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Management of game species may involve a risk of alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from farms or those belonging to distant geographical areas are introduced to increase population density or trophy "quality". In Spain, red deer (Cervus elaphus) from different European subspecies have been introduced to increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land-owners from importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some critical step in the production or commercialization process may be a good model to apply in protecting genetic properties of exploited species.
Animal Biodiversity and Conservation 26.2 (2003)
© 2003 Museu de Ciències NaturalsISSN: 1578–665X
Forum – 81
Carranza, J., Martínez, J. G., Sánchez–Prieto, C. B., Fernández–García, J. L., Sánchez–Fernández, B., Álvarez–
Álvarez, R., Valencia, J. & Alarcos, S., 2003. Game species: extinction hidden by census numbers.
Biodiversity and Conservation
, 26.2: 81–84.
Game species: extinction hidden by census numbers
.— Management of game species may involve a risk of
alteration of their genetic properties. Local adaptations may be disrupted if artificially selected individuals from
farms or those belonging to distant geographical areas are introduced to increase population density or trophy
“quality”. In Spain, red deer (
Cervus elaphus
) from different European subspecies have been introduced to
increase the size of trophies (antlers) of local populations. Legislation against these introductions is not effective
for various reasons, and once the individuals are in the Iberian peninsula it is virtually impossible to prevent their
spreading throughout the whole territory without a genetic tool to distinguish between autochthonous and
foreign specimens. We have developed such a genetic test and propose a strategy to dissuade land–owners from
importing foreign deer. Since deer are bred mainly for their antlers, our strategy is based on an agreement with
the National Trophy Body in Spain which rejects trophies from foreign populations. Rejection decreases the value
of the trophy so that it becomes more profitable to produce autochthonous deer. Using such a strategy at some
critical step in the production or commercialization process may be a good model to apply in protecting genetic
properties of exploited species.
Key words: Game species, Red deer, Genetic variability, Hybridization, Conservation, Trophy.
Especies de caza: procesos de extinción ocultos tras elevados tamaños de censo.—
La gestión de las especies de
caza puede conllevar riesgos de alteración de sus propiedades genéticas. Las adaptaciones locales pueden
deteriorarse si ejemplares producidos mediante selección artificial en granjas o procedentes de áreas geográficas
distantes, son introducidos para aumentar la densidad poblacional o la "calidad" de los trofeos de caza. En
España, se han introducido ejemplares de ciervo ibérico (
Cervus elaphus
) procedentes de distintas subespecies
europeas para aumentar así el tamaño de las cuernas (trofeos de caza) de las poblaciones autóctonas. La
legislación contra este tipo de introducciones no es eficaz por diversos motivos y, una vez introducidos los
ejemplares en la península ibérica, es prácticamente imposible prevenir su dispersión por todo el territorio sin
contar con herramientas genéticas que permitan diferenciar los ejemplares autóctonos de los foráneos. Nosotros
hemos desarrollado un test genético para este fin, y hemos propuesto una estrategia para disuadir a los
propietarios de llevar a cabo la importación de ejemplares foráneos. Puesto que los ciervos se crían
fundamentalmente por su cornamenta como trofeo de caza, nuestra estrategia se ha basado en un acuerdo con
la Junta Nacional de Homologación de Trofeos de Caza, para que ésta rechace los trofeos pertenecientes a
ejemplares foráneos. Este rechazo reduce el valor de los ejemplares procedentes de otras poblaciones y favorece
la producción de ciervo autóctono. Sugerimos que la utilización de estrategias de este tipo en puntos clave de
procesos de producción o comercialización, puede ser un buen modelo a aplicar para proteger las propiedades
genéticas de las especies sujetas a explotación por el hombre.
Palabras clave: Especies de caza, Ciervo ibérico, Variabilidad genética, Híbridos, Conservación, Trofeos cinegéticos.
(Recieved: 9 IV 03; Conditional acceptance: 10 VI 03; Final acceptance: 10 VII 03)
Game species:
extinction hidden by census numbers
J. Carranza, J. G. Martínez, C. B. Sánchez–Prieto,
J. L. Fernández–García, B. Sánchez–Fernández,
R. Álvarez–Álvarez, J. Valencia & S. Alarcos
82 – Forum Carranza et al.
