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Wildlife ranching including the hunting, collection, sales and husbandry of wild animals in captivity, is practised worldwide and is advocated as an approach towards the conservation of wild species. While many authors have explored the biological impacts of intensive wild population management, primarily with respect to disease transmission (especially in ungulates and fish), the evolutionary and demographic effects of wildlife ranching have been examined less intensively. We discuss this issue through the case of intensive wildlife management in southern Africa. The genetic consequences of this global practice, with an emphasis on Africa, were addressed by a motion passed at the 2016 IUCN World Congress- ‘Management and regulation of intensive breeding and genetic manipulation of large mammals for commercial purposes’. Here, we highlight concerns regarding intensive breeding programs used to discover, enhance and propagate unusual physical traits, hereafter referred to as ‘Intentional Genetic Manipulation’. We highlight how ‘Intentional Genetic Manipulation’ potentially threatens the viability of native species and ecosystems, via genetic erosion, inbreeding, hybridisation and unregulated translocation. Finally, we discuss the need for better policies in southern Africa and globally, regarding ‘Intentional Genetic Manipulation’, and the identification of key knowledge gaps.
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Conservation Genetics Resources (2019) 11:237–247
‘Intentional Genetic Manipulation’ asaconservation threat
Isa‑RitaM.Russo1 · SeanHoban2,10· PauletteBloomer3· AntoinetteKotzé4,5· GernotSegelbacher6·
IanRushworth7· CoralBirss8· MichaelW.Bruford1,9
Received: 11 July 2017 / Accepted: 10 January 2018 / Published online: 20 January 2018
© The Author(s) 2018. This article is an open access publication
Wildlife ranching including the hunting, collection, sales and husbandry of wild animals in captivity, is practised worldwide
and is advocated as an approach towards the conservation of wild species. While many authors have explored the biological
impacts of intensive wild population management, primarily with respect to disease transmission (especially in ungulates
and fish), the evolutionary and demographic effects of wildlife ranching have been examined less intensively. We discuss
this issue through the case of intensive wildlife management in southern Africa. The genetic consequences of this global
practice, with an emphasis on Africa, were addressed by a motion passed at the 2016 IUCN World Congress- ‘Management
and regulation of intensive breeding and genetic manipulation of large mammals for commercial purposes’. Here, we highlight
concerns regarding intensive breeding programs used to discover, enhance and propagate unusual physical traits, hereafter
referred to as ‘Intentional Genetic Manipulation’. We highlight how ‘Intentional Genetic Manipulation’ potentially threatens
the viability of native species and ecosystems, via genetic erosion, inbreeding, hybridisation and unregulated translocation.
Finally, we discuss the need for better policies in southern Africa and globally, regarding ‘Intentional Genetic Manipulation’,
and the identification of key knowledge gaps.
Keywords Genetic erosion· Hybridisation· Inbreeding· Wildlife· Selective breeding· Small populations· Southern
Africa· Translocation
Wildlife ranching entails the utilisation of non-domesticated
animals in captivity or in larger fenced areas (Nogueira and
Nogueira-Filho 2011). The industry’s value to conserva-
tion, along with its ecological sustainability and profitabil-
ity, is highly debated among conservationists (Nogueira and
Isa-Rita M. Russo and Sean Hoban are the Joint first authors.
Electronic supplementary material The online version of this
article ( contains
supplementary material, which is available to authorized users.
* Isa-Rita M. Russo
* Sean Hoban
1 School ofBiosciences, Cardiff University,
CardiffCF103AX, UK
2 Present Address: The Morton Arboretum, 4100 Illinois Route
53, Lisle, USA
3 Molecular Ecology & Evolution Programme, Department
ofGenetics, University ofPretoria, Private Bag X20,
Hatfield0028, SouthAfrica
4 National Zoological Gardens ofSouth Africa, PO Box754,
Pretoria0001, SouthAfrica
5 Department ofGenetics, University oftheFree State, PO
Box339, Bloemfontein9300, SouthAfrica
6 Department ofWildlife Ecology andManagement,
University ofFreiburg, 79106Freiburg, Germany
7 Ezemvelo KZN Wildlife, PO Box13053,
Cascades,Pietermaritzburg3202, SouthAfrica
8 CapeNature, Assegaaibosch Nature Reserve, Jonkershoek
Drive, Stellenbosch7599, SouthAfrica
9 Sustainable Places Institute, Cardiff University,
CardiffCF103BA, UK
10 National Institute forMathematical andBiological Synthesis
(NIMBioS), University ofTennessee, 1122 Volunteer
Boulevard, Knoxville, USA
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238 Conservation Genetics Resources (2019) 11:237–247
1 3
Nogueira-Filho 2011). The wildlife industry has grown rap-
idly over the past 10 years due to the high economic value of
wild animals across the globe, which includes sport hunting
in Europe, commercial ranching and the sales of American
bison (Bison bison Linnaeus, 1758) and ostrich (Struthio
camelus australis Gurney, 1868) in North America, ranching
for horn production in black and white rhinoceros (Diceros
binornis Linnaeus, 1758 and Ceratotherium simum Burchell,
1817),the trade of illegal bush meat in West Africa, and
legal trading in antelope since European settlers arrived
in Africa. In many regions, affected species once had vast,
inter-connected ranges. However when kept in enclosed
wildlife ranches, such species experience issues including
small population size, hybridisation, artificial selection and
breeding to create or enhance particular phenotypic traits
(see Fig.1). These practices potentially threaten the integrity
and viability of native species and ecosystems.
Here, we define wildlife ranching as the maintenance
and management (monitoring, feeding, culling, and trans-
location) of native/non-native animals within fenced land
for breeding, sales, hunting or wildlife viewing. Although
the ecological, evolutionary and economic risks associated
with an intensifying wildlife industry have been identified
in southern Africa by institutions such as the South African
National Biodiversity Institute (SANBI 2007), there are few
policies in place to regulate or mitigate them. Adherence to
best practices among wildlife ranchers seems to be patchy
(Dugmore 2013), while conservation agencies, tasked with
assessing the potential risks of selective breeding and trade
of wildlife resources, have voiced concerns about the genetic
integrity of individuals, populations and species (Nel 2015).
Here we focus on southern Africa due to recent and large
scale changes in practice in this region. Breeding opera-
tions in southern Africa have mainly focused on previously
unmanaged species such as Cape buffalo (Syncerus caffer
Sparrman, 1779), blue wildebeest (Connochaetes taurinus
Burchell, 1823), black wildebeest (Connochaetes gnou Zim-
merman, 1780), blesbok (Damaliscus pygargus phillipsi
Pallas, 1767), impala (Aepyceros melampus Lichtenstein,
1812) and sable antelope (Hippotragus niger Harris, 1838).
Legislative changes such as the private ownership of wildlife
in several African countries since the 1960s have resulted
in an increase in wildlife ranching, moving away from
traditional livestock farming (Lindsey etal. 2009). These
changes occurred in Namibia (1967), Zimbabwe (1960 and
1975) and in South Africa at different times depending on
the province (Lindsey etal. 2009). Recently, the 2016 IUCN
World Congress passed a motion focusing on ‘Intentional
Genetic Manipulation’, which was precipitated by the case
of southern Africa, but highlights the global scope of this
issue ( With
advances in biotechnology, intensification of land use, and
continued use of wildlife for viewing, breeding and hunting,
the issue of genetic manipulation of wildlife can be expected
to be increasingly raised in other countries around the world.
