CHAPTER 3 DIET OF LEOPARDS IN A HUMAN-DOMINATED LANDSCAPEshodhganga.inflibnet.ac.in/bitstream/10603/5431/11/11_chapter3.pdf · Asiatic lions Panthera leo (Saberwal et al. 1994; Vijayan

CHAPTER 3

DIET OF LEOPARDS IN A HUMAN-DOMINATED LANDSCAPE

A spiked metal collar to protect the dog from leopard attacks. Photographed in the northern state of Himachal Pradesh (Photo credit. B. Majumdar).

Chapter 3 Diet of leopards in a human dominated landscape

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3.1 INTRODUCTION

Many studies have found that the density of carnivores is strongly related to the

available prey biomass (Fuller & Sievert 2001; Carbone & Gittleman 2002;

Karanth et al. 2004a; Khorozyan et al. 2008; Carbone et al. 2010). Most of these

studies are based on prey and predator species in natural, semi-natural and

managed ecosystems (Fuller & Sievert 2001; Carbone & Gittleman 2002; Andheria

et al. 2007; Karanth et al. 2010). However, recent studies find that large carnivores

can also persist in largely human-dominated areas by relying fully or partially on

food resources associated with humans (Gehrt et al. 2010). The potential carrying

capacities of large carnivores in human-dominated landscapes thus needs to be

investigated in terms of abundance and availability of domestic prey species

(Boitani & Powell 2012).

The amount of available biomass for predators in the form of domestic animals

can be exceedingly higher than the wild prey biomass as seen in Brazil, Nepal

and Kenya (Schaller 1983; Seidensticker et al. 1990; Mizutani 1999). In fact, these

food resources can be so abundant that large carnivores can reach densities

comparable or even greater than their natural densities in the wild. For example,

densities of urban red foxes (Vulpes vulpes) were seen to be 15 times higher (Bino

et al. 2010), black bear (Ursus americanus) density was seen to be three times

higher in semi-urban areas, compared to densities in natural habitats because of

better foraging opportunities from crops, garbage, livestock and artificial feeding

(Beckmann & Berger 2003).

In India, several carnivore species such as wolves Canis lupus (Jhala & Giles 1991),

Asiatic lions Panthera leo (Saberwal et al. 1994; Vijayan & Pati 2002; Meena et al.

2011) and striped hyaenas Hyaena hyaena (Shilpi et al. 2009; Singh et al. 2010)

reside in human-dominated landscapes and feed on livestock. Tigers Panthera

tigris are also known to attack livestock in and around protected areas (Sekhar

1998; Karanth & Gopal 2005; Thirgood & Woodroffe 2005) .

Chapter 3 Diet of leopards in a human-dominated landscape

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However, of all the large carnivores in India, the leopard (Panthera pardus) is the

most adaptable, using a variety of habitats and feeding on a wide range of

domestic prey (Daniel 2009; Hunter et al. In Press). Their behavioral resilience

also allows them to live close to human settlements (Nasik Gazetteer 1838; Daniel

2009) where they prey on a range of domestic animals (Seidensticker et al. 1990).

In India, because laws prevent the killing of leopards and the people are

generally tolerant even of large dangerous wild animals, species like the leopards

do occur in human-use areas (Karanth et al. 2009; Karanth et al. 2010). Under

these circumstances the high density of domestic animals (Thornton et al. 2002;

FAO 2005) could form a stable and abundant prey base for leopard populations

to persist in human-dominated landscapes, far away from protected conservation

areas (Chapter 1) without periodic immigrations from the latter required to

sustain them. This conservation context, may provide unique conservation

opportunities to save viable meta-populations of species like the leopards entirely

outside the protected area system, despite India’s high population densities and

economic growth.

Although there is documentation of widespread occurrence of leopards across

India (Pati et al. 2004; Daniel 2009; Athreya et al. 2011), there have been very few

studies to assess their diet and prey availability in human-dominated landscapes.

In fact, the common notion is that the leopards are present in the human-use

landscapes because of lack of wild prey in the forested regions.