J. Carranza, C. B. Sánchez–Prieto, B. Sánchez–Fernández, R. Álvarez–Álvarez, J. Valencia & S. Alarcos, Cátedra de
Biología y Etología, Fac. de Veterinaria, Univ. de Extremadura, 10071 Cáceres, España (Spain).
J. G. Martínez, Dept. de Biología Animal y Ecología, Fac. de Ciencias, Univ. de Granada, 18071 Granada, España
J. L. Fernández–García, Dept. de Zootecnia, Fac. de Veterinaria, Univ. de Extremadura, 10071 Cáceres, España
Corresponding author: J. Carranza
Animal Biodiversity and Conservation 26.2 (2003) Forum – 83
In many natural areas, hunting is a traditional
economic activity that may be fully compatible
with conservation of autochthonous game if sus-
tainable management practices are established.
However, in view of the fact that many game
species have a wide distribution and large
populations, it is often considered that hunting
and other related management practices can be
continued without the need to take ecological and
genetic parameters into account. Indeed, the grow-
ing economic interest in hunting promotes prac-
tices that aim to increase census size as well as to
improve (from a human point of view) some of the
animal traits, but such measures may endanger the
conservation of other natural features of the spe-
cies or populations. A good example of this is the
risk of hybridization after individuals are released
into natural populations for hunting purposes.
In general, hybridization as the result of
human release of farm–reared individuals or
exotic species or subspecies is a serious con-
servation problem, particularly among ex-
ploited animal species. The generally nega-
tive consequences of hybridization have been
widely acknowledged and reviewed (RHYMER
& SIMBERLOFF, 1996; ALLENDORF et al., 2001),
and are related to the reduction of fitness in
hybrids, the distortion of the genetic struc-
ture of populations and the disruption of
locally co–adapted gene complexes. Hatch-
ery–reared fishes, such as the Iberian brown
trout are a clear example. The introduction
of hatchery trout is genetically homogenising
the populations in the Iberian peninsula, dis-
torting ancestral patterns of genetic varia-
tion (MACHORDOM et al., 1999). Further exam-
ples can be seen in farm–reared game spe-
cies. It is simple and frequent practice on
farms to hybridise different subspecies, artifi-
cially selecting individuals with the desired
phenotypes (see
or After their
release, they may genetically contaminate the
locally–adapted wild populations with foreign
or artificially–selected genotypes. Farm deer,
for instance, are selected for release into natu-
ral populations for hunting purposes accord-
ing to antler size, as larger antlers represent
more highly valued trophies. As a consequence
of this practice, throughout Europe autoch-
thonous deer are hybridising with released
specimens which may be foreign or artifi-
cially–selected. This may account for the hy-
brid red deer subspecies, originally occurring
in Central Europe, which clearly jeopardises
the genetic integrity of each subspecies. Al-
though it is important, this problem is more
easily overlooked than the case of hybrids
arising from the introduction of exotic spe-
cies or their escape from farms or enclosures,
as in the case of the introgression of sika
deer (
Cervus nippon
) genes into the gene
pool of native Scottish red deer (
GOODMAN et al., 1999), or the hy-
bridization between white–tailed deer
Odocoileus virginianus
) and mule deer
Odocoileous hemionus
), or between exotic
red deer and elk (
Cervus canadensis
) in some
areas of the United States (DERR, 1991, ON-
The problem affecting European red deer
has already reached the Iberian subspecies
Cervus elaphus hispanicus
). Deer with larger
antlers are more profitable for owners of hunt-
ing estates, which encourages them to intro-
duce specimens from other European subspe-
cies into their properties. The introduced indi-
viduals can reproduce and hybridise with local
deer, and are permitted to be moved within
Spain and Portugal. On some estates, non-
autochthonous deer have intentionally been
hybridised with Iberian species under control-
led conditions, and hybrids may be purchased
by other estates to “improve” the quality of
the trophies in their populations. This practice
represents a silent but true extinction risk for
the Iberian red deer subspecies.
