant influences aspects of brown hyaena feeding ecology, home range and population estimates. Scat analysis was used to determine the seasonal diet of brown hyaena. Brown hyaena have access to a regular supply of carrion at the vulture restaurant which during my study contributed 43% to their overall diet. The remaining 28% was made up of smaller prey items, and 9% plant material. Population data were collected by camera traps placed across the property over a 15-month period, in which time 5 independent capture-recapture surveys were done. In order to test for population closure and to select the best models for capture probability, the Program CAPTURE was used. The program DENSITY 5.0. was used to run non-spatial capture-recapture analyses. Over the 15-month survey period abundance estimates ranged from 4 to 6 individuals per three-month capture period, resulting in density estimates of 13 to 20 individuals per 100 km2. The density estimates obtained from my study are higher than those calculated for brown hyaenas in arid areas, but similar to those of small reserves in the Eastern Cape province of South Africa. Home range estimates were calculated by using satellite collar data in QGIS V2.18 and generated using the adehabitatHR package (version 0.4.1.9) (Calenge 2006) in program R 3.5.0 (R Core Team 2018). Two methods for home range estimates were used and compared - Kernel Utilisation Distribution and Minimum Convex Polygons. Two of the three collared, hyaena were found to make regular use of the vulture restaurant and their home ranges were smaller than that reported elsewhere. The relatively small home ranges may suggest that there are sufficient resources available within Mogale's Gate for these brown hyaenas. The results from my study indicate that food resources provided by a permanent vulture restaurant influences the diet, population density, and home range size of individual brown hyaenas. It is suggested that in an area such as the Magaliesberg Biosphere Reserve, where large predators such as lion, cheetah and wild dog no longer occur, the vulture restaurants in the region act as an alternative food source for brown hyaenas, maintaining potentially viable populations and thus acting as a buffer to local extinction for this species.

Voorheen is studies oor die bruin hiëna meestal gedoen in taamlik uitgestrekte en droë stelsels soos die Namibwoestyn, die Kalahari in suidelike Afrika en die savannas van Botswana en die noorde van Suid-Afrika. In die laaste jare is studies oor hierdie hiënaspesie egter in kleiner gebiede, ander habitatte en gebiede met ander grondgebruike gedoen. Ek het die voedingsgewoontes en ruimtelike ekologie van die bruin hiëna in ʼn klein, beskermde gebied (3 060 ha), genaamd die Mogale's Gate Biodiversity Centre, in die Gauteng provinsie in Suid-Afrika bestudeer. Na aanleiding van ʼn aanvanklike studie oor die teenwoordigheid van spesies wat ʼn aanvullende voedselbron gebruik, was die doel van hierdie studie om vas te stel of die langdurige teenwoordigheid van ʼn voerplek vir aasvoëls op die eiendom enigsins ʼn uitwerking op bruin hiënas se voedingsekologie, tuisveld en geskatte bevolking het. Die seisoenale dieet van bruin hiënas is aan die hand van ʼn SCAT-ontleding bepaal. Die aas wat hulle gereeld by die aasvoëlvoerplek kry, het in die studie tydperk 47% van die bruin hiënas se dieet uitgemaak. Soogdier prooi, plant materiaal en voël reste het die oorblywende 53% uitgemaak. Die bevolkings data is oor 15 maande versamel met behulp van kameras wat oral op die eiendom versteek is. In hierdie tydperk is vyf onafhanklike vang-hervang opnames gedoen. Om vir bevolkings digtheid te toets en die mees geskikte modelle vir vangswaarskynlikheid te kies, is die CAPTURE-program gebruik. Die nieruimtelike vang-hervang ontleding is met behulp van die DENSITY 5.0.-program gedoen. In die 15-maande tydperk is vier tot ses individue elke drie maande gevang. Gevolglik is die bevolkings digtheid op 13 tot 20 individue per 100 km2 geskat. Ofskoon die bevolkingsdigtheidskattings in hierdie studie hoër is as dié vir bruin hiënas in droë gebiede, stem dit ooreen met dié van bruin hiënas in klein reservate in die Oos-Kaap provinsie van Suid-Afrika. Die oppervlakte van tuisvelde is met satelliet halsband data in QGIS V2.18 geskat, en met die adehabitatHR-pakket (0.4.1.9-weergawe) (Calenge 2006) in die program R 3.5.0 (R Core Team 2018) gegenereer. Kernel Utilisation Distribution en Minimum Convex Polygons, die twee metodes waarvolgens die oppervlakte van tuisvelde geskat is, is met mekaar vergelyk. Twee van die drie hiënas met halsbande het die aasvoëlvoerplek gereeld besoek, en hulle tuisvelde was kleiner as dié wat elders opgemerk is. Hulle betreklik klein tuisvelde kan beteken dat daar by Mogale’s Gate genoegsame voedsel vir hierdie bruin hiënas is. Ek het in hierdie studie gevind dat die voedsel by die permanente aasvoël voerplek die dieet, bevolkings digtheid en grootte van sommige bruin hiënas se tuisveld beïnvloed. Daar word aanbeveel dat die aasvoël voerplekke in gebiede soos die Magaliesberg-biosfeerreservaat, waar groot predatore soos leeus, jagluiperds en wildehonde nie langer voorkom nie, as alternatiewe voedselbron vir lewensvatbare bevolkings van bruin hiënas aangewend word om hierdie spesie van uitsterwing te red.

