Perdix Perdix Research Articles

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.

A landscape-based approach to design flower blocks may reduce mammalian predator activity and protect ground-nesting farmland birds

AbstractHigh predation rates threaten many ground-nesting farmland birds and are difficult to address through conventional measures such as lethal predator control or fencing. Landscape-based approaches for conservation measures promise an alternative by reducing predator - bird encounters, but require detailed knowledge of landscape effects on predation risk. Different habitat elements attractive to predators could have opposing effects on neighbouring nesting habitats, with implications for conservation: Increased predation risk due to higher predator activity (A) or reduced predation risk by distracting predators (B). Here we focus on the placement of conservation measures using flower blocks targeted at Grey Partridges in a Central European Farmland. Based on a three-year camera trap dataset, we investigated effects of landscape structure and composition on mammalian predator activity within flower blocks at two scales (100 m and 500 m radius around the camera) with generalized linear mixed models. Length of linear edge structures, i.e., field block borders, was most important, with a greater availability of linear edge structures leading to a decrease in predator activity at both scales (hypothesis B). Conversely, predator captures at both scales increased with increasing extensive vegetation area (i.e., permanent grassland, flower blocks and fallows) and in proximity to roads, indicating that these may attract predators and increase predator densities (hypothesis A). Our results suggest that a landscape-based approach can mitigate predation risk for ground-nesting birds in flower blocks and analogous conservation measures. Highly structured, small-scale agricultural landscapes seem to be particularly important for reducing mammalian predator activity in flower blocks.

Comparison of pesticide contamination between captive-reared and wild grey partridges: insights into environmental exposure disparities.

Pesticide contamination is often cited as a key factor in the global decline of farmland birds. However, the majority of studies on pesticide exposure in non-target fauna are not representative of what happens in nature because they are limited to artificial conditions. The aim of this study was to define and compare, for the first time, pesticide contamination in grey partridges (Perdix perdix) from two different contexts, i.e., captivity vs. the wild. Blood samples taken from 35 captive and 54 wild partridges in 2021-2022 were analysed for 94 pesticides most commonly used in French agriculture. Captive partridges had 29 molecules detected in their blood (12 herbicides, 14 fungicides, and three insecticides) compared to wild partridges, which had 50 molecules (13 herbicides, 23 fungicides, and 14 insecticides). Of these pesticide compounds found in individuals, 26 were banned. Captive partridges had significantly fewer pesticide molecules than wild partridges, with one to 14 pesticides per captive individual and 8 to 20 pesticides per wild individual. Nineteen molecules were common to both groups, with concentrations up to three times higher in wild partridges than in captive partridges. Our results thus show multiple exposures for most of our individuals, especially in wild partridges, which can lead to cocktail effects, which are never considered. Furthermore, the difference in contamination between the wild and captive partridges reflects the multiple routes of contamination in nature, in particular, due to the use of a wide range of habitats by wild partridges.

Combining Historical and Molecular Data to Study Nearly Extinct Native Italian Grey Partridge (Perdix perdix) at the Turn of the Twentieth Century.

The grey partridge (Perdix perdix Linnaeus, 1758), is a polytypic species with seven recognized subspecies, including P. p. italica (Hartert, 1917), which is endemic to Italy. Until World War II, the species was widespread across Europe but severely declined due to anthropogenic causes, jeopardizing the Italian subspecies gene pool. Genetic characterization and haplotype identification were performed by analyzing the 5'-end of the mitochondrial control region (CR). A total of 15 haplotypes were detected, seven of which were present in the population before 1915. Among them, three haplotypes were never detected again in the individuals collected after 1915. Interestingly, eight of the 15 haplotypes detected in Italian museum samples belonged exclusively to individuals collected after 1915. The obtained data highlight a high presence of specimens originating from other European populations and, despite all the conservation efforts, suggest an uncertain situation of the subspecies in Italy. This research was strongly backed up by extensive bibliographic research on historical documents, allowing the identification of hundreds of restocking events all over Italy. This is an integral part of this research and has laid the foundations for identifying and circumscribing historical periods in which introductions from the rest of Europe had different pressures, aiming to define a baseline.

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.