After hunting a big stag, the trophy class is
determined from a rate table based mainly on
antler size and width and number of tines. Tro-
phies are ranked and given prizes (gold, silver
and bronze medals). The ranking of trophies is
controlled by the Spanish Trophy Measurement
Body (Junta Nacional de Homologación, JNH),
which depends on the Ministry of the Environ-
ment. In the present study, a strategy to preserve
Iberian red deer genetic identity has been devel-
oped, with possible application to other similar
cases. The specific objective of the present project
was to provide the JNH with genetic markers to
identify trophies belonging to foreign deer. Two
types of genetic markers were developed. The
first is a dominant multilocus marker, that is,
presence/absence of bands depending on the sub-
species studied (similar to DNA “fingerprinting”
but by PCR amplification) and, the second is a
variant of the RFLP–PCR assays (codominant
marker) using different restriction enzymes. These
two procedures show a range of different geno-
types as a result of subspecific polymorphisms
(Fernández–García et al., unpublished data). The
JNH has decided to apply this test to trophies and
those proving to come from introduced deer will
be rejected from the Spanish ranking. Rejected
trophies will lose their value and it is expected
that owners will thus be dissuaded from import-
ing foreign deer. Although the rejection of such
trophies may represent a setback for the eco-
nomic activity on some estates, it is considered
that promoting the production of autochthonous,
wild–reared red deer will be beneficial for big–
game producers in general, since Iberian red deer
could be promoted as an exclusive product to
international hunters. Conservation of many natu-
ral areas in Spain depends on the adequate ex-
ploitation of natural resources, including hunt-
84 – Forum Carranza et al.
ing. Increasing the value of natural products may
contribute to conservation if their exploitation is
more compatible with the preservation of
biodiversity than alternative uses of the land,
such as livestock or agriculture.
Other game species are equally threatened. Roe
deer (
Capreolus capreolus
) is also being introduced
from foreign populations. The wild boar (
Sus scrofa
is being crossed with the domestic pig to increase
the number of offspring per litter. It is produced
under controlled conditions and the hybrids are
released to the wild. Both cases are big–game
species and the same strategy could be applied as
there are trophies which are submitted to the JNH.
Genetic markers for these are currently being de-
veloped. However, there are other well-known ex-
amples such as the red partridge (
Alectoris rufa
which is hybridised on farms to provide thousands
of individuals for the increasing demand for mas-
sive hunting. In these cases, the “trophy–rejection”
strategy is not applicable, but some other type of
control can surely be implemented.
Although the examples presented here refer
to game species, similar guidelines may be used
in other conservation tasks regarding exploited
species all over the world. A key to the present
project was to identify a bottleneck in the man-
agement process of a species or its products, and
to design a strategy which in some way would
determine the quality of the original product in
agreement with competent authorities.
The authors wish to thank JNH, the CIC delega-
tion in Spain, and the many people who collabo-
rated by providing deer samples. Spanish Minis-
try of the Environment, "Fundación Biodiversidad"
Government of Extremadura and project
REN 2001–1524 from Ministerio de Ciencia y
Tecnología contributed to financial support.
WENBURG, J. K., 2001. The problems with
hybrids: setting conservation guidelines.
, 16: 613–622.
DERR, J. N., 1991. Genetic interactions between
white–tailed and mule deer in the south–
western United States.
J. Wildl. Manage.
55: 228–237.
ABERNETHY, K. & PEMBERTON, J. M., 1999. Intro-
gression through rare hybridization: a ge-
netic study of a hybrid zone between red
and sika deer (Genus
) in Argyll, Scot-
, 152: 355–371.
ALMODOVAR, A. & PLA, C., 1999. Allozyme diver-
sity in brown trout (
Salmo trutta
) from Central
Spain: genetic consequences of restocking.
Freshwater Biology
, 41: 707–717.
1991. Report and recommendations on game
farming and ranching of big game in On-
tario: implications for native wildlife and
RHYMER, J. M. & SIMBERLOFF, D., 1996. Extinction
by hybridization and introgression.
Annu. Rev.
Ecol. Syst
., 27: 83–109.
... Anthropogenic hybridization, defined here as humanmediated gene flow between individuals from different species, subspecies or evolutionary units, in red deer has proved to be relatively frequent throughout Europe (review in Iacolina et al., 2019). However, there is still a knowledge gap concerning its extent in many European countries, including the Iberian Peninsula (Portugal and Spain), where introductions of red deer from Central, Northern and Eastern Europe have been reported since, at least, the middle of the twentieth century (Carranza, 2003;Vingada et al., 2010). Anthropogenic hybridization in Iberia is mainly focused on improving the trophy, through crossbreeding with higher performance individuals from Central, Northern, and Eastern Europe, traditionally classified as different subspecies (C. ...
