Genetic Identity of the Red-legged Partridge (Alectoris rufa, Phasianidae) from the Island of Madeira

Restocking from captive-reared red-legged partridges ( Alectoris rufa ) is a frequent practice in some Spanish regions, due to the strong decrease of wild populations size in the last years. Chukar partridges ( A. chukar ), which never lived as wild game birds in Spain, are more prolific and efficient meat producers, being legally bred in many Spanish farms to be directly sent to slaughterhouses. Releasing foreign partridges species or hybrids is strictly forbidden by hunting and environment preservation laws. However, eventual hybridization with chukar partridges in breeding farms is a worrying possibility as, in many cases, farms produce birds for both meat and restocking purposes. DNA analyses might be useful to elucidate the genetic purity of wild or farmed partridges. Single Strand Conformation Polymorphisms (SSCP´s) were studied on individual DNA samples from Spanish supposed red-legged and captive chukar partridges. Two mitochondrial (Cytochrome B and D-loop) and one nuclear (Ribosomal DNA-intervening transcribed spacer, ITS) regions were considered for Polymerase Chain Reaction (PCR) design and further polyacrylamide gel electrophoresis. The results suggest that these techniques might identify interspecific A. rufa x A. chukar hybrids among wild and captive supposed red-legged partridges by detecting chukar partridge ancestors in their genealogies. On the other hand, these markers showed intra population genetic variability.

DNA-based studies using avian feces are scarce and deal only with large-sized species. The red-legged partridge, Alectoris rufa, is a medium-sized member of the order Galliformes. Our goal was to set up a fast, noninvasive procedure for mitochondrial DNA (mtDNA) genotyping of A. rufa fecal samples. We focused on the protected population from Elba Island (Tuscan Archipelago National Park, Italy). Dry A. rufa fecal samples (n = 30) were collected in winter. Both the cytochrome b gene (1,092 bp) and the control region (ca. 1,155 bp) were amplified by means of semi-nested PCRs. Twenty-five samples were successfully sequenced for both genes: 8 showed A. rufa mtDNA lineage and 17 chukar partridge (A. chukar), an exotic species. Mixed maternal ancestry suggests A. rufa x A. chukar hybridization. Our protocol allows noninvasive mtDNA genotyping of any Alectoris species and appears suitable to investigate protected populations as well as those existing either at very low density or inhabiting poorly accessible regions.

In recent years, the use of the red-legged partridge (Alectoris rufa) for cynegenetic purposes has increased dramatically, and captive-bred individuals are released to reinforce wild populations. A problem appears at the farm level where partridges can be crossed with non-native species that are better adapted to captivity, like Alectoris chukar. In this study we use a set of eight RAPD markers to identify a possible hybridization of A.rufa with A.chukar partridges. A total of 1510 individuals were analysed, grouped into pools of five birds each. We obtained a frequency of genetic introgression in red-legged partridge near to 50%. These results show that a high percentage of hybridization in captive populations of Spanish partridges is present, and that more thorough control systems should be established in breeding farms for re-stocking purposes.

Comparative genetic analysis between red-legged partridges (<i>Alectoris rufa</i>) and chukar partridges (<i>A. chukar</i>): identification of single-nucleotide polymorphisms

Heavily managed wildlife may suffer from genetic homogenization and reshuffling of locally adapted genotypes with non-native ones. This phenomenon often affects natural populations by reducing their evolutionary potential and speeding up the ongoing biodiversity crisis. For decades, the red-legged partridge (Alectoris rufa), an intensively managed gamebird of conservation concern and considerable socio-economic importance, has been subjected to extensive releases of farm-reared hybrids with the chukar partridge (Alectoris chukar) and translocations irrespective of subspecific affinity. These practices have led to serious concerns that the genetic integrity and biogeographic structure of most red-legged partridge populations are irreversibly affected, as suggested by previous studies based on few genetic markers. Using over 168 000 genome-wide loci and a sampling across the entire A. rufa range, we detected unexpectedly limited and spatially uneven chukar introgression as well as significant intraspecific structure. We demonstrate that species widely feared to have irretrievably lost their genetic identity are likely to be much less affected by unsuitable management practices than previously assumed. Our results spell the need for a radical re-think on animal conservation, possibly restoring native status to populations long treated as compromised. Our study exemplifies how the application of innovative conservation-genomic methods is key to solving wildlife management problems dealing with introgressive hybridization worldwide.