Early Neolithic avifaunal remains from southeast Anatolia provide insight into Early Holocene species distributions and long‐term shifts in their range

Based on the species‐rich avifaunas from Early Neolithic sites across Upper Mesopotamia (southeast Türkiye, northern Syria, northern Iraq), we compared seven species' Early Holocene distribution patterns with that of their modern species ranges. The avifaunal remains from four sites were analysed by the authors and bird identifications from 10 additional sites were extracted from published reports. In the case of the Common Crane Grus grus, Grey Partridge Perdix perdix and Black Francolin Francolinus francolinus, shifts in distributions relate to significant changes in climate marking the transition from the Pleistocene to the Holocene. In contrast, the massive decline of the Griffon Vulture Gyps fulvus represents a more recent phenomenon related to anthropogenic impact on their habitats and food sources. For the Black‐bellied Sandgrouse Pterocles orientalis and the Pin‐tailed Sandgrouse P. alchata, changes in distributional range from the Early Holocene to the present could not be detected. Finally, a single bone of Macqueen's Bustard Chlamydotis macqueenii at Göbekli Tepe is unexpected and conceivably we are dealing with the remains of a rare vagrant, more likely to be found in dry steppe and desert habitats, which were located south of the study area at that time. This study highlights the value of archaeozoological finds in helping to understand how species distributional ranges have changed over time. Similarly, our work suggests that authors studying archaeozoological data should not assume that present‐day distributional ranges of taxa of interest represent the ranges of these species in the past.

32. Design of a parentage assignment panel for cage-free reproduction of grey partridge

32. Design of a parentage assignment panel for cage-free reproduction of grey partridge

Richard Maack's Vilyui expedition in the study of avifauna and gallinaceous birds (Gallinaceae) of Eastern Siberia

The article is dedicated to the 170th anniversary of the Vilyuisk (Yakutia) expedition organised by the Siberian (Irkutsk) branch of the Imperial Russian Geographical Society (1853-1885). It was led by Richard Karlovich Maack (Germ. Richard Otto Maack), a Russian naturalist of German origin and explorer of Siberia and the Far East. It also contains some information on the Pribaikalia and Transbaikalia, taken along the way during the subsequent Amur (1855-1856) and Ussuri (1859-1960) expeditions. The route, dates, and composition of the expedition are described and the contribution of the scientist to various fields of natural science and, above all, to the study of vertebrates of the region is evaluated. Scientists have identified the habitat of amphibians and reptiles (4 species), birds (121), mammals (34), which is relatively large against the background of regional studies conducted in Eastern Siberia at that time. According to the lists of bird species published in the fundamental work of the scientist "Vilyuisky district of the Yakut region" [1883-1887], the distribution of 5 species of Gallinaceous birds (Gallinaceae) in the middle of the XIX century was revealed – Hazel Grouse, Western and Black-billied Capercaillies, Black Grouse, Willow Ptarmigan. For Transbaikalia and Pribaikalia, the habitat of two more species is noted - Gray and Bearded Partridges. The Common Pheasant was accounted for by R. K. Maack only in the Amur region and the Amur region (Far East). In general, over the century and a half of the history of studying Gallinaceous birds, their species composition has practically not changed in the researcher's work area. In Yakutia, it was replenished with species from the eastern and southern regions, living there Rock Partridge and Siberian Grouse. On the scale of Eastern Siberia, only the Pheasant is currently supplementing the Gallinaceous birds list as a new species in the region, documented in the south of Eastern Siberia – in the Eastern Sayan bordering the Baikal region and in some places of Transbaikalia (not yet precisely confirmed).

Catalogue of stuffed birds with atypical colouration and developmental anomalies deposited in the State Museum of Natural History NASU, Lviv, Ukraine