... It is noted, however, that the methodology used in this study to assess nuclear admixture only distinguishes native from non-native individuals until the second-generation backcross (Figure 2), which in fact may be an underestimation of the real status of hybridization levels (McFarlane and Pemberton, 2019). Indeed, this overall result (nuclear and mitochondrial DNA information) was expectable given the previous reports and in situ observations showing that translocations of non-native red deer to the Iberian Peninsula have occurred since, at least, the middle of the twentieth century (Carranza, 2003;Vingada et al., 2010). Thus, the introgression of non-native mitochondrial DNA haplotypes together with the degree of admixture suggested by NEWHYBRIDS (Figure 5) is consistent with past introductions of non-native red deer followed by frequent crossbreeding with native individuals. ...
... The preservation of the native genetic characteristics of the Iberian red deer has deserved special attention from researchers and society in general over the last two decades, owing to increasing conservation concerns and the need to protect endogenous resources. Thus, genetic assessments of translocated animals have become frequent, which together with trophy certification assessments have limited this practice over the last years (Carranza, 2003;Vingada et al., 2010). However, pure nonnative individuals are still detected in Iberian populations (21 individuals, 1.9%). ...
Full-text available
Anthropogenic hybridization is one of the greatest threats to global biodiversity. It incites human-mediated gene flow between non-native/exotic and native taxa, which can have irreversible effects on native species or locally adapted populations, eventually leading to extinction. The red deer, Cervus elaphus, is a game species that, due to its extraordinary economic value, has been introduced in several regions throughout Europe. However, the consequences of those introductions on native populations, namely on their genetic background, have been poorly addressed. This study is focused on the Iberian Peninsula and aims to: (i) assess the extent of anthropogenic hybridization/introgression of introduced red deer into the native Iberian populations; (ii) evaluate the impact of red deer management regimes on the observed hybridization/introgression patterns; and (iii) assess how hybridization/introgression influence the current genetic diversity of native Iberian populations. A set of 11 microsatellites and a 329 bases pair fragment of the mitochondrial D-loop gene were used to estimate nuclear admixture and mitochondrial introgression in 1,132 individuals sampled across 46 red deer populations throughout Iberia. A Bayesian approach implemented in the STRUCTURE program was employed to investigate the proportion of admixture between native populations and non-native red deer. Results showed that 17% of individuals presented signs of non-native recent ancestors and 10.1% had non-native mitochondrial haplotypes, reaching an overall hybridization/introgression rate of 23%. Non-native or hybrid individuals were found throughout 40 Iberian red deer populations, and the percentages per population varied between 3.3 and 75.0%, independently of the management regime. Mitochondrial introgression was observed across 15 Iberian red deer populations, being more frequent in free-ranging individuals (16.2%) than in fenced populations (9.2%) but was completely absent from public-owned populations. Nuclear genetic diversity correlated positively with the proportion of hybrid individuals in public-owned populations. The genetic footprint of historical and current human-mediated translocations of non-native red deer into the Iberian Peninsula is evidenced in this study, highlighting the need to implement effective measures to avoid such practices both in Portugal and Spain, in order to preserve the endogenous genetic patrimony of the Iberian red deer populations.
... Most of current distribution of red deer in the Iberian Peninsula has resulted from many translocations, some of them documented, and others probably not, from a few remaining populations (Cabrera 1914;Blanco 1998;Carranza 2010). We do not have evidence of any current red deer population in Spain that have been established mainly by restocking with non-Iberian red deer, although some individuals or stocks exist at particular hunting estates that may belong to other European subspecies or may be hybrids between Iberian and foreign red deer (Carranza et al. 2003;Carranza 2010;Fern andez-Garc ıa et al. 2014). According to the available information (Soriguer et al. 1994;Crespo 2013), we can consider Extremadura, Sierra Morena, and Montes de Toledo as the main areas where native populations persisted, roughly throughout a large discontinuous region in western and central-southern Spain. ...