Genetic introgression with exotic genomes represents a major conservation concern for the red-legged partridge (Alectoris rufa, Phasianidae). In particular, massive releases of chukar partridges (Alectoris chukar) and/or red-legged × chukar partridge hybrids for hunting purposes have cast serious doubts on the Italian present-day occurrence of wild A. rufa populations not affected by introgressive hybridization. This study investigates the genetic structure of red-legged partridges populations in two ecologically different areas in Northern Italy. Analysis of maternal mitochondrial DNA and biparental microsatellite markers excluded the presence of hybridization in a typical agricultural habitat where hunting and release of reared birds are strictly banned. By contrast, signs of chukar introgression were detected in a perifluvial habitat unusual for the red-legged partridge in Italy. The present study documents the first red-legged partridge population with no genetic evidences of recent chukar introgression presently living in Italy. We recommend that urgent conservation actions are taken to preserve the genetic integrity of this population from the risk of hybridization with farm-reared birds and to support its long-term conservation.

Mitochondrial and nuclear markers for the authentication of partridge meat and the specific identification of red-legged partridge meat products by polymerase chain reaction

In the last decades, the release of large numbers of farmed-reared birds became a widespread management practice for game species. The red-legged partridge (Alectoris rufa) is a quarry species with a high economic impact in rural areas of southwest Europe. In order to increase productivity and produce heavier birds, farmed red-legged partridges have often been hybridized with Chukar partridges (A. chukar), although these species have allopatric distribution ranges. During restocking, hybrid birds may be released into wild populations and may subsequently successfully breed, thus threatening the genetic integrity of native A. rufa populations. In this study, we compared several phenotypic indicators (body size, body condition and physiological state) between “pure” and hybrid partridges in order to evaluate the possible consequences of A. chukar genetic introgression into A. rufa. For this purpose, we captured 115 wild red-legged partridges during the breeding seasons 2003–2005 in four game estates of central Spain. We observed a greater occurrence of hybrid A. rufa × A. chukar partridges nearby the sites where the release of farmed-birds took place. We also found that hybrid males were smaller and hybrid females had better body condition and lower plasma carotenoid concentration than pure partridges of the same sex. Low carotenoid levels in blood plasma might be a limitation for female reproduction (fewer carotenoids available for ornamentation or to allocate to eggs). Overall, our results showed a greater occurrence of hybrids near restocking areas and phenotypic differences between hybrids and “pure” partridge in the wild. Genetic controls of farm-reared partridges should be a key step to prevent the releases of hybrids and ensure the maintenance of the genetic integrity of wild red-legged partridge populations.

Island canaries (Serinus canaria) are characterised as a species living exclusively on North Atlantic islands, mainly on the Azores, Madeira and Canary Islands. Although they are very common in their habitats, their behaviour and breeding system has only recently been studied systematically. To advance the understanding of their ecology and to see if the rather isolated archipelagos are already promoting a genetic differentiation, we investigated their phylogeographic relationship as revealed by mtDNA sequences of the cytochrome b gene and investigated whether this measure corresponds to morphological characteristics within the islands. Genetic distances were very low throughout the distribution range of the species. Although the variation of genetic distances within the population of Pico (Azores) was larger than that on Madeira and Canary Islands, the genetic distances between island populations were very low throughout which prevented a clear phylogeographic differentiation. Moreover, morphological measurements did not reveal a consistent pattern to reliably separate the populations, although the measures of beak length and body weight revealed a clear island-specific differentiation. These data lead to the assumption that the colonisation of the Atlantic islands by the canaries occurred very recently, while there is no persisting gene flow between the populations.