Birds with atypical colouration and developmental anomalies very rarely occur in the wild, and museum collections of such specimens have been formed over centuries. Today, their scientific importance is growing due to the emergence of new opportunities in genetic research, and distribution of information on the collections of this kind is a useful thing. The digitization of collections becomes especially important in times of war, because currently none of the museum collections in Ukraine have guarantees against possible losses. The collection of stuffed birds with atypical colouration and developmental anomalies, deposited in the State Museum of Natural History, NASU includes 157 specimens of 44 species. It was collected from 1850 to 1930. Later, only one stuffed bird was received in 2012. The collection was formed both as a result of the activities of museum staff (hunting, buying at markets) and the receipt of numerous gifts to the museum's founder, Volodymyr Didushytskyi. Among the species, the most numerous are the house sparrow Passer domesticus L., 1758 – 24 spec., the grey crow Corvus cornix L., 1758, the rook Corvus frugilegus L., 1758 and the village swallow Hirundo rustica L., 1758, presented by 11 spec. each, and the grey partridge Perdix perdix L., 1758 – 9 spec. Some 117 specimens were collected from the present territory of Ukraine, 28 spec. from the present territory of Poland, and the place of collection of the remaining 12 specimens is unknown. In Ukraine, most specimens were collected in Lvivska province (89); the rest – in Ternopilska province (15), Ivano-Frankivska province (12) and Volynska province (1). In Poland, 12 specimens were collected in the Podkarpackie voivodeship, 11 spec. in the Małopolskie voivodeship, 2 spec. in the Lubelskie voivodeship and 1 spec. in the Lódzkie voivodeship. Among all localities, the largest number of specimens was collected from Lviv City and its environs – 24, form the village of Peniaky, Zolochivskyi district, Lvivska province – 12, and from Kraków City and its environs – 11. At the end of 2023, the entire collection was digitized as a part of the project "Crisis Inventory and Leap to Digitalization of Museum Records" Tustan NGO, “Tustan” State Historical and Cultural Museum, NeMo: Ukrainian Heritage Monitoring Lab and the NGO “Centre for Museum Development” with the financial support of the European Union. Each exhibit was photographed in six projections: front, left and right sides, back, bottom, and in the most favourable exhibition position. The catalogue was prepared within the framework of the project "Methodological principles of expert evaluation of the scientific potential of natural history collections" of the Department of Applied Museology of the State Museum of Natural History, National Academy of Sciences of Ukraine, state registration No.0122U001440.

In ovo feeding of methionine affects antioxidant status and growth-related gene expression of TETRA SL and Hungarian indigenous chicks

Methionine (Met) plays a substantial role in poultry due to its involvement in several pathways, including enhancing antioxidant status and improving growth performance and health status. This study examined how in ovo feeding of Met affects hatching performance, antioxidant status, and hepatic gene expression related to growth and immunity in the TETRA-SL LL hybrid (TSL) commercial layer and Hungarian partridge colored hen (HPC) indigenous genotypes. The eggs were injected with saline, DL-Met, and L-Met on 17.5 days of embryonic development. The results showed that the in ovo feeding of DL-Met significantly increased the hatching weight and ferric reducing the ability of the plasma (FRAP) compared with L-Met. The in ovo feeding of either Met source enhanced the liver health and function and hepatic antioxidant status of the chicks. The genotype’s differences were significant; the TSL genotype had better hatching weight, an antioxidant defense system, and downregulated growth-related gene expression than the HPC genotype. In ovo feeding of either Met source enhanced the chicks' health status and antioxidant status, and DL-Met improved the hatching weight of the chicks more than L-Met. Genotype differences were significantly evident in the responses of growth performance, antioxidant status, blood biochemical parameters, and gene expression to Met sources.

Plasma cholesterol and triglyceride levels in black-necked pheasants, gray and chukar partridges with cannibalism treated with silymarin and tryptophan

Plasma cholesterol and triglyceride levels were studied in black-necked pheasants, gray partridges and chukar partridges divided into 4 groups (n=12 in each group; n=6 by sex): first group (negative control) – clinically healthy birds, second group – birds treated with tryptophan, third group – birds treated with sylimarin, fourth group (positive control) – birds with signs of cannibalism. In the pheasants and chukars with signs of cannibalism, cholesterol levels were higher than these in the control group. On the opposite, the triglyceride levels in the other three groups of birds with canniba­lism were substantially lower than those in the healthy group. Supplementation with tryptophan tended to increase blood cholesterol and triglycerides in pheasants, gray and chukar partridges. In the groups treated with silymarin, the levels of the studied indicators were significantly higher in comparison to birds with cannibalism.