Here we (1) summarise the historical situation and current
‘Intentional Genetic Manipulation’ practices in the southern
African wildlife industry, (2) describe the novel challenges
posed by these practices with examples, including paral-
lels with the related practice of aquaculture and (3) discuss
potential decisions-making processesto ensure the future
sustainable use of wildlife resources. We focus primarily
on genetic concerns but recognise that non-genetic analyses
are important (e.g. Cloete etal. 2015), since there are many
aspects of wildlife ranching that may raise concern.
While many genetic concerns have been described (Lind-
sey etal. 2006) in aquaculture (Lafferty etal. 2015), evolu-
tionary implications of wildlife ranching (including changes
in effective population size, inbreeding, rapid spread of
novel alleles, sterility of hybrids, inbreeding, and outbreed-
ing depression) have received less attention but remain cru-
cial factors in conservation. We evaluate the current status
of wildlife ranching in southern Africa as an example to
highlight these concerns. We include a description of the
industry and relevant legislation in South Africa for context,
as this case is well-documented and timely, but where appro-
priate we highlight global connections and implications.
South Africa
South Africa, as a signatory to the Convention on Biological
Diversity (CBD), has committed to implement reasonable
measures for achieving biodiversity conservation and sus-
tainable use of wildlife resources. The South African Con-
stitution mandates the government to develop and implement
legislative measures for environmental protection. Close to
9% of the country’s land is included under terrestrial pro-
tected areas. However, much of South Africa’s semi-natural
land is under private ownership with approximately 9000
properties covering an area of more than 170,000km2
Fig. 1 A black (left) and common impala on the right. Picture: Agri-
connect. (Color figure online)
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239Conservation Genetics Resources (2019) 11:237–247
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(Taylor etal. 2016). Approximately 20% of South Africa’s
land (~ 1,220,000km2) is used for wildlife activities includ-
ing hunting, ecotourism and live trade (Taylor etal. 2016),
of which 6% is used for intensive breeding. The majority
of South Africa’s ‘biodiversity estate’ is not secured in for-
mally protected areas. For example, protected areas within
the historical distribution of bontebok (Damaliscus pygar-
gus pygargus Pallas, 1767) contain fewer than 500 individu-
als, whereas several thousandindividuals are under private
ownership (Radloff etal. 2015; Fig.2). South Africa is not
unique in this regard, for instance in the USA there are cur-
rently around 500,000 American bison in captive commer-
cial populations on about 4000 privately owned ranches of
which only 4% (20,000) are in conservation herds (Hedrick
The total turnover of the wildlife industry in South Africa
was estimated at USD 8.1billion in 2015 including USD
119million from wildlife auctions (Janovsky 2015). The
World Tourism Organisation (WNWTO) has reported that
global wildlife tourism is growing at a rate of about 10% per
year. Individual animals can be extremely valuable,recently
a kudu bull (Tragelaphus strepsiceros Pallas, 1766) was sold
for USD 629,800, a sable antelope for USD 1,809,000, and a
roan antelope (Hippotragus equinus sp. Saint-Hilaire, 1803)
for USD 636,500 (Table1). These prices seemingly reflect
an increasing demand for ‘quality animals’ with exceptional
morphological features including horn length, body size,
coat colour and coat pattern (Cloete etal. 2015) and the will-
ingness of wildlife ranchers or investors to pay these prices.
Some wildlife owners have recently been deriving a large
proportion of their income from unusual colour and other
morphological variants (Nel 2015). Sophisticated market-
ing strategies are employed to highlight ‘quality’ gene-pools
(see Animals are now
regarded as a financial investment, stimulating the estab-
lishment of new wildlife ranches every year (Cloete etal.
RSA Provinces
Bontebok (Damaliscuspygarus pygarus)
Blesbok (Damaliscuspygarus phillipsi)
Fig. 2 Historical ranges of bontebok (light blue) and blesbok (grey) in South Africa. Red lines indicate provincial boundaries. Data represent
known species distributions as of 30 March 2017 (Birss etal. 2017). (Color figure online)
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240 Conservation Genetics Resources (2019) 11:237–247
1 3
2015). Trophy hunting also drives markets (and is linked
to evolutionary changes) in other parts of the world, where
individuals of a certain coat colour, trophy size or shape are
more likely than others to be removed from the population
(Allendorf and Hard 2009).
South Africa currently has an estimated 20million head
of game on private land, whereas 50 years ago, a census of
all game numbered approximately 575,000 (Oberem 2015;
Taylor etal. 2016). Therefore, numerically there is currently
more wildlife in SA than there has been since the large-scale
exterminations by outbreaks of bovine pleuropneumonia
(1850), rinderpest (1896), and hunting by explorer-hunters/
settlers (Bond etal. 2004). Parallel increases in wildlife pop-
ulation size have been observed in many parts of the world
(e.g. Henrruzo and Martinez-Jauregui 2013). This increase
in numbers, however, does not necessarily contribute to
biodiversity/conservation. The Red List of South African
mammals highlighted this issue where many mammal popu-
lations are not ‘wild’ and therefore do not contribute to the
IUCN criteria, and thus would not receive the same protec-
tion as wild populations (Taylor etal. 2016). Populations
containing inter and intra-specific hybrids (as are increas-
ingly appearing on wildlife ranches) are also not given equal
protection in many countries including the US Endangered
Species Act (Allendorf etal. 2004).
The role oflegislation
Legislation on nature conservation and wildlife manage-
ment is often locally devolved, as it is in South Africa,
where it has been developed and implemented at both
national and provincial levels. Legislative standardisation
can thus prove challenging: conditions under which species
may be translocated, released and bred may differ among
regions, and in general, breeding under intensive condi-
tions is poorly regulated. In South Africa, State owned
protected areas capture and sell excess animals, so wild
animals can sometimes be bought to bring new genetic
material to breeding ventures. In addition, protected areas
may have their own breeding projects focusing on con-
servation breeding principles [e.g. the disease-free buffalo
project of the South African National (SAN) Parks], and
these animals may also enter into private ownership.
In South Africa, recent government-initiated stake-
holder forums have emphasised the importance of the
wildlife economy and resulted in a recent policy shift
where game ranching is now recognised as both legiti-
mate and an important driver of the country’s agricul-
tural economy and future wellbeing. Consequently, the
Department of Agriculture, Forestry and Fisheries (DAFF)
recently amended the Animal Improvement Act of 1998
(SA Government Gazette 2016) to include 12 wildlife
species in addition to domestic species, confirming that
game ranching is nationally supported. This amendment
was published without any consultation with major role
players in the wildlife industry as required by law (Naude
2016). Further discussion around the implications of the
new legislation and expansion of the wildlife economy
for long-term biodiversity management and conserva-
tion is therefore needed between all parties involved. In
a similar vein, ostrich has been recognised as a domestic
speciesby the USDA (United States Department of Agri-
culture) and has been included in the Agriculture Cen-
sus since 2002 ( The global
implications of legislation and expansion of the wildlife
Table 1 Average price trends and record wildlife auction prices for commonly traded species (most prices reflect adult bulls) adapted from
Cloete etal. 2015
Values in parentheses refer to horn length in inches for the animals that were sold for these record prices. Prices are given in US Dollars (USD)
using an exchange rate of 14.92
Wildlife species Price trend 2013–2015 Record price Wildlife species Price trend
Record price
Blue wildebeest 234–348 16,750 Kudu 737–4020 629,800 (66)
Golden blue wildebeest 38,190–67,000 180,900 Kudu/black 15,410–100,500 100,500
King blue wildebeest 167,500 871,000 Gemsbok 361–455 2680
Cape Buffalo 20,100–134,000 11,792,000 (55) Red Gemsbok 24,120–268,000 636,500
East African Buffalo 134,000–187,600 670,000 Roan 24,120–37,520 636,500 (31)
Blesbok 107–234 670 Sable 2747–6231 154,100
Blesbok/white 187–710 Sable (Zambian) 67,000–154,100 1,809,000
Blesbok/white saddlebacked 281,400 Springbok 127–147 871
Blesbok/yellow 3819–67,000 100,500 Springbok/black 368–670 2412
Impala 107–589 60,300 (27.5) Springbok/coffee – 174,200
Impala/black 16,348–46,900 214,400 Springbok/Kalahari 388–1407 8713
Impala/saddle-backed 46,900–284,750 502,500
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241Conservation Genetics Resources (2019) 11:237–247
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economy for biodiversity management therefore needs
careful consideration.