To better understand leopard diet and the abundance of prey in a rural, human-

dominated landscape, we analysed the diet of leopards, estimated available prey

densities and biomass present in a rural agricultural landscape in western

Maharashtra. Based on the results obtained, the factors that might be key

determinants of leopard abundances in human-dominated landscapes, and their

relevance as conservation tools for mitigating levels of leopard-human conflicts

are discussed.


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3.2 METHODS

3.2.1 STUDY AREA

The study was conducted in an irrigated valley in the Ahmednagar district

(19.576959 N 73.937123 E to 19.460715 N 74.089954 E) of western Maharashtra,

India. The area sampled for leopard scat (faeces) in this study covered 238 km2 of

an agricultural landscape largely dominated by croplands around the town of

Akole which has a population of ~ 20000 people. Approximately 80% of the

human population in the district is rural with the farming of sugar cane, millets,

and vegetables being the major source of livelihood. Rainfall varies from 1000 to

2000 mm per year. Census of India (2011) reports an average population density

for Ahmednagar district of 266 people/km2 in 2011. The nearest protected area

from the study site is Kalsubai Harishchandragarh Wildlife Sanctuary (299 km2),

situated 18 km away from the western edge of the study area (Figure 3.1).

Figure 3.1. Scats were collected in the intensive study area located in the Ahmednagar district, Maharashtra. The scat collection was carried out between December 2007 and April 2009 in the human-dominated irrigated landscape.


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The wild carnivores that occur in the study area are the leopard, striped hyaena,

golden jackal (Canis aureus), Bengal fox (Vulpes bengalensis), jungle cat (Felis chaus)

and rusty spotted cat (Prionailurus rubiginosus). No wild ungulate species have

been recorded. Many occupational groups live in this landscape but the

dominant group in this irrigated valley are the settled farmers who own land and

livestock. Additionally, pastoral, migratory shepherds with large herds of sheep

and goats arrive annually in the dry season to pasture on crop-residues in the

fields.

3.2.2. ESTIMATING DENSITY OF DOMESTIC ANIMALS IN THE STUDY

AREA

Information from government records on livestock density across the entire

district indicates an overall density of 176 livestock/km2 (Livestock census 2003

from the Directorate of Economics and Statistics, Planning Department,

Government of Maharashtra). This figure does not take into account the density

of feral/semi-feral dogs and cats, which are also a part of potential leopard diet.

Domestic dogs are reported in very high densities in many parts of the world,

from rural and urban areas in north American and Mexico (Daniels & Bekoff

1989) as well as in India (Hiby et al. 2011). In order to get a more detailed

overview of prey available within the study area, a random sample of resident

farmers (n = 77) were interviewed to obtain the species and number of all owned

domestic animals (Chapter 4). The density of houses were obtained by digitizing

all the houses in the sampled area (Chapter 4) and this along with the density of

domestic animals obtained from the interviews were used to calculate the density

of different domestic animal species.

3.2.3. DIET ANALYSIS

Scats (faeces) of large carnivore species were collected by walking trails typically

used by leopards such as foot paths, edges of fields, paved roads, dry stream

beds etc. These trails were identified using Google Earth online maps (Google

Earth Version 6.1.0.5001. [Software]) and were surveyed using three methods (i)

130 km of trails were walked a total of three times between December 2007 and


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April 2008, with a three week interval between each sampling session. (ii) a more

intensive sampling was carried out where 85 grid cells of 1 km2 each were

overlayed on Google Earth (Google Earth Inc. Version 6.1.0.5001. [Software]) and

an average of 2.37 ± 0.86 (sd) km of road/path within each cell was covered on

foot to search for scats. (iii) Furthermore, scats were collected opportunistically

from December 2007 to April 2009. All the three methods were used since apriori

information on where to locate leopard scats in a human-dominated landscape

was not available.