A tiny duck (<em>Sibirionetta formozovi</em> sp. nov.), a giant grey partridge (<em>Titanoperdix felixi</em> gen. et sp. nov.), a new rail (<em>Porzana payevskyi</em> sp. nov.), and other birds from the Early Pleistocene of Baikalian Siberia

The paper describes fossil birds from the Early Pleistocene (Gelasian) of Malye Goly locality in the Baikal area of the East Siberia (Irkutsk Region, Russia). This is the first studied bird fauna from the Early Pleistocene of the Northern Asia, shedding the first light on the early Quaternary bird associations of the Siberia. A tiny fossil duck Sibirionetta formozovi sp. nov. is the first fossil representative of the modern genus Sibirionetta, the modern endemic of Eastern Siberia. This find documents the long-time (at least since the Early Pleistocene) presence of these ducks in the region. A new large pheasant-sized phasianid bird Titanoperdix felixi gen. et sp. nov. is a large-sized representative of the grey partridge evolutionary lineage (Perdicini). This find is in agreement with the fact that modern relatively small grey partridges (genus Perdix) are phylogenetically nested within the larger-bodied pheasants. Among other birds from the locality are Tadorna tadorna, three other ducks (including one diving form), Perdix cf. dauurica, Porzana payevskyi sp. nov., Podicipedidae gen. indet., Scolopacidae gen. indet., and Corvidae gen. indet. The assemblage indicates a rather productive water body with mostly open landscapes in the vicinity. The avifauna from Malye Goly does not show any considerable affinity with the Late Pliocene avian assemblages from Southern Transbaikalia and Northern Mongolia, as well as with the Early Pleistocene bird fauna of Eastern China, and thus most likely represents a separate paleornithogeographical unit. Porzana payevskyi sp. nov. is one of the oldest confirmed representatives of Porzana s.s. in the fossil record, supporting the Asian origin of the genus and a probable out-of-Asia dispersal to North America in the Early Pleistocene.

STUDY REGARDING THE EVOLUTION OF THE WILD ANIMALS POPULATIONS FROM SEACA HUNTING FUND (OLT COUNTY)

The prospects for game fauna, edible or non-edible, for game culture or just for bringing their populations under control, are only likely and different from species to species. The purpose of this paper is to follow the evolution of the populations of game fauna in the Seaca No. 4 Hunting Fund (Olt County) in the period 2011–2021, in order to deepen and improve the existing game management. The surface of the game reserve is 8,661 ha and overlaps with 3 protected areas. During the research period, 9 representative species of hunting interest were identified, important from an ecological, economic and aesthetic point of view: 7 mammal species (belonging to 3 orders, 5 families) and 2 bird species (Phasianidae). Of the species of game interest studied, only the European fallow deer (an artificially introduced species), roe deer and red fox showed an increase in the number of animals, their hunting quotas and, therefore, their harvests during the research period. We mention the reduction in the wild boar herds, in spite of the special care taken by the administrator to supplement their food requirements, and the appearance and multiplication of jackals in the area, the multiplication of red foxes and the reduction in the European hare and gray partridge numbers. Comparing the actual and optimum populations in 2021, it can be observed that the actual population of roe deer, red deer and pheasant is close to the optimum population level. Thus, during the research period, the herds of hunting fauna were relatively high and balanced, in accordance with the diversity of the habitats and the large number of facilities for hunting. The need is felt to protect the habitats and further develop the territory where game is taken care of and harvested in the context where the habitats are subject to alarming changes, which affect both the trophic capacity and the shelter needed by the game. The hunters from the studied hunting fund must maintain a sincere and constructive dialogue with the other actors in the field, in order to be able to take, jointly, the most appropriate measures for the conservation of wild fauna, without harming protected areas, agricultural production, forestry, etc.

Methionine sources and genotype affect embryonic intestinal development, antioxidants, tight junctions, and growth-related gene expression in chickens