... Male-biased dispersal, along with the existence of barriers between populations (P erez-Espona et al. Gene flow between Iberian lineages may have increased in recent times, either because of the increased size of populations and their geographic ranges during the last century in Spain (Carranza 2010), or by artificial translocations under the rise of hunting management in the last three or four decades (Mart ınez et al. 2002;Carranza et al. 2003;Carranza 2010), which may also be oriented to males. In fact, our analysis has detected some individuals (males) that did not assign to the genetic cluster to which their sampling population belonged, suggesting recent dispersal or translocations. ...
... To which extent we should rely on mitochondrial or genomic DNA to define evolutionary significant units (ESU) may be debatable (Moritz 1994;Crandall et al. 2000;Wan et al. 2004), but it is increasingly clear that we should use a suite of different genetic markers to understand the processes and decide on their relevance for preservation (Fraser and Bernatchez 2001). Restocking with foreign deer is still common in current red deer populations in spite of legal regulations against this practice (see e.g., Carranza et al. 2003;Carranza 2010). In spite of these actions, our results show a clear phylogeographic pattern in current red deer populations in Spain. ...
Full-text available
Red deer populations in the Iberian glacial refugium were the main source for postglacial recolonization and subspecific radiation in north-western Europe. However, the phylogenetic history of Iberian red deer (Cervus elaphus hispanicus) and its relationships with northern European populations remain uncertain. Here, we study DNA sequences at the mitochondrial control region along with STR markers for over 680 specimens from all the main red deer populations in Spain and other west European areas. Our results from mitochondrial and genomic DNA show contrasting patterns, likely related to the nature of these types of DNA markers and their specific processes of change over time. The results, taken together, bring support to two distinct, cryptic maternal lineages for Iberian red deer that predated the last glacial maximum and that have maintained geographically well differentiated until present. Haplotype relationships show that only one of them contributed to the northern postglacial recolonization. However, allele frequencies of nuclear markers evidenced one main differentiation between Iberian and northern European subspecies although also supported the structure of both matrilines within Iberia. Thus, our findings reveal a paraphyletic nature for Iberian red deer but also its genetic identity and differentiation with respect to northern subspecies. Finally, we suggest that maintaining the singularity of Iberian red deer requires preventing not only restocking practices with red deer specimens belonging to other European populations but also translocations between both Iberian lineages.
... Different breeding programmes can be used to improve the product quality or the productivity, and the breeding stock can be selected and/or hybridised with animals belonging to various subspecies/species (Carranza, 2010). Where animals escape from such parks or are deliberately released into wild populations, such manipulations may have a signifi cant impact on the genetics of the native wild stock and may contaminate the local gene pool (genetic introgression, 'swamping'), leading to hidden extinctions of native lineages (Carranza et al., 2003). ...
... For example, red deer from Northern and Eastern Europe have been introduced into Spain, to be crossed with native Iberian red deer in farms or under controlled conditions in hunting estates, to produce hybrid, big antlered stags for the hunting market (Carranza et al., 2003). Feral sika deer have hybridised with native red deer in the Czech Republic and in Scotland, affecting its appearance and the size of some measurable traits (e.g. ...
... Genetic introgression is controlled by a genetic test that is applied to red deer trophies when they are submitted to the Spanish Trophy Commission where they are measured and catalogued according to the criteria of the International Council for Game and Wildlife Conservation (CIC). If genetic tests indicate that some trophies do not belong to pure Iberian red deer specimens, then the Spanish Commission will reject them as candidates to be included in the Spanish records (Carranza et al., 2003). This measure has resulted in a decrease in the value of hybrids as trophies and is producing the desired effect i.e. a reduction in the introduction of foreign deer in Spain. ...
... Desde el punto de vista numérico no sufre amenaza alguna. Sin embargo, a pesar de su elevado número y de la tendencia a la expansión de sus poblaciones y áreas de distribución (Gortázar et al., 2000), el ciervo ibérico se enfrenta a un riesgo real de alteración genética que podría suponer su desaparición como subespecie ibérica (Carranza yCarranza et al., 2003a). Estos riesgos se derivan de criterios erróneos en su manejo como especie de caza. ...