Two researchers walked on either side of the trail and all scats judged to be of

large carnivore origin based on size, shape and ancillary evidence like scrape

signs and tracks were collected, measured and stored in zip lock bags, with GPS

co-ordinates noted for location information. The scats were later transferred to a

polythene bag and part of the scat transferred into vials for storage in absolute

alcohol for subsequent DNA analyses (Navya et al. In Preparation). Visual

identification of scats is not always reliable (Farrell & Roman 2000) and at the

study site, domestic dogs which occur at high densities were seen to feed on

carcasses of livestock which could have biased the results. The diet analysis was

conducted only on scats whose species origin was confirmed by DNA analyses

and on scats that were collected at leopard scrape signs (Figure 3.2).

Figure 3.2. Leopard scat at a scrape at the side of a mud road at the study site in Akole.


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The scat analyses was carried out as described by Mukherjee & Goyal (1994) and

Mukherjee (2001) as well as in other diet studies of large cats (Karanth &

Sunquist 1995; Andheria et al. 2007; Odden 2007; Khorozyan et al. 2008). The

scats were washed and dried, the prey species were identified visually from

presence of claws or hoof parts and finally a microscopic study of 25 randomly

chosen hair samples mounted in DPX mountant as detailed in Mukherjee &

Goyal (1994) was carried out. Prey species identification was based on

comparison with reference slides of known hair samples from domestic animals

in the study site and from wild prey reference slides obtained from collections

maintained at the Centre for Wildlife Studies, Bangalore and Bombay Natural

History Society, Mumbai. Scats that were too degraded or with little prey remains

were not used in the analysis.

The frequency of occurrence of the different prey species (percent of total number

of scats they occur in) was first calculated. However, this variable (A) can be

misleading because smaller prey species contribute more to a ‘field collectible’

scat compared to a larger species (Floyd et al. 1978; Karanth and Sunquist 1995,

Klare et al. 2011). Based on feeding trials on captive mountain lions (Puma

concolor), Ackerman et al. (1984) derived a regression equation to obtain the

biomass of different prey species consumed as well as the relative number of

individuals consumed based on the ‘field collectible’ scats. Mountain lions are

similar in size to leopards and the method has been used previously for leopards

by (Karanth and Sunquist 1995; Andheria et al. 2007; Khorozyan et al. 2008).

The regression equation takes the form:

y = 1.98 + 0.35 x

where y is the correction factor based on number of field collectible scats

obtained for a given weight of prey species and x = average weight of prey

species. The relative biomass (D) and the relative number of prey species

consumed (E) were obtained using the equation

D = (AxY)/∑(AxY) x 100

E = (D/X)/∑(D/X) x 100.


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The amount of prey biomass (Khorozyan et al. 2008) available in the landscape

(Bprey = Dprey x Wprey) was obtained by using density estimates (Dprey) of the

4 most common prey species; domestic goats, dogs, calves and cats estimated

from interview data (Chapter 4). The average weight of the species (Wprey) was

obtained from a livestock veterinarian working in the region. Only calf weight

(not adult cattle) was used because information from compensation records

indicated that only one cow was attacked in three years at the study site but

calves were preyed on in relatively higher numbers (Chapter 4).

In order to assess the feedings habits of leopards in relation to what is available,

the Ivelev’s selectivity index (1961) was used

E = ri-pi ri+pi

where ri is the relative abundance of prey item i in the gut (as a proportion of

total gut contents), pi is the relative abundance of the same prey item in the

environment (Strauss 1979). E has a range from -1 to +1 where negative values

indicate that the particular prey item is avoided or not accessible and positive

values indicate that it is selected for or is more available.

3.3 RESULTS

Leopard scats which were confirmed using DNA analysis were collected

throughout the sampled area, including close to houses, on a diversity of trail

types including dirt and paved roads. The average distance of leopard scats from

nearest house was 213 m (range = 10 - 850 m), and from roads 140 m (range = 0 -

815 m). Two scats were even found on the main street of the large Akole town.

Among 265 scats that were collected, 80 were identified as leopard scats based on

the DNA analyses and 43 identified based on presence of tracks or scrapes.