Examples fromthewildlife industry
Wildlife breeding has recently focused on finding and
perpetuating rare or novel morphs or forms(for exam-
ple, black vs. common impala; see Table2; Fig.1). These
morphs or forms do not confer any selective advantage on
the individuals, and are highly likely to have negative con-
sequences at the individual and population level (Hetem
etal. 2009). Rare colour morphs may have a recessive or
epistatic nature such that the morph will not be observed
in ‘carriers’ (Anderson etal. 2009).
The interface between farmed and natural land is very
likely to be porous since biosecurity in wildlife ranches is
not 100% effective (e.g. Grobler etal. 2011) and as such,
alleles at high frequencies in ranched animals could poten-
tially circulate undetected in natural populations, espe-
cially if recessive. Selection against desirable phenotypes
(unnatural selection) may decrease survival in the wild
(Allendorf and Hard 2009). For example, the colour and
structure of an animal’s pelt are associated with adap-
tation to the thermal environment. Hetem etal. (2009)
reported that black springbok forage less in winter because
the metabolic cost of homeothermy is lower, but may be
disadvantaged during hotter periods. In contrast, white
springbok will be more protected from solar heat load but
less able to meet the energy cost of homeothermy in winter
(Hetem etal. 2009). Metabolic costs may therefore par-
tially explain the rarity of springbok colour morphs in the
wild. Colouration in mammals is especially important in
crypsis, in which (1) the body colour resembles or matches
the natural background of the environment that varies with
season and age or (2) where colour patterns on the body
match patterns of light and dark in the surrounding habitat
(Hetem etal. 2009). In a more recent example, two inde-
pendent loss-of-function mutations in a Wrangel Island
mammoth at the locus of FOXQ1 have been observed
(Rogers and Slatkin 2017). These independent mutations
confer a satin coat phenotype which result in translucent
fur but normal pigmentation (Rogers and Slatkin 2017).
Challenges andpotential decision‑making
Selective breeding
Ranchers are increasingly carrying out ‘Intentional Genetic
Manipulation’ for desirable traits such as larger horns for tro-
phies, colour morphs and bigger animals for meat production.
There has been much interest in the production of game meat
in South Africa and Namibia over the last 50years (Taylor
etal. 2016) with 1350 tonnes of game meat consumed (Taylor
Table 2 Known desirable colour variants and other variants of ‘wild-type’ animals which have been sold at recent auctions
Species Colour variants Other variants
Blesbok Apache, bronze, coffee, copper, curly hair (woolly), skilder,
red, speckled, top deck, dappled, masked, painted, saddle-
backed, silver, white, white saddle-back, yellow
Buffalo White Disease free buffalo, east African, east African × southern
African, horn and body size
Eland King cape, white, skilder Cape eland, Livingstone’s, horn length and number of stripes
Impala Black, black-backed, black-nosed, grey, midnight, royal,
saddle-backed, white, white-flanked, white painted
East African × southern African impala (horn length)
Lechwe Red, yellow Horn length, cross with waterbuck
Kudu Black, brown, white, zebra-striped Horn length, cross with nyala
Nyala Cold adapted nyala, horn length, cross with kudu
Gemsbok Dappled, golden, ivory, red, white, yellow, skilder, cardinal,
Heartwater gemsbok, Kalahari, horn length
Reedbuck Horn length
Roan Western Africa × southern Africa roan (horn length)
Sable Golden Malawian sable, Matetsi Tanzanian, Zambian, West Zam-
bian, various crosses, horn length
Springbok Black, blue, coffee, copper, cream, damara, dappled, king,
ivory, painted, royal, white
Heartwater springbok, Kalahari
Blue Wildebeest Gold with markings, golden (tuli), king (including marking
variants), golden king
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242 Conservation Genetics Resources (2019) 11:237–247
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etal. 2016) and 450 tonnes of wild meat exported annually
during the early 2000s (National Agricultural Marketing
Council, NAMC 2006). ‘Intentional Genetic Manipulation’
can lead to genetic erosion due to founder effect, genetic drift
and inbreeding, potentially resulting in the fixation of delete-
rious alleles that may be co-inherited with anthopogenically-
desired traits (Frankham etal. 2010). Loss of heterozygosity
and allelic diversity may impact on a species’ evolutionary
potential and the reproductive potential of captive stock.
Some of these traits such as coat colour may be genetically
linked to behavioural changes (Jacobs etal. 2016). Genetic
exchange between farmed and wild populations could result
in substantial alteration of local allele frequencies in natu-
ral populations, decreasing short-term fitness and long-term
evolutionary potential as shown in Atlantic salmon (Perrier
etal. 2013). Unintentional selection is also likely to occur on
wildlife ranches due to the absence of predators, the practices
of supplementary feeding and water provision, and the provi-
sion of veterinary care. The diminution of natural selection
may encourage traits or behaviours that are maladaptive in
the wild (Frankham etal. 2010). In both plants and animals,
managed populations have converged on a ‘domestication
syndrome’, featuring sets of traits that may be beneficial in
captivity (Wright 2015).
Management decisionsinclude the implementation of barri-
ers or buffer zones between ranched and wild populations as
seen in the case of buffalo and cattle and monitoring of both
gene pools using molecular markers (Hansen etal. 2012).
Guidelines for breeding, population isolation and transloca-
tion should be developed after scientific investigation and
determination of their feasibility, social acceptability and
effectiveness. Small scale implementation of trial manage-
ment plans could be performed or an adaptive management
approach could be taken to establish which practices best
conserve genetic variation and fitness. The fisheries industry
often performs careful evaluation of the genetic status of
their stock and of the genetic contact between stocked and
wild populations (Begg etal. 1999).
Sound policy must be underpinned by scientific informa-
tion. There is an urgent need to understand the underlying
genetic basis of the traits that are currently being selected on
wildlife ranches and to determine how allele frequencies dif-
fer between ranched and wild populations. This knowledge
can be achieved through analysis of candidate genes, experi-
ments and/or by using shared records on breeding outcomes
from the ranchers, though we recognise that the genetic basis
of some traits will be more difficult than others to docu-
ment (Hoban etal. 2016). There is now a broader knowledge
base on the genetic underpinning of coat colour in wild and
domestic animals (e.g. Anderson etal. 2009), which can
be expanded upon. Additional data regarding colour genes
are given in the Supplementary materials. For an illustra-
tion of four different colour gene types and a description
of the primary colour genes in horses see Supplementary
material 1 (Table1) and 2, respectively. Policy needs to be
co-developed in an open, transparent, and fair fashion. This
should include thedevelopment ofregulatory frameworks
tofindthe right balance between biodiversity and economic
interest (Cook etal. 2013).