... Las principales amenazas son tres: 1.-la entrada de ejemplares procedentes de otras subespecies europeas: principalmente de Cervus elaphus hyppelaphus, introducidos con la finalidad de cruzarlos con los autóctonos y producir individuos con trofeos de mayor tamaño. Existe igualmente la posibilidad de entrada de material genético (semen) sin que se importen ejemplares (Carranza et al., 2003a). 2.-los cambios genéticos producto de la fragmentación y aislamiento de sus poblaciones: tanto las cercas cinegéticas como la desproporción de sexos en muchas áreas sin cercas cinegéticas, pueden contribuir a acentuar la pérdida de variabilidad genética (Martínez et al., 2002). ...
... Hybridization after translocations might cause outbreeding depression due to genetic incompatibility and reduced local adaptation [179,180]. Moreover, translocated individuals swamp the genetic variation of the native populations and, hence, increase homogenization and reduce genetic diversity of a species scale [179][180][181]. Additionally, migrants might put native populations at risk by introducing new pathogens or pathogen strains and altering host-pathogen relationships [182][183][184]. ...
Full-text available
Host genetic diversity tends to limit disease spread in nature and buffers populations against epidemics. Genetic diversity in wildlife is expected to receive increasing attention in contexts related to disease transmission and human health. Ungulates such as wild boar (Sus scrofa) and red deer (Cervus elaphus) are important zoonotic hosts that can be precursors to disease emergence and spread in humans. Tuberculosis is a zoonotic disease with relevant consequences and can present high prevalence in wild boar and red deer populations. Here, we review studies on the genetic diversity of ungulates and determine to what extent these studies consider its importance on the spread of disease. This assessment also focused on wild boar, red deer, and tuberculosis. We found a disconnection between studies treating genetic diversity and those dealing with infectious diseases. Contrarily, genetic diversity studies in ungulates are mainly concerned with conservation. Despite the existing disconnection between studies on genetic diversity and studies on disease emergence and spread, the knowledge gathered in each discipline can be applied to the other. The bidirectional applications are illustrated in wild boar and red deer populations from Spain, where TB is an important threat for wildlife, livestock, and humans.
... As rewilding initiatives are proliferating in Europe, genetic diversity patterns can be used as a relevant proxy for choosing suitable populations for translocations, within a conservation context. Captive-reproduced stocks of ungulates are common in some regions of Europe e.g., [59], but choosing a source population genetically different and/or from different ecological conditions, might result in the disruption of the gene pool and local adaptations of target populations [60,61]. According to the Law of Reintroductions from IUCN (1998), source populations must be genetically related with the native population and show similar ecological characteristics. ...
Full-text available
The roe deer (Capreolus capreolus) is native and widespread in Europe and its phylogeography has been clarified in the last decades. Southern peninsulas are considered as reservoirs of genetic diversity and the source for the recolonization of Europe after the last glacial maximum. Even though roe deer populations have been genetically characterized, there is a major knowledge gap about the populations at the western edge of its distribution. To fill this caveat, and based on mitochondrial and nuclear DNA data, we aim to: (i) characterize the genetic diversity and structure of roe deer in western Iberia; (ii) clarify the origins and phylogeographical affinities of these populations, namely the relict population from Peneda Gerês National Park (PNPG, Portugal) and the likely allochthonous populations from central and south (CS) Portugal; (iii) discuss the implications of our findings for the management and conservation of the roe deer. Three major genetic clusters were inferred based on nuclear genotypes and were structured in a similar way as the three major mtDNA clades present in Iberia. Patterns inferred with nuclear markers confirmed PNPG as a relict population. Roe deer from CS Portugal share haplotypes with Central Europe rather than with other western Iberian populations, confirming its mainly allochthonous origin. Our results highlight western Iberia as a diversity hotspot for roe deer. We highlight the role of intraspecific genetic diversity as a source of resilience against ongoing global changes; the need for transboundary management and the importance of genetic data to inform management and conservation. When considered, repopulation or translocation measures should follow the IUCN Law of Reintroductions and meticulously conducted in order to preserve the genetic heritage of the species.
... For the conservation of natural populations of red-legged partridge, the release into the wild of hybrid specimens can be extremely dangerous [7]. Although hybrids are less adapted to the field, uncontrolled restocking may lead to a widespread introgression of foreign genetic material into locally adapted red-legged partridge populations [1,5,6], eventually causing the extinction of the red-legged partridge as a wild species [8]. For this reason, the administrations with competences in game management and conservation of nature should establish a control system for both farms and natural environments to preserve the genetics of red-legged partridge wild populations. ...