Among these 123 leopard scats, 85 had recognisable remains of prey species, and

was used for diet analysis. The average diameter at the thickest section, of 110

intact leopard scats was 25.15 ± 5.2 (sd) mm (range 11.5 - 38.3mm). The scats


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contained a total of 131 prey items consisting of 11 prey species (Table 3.1). Fifty-

six percent of the scats contained one prey species, 21% had 2 species, 8% had 3

species, 3% had 4 species and 5 species were seen only in one scat.

Table 3.1. Diet of leopards in the Akole study area assessed from 85 scats collected from a human-dominated landscape between December 2007 and April 2009. The estimated figures reported in the Table are A which is the frequency of occurrence of the prey item in the scats, x is the average weight of the species in kilograms, Y is a correction factor for each prey species consumed by leopards obtained from Ackerman et al. (1984), D is the relative biomass found to be consumed by leopards (D) and E is the relative number of prey individuals consumed.

Prey species A % x(kg) Y(kg/scat) D(%) E

Primate sp. 0.77 10.00 2.33 0.70 0.27Civet sp. 2.31 2.00 2.05 1.85 3.61

Mongoose sp. 3.08 2.00 2.05 2.47 4.82Domestic pig 3.08 20.00 2.68 3.22 0.63

Bird sp. 3.85 1.00 2.02 3.03 11.84Sheep 5.38 30.00 3.03 6.38 0.83

Rodent sp. 6.92 0.50 2.00 5.41 42.25Goat 10.00 25.00 2.86 11.16 1.74Cow 10.77 40.00 3.38 14.23 1.39cat 15.38 2.00 2.05 12.33 24.09dog 38.46 18.00 2.61 39.24 8.52

100.00 100.00

Domestic animals (including dogs) constituted 86.56% of the prey biomass

consumed by leopards and the wild prey species present in the scats were civet,

rodent, primate, bird and mongoose (Table 3.1). In the case of rodents a higher

average weight of 500 gm (‘x’ in Table 3.1) was considered because of the

presence of the Lesser Bandicoot rat (Bandicota bengalensis) in the croplands. Dogs

were the most important prey species in the leopard diet, singly contributing

~40% of the biomass consumed.

Ivelev’s index which indicates how much the different prey species are consumed

in relation to availability shows that despite much higher biomass of goats and

calves present in the landscape, dogs and goats were preyed upon to a higher

extent by leopards either due to selection or increased availability (Figure 3.2;

Table 3.2).


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Figure 3.3. Diet selectivity based on scat analysis in leopards in Akole during December 2007-April 2009 based on the frequency of different prey types in scats in relation to availability of these prey types in the area. Species that show positive index values are more selected for/more available than species that have negative values.

Table 3.2: Density (numbers/km2) of different types of domestic animals in the study area which were obtained from interviews of a random sample of households conducted in Akole between September 2007 and September 2009.

N = 77 Buffalo Cowadult

Cowcalf

Goat Sheep Dog Cat Chicken

Average number per house(Range)

0.11(0 - 1)

2.7(0-18)

0.9(0-8)

2.9(0-40)

0.06(0-1)

0.40(0-5)

1(0-6)

1.8(0-50)

Density/km2 7 162 54 174 4 24 61 109Biomass/km2 2450 56700 2440 4350 120 432 108 109

If the density of the most common prey species (goat, calves, cats and dogs)

obtained from scat analysis is considered, the potential prey biomass for leopards

in the study area is 733000 kg/100 km2 (Table 3.2). This figure does not include

the biomass of adult cattle which were not considered because mainly calves are

predated upon by leopards (Chapter 4). If adult cattle are considered, they occur

at a density of 169/km2 and contribute an additional 5915000 kg/100km2

(average weight = 350 kg).

The regression equation from (Carbone & Gittleman 2002) which used data from

25 different carnivore species and regressed prey biomass with predator biomass,

estimate that 10,000 kgs of prey to be related to 90 kg of predator, irrespective of

-0.9000-0.6750-0.4500-0.2250

00.22500.45000.67500.9000

goat calf cat dog


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size of the predator. If the biomass of all the domestic mammals at the study site;

adults cattle, calves, goats, dogs and cats, are taken into account, they form

6670900 kgs/100 km2 of potential prey biomass and as per Carbone &

Gittleman’s (2002) equation this amount is capable of supporting 60 leopards/100

km2.