Small populations
Effective management of small or disconnected populations
has been identified as a core problem in conservation biology
since the inception of the discipline. In addition to genetic
issues, small populations often feature breakdown of normal
behaviours, and demographic instability with high extinc-
tion potential. Small populations on wildlife farms are also
subject to the frequent removal of individuals for hunting or
breeding. In such populations, a few males may dominate
reproduction within a population or several subpopulations
via the deliberate use of stud animals (Garnier etal. 2001).
Such issues are likely to be especially problematic in many
southern African wildlife species, regardless of whether they
are found on wildlife ranches, since many of these species
have historically featured very large populations distributed
over vast areas (see Figs.2, 3; Birss etal. 2017).
Traditional approaches include well-planned breeding and
translocations in addition tokeepingdetailed records (stud-
books) which includegenetic data e.g. results fromparent-
age analyses (Leus etal. 2011). For example, transloca-
tion records have enabled better management of Alpine
ibex (Capra ibex Linnaeus, 1758) populations (Biebach
and Keller 2009). Genetic monitoring can be performed to
establish status and trends and help decide when to bring in
animals from other populations (e.g. Iyengar etal. 2007).
A private reserve of scimitar-horned oryx (Oryx dam-
mah Cretzschmar, 1827) in the United Arab Emirates has
recently been evaluated for its genetic importance to the
whole species (El Alqamy etal. 2012). Population viability
analysis can be coupled with monitoring to help model,
understand and predict the future consequences of differ-
ent management strategies (Pierson etal. 2015). Software
that combines elements of natural population simulations
(e.g. Vortex; Lacy 2000) and population management (e.g.
PmX; Lacy etal. 2012) can also be applied. Several online
data recording systems now exist to help with these efforts:
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243Conservation Genetics Resources (2019) 11:237–247
1 3
for example, the South African Stud Book and Animal
Improvement Association (, and
the Independent Wildlife Registering Authority system
Policy and guidance is needed to develop and promote
best practices for sustainability, similar to goals for zoo
populations (Lacy etal. 2012). Zoo populations are care-
fully managed to alleviate small population problems, with
frequent transfer of individuals for mating (Lacy 2013). Sci-
entists and wildlife ranchers should be encouraged to co-
develop metapopulation and population management plans
for each species, as has been done for wild dogs, lions and
other predators (Miller etal. 2015). This may, for example,
include guidelines for the number of individuals needed to
be translocated to maintain genetically healthy populations
after taking into account the costs and benefits. Another way
to alleviate negative effects in small/fragmented populations,
especially populations that have been strongly reduced by
anthropogenic activities, may be to allow managed gene
exchange between two or more closely related populations
or even, in extremis, subspecies (Frankham 2015; Frankham
etal. 2017). There are numerous arguments for and against
this approach and each case should be evaluated on its
own merits. General considerations include (i) limiting
gene exchange to within the same taxon, (ii) considering
whether exchanging populations are adapted to similar envi-
ronments, (iii) testing whether the populations have fixed
chromosomal differences and (iv) evaluating whether gene
flow has occurred between the populations within the recent
past (500years has been suggested; Frankham etal. 2011).
Conservationists and scientists should therefore attempt to
evaluate the risks of outcrossing for the species of interest.
Data from previous studies showed that 93% of such events
resulted in fitness benefits (improved growth rates, fertil-
ity,and survival) for the outcrossed population. Only nine
cases showed deleterious effects and one study showed mild
outbreeding depression (Frankham 2015).
Hybridisation andtranslocation
Hybridisation can and does occur in nature between closely
related species (e.g. black wildebeest and blue wilde-
beest; Grobler etal. 2011), subspecies (bontebok and bles-
bok, D. p. phillipsi; Van Wyk etal. 2013) or genetically
RSA Provinces
Blue wildebeest (Connochaetestaurinus)
Black wildebeest (Connochaetes gnou)
Fig. 3 Historical distribution ranges of blue (light blue) and black
wildebeest (grey).The overlap between blue (right) and black (left)
wildebeest distributions is indicated by the darker blue colour. Red
lines indicate provincial boundaries. Data represent known species
distributions as of 30 March 2017 (Birss etal. 2017). (Color figure
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244 Conservation Genetics Resources (2019) 11:237–247
1 3
differentiated populations. Human-mediated hybridisation
may occur due to changes in the distribution and abundance
of a species, removal of landscape or behavioural barriers,
or introduction of non-native species (Allendorf etal. 2001).
Between 130,000 and 167,000 animals (http://www.wtass.
org/Default.aspx; Dry 2013) are estimated to be translocated
annually in South Africa but these numbers may be underes-
timates (Taylor etal. 2016). Due to the rapid rate of ongoing
translocations in wildlife farming, documentation is scarce.
Hybridisation may be deliberate, accidental or both.
Deliberate hybridisation is known between greater kudu
(Tragelaphus strepsiceros Pallas, 1766) and nyala (T. angasii
Angas, 1849), waterbuck (Kobus ellipsiprymnus Ogilby,
1833) and lechwe (K. leche Gray, 1850) and southern-west-
ern sable (Hippotragus equinus equinus Saint-Hilaire, 1803)
and roan (H. e. koba, Gray 1872). The historical distribu-
tion of black and blue wildebeest overlapped but hybridisa-
tion may have been prevented by the presence of plentiful
con-specific mates and no restriction to movement (Fig.3;
Supplementary material3). However, farming both spe-
cies on the same land with few or no con-specific mates
may encourage hybridisation (Grobler etal. 2011; Dalton
etal. 2014) and this is a general risk of game farming (e.g.
Blanco-Aguiar etal. 2008). Hybridisation can have posi-
tive effects such as heterosis (hybrid vigour) and genetic
rescue of inbred populations. Crossing closely related spe-
cies/subspecies may be a solution for taxa that have been
reduced due to human impact (Frankham etal. 2017). How-
ever, negative effects of hybridisation include loss of local
adaptations and unique traits, reduced fertility and offspring
viability which can lead to extinction (Wolf etal. 2001), and
outbreeding depression which has, for example, been docu-
mented in southern Africa (e.g. greater kudu-nyala; Dalton
etal. 2014). Furthermore, species are routinely introduced
beyond their historical distributions (different climatic con-
ditions/vegetation/ecosystems), e.g. black wildebeest in
Namibia (Lindsey etal. 2006) and Botswana (I Rushworth,
personal communication, Ezemvelo KZN Wildlife). We
therefore propose that the climate requirements of the focal
species should be understood and matched to current/future
climate at the translocation site by measuring key climate
parameters (see the IUCN Guidelines for Reintroductions
and Other Conservation Translocations).
In order to conserve biodiversity by safeguarding the genetic
integrity of each species/subspecies (sensu the Convention
on Biological Diversity’s Aichi Target 13, http://www.cbd.
int/sp/targets/), national and provincial policy needs to clar-
ify which species may be kept on the same land, for example
prohibiting co-enclosure of closely related species/domes-
ticated relatives to prevent hybridisation events (Hedrick
2009; Grobler etal. 2011, see Supplementary material 3
and 4). Other decisions include isolating suspected hybrid
groups in adequate, regularly inspected enclosures. When
hybridisation is deemed detrimental, no translocations
should be allowed until reliable genetic tests to screen for
hybrids have been conducted. If hybrids are found in a
population, and sufficient genetic variation exists in non-
hybrid populations, owners may be encouraged to remove
all unwanted animals with compensation from the govern-
ment (see wolf-dog hybridisation; Vilà etal. 2003). Another
option is to incentivise or mandate wildlife ranchers to reg-
ister populations of species where the taxonomic integrity
of that species has been preserved (based on management
history and genetic tests) and to tightly control introductions
into and translocations from these populations. In contrast,
some may argue that actions such as deliberate admixture
by introducing individuals from related subspecies may
be necessary to recover population fitness even though the
taxonomic integrity of a species may be temporarily dis-
rupted (Stowell etal. 2017). This issue of genetic rescue to
prevent species from extinction is debated in the literature
(Frankham 2015; Stowell etal. 2017). However, here we
refer to the issue of deliberate subspecies admixture where
there is no threat of extinction or reduced population fitness
to either of the subspecies. Therefore we do not recommend
this as a first course of action for viable species/subspecies
unless a risk assessment has been carried out to assessthe
likelihood of outbreeding depression.