Mediterranean red-legged (Alectoris rufa) and rock (Alectoris graeca) partridge populations are affected by genetic pollution. The chukar partridge (Alectoris chukar), a species only partly native to Europe, is the most frequently introgressive taxon detected in the genome of hybrid partridges. Both theoretical (evolutionary) and practical (resources management) matters spur to get insight into the geographic origin of the A. chukar hybridizing swarm. The phenotypic A. rufa populations colonizing the easternmost part of the distribution range of this species, the islands of Elba (Italy) and Corsica (France), were investigated. The analysis of both mitochondrial (mtDNA: Cytochrome-b gene plus Control Region: 2,250 characters) and nuclear (Short Tandem Repeats, STR; Random Amplified Polymorphic DNA, RAPD) genomes of 25 wild (Elba) and 20 captive (Corsica) partridges, disclosed spread introgression of chukar origin also in these populations. All mtDNA haplotypes of Elba and Corsica partridges along with those we obtained from other A. rufa (total, n = 111: Italy, Spain, France) and A. graeca (n = 6, Italy), were compared with the mtDNA haplotypes of chukars (n = 205) sampled in 20 countries. It was found that the A. chukar genes detected in red-legged (n = 43) and rock partridges (n = 4) of Spain, France and Italy as well as in either introduced (Italy) or native (Greece, Turkey) chukars (n = 35) were all from East Asia. Hence, a well-defined geographic origin of the exotic chukar genes polluting the genome of native Mediterranean A. rufa and A. graeca (inter-specific level) as well as A. chukar (intra-specific level), was demonstrated.

This special issue on The Nordic Tourists in the Atlantic Islands of Azores, Madeira and Canaries was prepared in 2012, when the economic crisis had started in 2008, with the aim to focus if Nordic tourists’ flux in Atlantic Islands was common and persistent along the years, representing an important proportion of the tourists in these islands. Despite its importance, no research has yet analyzed this tourism flux in the Atlantic islands. This special issue focuses on Atlantic islands, aimed at understanding the role of Scandinavian Tourists in Atlantic Islands. The call for papers received 15 papers from which 6 were selected based on their quality. The selected papers were presented in a conference held in Azores by the Regional Observatory of Tourism from Azores to discuss the accepted papers on 29 April May 2012. This special issue contains papers that went through a revision process in the conference, and each paper was revised by two blind reviewers. Some papers had to be revised twice and the final result is presented here. In this introduction, I present a description of Nordic tourism since 2002 in these islands that serve as the subject of the papers.

An open platform system based on SNP type genetic markers for discrimination between Alectoris rufa and Alectoris chukar

Characterization of red-legged partridge (Alectoris rufa) sperm: Seasonal changes and influence of genetic purity

Non-native and hybrid in a changing environment: conservation perspectives for the last Italian red-legged partridge (Alectoris rufa) population with long natural history

The analysis of 135 mitochondrial D-loop sequences of the Iberian autochthonous red-legged partridge (Alectoris rufa) from wild population hunting bags from various locations and fowl runs in Spain yielded 37 different haplotypes. Among these, three haplotypes correspond to chukar partridges (Alectoris chukar), indicating genetic introgression from birds illegally introduced for restocking: three individuals carrying such haplotypes where found in natural populations, one appeared among those sampled on a mass reproduction farm and the remaining 10 in another fowl-run. The geographical origin of the contaminating chukar haplotypes could be assigned to the most easterly area of the chukar partridge geographical distribution in China. Molecular diversity parameters in the A. rufa samples indicate a considerable amount of genetic variation. ΦST showed significant differences among populations that are not explained by geographical distance alone. Particularly, one northern population (Palencia) shows a certain degree of genetic differentiation that could reflect a previously suggested subspecies division.