Methionine (Met) is an essential and first limiting amino acid in the poultry diet that plays a significant role in chicken embryonic development and growth. The present study examined the effect of in ovo injection of DL-Met and L-Met sources and genotypes on chicken embryonic-intestinal development and health. Fertilized eggs of the two genotypes, TETRA-SL layer hybrid (TSL) — commercial layer hybrid and Hungarian Partridge colored hen breed (HPC) — a native genotype, were randomly distributed into four treatments for each genotype. The treatment groups include the following: 1) control non-injected eggs (NoIn); 2) saline-injected (SaIn); 3) DL-Met injected (DLM); and 4) L-Met injected (LM). The in ovo injection was carried out on 17.5 d of embryonic development; after hatching, eight chicks per group were sacrificed, and the jejunum was extracted for analysis. The results showed that both DLM and LM groups had enhanced intestinal development as evidenced by increased villus width, villus height, and villus area (P < 0.05) compared to the control. The DLM group had significantly reduced crypt depth, glutathione (GSH) content, glutathione S-transferase 3 alpha (GST3), occludin (OCLN) gene expression and increased villus height to crypt depth ratio in the TSL genotype than the LM group (P < 0.05). The HPC genotype has overexpressed insulin-like growth factor 1 (IGF1) gene, tricellulin (MD2), occludin (OCLN), superoxide dismutase 1 (SOD1), and GST3 genes than the TSL genotype (P < 0.05). In conclusion, these findings showed that in ovo injection of Met enhanced intestinal development, and function, with genotypes responding differently under normal conditions. Genotypes also influenced the expression of intestinal antioxidants, tight junction, and growth-related genes.

Citizen science and diet analysis shed light on dog-wildlife interactions in Italy

Domestic dogs Canis familiaris may cause a range of impacts on wildlife through predation, competition, pathogen transmission, harassment and hybridisation with wolves and other wild canids, yet such effects are less known than those of other domestic species.In this work, we have combined citizen science data and information collected by scientists on the potential impact of free-ranging dogs on wildlife in Italy. Citizen science data, obtained through online surveys on social networks, consisted of pictures of wildlife killed or harassed by dogs from 2002 to 2022. Additional records were collected from articles in newspapers. We also provide the results of a diet analysis from domestic dog scats, collected in the countryside in central Italy in 1998–1999, for which we assessed prey selection by comparing consumption with availability. The citizen science survey provided 589 records: dogs attacked and killed 95 species, mostly mammals and birds, including small game species. Among species of conservation concern, dogs attacked/killed Mustela putorius and Hystrix cristata, both included in Annex IV of the Habitats Directive, and the Italian endemic Lepus corsicanus and Passer italiae. Over 90% of the attacks were caused by unleashed dogs in the presence of their owner in urban and periurban areas. The 148 dog scats analysed contained 30 prey species, mainly mammals, which made the staple of the dog diet, followed by amorphous material, most likely pet food. Remains of domestic sheep were frequent in the diet, as were hares Lepus europaeus and roe deer Capreolus capreolus among wild mammals. Wild boar Sus scrofa ranked first among the selected prey species, followed by hares, whereas roe deer and grey partridges Perdix perdix were negatively selected. The mitigation of the impact of domestic carnivores on wildlife strongly requires awareness raising to promote responsible pet ownership and strict avoidance of dogs’ free-ranging behaviour, especially where encounters with wildlife are most likely.

Will passive acoustic monitoring make result‐based payments more attractive? A cost comparison with human observation for farmland bird monitoring

AbstractResult‐based payments (RBPs) reward land users for conservation outcomes and are a promising alternative to standard payments, which are targeted at specific land use measures. A major barrier to the implementation of RBPs, particularly for the conservation of mobile species, is the substantial monitoring cost. Passive acoustic monitoring may offer promising opportunities for low‐cost monitoring as an alternative to human observation. We develop a costing framework for comparing human observation and passive acoustic monitoring and apply it to a hypothetical RBP scheme for farmland bird conservation. We consider three different monitoring scenarios: daytime monitoring for the whinchat and the ortolan bunting, nighttime monitoring for the gray partridge and the common quail, and day‐and‐night monitoring for all four species. We also examine the effect of changes in relevant parameters (such as participating area, travel distance and required monitoring time) on the cost comparison. Our results show that passive acoustic monitoring is still more expensive than human observation for daytime monitoring. In contrast, passive acoustic monitoring has a cost advantage for nighttime as well as day‐and‐nighttime monitoring in all considered scenarios.

