Partridge Populations Research Articles

High Diversity Unveiled by the First Genetic Survey on Wild and Captive Barbary Partridge (Alectoris barbara) from Morocco

Characterizing genetic diversity and structure is paramount in wildlife conservation management. Surprisingly, however, there are species that, despite being intensively managed, are largely overlooked in terms of genetic makeup. The Barbary partridge (Alectoris barbara), a medium-sized galliform native to northern Africa, is one such exemplary case. Since the early 2000s, a couple of breeding farms in Morocco have been operating using wild breeders. At that time, no genetic data were available for local wild populations, nor had the founders been genetically screened. After two decades, the degree of genetic diversity of wild Barbary partridge populations remains unknown. In this study, we genotyped the mitochondrial DNA control region (ca. 1000 bp) in wild and captive A. barbara populations from Morocco. Overall, we found a high and well-distributed genetic diversity, with a moderate differentiation between captive and wild populations likely attributable to either the sharing of widespread and allegedly ancestral haplotypes or the extensive release of farm-reared individuals. Nevertheless, the occurrence of private haplotypes across all the wild populations calls for separate management. A more comprehensive sampling and the use of genome-wide loci is advisable to achieve a thorough understanding of the genetic diversity of the Barbary partridge and define management units accordingly.

Quantifying the predation impact of an expanding mesocarnivore on declining small‐game species

AbstractHuman‐wildlife conflicts have increased and are particularly acute when predators are involved. A frequent source of conflict is some people's misbeliefs related to the alleged impact of predators on game species and livestock. In this context, quantifying the impact of expanding predators on their prey can be useful in designing conflict mitigation strategies. We estimated the predation impact of the Egyptian mongoose (Herpestes ichneumon), an expanding mesocarnivore in southwestern Europe, on European rabbit (Oryctolagus cuniculus) and red‐legged partridge (Alectoris rufa) populations, two declining prey species highly valued by hunters. We estimated mongoose densities in three areas of central Spain through live capture, GPS/VHF tagging, camera‐trapping and spatial mark‐resight models. Rabbit and partridge densities were estimated through transect counts and distance sampling. We quantified the mongoose diet by scat analysis. Finally, we compared the number of individuals consumed by the predator population with the estimated total prey populations. European rabbits were the most important mongoose food in two of the study areas, whereas red‐legged partridges were rarely consumed in all the areas. Rabbit density varied widely among study areas (14.0–881.4 rabbits/km2), while partridge density was low in all the areas (2.3–6.9 partridges/km2). The predation impact on rabbits was low in the area with the highest rabbit density (1.9–3.8% of estimated population) and higher (5.6–29%) in the other areas. In contrast, the predation impact on partridge populations was low (<9%) in all the study areas. This is the first study that estimates the Egyptian mongoose impact on small‐game species, a necessary step to deal with the conflicts over the management of this expanding species. The study of predation impact may contribute to the effective management of human‐wildlife conflicts involving predators, by improving the understanding of where additional management may take place to protect prey species or deter predator populations.

Predation of Rock Partridge Alectoris graeca saxatilis nests incubated by males and females in the French Alps

ABSTRACT Capsule The predation of incubated nests was investigated in an Alpine population of Rock Partridges, showing a double-nesting behaviour by females that can lay two clutches in succession, one incubated by the mated male and the second by the female. Aims To compare the nest predation rate and hatching success between incubating males and females in relation to the potential effects of year, nest age, and environmental characteristics (presence of nest cameras, visibility of the clutch, and vegetation cover around the nest). Methods The fate of 100 nests incubated by radio-tracked birds was monitored daily over 1738 days using cameras, and with temperature loggers placed in the nest cup. Nest predation rates and daily predation rates were calculated and modelled. Results Egg predation was the main cause of nest loss (87%) followed by predation of the incubating parent during recess periods off the nest (10%). Only mammals were identified as nest predators, and predation events were less frequent during the day than at night. We found no difference in predation rates between nests incubated by males or females. Daily and 25-day predation rates were calculated as 0.02 (95% CI: 0.01–0.03) and 0.39 (95% CI: 0.29–0.49), respectively. Median hatching success was 0.91 (n = 53 nests) and did not differ between sexes. Conclusions The similar level of nest predation between incubating males and females suggested a duplication of the reproductive output of a pair by double-nesting. Consequences of this breeding system were an increase in productivity at the population level. There was no difference in hatching success in nests incubated by either sex and there were no observations of surviving males deserting their nests, suggesting that care during incubation was similar in males and females. Variation in the rate of double-nesting may contribute more than nest predation to the annual variation in reproductive output.