Data should be maintained for each individual and all
actions (for example, translocations) should be recorded.
It is also important to conduct educational campaigns for
landowners and officials on genetic principles/issues such
as hybridisation.
Genetic techniques and software tools can help to identify
hybrids and determine the extent of hybridisation in order
to inform policy makers (Supplementary material 3 and 4).
Local molecular genetic facilities in countries such as South
Africa, Botswana and Namibia are readily available but the
methods carried out should be standardised and laboratories
should be encouraged to exchange baseline reference data
where mutually beneficial. Such services are increasingly
available worldwide.
A crucial need is to establish and agree upon the ‘natural’
ranges (including historical, current and translocated ranges)
of wildlife species and the genetic variants (including sub-
species) within them. Genetic and other data within species
need to be available to identify evolutionarily significant
units (ESUs) and management units (MUs) which allow for
the preservation of genetic variation within species. It is also
important to identify the appropriate units for conservation
in order to maintain ecological and evolutionary processes
(Funk etal. 2012). For example, the South African Depart-
ment of Environmental Affairs (DEA) is producing range
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245Conservation Genetics Resources (2019) 11:237–247
1 3
maps for all indigenous species (e.g. Birss etal. 2017) and
this activity is ongoing worldwide in pursuance of Article
7 of the Convention on Biological Diversity. Ecological
and genetic information should be integrated into range
definitions, as well as historical distributions. Combining
range maps and current knowledge of breeding outcomes
can inform the level of translocation that may be considered
detrimental to the species and this knowledge may improve
decisions regarding translocations.
Future technologies
Given new technologies such as CRISPR/CAS9 gene edit-
ing, it is possible that genetically modified organisms will
soon appear in the game ranching industry, as it has already
in aquaculture (Howard etal. 2004). A regulated approach
needs to be formulated for the implementation of these
methods since genetically modified genetic material could
thus enter wild populations, via unintended consequences.
For example, in Howard etal. (2004) it has been reported
that genetically modified male medaka fish have an over-
whelming mating advantage while their offspring suffer
from a survival disadvantage relative to the wild type. This
mechanism will ultimately lead to population extinction
because of the viability disadvantage. More recent examples
of genetic modification involve CRISPR and eradication of
invasive species such as rats (Owens 2017). Potentially any
species could be subject to CRISPR modification, though it
is not clear when it may be applied to large mammals.
In summary, we suggest the following key steps for this
1. New guidelines, policy and legislation, informed by sci-
entific evidence and expert wildlife ranching knowledge,
should be developed and enforced globally, including
in southern Africa, via collaboration between wildlife
ranchers, scientists, community members, government,
and management authorities.
2. A lack of evidence remains in key areas such as the
genetic basis of commonly selected traits, knowledge of
range distributions, species’ boundaries, impact of unin-
tentional selection, and the required effective population
size to manage wildlife species. Partnerships between
scientists and ranchers, individually and on large scale
through shared, open data, can help to obtain such
knowledge. Scientists also need to develop and broad-
cast case studies of representative outcomes.
3. Specific recommendations based on the long-term moni-
toring of genetic effects within intensively managed
populations are needed.
4. Educational/outreach material is needed on the conser-
vation, environmental, social, and economic dimensions
of ‘Intentional Genetic Manipulation’, including online
educational resources(Hoban etal. 2013).
5. Open recording of animal breeding and movement
across all wildlife ranches and other conservation areas
with the integration of genetic tools should be encour-
aged to track translocations and provide knowledge on
stock genetic diversity and species’ divisions.
6. Yearly forums for involved stakeholders should be held
to share information, facilitate communication, and host
training sessions.
Acknowledgements This manuscript is an outcome from a workshop
held at the National Zoological Gardens (NZG) of South Africa, jointly
organised with ConGRESS (Conservation Genetic Resources for Effec-
tive Species Survival, European Commission Framework 7 Coordina-
tion and Support Action project) to transfer knowledge and tools in
conservation genetics to management professionals and policy makers
in South Africa. The meeting was funded by the National Research
Foundation (NRF) under the Knowledge, Interchange & Collabora-
tion (KIC) Fund for Scientific Events/Travel Grants. SH was partly
supported by the National Institute for Mathematical and Biological
Synthesis (NIMBioS).
Compliance with ethical standards
Conflict of interest The authors declare that they have no conflict of
Open Access This article is distributed under the terms of the Creative
Commons Attribution 4.0 International License (http://creativecom-, which permits unrestricted use, distribu-
tion, and reproduction in any medium, provided you give appropriate
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... The same species and African wildlife biomass and diversity are now the target of a multimillionaire tourism industry that makes wildlife a highly profitable business for private operators and African countries [18]. This has led to an increased role in active management of some mammal species, including a growing occurrence of translocations as a means to repopulate or restock protected areas that have lost their native stock of some of the most charismatic species [19][20][21][22], to realize the optimal management for threatened taxa (e.g., [23,24] in the case of the Cape mountain zebra) or for the ecological restoration of particular regions (e.g., [25,26]). Active management operations are often valuable from the conservation point of view, but some of them have been inappropriate or even damaging to the genetic integrity of autochthonous populations of particular species (cf. ...
... Active management operations are often valuable from the conservation point of view, but some of them have been inappropriate or even damaging to the genetic integrity of autochthonous populations of particular species (cf. [27] for mitigation translocation cases), such as in the case of the wildebeest (see [28][29][30]), or whole communities (for evaluation of ungulate translocations, especially in Southern Africa, see [21,31,32]). ...
... In the present contribution, we aimed to critically review translocations of some mammals in Africa as a conservation tool, partly using giraffes as a case-study because of the current progress in understanding their diversification across Africa and emphasizing some causes of concern relating the possible negative outcomes for the conservation of evolutionary history in a unique continent. Following an increasing emphasis on financial viability, many extralimital species-i.e., species that historically did not occur in an area-or stocks of atypical phenotypes (under "intentional genetic manipulation" [21]) were introduced into private and public reserves to increase public experiences with the intention of increasing ecotourism attractions [33]. Although translocations are not a totally new tool in African conservation, it seems that many current projects are being realized primarily for financial reasons rather than conservation considerations. ...