If the biomass of only the owned dogs and cats is considered, their biomass of

~54000 kgs/100 km2 can support a 45 kg predator at 10.8 individuals/100 km2

which is close to the density estimate of both, leopard and hyaenas (Chapter 2)

obtained at the study site (Table 3.3). That mainly dogs and cats are more

‘available’ or more ‘selected’ by leopards is probably because goats and calves are

protected by the farmers (Chapter 4).

3.4. DISCUSSION

The relationship between large felids and humans is a complex one, and the

spectrum of interactions range from fascination to fear (Loveridge et al. 2010a).

On the one hand, they are symbolised as flagship species whose conservation

helps protect vast wild areas because of their role as apex predators (Treves &

Karanth 2003). However, at the local level, where humans and large felids share

space, farmers face loss of property and human life and also have to deal with the

anxiety and lifestyle changes brought about by the presence of a large carnivore

(Treves & Naughton-Treves 2005). Retaliatory killings are an important cause of

large cat mortality the world over and in order to address this, an increasing

number of studies are focusing on human large cat conflict issues (Inskip &

Zimmermann 2009). Even though depredation on livestock is a widespread

occurrence (Linnell et al. 2012), domestic livestock usually form a small part of

large felid diet and complete dependency on domestic species has rarely been

observed. The biomass of livestock can be extremely high in human-dominated

areas, much more than that of wild prey in surrounding forest areas as is seen in

Brazil, Nepal and kenya (Schaller 1983; Seidensticker et al. 1990; Mizutani 1999).

Domestic animals are also much easier to attack because they lack anti-predatory

behaviour unlike their wild counterparts (Diamond 2002).


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This study for the first time reports that leopards (Chapter 1) in a rural Indian

landscape can subsist almost entirely on a diet of domestic animals and attain

reasonably high densities as well. Furthermore, despite the density of goats being

7 times that of domestic dogs, goats formed only 11% of the prey biomass of

leopards whereas dogs formed 40%. This is likely to be related to the lower

accessibility leopards have to goats compared to dogs because goats are generally

protected by the farmers. Domestic cats also appear to be very important prey in

the leopard’s diet, contributing 12% of the biomass consumed despite being

much smaller in size compared to dogs and goats. The density of livestock in

India is extremely high; for example, the sheep and goat density in 2007 obtained

from the Department of Agriculture, India (2010) is reported at 22/km2 and 43/

km2 respectively. At the study site the densities were much higher with 174

goats/km2 and 162 cows/km2. Thus for a wild carnivore, rural landscapes in

India can potentially be a prey rich areas with a staggeringly high biomass of

domestic prey species.

In natural ecosystems predator density is known to be strongly correlated to prey

biomass (Carbone & Gittleman 2002; Karanth et al. 2004a; Marker & Dickman

2005; Beckmann & Lackey 2008; Khorozyan et al. 2008; Bino et al. 2010). Based on

the conversion by Carbone & Gittleman (2002), the amount of total prey biomass

present at our study site could in theory support 10 times the number of leopards

than what is present. The reason why the density of leopards is lower despite

such a high biomass of prey is likely to be related to the lower availability of

domestic stock to leopards because they are protected by the farmers (Chapter 4)

and the fact that large stock are not predated upon by leopards. It should be

noted that most cattle at the study site are larger hybrid varieties and not the

smaller indigenous breeds.

The results show that the biomass (kg) of owned dogs and cats are sufficient

(Carbone & Gittleman 2002) to sustain the observed density of leopards (average

weight = 45 kg) and hyaenas. It should be noted however that although there is

no mention in literature of the striped hyaena attacking livestock, the local people


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in the study site report that hyaenas prey on dogs and calves but this could not

be verified.