Distance to the edge and other landscape features influence nest predation in grey partridges

AbstractPredation and habitat deterioration are the main reasons for the strong decline of ground‐nesting farmland birds such as the grey partridge Perdix perdix in Europe. Grey partridge nests and incubating females are especially vulnerable to predation. We have previously demonstrated that predator activity is much lower inside flower blocks (agri‐environment schemes sown with a flower seed mix) than at their edges and that predator activity in flower blocks depends on the surrounding landscape. Here, we investigate whether these differences in predator activity translate into differences in grey partridge nest predation and assess predation patterns relative to landscape and nest site characteristics. We recorded the success of 56 nests of radio‐tagged grey partridges between 2009 and 2017 in an agricultural landscape in Central Germany. We used Bayesian logistic regression to analyse the effects of nest site and landscape characteristics on nest predation on a subset of 46 nests (21 nests successful, 25 predated). Distance to the edge of the nesting habitat was the most important predictor, reducing predation probability from 66.8% at the edge to 18.5% at 85.5 m. Predation probability decreased with increasing length of habitat borders, habitat diversity and the area of permanent grasslands and fallows. Predation probability was higher further from settlements and increased with increasing woodland area in the agricultural matrix. When considering linear landscape structures, nest predation patterns matched the patterns of predator activity from our previous studies. Results suggest that the distance to the edge of the nesting habitat is most important and that nest predation may be reduced by providing sufficiently broad nesting habitats. Nest predation may further be minimized by increasing habitat diversity and coverage of extensive vegetation types and by establishing conservation measures for grey partridges further away from woodlands. These measures may also benefit other ground‐nesting farmland birds.

Habitat preferences and similarities of Grey Partridges and Common Pheasants in agricultural landscapes under organic and conventional farming

Agricultural landscapes had been inhabited by a vast number of bird species in the past; however, especially in the last decades, agricultural intensification had negatively affected habitat composition. Habitat heterogeneity decreased and the number of many species inhabiting farmland has severely declined. These landscapes still offer a home for species, but with decreasing environmental variability, less suitable habitat might be available and interspecific competition might have been altered. Agricultural fields under organic farming are often assumed to provide adequate habitats for farmland birds, thus competition for these areas might be high and affect species’ habitat selection. We compared habitat selection of two typical farmland bird species, Grey Partridges (Perdix perdix) and Common Pheasants (Phasianus colchicus), to determine the extent of habitat overlap in agricultural landscapes under organic and conventional farming in spring. Our study showed that both species preferred study squares with high habitat heterogeneity. In addition, squares with agricultural fields (e.g. without culture, winter cereals and fallow land) under organic farming were preferred by Grey Partridges, while Common Pheasants were mainly found on study squares containing agricultural fields under conventional farming. A broad habitat width in respect to food selection might have driven habitat choice of Common Pheasants; however, occupation of agricultural fields under organic farming by Grey Partridge males might also explain habitat selection of Common Pheasants. Awareness should be raised when releasing captive-rearing pheasants because interspecific competition between Grey Partridges and Common Pheasants could also affect fecundity and survival of both species.

Neonicotinoids: Still present in farmland birds despite their ban

Neonicotinoids (neonics) are the most widely used insecticides worldwide and are considered to be of low risk to non-target organisms such as vertebrates. Further, they are reported to be rapidly excreted and metabolized, reducing their potential toxicity. Nevertheless, growing evidence of adverse effects of neonics on farmland bird species raise questions about the purported harmless nature of these pesticides. We attempted to search for pesticide residues in species of different trophic levels and at different life stages, by using multiple bird monitoring programs on a Long-Term Socio-Ecological Research (LTSER) platform. Three passerine birds—the blackbird (Turdus merula), cirl bunting (Emberiza cirlus), and common nightingale (Luscinia megarhynchos)—that feed on seeds and invertebrates were monitored during their reproductive period, and the grey partridge (Perdix perdix) that feeds on seeds was monitored during its wintering period. We also monitored chicks of an apex predator—the Montagu's harrier (Circus pygargus)—that preys mostly upon common voles but also upon insects. We found that the birds' blood samples showed presence of residues of five neonics: three banned since 2018 in France—clothianidin, thiacloprid, and thiamethoxam—and two—dinotefuran and nitenpyram—used for veterinary purposes only. While none of these neonics was detected in blackbirds, all were present in grey partridges. Clothianidin was detected in all species, except blackbirds. Concentrations of the three banned neonics were similar or higher than concentrations found in birds monitored elsewhere before the ban. These findings raise questions about the persistence of neonics within the environment and the mode of exposure to wild fauna. Future investigations on the sublethal effects of these neonics on life-history traits of these farmland birds may help in providing a better understanding of the effects of exposure of bird populations to these insecticides, and also to the consequent effect on human health.

Орел-могильник в Республике Татарстан — продолжение исследований

Орел-могильник в Республике Татарстан — продолжение исследований