Dinyakišišo tša peleng ka ga phiri ye tsooto di dirilwe kudu ka mafelong a magolo a komelelo, a go swana le ka Leganateng la Namib, ka dileteng tša ka Kalahari tša borwa bja Afrika le ka mafelong a mehlare ye mentši a ka Botswana le ka leboa la Afrika Borwa. Mo mengwageng ye e sa tšwago go feta,dinyakišišo tše di dirilwego ka ga mehuta ye di lebeletše kudu mafelo a mannyane le ka madulong a diphoofolo a mehutahuta le ka go mehuta ya tšhomišo ya naga. Dinyakišišo tša ka di nyakišišitše mabapi le go fepa le phedišano le diphedi tše dingwe ga phiri ye tsooto mo lefelong le lennyane leo le šireleditšwego (la dihekthara tše 3060), e lego lefelo laMogale's Gate Biodiversity Centre, ka Phrobentsheng ya Gauteng ya ka Afrika Borwa. Ka morago ya dinyakišišo tše di dirilwego peleng mabapi le go ba gona ga mehuta ye ka go diriša mothopo wa dijo wa tlaleletšo, maikemišetšomagolo e bile go tseba ka fao go ba gona ga lefelo la go fepela manong leo e lego kgale le le gona mo lefelong le go huetšago mabaka mabapi le go iphepa ka phiri ye tsooto ge e dutše e phedišana le diphedi tše dingwe, lefelong leo e dulago go lona le dikakanyo mabapi le palo ya tšona. Tshekatsheko ya Scate šomišitšwe ka go nyaka go tseba seo phiri ye tsooto e se jago ka dihla tše dingwe. Phiri ye tsooto e kgona go fihlelela kabo ya kgafetšakgafetša ya ditopo tša diphoofolo ka lefelong la go fepela manong,gomme se se bile le seabe sa 47% go dijo tša tšona ka kakaretšo ka nakong yeo ke bego ke nyakišiša ka yona. 53% ye e šetšego yona ke ya ge e eja diphoofolo tša diamuši, dimela le mašaledi a dinonyana. Tshedimošo ka ga palo ya tšona e ile ya tšewa ka molaba wa setšeadiswantšho seo se beilwego go ralala le lefelo le mo lebakanakong la dikgwedi tše 15, gomme ka yona nako yeo go ile gwa dirwa diphatišišo ka go tšea diswantšho leboela makga a mahlano ka fao go ikemego.Ka nepo ya go dira teko ya go felela ga palo ya tšona le go kgetha mekgwa ye mekaone ya kgonagalo ya go tšea diswantšho,Lenaneo la CAPTUREle ile la šomišwa. Lenaneo laDENSITY 5.0.le ile la šomišwa go dira tshekatsheko ya go tšea diswantšho leboelela. Mo nakong ya dikgwedi tše 15 ya dinyakišišo,dikakanyo tša bontši bja tšona go thomile go tše nne go fihla go tše tshela ka nako ya go tšea diswantšho ya dikgwedi tše tharo, gomme se sa feletša ka dikakanyo tša bontši bja tše 13 go fihla go tše 20 kadisekwerekhilometara (km2) tše 100. Kakanyo ya bontši bja tšona yeo e hweditšwego go dinyakišišo tša ka e godimo go feta yeo e hlakantšwego ya phiri ye tsooto ka mafelong a komelelo, eupša go swana le tšeo di dulago ka mafelong a bolotaphoofolo a mannyane ka phrobentsheng ya Kapa Bohlabela ya Afrika Borwa. Dikakanyo mabapi le mehuta ya mafelo ao di dulago go ona di hlakantšwe ka go šomiša tshedimošo ya sathalaete ka goQGIS V2.18 gomme tshedimošo ye ya tšweletšwa ka go šomiša mohuta wa adehabitatHR (bešene ya 0.4.1.9) (Calenge 2006) ka go lenaneo laR 3.5.0 (R Core Team 2018). Mehuta ye mebedi ya go nyakišiša ka ga madulo a tšona e ile ya šomišwa le go bapetšwa:e lego Kernel Utilisation Distribution and Minimum Convex Polygons. Tše pedi tša diphiri tše tharo tšeo di bapeditšwego go hweditšwe gore di fela di šomiša lefelo la go fepela manong gomme mehuta ya mafelo ao di dulago gona go hweditšwe e le a mannyane go fetwa ke ka fao go begilwego go gongwe. Madulo ao a lego a mannyane kudu a ka be a šišinya gore go na le methopo ye e lekanego ya dijo ye e hwetšagalago ka lefelong laMogale's Gateyeo e fepago phriri ye tsooto. Dipoelo go tšwa dinyakišišong tša ka di laetša gore methopo ya dijo yeo e abjago ke lefelo la go fepela manong la sa ruri le huetša mehuta ya dijo, bontši bja tšona le bogolo bja lefelo leo phiri ye tsooto nngwe le ye nngwe e dulago go lona. Go akanywa gore ka lefelong la go swana lela Bolotaphoofolo la Magaliesberg Biosphere Reserve, fao dibata tše kgolo tša go swana le tau, lengau le lehlalerwa di sa hlwego di hwetšagala, mafelo a go fepela manong ka mo lefelong le a šoma bjalo ka mothopo wa dijo wa boikgethelo wa phiri ye tsooto, gomme se se tšwetša pele go ba gona ka bontši ga tšona gomme sa šoma bjalo ka seo se thibelago gore mohuta wo wa diphiri o se ke wa hwelela.