Local sub‐population dynamics of a central European grey partridge meta‐population support large‐scale conservation approach to halt its ongoing decline

Many farmland birds such as the grey partridge Perdix perdix are experiencing sharp declines across Europe, which can lead to fragmentation and increasing isolation of local populations. Understanding the population dynamics of these local populations is becoming increasingly important for effective conservation efforts. In this study, we used data from grey partridge transect counts with call playback from 2006 to 2023 to investigate the population dynamics of a grey partridge population in central Germany. We employed generalized linear mixed models to model the long‐term meta‐population trend and assessed synchrony between local sub‐populations by calculating the cross‐correlation and the Loreau and de Mazancourt community‐wide synchrony. Additionally, we assessed stability by comparing the extent of yearly fluctuations between sub‐populations and the regional meta‐population by analysing variances. Our analysis revealed that the studied meta‐population remained stable over the course of the study period, despite ongoing declines observed in other regions of Germany. Furthermore, we found that the population dynamics of the sub‐populations were largely asynchronous, and the extent of variance in the sub‐populations was significantly greater than in the meta‐population. The low synchrony between sub‐populations indicates a prevalence of local factors affecting population dynamics, but further research is needed to identify these factors. Our results suggest that asynchrony between sub‐populations may play a role in stabilizing meta‐populations at the landscape level. Based on our results, we argue that large‐scale conservation projects that are able to encompass these population dynamics may help ensure the long‐term persistence of the grey partridge.

Population Response to Habitat Management from an Endangered Galliform: The Pyrenean Grey Partridge Recovery Project in Lago de Sanabria (2000–2023)

The Pyrenean grey partridge (Perdix perdix hispaniensis) is an endangered and insufficiently studied galliform occurring in upland habitats dominated by shrublands in Spain, France, and Andorra. Aiming to develop tailored management to favour the species, we studied the effect of habitat management on a partridge population located in Zamora province within the Galician–Duero mountains as part of a long-term project promoted by the regional government (Junta Castilla y León). Management was based on carrying out conservation and recovery of optimal habitats through clearing shrublands (either plots or linear) distributed in a “core area” of 45 km2, conducting tracks with beaters and pointing dogs during autumn in three areas, and comparing the partridge abundance before (2000–2006) and after (2007–2023) management. Habitat management increased partridge abundance values in two areas (1.46 and 1.68 times higher) and had no effect on the remaining one. The pattern of grey partridge abundance during the study was irregular and not influenced by the weather, and the highest abundance values were reached 8–10 years after habitat measures were implemented for the first time. Habitat management allowed high autumn abundance to be reached (mean kilometre abundance values of 2.94 and 3.74 birds/km in two areas), while the mean number of birds per family group was not affected by management (nine birds/group). When aiming to recover Pyrenean grey partridge populations, habitat management should be based on the conservation and management of shrublands to provide mixed habitats in the medium and long term, ensuring regular partridge monitoring.

The impacts of land use change on partridge’s population in the Marghazar valley of Swat District, Pakistan

Abstract In landscape ecology, it has become increasingly essential to understand the consequences of past, current, and future human land use patterns for biodiversity and ecosystem function. The most significant factor affecting biodiversity loss is land-use and land-cover change (LULCC). We examine here the impact of long-term changes in LULCC from 2000–2020 on the biodiversity of Marghazar valley in Swat District. Information was also gathered on the perceptions of the surrounding communities based on the flow of ecosystem services (ES), historical changes, and the causes of those changes. Satellite imagery data were used to map LULCC, identify possible causes, and assess the impact of LULCC on the population of partridges. In the last 20 years, forest area has reduced by 23 km2 (33%) and the seasonal water body has declined by 1.015 km2 (2.15%). There was a 38.5 km2 decrease in agricultural land. In contrast, the built-up area increased by 384%, resulting in a total growth of 26.3 km2 and an expansion of 41.1 km2 grassland. Deforestation, agricultural expansions, urbanization, economic considerations and changes in land tenure policy were identified to be the main drivers of LULCC. The primary impact of LULCC on partridges in the studied area are land degradation, population declines, habitat disruption, displacement of partridges by livestock and increasing human-wildlife conflicts. Despite ongoing human pressure, the Marghazar valley still provides extensive habitat for wildlife. Interventions may be needed to maintain biodiversity and ensure long-term ecological services in the area.