The results also show that dogs are a very important food resource for leopards,

and their density at the study site is also very high. The proclivity of leopards

towards killing and eating dogs has been noted commonly in anecdotal literature

(Daniel 2009). Two studies carried out within protected areas in the states of

Maharashtra and Jammu & Kashmir report the importance of dog as a prey for

leopards (Edgaonkar & Chellam 2002; Shah et al. 2009). Domestic dogs are

ubiquitous in the Indian landscape with an estimated population of 25 million

(Menezes 2008) and occur at very high densities with one dog/36 people

(Menezes 2008). The domestic dogs in rural India tend to be attached to a house

and normally have formal owners, although they are often left to forage for

themselves and few attempts are made to vaccinate dogs or prevent pregnancy.

The only current method of controlling dog populations, which is mainly carried

out in urban areas, is where dogs are sterilised and then released back where they

were captured from (Hiby et al. 2011). Free-ranging domestic dogs in India are

known to represent a major public health problem with respect to zoonotic

transmission of diseases such as rabies. There are many ecological and health

reasons why controlling domestic dog populations in India is desirable, although

there are a range of social, cultural and legal obstacles to do so through direct

action.

The same obstacles also exist with respect to the options available to the wildlife

management authorities with respect to directly managing leopards in this

landscape. The question therefore arises to what extent leopards can be managed

indirectly, via controlling the abundance of their prey. It is also of interest to note

here that more people at the study site are attacked by rabid dogs than by

leopards (personal observation).

Studies on carnivores associated with human habitations have shown that food

resource associated with humans such as garbage, poultry, and waste play an


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important role in maintaining their populations at high densities (Beckmann &

Berger 2003; Bino et al. 2010). Thus, high levels of freely available organic waste is

likely to be a key factor in maintaining high densities of domestic and semi-feral

dogs. This abundant prey resource is likely to play a very important role in

allowing the persistence of some wild carnivore such as leopards and hyenas at

relatively high densities in human-dominated landscapes. The question arises as

to how they would respond to decreases in prey? Although Beckmann & Berger

(2003) and Bino et al. (2010) recommend that decreasing the food resources is the

most effective strategy at reducing urban/suburban fox and bear populations in

North America, this management strategy needs to be studied and evaluated in

rural landscapes in India.

The results of this diet study have revealed how leopards are able to maintain

themselves at relatively high densities in a human-modified landscape devoid of

any suitable wild prey species. Although large carnivore depredation on livestock

is a ubiquitous phenomena, the results from this study represents an extreme case

of leopard dependency on domestic and semi-feral animals for prey. On one hand

it is a positive testimony to the adaptability of leopards as well as to the generally

tolerant nature of the local society. However, high densities of leopards among

high density of people could potentially lead to serious conflict because of

increased encounters between humans and leopards. Given this close spatial

proximity between leopards and humans at the study site where all night time

attacks on livestock occur at homesteads, it is surprising that there have been no

incidents of human fatalities in the study area.

The leopard’s selection for less protected and commercially unimportant dogs

and cats means that their economic impact through predation on valuable

livestock is lower than expected. This implies that the level of conflict is largely

going to be driven by the local people’s fear of leopards foraging in the proximity

of their houses, as well as value of some dogs as pets, both sentiments which are

dependent on human’s perception towards the leopards.


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This work for the first time reports findings that are similar to other studies on

urban carnivores which reside in highly modified human-use landscapes and are

dependent on food associated with humans. This work also highlights how little

we know of the ecology of large carnivores outside protected areas. Although the

news is welcome and bodes well for many wildlife species, it also highlights the

urgent need for science-based management to deal with potentially conflict

causing species in human-use areas. The cultural tolerance of India people has to

be acknowledged and appreciated due to which many species of large carnivores

still persist despite a billion people. However, the management of perceptions of

the local people is extremely important so that conflict levels are not exacerbated.

These aspects are dealt with in the next two chapters of this thesis.


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Documents

CHAPTER 3 DIET OF LEOPARDS IN A HUMAN-DOMINATED LANDSCAPEshodhganga.inflibnet.ac.in/bitstream/10603/5431/11/11_chapter3.pdf · Asiatic lions Panthera leo (Saberwal et al. 1994; Vijayan