The red-legged partridge (Alectoris rufa) is one of the most emblematic game species in Southern Europe. For the conservation of its natural populations against hybridization with chukar partridges (Alectoris chukar) a public and agreed control system able to detect genetic introgression between the two species should be established. As the already available method has not been implemented yet, this paper presents an improvement of the genetic analysis technique by using an open platform system to optimize the diagnostic procedure. Here we present the results obtained from the design of an Open ArrayTM platform with the available SNPs with proved diagnosis capacity between the two species of interest. By this procedure we genotyped 380 partridge samples, both from farms and field populations, which resulted in an overall percentage of genotyping performed with success of 99.64%. The Open Array genotyping plates showed high performance, specificity and an easy reproducibility compared to conventional techniques of genotyping.
... Some introgression from the central European populations was detected in the Iberian red deer populations analyzed (SLR, ASR, MT6, PNSAPA and PNM). This introgression might be explained by past human translocations from the central and northern European countries into Portugal and Spain [41,128]. ...
Full-text available
The red deer (Cervus elaphus) is a widespread wild ungulate in Europe that has suffered strong anthropogenic impacts over their distribution during the last centuries, but also at the present time, due its economic importance as a game species. Here we focus on the evolutionary history of the red deer in Iberia, one of the three main southern refugial areas for temperate species in Europe, and addressed the hypothesis of a cryptic refugia at higher latitudes during the Last Glacial Maximum (LGM). A total of 911 individuals were sampled, genotyped for 34 microsatellites specifically developed for red deer and sequenced for a fragment of 670 bp of the mitochondrial (mtDNA) D-loop. The results were combined with published mtDNA sequences, and integrated with species distribution models and historical European paleo-distribution data, in order to further examine the alternative glacial refugial models and the influence of cryptic refugia on European postglacial colonization history. Clear genetic differentiation between Iberian and European contemporary populations was observed at nuclear and mtDNA levels, despite the mtDNA haplotypes central to the phylogenetic network are present across western Europe (including Iberia) suggesting a panmictic population in the past. Species distribution models, fossil records and genetic data support a timing of divergence between Iberian and European populations that overlap with the LGM. A notable population structure was also found within the Iberian Peninsula, although several populations displayed high levels of admixture as a consequence of recent red deer translocations. Five D-loop sub-lineages were found in Iberia that belong to the Western European mtDNA lineage, while there were four main clusters based on analysis of nuclear markers. Regarding glacial refugial models, our findings provide detailed support for the hypothesis that red deer may have persisted in cryptic northern refugia in western Europe during the LGM, most likely in southern France, southern Ireland, or in a region between them (continental shelf), and these regions were the source of individuals during the European re-colonization. This evidence heightens the importance of conserving the high mitochondrial and nuclear diversity currently observed in Iberian populations.
... Recent regulations have attempted to reduce this practice, requiring genetic tests of trophies prior to their entry into Spanish records to ensure they are not hybrids. Some regions of Spain have begun to require these genetic tests prior to authorizing translocations, and some landowners utilize these genetic tests to purge hybridization from their herds (Carranza et al. 2003;Carranza 2010). ...
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Abstract Distinct cultural and legal histories governing the property rights that regulate wildlife and land tenure in California and Spain have created dissimilar hunting systems. The differences that are manifest in the methods of hunting, the economic return to landowners, the actions taken to manage game species, and the accompanying environmental effects. Private landowners in Spain retain greater control of game species, while in California, the state and federal government exerts greater authority. After providing background on the game species and systems of hunting in California and Spain, a review of the legal and cultural history illustrates how distinct systems evolved in places that are similar in many other ways. In terms of economics, hunting revenue in Spain is often greater than in California, due to higher hunter participation rates, fewer governmental restrictions that limit the commercialization of hunting, and greater liberties in hunting methods and game management practices. As such, income from hunting provides a greater incentive for Spanish landowners to maintain areas of habitat for game species. Some of the greatest contrasts between these places are illustrated in wildlife management practices, where Spanish landowners can implement far more intensive practices to manipulate populations of game species. Numerous environmental effects can result from these management practices, which include changes to vegetation, erosion, genetic impacts, invasive species introductions, and impacts to non-game species.