Genetic diversity in see-see partridge (Ammoperdix griseogularis, Galliformes) populations from sub-Himalayan Mountain ranges of Pakistan

We used Random Amplified Polymorphic DNA (RAPD) markers to investigate the genetic structure of two populations of see-see partridge (Ammoperdix griseogularis, Galliformes) from the Suleiman range, in the Pakistani Himalayan region. The see-see partridge is a vulnerable species with a distribution in the Middle East and central Asia. The percentage of polymorphic bands (94.05%), Shannon Index (H = 0.455) and Nei’s average gene diversity (I = 0.298) of A. griseogularis at species level were rather high when compared with other avian species. 17% of polymorphic loci showed statistically significant differences in their allelic frequencies. The G (Nei’s coefficient of genetic variation) values indicated low levels of differentiation (G = 0.08). A genetic distance D of 0.05 indicated that both populations were to some degree in isolation but their differentiation was not significant. Overall, our genetic data can support action plans aiming to locally preserve differentiated genetic resources that, in the future, could potentially result in ecologically and behaviourally differentiated populations. In view of the rapid environmental changes that the Himalayan region has been experiencing in the last decade, this study could help in conservation plans.

Genomic Variation, Population History, and Long-Term Genetic Adaptation to High Altitudes in Tibetan Partridge (Perdix hodgsoniae).

Species residing across elevational gradients display adaptations in response to environmental changes such as oxygen availability, ultraviolet radiation, and temperature. Here, we study genomic variation, gene expression, and long-term adaptation in Tibetan Partridge (Perdix hodgsoniae) populations residing across the elevational gradient of the Tibetan Plateau. We generated a high-quality draft genome and used it to carry out downstream population genomic and transcriptomic analysis. The P. hodgsoniae populations residing across various elevations were genetically distinct, and their phylogenetic clustering was consistent with their geographic distribution. We identified possible evidence of gene flow between populations residing in <3,000 and >4,200 m elevation that is consistent with known habitat expansion of high-altitude populations of P. hodgsoniae to a lower elevation. We identified a 60 kb haplotype encompassing the Estrogen Receptor 1 (ESR1) gene, showing strong genetic divergence between populations of P. hodgsoniae. We identified six single nucleotide polymorphisms within the ESR1 gene fixed for derived alleles in high-altitude populations that are strongly conserved across vertebrates. We also compared blood transcriptome profiles and identified differentially expressed genes (such as GAPDH, LDHA, and ALDOC) that correlated with differences in altitude among populations of P. hodgsoniae. These candidate genes from population genomics and transcriptomics analysis were enriched for neutrophil degranulation and glycolysis pathways, which are known to respond to hypoxia and hence may contribute to long-term adaptation to high altitudes in P. hodgsoniae. Our results highlight Tibetan Partridges as a useful model to study molecular mechanisms underlying long-term adaptation to high altitudes.

Understanding the impact of wild boar on the European wild rabbit and red-legged partridge populations using a diet metabarcoding approach

European wild rabbit (Oryctolagus cuniculus) and red-legged partridge (Alectoris rufa) are main small game species of conservation concern in Mediterranean ecosystems. To date, their presence in wild boar’s (Sus scrofa) diet and factors driving their consumption have been little investigated. A genetic metabarcoding approach was used on 80 wild boar faeces collected from four hunting estates devoted to small game hunting during two different seasons. Abundances of wild boar, rabbits and partridges were first estimated. Results showed DNA of seventeen chordate species. The highest frequency of occurrence (FO) corresponded to mammals and birds, with 77.6 and 22.3%, respectively. DNA of game species was detected in 39/71 (FO = 55.0%) samples, highlighting the presence of European wild rabbit in 27 (FO = 38.0%) and red-legged partridge in eight (FO = 11.3%). Dietary composition varied between seasons and estates, being rabbit the main responsible (explaining 35.26% and 39.45% of differences, respectively). Rabbit FO in the diet was positively related to the abundance of wild boar and rabbit density on the estate. It was greater in autumn and in estates where rabbits were hunted. Regarding red-legged partridge, a significant and positive relationship between its population density and its diet FO was observed, without significant differences between seasons or estates. Overall, our results suggest wild boar as an opportunistic species whose diet is largely determined by the relative availability of different food resources. Its ecological role concerning small game species in Mediterranean agroecosystems seems to be more related to consumption of carrion during the hunting season than to direct predation.