Full-text available
Ecotourism can fuel an important source of financial income for African countries and can therefore help biodiversity policies in the continent. Translocations can be a powerful tool to spread economic benefits among countries and communities; yet, to be positive for biodiversity conservation, they require a basic knowledge of conservation units through appropriate taxonomic research. This is not always the case, as taxonomy was considered an outdated discipline for almost a century, and some plurality in taxonomic approaches is incorrectly considered as a disadvantage for conservation work. As an example, diversity of the genus Giraffa and its recent taxonomic history illustrate the importance of such knowledge for a sound conservation policy that includes translocations. We argue that a fine-grained conservation perspective that prioritizes all remaining populations along the Nile Basin is needed. Translocations are important tools for giraffe diversity conservation, but more discussion is needed, especially for moving new giraffes to regions where the autochthonous taxa/populations are no longer existent. As the current discussion about the giraffe taxonomy is too focused on the number of giraffe species, we argue that the plurality of taxonomic and conservation approaches might be beneficial, i.e., for defining the number of units requiring separate management using a (majority) consensus across different concepts (e.g., MU-management unit, ESU-evolutionary significant unit, and ECU-elemental conservation unit). The taxonomically sensitive translocation policy/strategy would be important for the preservation of current diversity, while also supporting the ecological restoration of some regions within rewilding. A summary table of the main translocation operations of African mammals that have underlying problems is included. Therefore, we call for increased attention toward the tax-onomy of African mammals not only as the basis for sound conservation but also as a further opportunity to enlarge the geographic scope of ecotourism in Africa.
... Although colour variant breeding has attracted the attention of both local and international investors, it has also received criticism from key stakeholders and role players in the industry. Some have questioned the conservation consequences of selecting for colour variations that are infrequently seen in the wild (Russo et al. 2019). Specific concerns regarding the intensive breeding of wildlife have been raised, which include the distortion of the natural process of evolution, the loss of genetic diversity due to isolation and inbreeding, the fixation of deleterious alleles, weakened resilience to environmental changes and reduced reproductive fitness of captive stock (Miller et al. 2016;Russo et al. 2019). ...
... Some have questioned the conservation consequences of selecting for colour variations that are infrequently seen in the wild (Russo et al. 2019). Specific concerns regarding the intensive breeding of wildlife have been raised, which include the distortion of the natural process of evolution, the loss of genetic diversity due to isolation and inbreeding, the fixation of deleterious alleles, weakened resilience to environmental changes and reduced reproductive fitness of captive stock (Miller et al. 2016;Russo et al. 2019). Consequently, the colour variant market has declined considerably in recent years. ...
... org/). Genetic research concerning the golden wildebeest will be able to facilitate breeding management and will also enable game ranchers to make informed decisions regarding the viability of golden wildebeest ranching (Russo et al. 2019). This study, therefore, aimed to (i) identify single nucleotide polymorphisms (SNPs) that are significantly associated with coat colour in blue wildebeest by performing a genome-wide association study (GWAS), (ii) identify whether any of the marker sequences that flank the significant SNPs mapped to genes with known functional roles in pigmentation, (iii) identify gene combinations that could play a role in determining coat colour in blue wildebeest, and (iv) elucidate the mode of inheritance of the golden coat colour variation. ...
The golden wildebeest, a colour variant of the blue wildebeest (Connochaetes taurinus taurinus), is one of the most common colour variant animals that South African game ranchers breed for. Based on pedigree records, the prevailing hypothesis is that the golden coat colour is an autosomal recessive trait. However, the genetic basis of the golden coat colour phenotype has not been investigated. A genome-wide association study (GWAS) was performed with 14 624 single nucleotide polymorphisms (SNPs) to identify putative candidate genes involved in blue wildebeest pigmentation. A total of 374 SNPs were significantly associated with coat colour (P value ≤ 0.001). Five of these SNPs mapped to four different Bos taurus orthologous genes that could be involved in pigmentation based on previous literature reports. An additional three SNPs with an association P value ≤ 0.05 mapped to well-known pigmentation genes and were also considered. Based on the reported biological function of the genes, the myosin VC (MYO5C), myosin VIIA (MYO7A), solute carrier family 6 member 3 (SLC6A3), solute carrier family 28 member 2 (SLC28A2), dopamine receptor D2 (DRD2), frizzled class receptor 4 (FZD4) and tyrosinase (TYR) genes are promising candidate genes that could contribute to coat colour determination in blue wildebeest. Based on the number of identified candidate genes, gene–gene interaction analysis, and their determined mode of inheritance, coat colour in blue wildebeest could rather be a quantitative threshold trait. This study provides a basis for further investigation on the genetic mechanisms of pigmentation in blue wildebeest.
... Wildlife ranching, where wild animals are managed in fenced areas, is practiced in various regions around the world, including North America, Europe and Africa [1][2][3][4][5]. Whether wildlife ranching is beneficial for conservation is often debated [6][7][8]. ...
... Whether wildlife ranching is beneficial for conservation is often debated [6][7][8]. While wildlife ranching preserves habitat that would otherwise be converted for other land-use types [9], it also comes with the pitfalls of small population sizes and fragmentation of populations due to fencing that could result in loss of genetic diversity of many species, not just those of economic interest on the ranch [5,10]. Furthermore, wildlife ranching often involves intensive breeding of wildlife, or intentional genetic manipulation [5], for a single, or multiple, traits. ...
... While wildlife ranching preserves habitat that would otherwise be converted for other land-use types [9], it also comes with the pitfalls of small population sizes and fragmentation of populations due to fencing that could result in loss of genetic diversity of many species, not just those of economic interest on the ranch [5,10]. Furthermore, wildlife ranching often involves intensive breeding of wildlife, or intentional genetic manipulation [5], for a single, or multiple, traits. This can exacerbate the fixation or loss of alleles at a rate much higher than would occur through drift or natural selection [11]. ...
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Wildlife ranching, although not considered a conventional conservation system, provides a sustainable model for wildlife utilization and could be a source of valuable genetic material. However, increased fragmentation and intensive management may threaten the evolutionary potential and conservation value of species. Disease-free Cape buffalo (Syncerus caffer caffer) in southern Africa exist in populations with a variety of histories and management practices. We compared the genetic diversity of buffalo in national parks to private ranches and found that, except for Addo Elephant National Park, genetic diversity was high and statistically equivalent. We found that relatedness and inbreeding levels were not substantially different between ranched populations and those in national parks, indicating that breeding practices likely did not yet influence genetic diversity of buffalo on private ranches in this study. High genetic differentiation between South African protected areas highlighted their fragmented nature. Structure analysis revealed private ranches comprised three gene pools, with origins from Addo Elephant National Park, Kruger National Park and a third, unsampled gene pool. Based on these results, we recommend the Addo population be supplemented with disease-free Graspan and Mokala buffalo (of Kruger origin). We highlight the need for more research to characterize the genetic diversity and composition of ranched wildlife species, in conjunction with wildlife ranchers and conservation authorities, in order to evaluate the implications for management and conservation of these species across different systems.
... Game ranches partake in various wildlife-based activities, including breeding, recreational hunting, live trade, and can have a direct impact on the genetic diversity of wildlife. In their review, Russo et al. (2019) highlight the dearth of genetic monitoring and appreciation of genetic consequences in game populations among wildlife ranchers, despite evidence of activities that may genetically affect the concerned populations in the industry. Recreational or trophy hunting is used as an option to manage population numbers and curb illegal hunting, as well as provide incentives to private landowners and state entities to participate in wildlife conservation (Di Minin et al., 2021). ...
... Other surveys record introduced game animals in areas where they had not previously occurred (Ehlers-Smith et al., 2017;Zungu et al., 2020) because of these perceived benefits. Game farmers in South Africa have in certain cases deliberately promoted interspecific and intraspecific hybridization to obtain rare phenotypes or color variants (Lindsey et al., 2007;Russo et al., 2019;Selier et al., 2018). Furthermore, certain traits may be favorable (Taylor et al., 2016), and farmers may be selectively breeding for these and in doing so reduce the genetic variation within populations through artificial selection (Lindsey et al., 2007;Selier et al., 2018). ...