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Rates of hybridization and introgression are increasing dramatically worldwide because of translocations of organisms and habitat modifications by humans. Hybridization has contributed to the extinction of many species through direct and indirect means. However, recent studies have found that natural hybridization has played an important role in the evolution of many plant and animal taxa. Determining whether hybridization is natural or anthropogenic is crucial for conservation, but is often difficult to achieve. Controversy has surrounded the setting of appropriate conservation policies to deal with hybridization and introgression. Any policy that deals with hybrids must be flexible and must recognize that nearly every situation involving hybridization is different enough that general rules are not likely to be effective. We provide a categorization of hybridization to help guide management decisions
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In this article we describe the structure of a hybrid zone in Argyll, Scotland, between native red deer (Cervus elaphus) and introduced Japanese sika deer (Cervus nippon), on the basis of a genetic analysis using 11 microsatellite markers and mitochondrial DNA. In contrast to the findings of a previous study of the same population, we conclude that the deer fall into two distinct genetic classes, corresponding to either a sika-like or red-like phenotype. Introgression is rare at any one locus, but where the taxa overlap up to 40% of deer carry apparently introgressed alleles. While most putative hybrids are heterozygous at only one locus, there are rare multiple heterozygotes, reflecting significant linkage disequilibrium within both sika- and red-like populations. The rate of backcrossing into the sika population is estimated as H = 0.002 per generation and into red, H = 0.001 per generation. On the basis of historical evidence that red deer entered Kintyre only recently, a diffusion model evaluated by maximum likelihood shows that sika have increased at approximately 9.2% yr-1 from low frequency and disperse at a rate of approximately 3.7 km yr-1. Introgression into the red-like population is greater in the south, while introgression into sika varies little along the transect. For both sika- and red-like populations, the degree of introgression is 30-40% of that predicted from the rates of current hybridization inferred from linkage disequilibria; however, in neither case is this statistically significant evidence for selection against introgression.
I used protein electrophoresis to estimate the degree of genetic exchange between white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus) from areas of sympatry throughout the south-western United States. Allelic variation from 25 presumptive gene loci were assayed from 201 deer from 31 localities. Although interspecific hybridization has been previously documented with both nuclear and mitochondrial markers, most areas of sympatry in the Southwest displayed little evidence of nuclear gene introgression. Nevertheless, hybridization was evident from some localities with 2.0% of the white-tailed deer and 1.7% of the mule deer heterozygous at one of 2 diagnostic nuclear loci. Changing environmental conditions that provide a competitive advantage of 1 species over the other may result in ephemeral areas of hybridization. Studies designed to ascertain the ecological and concomitant behavioral changes in these areas could be used to predict and identify potential areas of genetic interaction between these 2 species.
1. The brown trout (Salmo trutta) represents one of the main freshwater resources in Spain, but habitat alterations and overharvesting have contributed to the decline or disappearance of numerous natural populations. In addition, reinforcement programs of wild populations based on releases of hatchery reared fish of exogenous origin compromise the conservation of remnant native trout resources. 2. We present allozymic data from Central Spain trout populations including stocked and unstocked populations. Although the levels of genetic variation observed were low and affected by hatchery releases (p = 18.23%, Ho= 3.39%), they were within the range observed in other European areas. 3. The effective introduction of hatchery reared fish is genetically homogenising the populations in the studied area and disturbing the ancestral pattern of genetic variation that distinguishes the Tajo and Duero basins. Within the eight natural populations analysed, seven had alleles assigned to the foreign trout. The introgression in these populations, following the LDH-5*90 allele frequency, ranged between 2% and 29.4%, but those values are not in concordance with the respective stocking effort undertaken in each population. Moreover, the release of hatchery-reared fish does not solve the problems related to the reduced size of wild populations and their recruitment instability.
Report and recommendations on game farming and ranching of big game in Ontario: implications for native wildlife and conservation
  • Ontario
  • Of
  • Hunters
ONTARIO FEDERATION OF ANGLERS AND HUNTERS, 1991. Report and recommendations on game farming and ranching of big game in Ontario: implications for native wildlife and conservation.