Feeding on grains containing pesticide residues is detrimental to offspring development through parental effects in grey partridge

Numerous toxicological studies have shown that ingestion of pesticides can induce physiological stress in breeding birds, with adverse consequences on egg laying parameters and offspring quality through parental effects. However, previous studies do not mimic current levels of pesticide residues in typical landscapes, and they do not consider potential cocktail effects of pesticides as they occur in the wild. Herein, we explored whether realistic pesticide exposure affected reproduction parameters and offspring condition through parental effects in Grey partridge. We fed 24 breeding pairs with either seeds from conventional agriculture crops treated with various pesticides during cropping, or organic grains without pesticide residues as controls. The conventional and organic grain diets mimicked food options potentially encountered by wild birds in the field. The results showed that ingesting low pesticide doses over a long period had consequences on reproduction and offspring quality without altering mortality in parents or chicks. Compared with organic pairs, conventional pairs yielded smaller chicks at hatching that had a lower body mass index at 24 days old. Additionally, these chicks displayed lower haematocrit when body mass index was higher. Therefore, ingestion of conventional grains by parents resulted in chronic exposure to pesticide residues, even at low doses, and this had detrimental consequences on offspring. These results demonstrate a sublethal effect of pesticide residues through parental effects. The consequences of parental exposure on chicks might partly explain the decline in wild Grey partridge populations, which raises questions for avian conservation and demography if current agrosystem approaches are continued.

Gastrointestinal parasites in red-legged partridges (Alectoris rufa) hunted in Spain: a warning to game managers

Red-legged partridge (Alectoris rufa) populations are currently declining in the Iberian Peninsula, mainly due to habitat degradation and hunting pressure. In addition, the release of farm-reared partridges may introduce pathogens, including parasites, to wild populations. The presence of digestive parasites in red-legged partridges hunted in fifteen Spanish provinces was studied. Fecal samples and gastrointestinal tracts were collected, analyzed, and the morphometric identification of parasites was carried out. Eimeria spp. oocysts, nematode, cestode and trematode eggs were observed in fecal samples. Adult nematodes (Ascaridia galli, Ascaridia compar, Heterakis gallinarum, Heterakis tenuicauda, Trichostrongylus tenuis, Subulura spp., Cyrnea spp. and Aonchotheca caudinflata), tapeworms (Raillietina tetragona, R. echinobothrida, R. micracantha, Rhabdometra nigropunctata, and Choanotaenia infundibulum), and trematodes (Brachylaima spp., Brachylecithum spp., Dicrocoelium spp.) were identified in the gastrointestinal tracts. Significant statistical differences were found among climatic regions in the prevalence and intensity of Eimeria spp. infection, median intensity and the prevalence of indirect life cycle helminths, with Southern areas always showing higher infection values. The study provides information of the health status of red-legged partridges in Spain, highlighting the risk associated with the release of farm-reared partridges for restocking purposes. This should be taken into account to improve management strategies for the long-term conservation of the species.

Bill Variation of Captive and Wild Chukar Partridge Populations: Shape or Size

Traditionally, morphological characters are widely used to distinguish between interspecies and intraspecies. In addition to the size of morphological characters, shape has also been used as an indicator in the last decades. We evaluated the geometric morphometry and morphometric of the bill of Chukar Partridge, Alectoris chukar from captive and wild populations to determine the bill variation and population relationships. Although there was a size difference between the sexes, no shape difference was found. However, captive populations differed from wild populations in both size and shape. Although there was no difference in shape among wild populations, some differences were found in size. Moreover, bill sizes of captive populations were statistically longer than western, centre, and eastern wild populations. It was also shown that the western populations had the most significant variation among the wild populations. The results revealed that using the size and shape together was more effective in comparing populations.

Does provision of supplementary food to grey partridges Perdix perdix help their over-winter survival on upland hill farms in northern England?

Grey partridge populations in the UK have declined dramatically since 1970. These birds are mainly associated with lowland cereal farms, but they are also found on marginal hill farms in northern England where they frequent rough grasslands created by low-intensity sheep farming. Here, important populations remain, but the availability of winter food, particularly in years with prolonged snow appears a major limiting factor. To investigate whether food shortages in winter limit grey partridge survival, we experimentally tested whether we could improve their survival by increasing the provision of supplementary food within five study plots, each paired with a control, over two consecutive winters. Grey partridges found and used feeding stations, with discovery time on average 12 days earlier in the second winter. The frequency of hopper use also increased on four of the five fed plots in the second winter. We found no differences in an index of over-winter survival nor subsequent breeding success in relation to the feeding treatment. However, the study coincided with two mild winters with little snow and the provision of supplementary food may be more important in more severe winters with prolonged snow cover. Grey partridges readily used feed hoppers and we recommend their provision to provide emergency food sources in severe winter weather whilst longer-term land-use based solutions are sought.