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Genetic diversity is a fundamental measure of a populations ability to adapt to future environmental change. Subpopulations may carry unique genetic lineages that contribute to fitness and genetic diversity of species across their distribution range. Therefore, considerations, or lack thereof, of genetic diversity in wildlife management practices may result in either population persistence or extinction over time. Some management tools may pose a greater risk to a species' survival than others when populations are impacted. In South Africa, there has been great interest to translocate animals, sometimes with little consideration to the potential impacts on the species and/or populations survival. Thus, there is a need to collate scientific information to better inform decision‐making and review these management practices and their effects on populations. Here, we focus on three antelope species, the blue duiker (Philantomba monticola), oribi (Ourebia ourebi), and tsessebe (Damaliscus lunatus). We review the genetic status of each species across South Africa, with regards to taxonomy, genetic diversity and population structure, threats that may compromise the genetic diversity within species and across populations, conservation management actions and how they may compromise or benefit the genetic status and lastly make recommendations on possible alternative management actions and future research to inform conservation policy and sustainable management practice. In South Africa, there has been great interest to translocate animals, sometimes with little consideration for the genetic integrity of the species. Thus, in this review, we collate scientific information to better inform decision‐making and review these management practices and their effects on species integrity.
... and has actively engaged in a revised wording for post-2020 CBD genetic targets (especially Target 4 on species and Target 13 on genetic diversity, see Hoban et al., 2020;Laikre et al., 2021) as well as including genetic diversity in the Key Biodiversity Area standards (KBA Standards and Appeals Committee, 2020). CGSG has also organized a number of conservation genetics meetings at international conferences as well as producing and contributing to scientific literature relevant for decision making Russo et al., 2019). ...
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The Coalition for Conservation Genetics (CCG) brings together four eminent organizations with the shared goal of improving the integration of genetic information into conservation policy and practice. We provide a historical context of conservation genetics as a field and reflect on current barriers to conserving genetic diversity, highlighting the need for collaboration across traditional divides, international partnerships, and coordinated advocacy. We then introduce the CCG and illustrate through examples how a coalition approach can leverage complementary expertise and improve the organizational impact at multiple levels. The CCG has proven particularly successful at implementing large synthesis‐type projects, training early‐career scientists, and advising policy makers. Achievements to date highlight the potential for the CCG to make effective contributions to practical conservation policy and management that no one “parent” organization could achieve on its own. Finally, we reflect on the lessons learned through forming the CCG, and our vision for the future.
... This facilitation can produce unintended effects on local populations and on the balance of species within communities, frequently favoring domesticated species and species with broad ecological niches, rapid dispersal, and high rates of reproduction (McKinney and Lockwood 1999). Another more recent process of pruning involves genetic manipulations for suppression or sterilization of pests to foster the growth of more desirable species (Russo et al. 2019). ...
... Despite the typical genetic implications associated with small captive populations (e.g. inbreeding, genetic drift: Allendorf et al. 2008;Russo et al. 2018) and artificially manipulating a population, to date there are no reports or studies that have shown that wildlife ranching has compromised the genetic integrity of their wild relatives (although see Van Wyk et al. 2013). However, potential risks do exist, namely through changes in the genetic composition, evolutionary trajectory and adaptive potential of wild populations through the introgression with captive populations. ...
Technical Report
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Life on earth relates directly to the diversity of genes in space and time. The genomes of organisms encode the basic biological structures that define them, and allows individuals to survive and persist through time in changing environments. To this end, DNA can best be described as the foundation of all life on earth, it is recognised as an important component of biodiversity (together with species diversity and ecosystem diversity) and the importance of maintaining genetic diversity has been highlighted by the Convention on Biological Diversity. Genetic diversity can be defined as the amount of variation observed in the DNA of distinct individuals, populations or species. The maintenance of this diversity is of the utmost importance as genetic diversity allows species or populations to adapt to an ever-changing environment. Risks to genetic diversity include genetic erosion through e.g. habitat fragmentation and habitat loss, hybridisation and inbreeding, unsustainable use of species, disease via translocations of individuals, and species extinctions. Genetically modified organisms also present a risk through the escape of undesirable genes into native populations. To recognise and minimise genetic erosion, genetic diversity should be monitored over time for a given species or population. The value of long-term monitoring is well recognised; however, globally, there is a lack of temporal genetic datasets, as well as a lack of genetic diversity indicators and thresholds, with which data can be compared (such indicators have been developed, but lack specific genetic input). To date within South Africa, few short-term monitoring studies have been carried out that explicitly monitor temporal shifts in the genetic diversity of South African taxa. These studies serve as a baseline and provide valuable insight into ongoing and potential future monitoring programmes. The indicators to establish the status and to track trends for genetic diversity are not yet established. Using a case study to test indicators, trends at the national level were tracked by interrogating several high level metrics as indicators of genetic erosion. The case study analyses showed that the greatest historical impacts to phylogenetic richness for reptiles are in the northeast, southwest and the coastal margin of KwaZulu-Natal Province. For the case study, there are several hotspots of elevated genetic erosion in the last few decades, in particular northern KwaZulu-Natal Province, south-eastern Mpumalanga Province, northern Gauteng Province and southern and northern Limpopo Province. The case study highlights the types of indicators that could be used, but additional indicators and other case studies should be examined in the future. To promote future genetic monitoring programmes and studies, a national genetic monitoring framework is required that outlines how to prioritise species for monitoring, what genetic markers and metrics to use, how often populations should be monitored. Moreover, such a framework would not only outline how genetic diversity can be monitored at a population or species level, but be extended to include monitoring for genetic erosion at the national level.
... Despite the typical genetic implications associated with small captive populations (e.g. inbreeding, genetic drift: Allendorf et al. 2008;Russo et al. 2018) and artificially manipulating a population, to date there are no reports or studies that have shown that wildlife ranching has compromised the genetic integrity of their wild relatives (although see Van Wyk et al. 2013). However, potential risks do exist, namely through changes in the genetic composition, evolutionary trajectory and adaptive potential of wild populations through the introgression with captive populations. ...
... Although wild deer populations of Alberta have low hybridization rates, other populations may vary. Captive populations such as cervid farms are unlikely to stock both species in the same enclosure, but farmed animals can sometimes contribute to local allele frequencies and gene flow via escapes from the facility (Russo et al., 2019). ...
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Hybridization of mule deer (Odocoileus hemionus) and white‐tailed deer (O. virginianus) appears to be a semi‐regular occurrence in western North America. Previous studies confirmed the presence of hybrids in a variety of sympatric habitats but their developing molecular resources limited identification to the earliest, most admixed generations. For this reason, estimates of hybrid production in wild populations often rely on anecdotal reports. As well, white‐tailed deer populations’ continued encroachment into historically mule deer‐occupied habitats due to changes in land use, habitat homogenization, and a warming climate may increase opportunities for interspecific encounters. We sought to quantify the prevalence and extent of hybrid deer in the prairies of western Canada using a SNP assay with enhanced discriminating power. By updating the available molecular resources, we sought to identify and characterize previously cryptic introgression. We also investigated the influence of various parameters on hybridity by way of logistic regression. We observed overall hybridization rates of ~1.0%, slightly lower than that reported by previous studies, and found white‐tailed‐like hybrids to be more common than their mule deer‐like counterparts. Here, we build upon past studies of hybridization in North American deer by increasing hybrid detection power, expanding sample sizes, demonstrating a new molecular resource applicable to future research, and observing asymmetrical directionality of introgression.