Status and habitat description of the globally threatened Udzungwa Forest PartridgeXenoperdix udzungwensisthirty years after discovery

SummaryThe Udzungwa Forest PartridgeXenoperdix udzungwensiswas discovered in 1991 in the geologically old and eco-climatically stable Udzungwa Mountains (hereafter the Udzungwas) in Tanzania - a global biodiversity hotspot in the Eastern Arc Mountains of East Africa. The partridge is categorised as globally ‘Endangered’ and this study aims at assessing its population status and habitat requirements in the two separate montane forests where it was discovered c.30 years ago and for the first time using systematic playback technique. We estimate the partridge population at c.2,800 individuals (1,680–3,860) confined to less than 150 km2and now confined to a single forest and with a clearly declining distribution within the last few decades since its discovery. The species is confined to evergreen closed (semi-closed) canopy forest habitat with leaf litter and sedges on the forest floor for feeding and cover. The partridge has become an emblem for the high concentration of endemic species of the Udzungwa Mountains National Park. At the same time there is a risk that this species could go extinct without notice if the Tanzanian authorities do not tackle two envisaged main drivers, namely fragmentation of the evergreen forest area over the last few centuries and current illegal hunting. Hence it seems crucial to allow natural expansion of its forest habitat in the Udzungwas and to eliminate hunting in the other forest within its recently known distribution where the population has presumably been extirpated. The partridge is remarkable as its closest relatives are in South-east Asia and it is used as a flagship species for the Udzungwas, which has one of the highest concentrations of endemic species on earth.

Genome-wide markers redeem the lost identity of a heavily managed gamebird.

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.

The end of primary moult as an indicator of global warming effects in the Red-legged Partridge Alectoris rufa, a medium sized, sedentary species

Global warming affects ecosystem services, communities and populations, influencing the physiology, behaviour or environment of living beings, and hence impacts its survival or breeding. Identifying species susceptibility to warming is relevant in assessing risks to animal populations and ecological processes. The progressive increase in ambient temperature as a result of global warming might have an effect on the timing of primary moult. This could affect a bird’s annual cycle, influencing reproductive success and population dynamics.We describe a method to examine the potential effects of global warming on the primary moult process in a sedentary population of Red-legged Partridges (Alectoris rufa). We organised the factors that might influence the timing of moult end into a network and distinguished between environmental and intrinsic factors. We sorted the factors according to their contribution to quantitative moult models and constructed a diagrammatic scheme showing their interactions and effect on the end of primary moult over the annual cycle.In Red-legged Partridges, the timing of the end of moult varies according to age-sex class. We found no timing differences by age, but found significant timing differences by adult sex. More females overlap their moult with juveniles than males because female parental effort is higher, more females incubate and brood chicks. The timing of the end of moult varies by year due to conspecific interactions that change according to influences of the weather, habitat, and social and flock conditions. Parent birds synchronize their primary moult with the chick's growth, degree of cover and food resources. From the time of hatching to the following year, the date (day-length), social factors (conspecific interactions), and weather (resources) affect the timing of moult and the birds’ annual cycle.Global warming affects the timing of the end of moult and that of the annual cycle. If the extent of the breeding period is shortened, there could be a negative effect on population outcomes. Middle size prey species are key in trophic chains. Our results suggest that the timing of the end of moult could be used as a proxy measure of warming impacts on wildlife and ecosystems and also as a tool for the management of game birds.

Ecological value of different vegetated strip types in providing valuable insect-rich habitats for grey partridge chicks

The intensification and specialisation of agriculture has contributed to farmland wildlife decline, including farmland birds. Grey partridge is a farmland species which has experienced a significant decline across Europe in recent decades. Chick survival rate is a key determinant of grey partridge population change and depends essentially on the availability of insect food. In this study, ground-dwelling and canopy-dwelling insects were collected using pitfall trapping and sweep netting methodologies, respectively, on different strip types in an area established for the conservation of grey partridge. The aim was to further our understanding of the value of different vegetated strip types in providing insect-rich habitats for grey partridge chicks. Overall, wildflower strip (WS) provided the greatest insect abundance. Significantly more ground-dwelling insects were found on WS, natural regeneration (NS) and leguminous strips (LS) than on grass strip (GS). Canopy-dwelling insects were also significantly more abundant on WS compared to all other strip types. This study highlights that WSs may represent important habitats in providing insect-rich food for grey partridge chicks and sowing these strips may therefore play a key role in decreasing chick mortality and supporting grey partridge conservation. It also demonstrates that other different vegetated strip types may still provide strip-specific insect taxa, in addition to other valuable resources. This study recommends a complex mosaic of different strip types to provide key resources for grey partridge, such as insect and plant food, nesting habitats and overwinter cover.