The real‐world application of climate change adaptation practices in terrestrial wildlife conservation has been slowed by a lack of practical guidance for wildlife managers. Although there is a rapidly growing body of literature on the topic of climate change adaptation and wildlife management, the literature is weighted towards a narrow range of adaptation actions and administrative or policy recommendations that are typically beyond the decision space and influence of wildlife professionals. We developed a menu of tiered adaptation actions for terrestrial wildlife management to translate broad concepts into actionable approaches to help managers respond to climate change risks and meet desired management goals. The menu includes actions related to managing wildlife populations as well as managing wildlife habitat. We designed this resource to be used with the Adaptation Workbook, a structured decision‐support tool for climate adaptation. We describe real‐world examples in which managers have used the Wildlife Adaptation Menu to integrate climate adaptation considerations into wildlife management and conservation projects. Our examples illustrate how a comprehensive and structured menu of adaptation approaches can help managers brainstorm specific actions and more easily and clearly communicate the intent of their climate adaptation efforts. We present a structured, comprehensive menu of climate change adaptation strategies and approaches for managers of terrestrial wildlife. This menu can help managers define specific actions to implement and communicate the intent of their actions.
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As a result of processes such as habitat loss and overharvest, many species persist in small, isolated populations that experience reduced fitness, decreased evolutionary potential, and increased extinction risk. The goal of species conservation is to restore genetic diversity and adaptive potential caused by isolation and small population size. For populations trapped in an extinction vortex, habitat protection may be inadequate for successful conservation. Alternative actions such as deliberate admixture by introducing individuals from related subspecies may be necessary to recover population fitness. While there is precedent for such actions, admixture temporarily disrupts the taxonomic integrity of a species. Concerns for the taxonomic integrity or “naturalness” of a species may prevent the use of active interventions that involve admixture and transient hybrid gene pools even though extinction may be imminent. We explore the cultural barriers to using tools such as genetic rescue and make suggestions for overcoming those barriers. We focus mainly on examples from animals, but the same evolutionary processes are ongoing in other life forms and are subject to the same cultural barriers.
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Woolly mammoths (Mammuthus primigenius) populated Siberia, Beringia, and North America during the Pleistocene and early Holocene. Recent breakthroughs in ancient DNA sequencing have allowed for complete genome sequencing for two specimens of woolly mammoths (Palkopoulou et al. 2015). One mammoth specimen is from a mainland population 45,000 years ago when mammoths were plentiful. The second, a 4300 yr old specimen, is derived from an isolated population on Wrangel island where mammoths subsisted with small effective population size more than 43-fold lower than previous populations. These extreme differences in effective population size offer a rare opportunity to test nearly neutral models of genome architecture evolution within a single species. Using these previously published mammoth sequences, we identify deletions, retrogenes, and non-functionalizing point mutations. In the Wrangel island mammoth, we identify a greater number of deletions, a larger proportion of deletions affecting gene sequences, a greater number of candidate retrogenes, and an increased number of premature stop codons. This accumulation of detrimental mutations is consistent with genomic meltdown in response to low effective population sizes in the dwindling mammoth population on Wrangel island. In addition, we observe high rates of loss of olfactory receptors and urinary proteins, either because these loci are non-essential or because they were favored by divergent selective pressures in island environments. Finally, at the locus of FOXQ1 we observe two independent loss-of-function mutations, which would confer a satin coat phenotype in this island woolly mammoth.
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The devolution of user rights of wildlife in southern Africa has led to a widespread land-use shift from livestock farming to game ranching. The economic advantages of game ranching over livestock farming are significant, but so too are the risks associated with breeding financially valuable game where free-ranging wildlife pose a credible threat. Here, we assessed whether the conservation potential of game ranching, and a decentralized approach to conservation more generally, may be undermined by an increase in human-wildlife conflict. We demonstrate that game rancher tolerance towards free-ranging wildlife has significantly decreased as the game ranching industry has evolved. Our findings reveal a conflict of interest between wealth and wildlife conservation resulting from local decision-making in the absence of adequate centralized governance and evidence-based best practice. As a fundamental pillar of devolution-based natural resource management, game ranching proves an important mechanism for economic growth, albeit at a significant cost to conservation.
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Shared signaling pathways utilized by melanocytes and neurons result in pleiotropic traits of coat color and behavior in many mammalian species. For example, in humans polymorphisms at MC1R cause red hair, increased heat sensitivity, and lower pain tolerance. In deer mice, rats, and foxes, ASIP polymorphisms causing black coat color lead to more docile demeanors and reduced activity. Horse (Equus caballus) base coat color is primarily determined by polymorphisms at the Melanocortin-1 Receptor (MC1R) and Agouti Signaling Protein (ASIP) loci, creating a black, bay, or chestnut coat. Our goal was to investigate correlations between genetic loci for coat color and temperament traits in the horse. We genotyped a total of 215 North American Tennessee Walking Horses for the 2 most common alleles at the MC1R (E/e) and ASIP (A/a) loci using previously published PCR and RFLP methods. The horses had a mean age of 10.5 years and comprised 83 geldings, 25 stallions, and 107 mares. To assess behavior, we adapted a previously published survey for handlers to score horses from 1 to 9 on 20 questions related to specific aspects of temperament. We utilized principle component analysis to combine the individual survey scores into 4 factors of variation in temperament phenotype. A factor component detailing self-reliance correlated with genotypes at the ASIP locus; black mares (aa) were more independent than bay mares (A_) (P = 0.0063). These findings illuminate a promising and novel animal model for future study of neuroendocrine mechanisms in complex behavioral phenotypes.
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Population fragmentation is threatening biodiversity worldwide. Species that once roamed vast areas are increasingly being conserved in small, isolated areas. Modern management approaches must adapt to ensure the continued survival and conservation value of these populations. In South Africa, a managed metapopulation approach has been adopted for several large carnivore species, all protected in isolated, relatively small, reserves that are fenced. As far as possible these approaches are based on natural metapopulation structures. In this network, over the past 25 years, African lions (Panthera leo) were reintroduced into 44 fenced reserves with little attention given to maintaining genetic diversity. To examine the situation, we investigated the current genetic provenance and diversity of these lions. We found that overall genetic diversity was similar to that in a large national park, and included a mixture of four different southern African evolutionarily significant units (ESUs). This mixing of ESUs, while not ideal, provides a unique opportunity to study the impact of mixing ESUs over the long term. We propose a strategic managed metapopulation plan to ensure the maintenance of genetic diversity and improve the long-term conservation value of these lions. This managed metapopulation approach could be applied to other species under similar ecological constraints around the globe.
The country is gearing up to get rid of rats, possums, stoats and other invasive predators by 2050. Is it a pipe dream?
Uncovering the genetic and evolutionary basis of local adaptation is a major focus of evolutionary biology. The recent development of cost-effective methods for obtaining high-quality genome-scale data makes it possible to identify some of the loci responsible for adaptive differences among populations. Two basic approaches for identifying putatively locally adaptive loci have been developed and are broadly used: one that identifies loci with unusually high genetic differentiation among populations (differentiation outlier methods) and one that searches for correlations between local population allele frequencies and local environments (genetic-environment association methods). Here, we review the promises and challenges of these genome scan methods, including correcting for the confounding influence of a species' demographic history, biases caused by missing aspects of the genome, matching scales of environmental data with population structure, and other statistical considerations. In each case, we make suggestions for best practices for maximizing the accuracy and efficiency of genome scans to detect the underlying genetic basis of local adaptation. With attention to their current limitations, genome scan methods can be an important tool in finding the genetic basis of adaptive evolutionary change.