Cheilospirura hamulosa in the Rock Partridge (Alectoris graeca saxatilis): Epidemiological Patterns and Prediction of Parasite Distribution in France

The rock partridge (Alectoris graeca saxatilis) is an alpine Galliform with high conservation value. Several factors, including parasitic helminths, play a role in population dynamics, and consequently in the conservation management of wild Galliformes. The aim of this study was to assess the epidemiological characteristics of Cheilospirura hamulosa (Nematoda, Acuarioidea) in the Rock partridge population in France. Machine learning modeling algorithms were applied to identify the environmental variables influencing parasite occurrence, and to map parasite presence probability. The present work is based on a long-term sampling (1987–2019) conducted in the French Alps. C. hamulosa was found with a prevalence (P) of 39% (Confidence Interval—CI 95%: 34–43), and mean intensity of 7.7 (7.8 sd). The highest prevalence (P: 67%, CI 95%: 54–80) was detected in the period 2005–2009. Latitude was the most important variable shaping the parasite distribution, followed by altitude, annual mean temperature, temperature seasonality, and the amount of precipitation of the coldest quarter. The area suitable for parasite presence included 73% of the French Alps. This work represents the first epidemiological surveillance on C. hamulosa infection in the rock partridge. It provides evidence of a high level of infection and identifies priority areas at higher infection risk, where a close monitoring of the rock partridge populations should be carried out.

Habitat scarcity forms an ecological trap for the grey partridge (Perdix perdix) within a central European agricultural landscape

This study examines the habitat selection of grey partridge (Perdix perdix) and the effect of habitat type within partridge home ranges on nest site choice and nest success. Data were collected via radio-tracking in three different areas in the Czech Republic between 2002 and 2010. Compositional analysis was performed on 12 habitat types and uncultivated habitats (such as ruderals, field margins and game refuges) were selected the most during the pre-nesting and nesting periods. Grey partridges tended to nest in uncultivated habitats and avoided nesting in dominant cereal monocultures. We tested six variables that may determine nest site choice and success. Of these, the study area, proportion of selected habitat and habitat diversity (expressed by the Simpson’s diversity index) significantly affected nest placement in uncultivated habitats. Despite this, the lowest nest failure rate was observed in the predominant cereal habitat. Our findings suggest a possible ecological trap for partridges throughout our study areas. Due to the lack of uncultivated habitats, partridges favoured nesting in habitats with a higher predation risk. Conservation managers should increase the proportion of uncultivated areas and promote habitat diversity for partridge populations in central Europe.

Reducing nest predation of ground-nesting birds through conditioned food aversion

Populations of many ground-nesting bird species have declined substantially due to several factors, and predation can be a leading contributor to these declines. As a method for reducing the nest predation on ground-nesting birds, we tested whether conditioned food aversion (CFA) can reduce red-legged partridge (Alectoris rufa) nest predation by red foxes (Vulpes vulpes). With a before-after control-impact design we deployed 1329 artificial nests in two different habitats in Central Spain using thiram as an aversive. Artificial nests were monitored by camera traps to identify the red fox individuals during the predation events. 26 foxes were GPS-tagged to monitor their spatial movements and feeding behavior. Partridge density and productivity were monitored to assess the thiram treatment effect on partridge population. Thiram treatment decreased artificial nest predation by foxes in both study sites by 26.8–50.1%, but this was compensated by an increased predation by other predators, possibly enhanced by the availability of our artificial nests. 78% of identified foxes that ingested thiram-treated eggs, stopped nest predation after treatment. Foxes maintained stable territories during the whole study period. Partridge productivity was 132–677% higher in thiram-treatment areas than in control areas, and partridge density after treatment increased more in thiram-treated areas (193–292%) than in control areas (1.8–99%). Our study shows that CFA reduced ground nest predation by foxes, and had a positive effect on the partridge population despite the compensatory predation. This method could be used as a non-lethal tool for conservation of endangered ground-nesting bird species.