Captive Partridges Research Articles

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.

Birds feeding on tebuconazole treated seeds have reduced breeding output.

Drilled seeds are an important food resource for many farmland birds but may pose a serious risk when treated with pesticides. Most compounds currently used as seed treatment in the EU have low acute toxicity but may still affect birds in a sub-chronic or chronic way, especially considering that the sowing season lasts several weeks or months, resulting in a long exposure period for birds. Tebuconazole is a triazole fungicide widely used in agriculture but its toxicity to birds remains largely unknown. Our aim was to test if a realistic scenario of exposure to tebuconazole treated seeds affected the survival and subsequent reproduction of the red-legged partridge (Alectoris rufa). We fed captive partridges with wheat seeds treated with 0%, 20% or 100% of tebuconazole application rate during 25 days in late winter (i.e. tebuconazole dietary doses were approximately 0.2 and 1.1mg/kgbw/day). We studied treatment effects on the physiology (i.e. body weight, biochemistry, immunology, oxidative stress, coloration) and reproduction of partridges. Exposed birds did not reduce food consumption but presented reduced plasmatic concentrations of lipids (triglycerides at both exposure doses, cholesterol at high dose) and proteins (high dose). The coloration of the eye ring was also reduced in the low dose group. Exposure ended 60 days before the first egg was laid, but still affected reproductive output: hatching rate was reduced by 23% and brood size was 1.5 times smaller in the high dose group compared with controls. No significant reproductive effects were found in the low dose group. Our results point to the need to study the potential endocrine disruption mechanism of this fungicide with lagged effects on reproduction. Risk assessments for tebuconazole use as seed treatment should be revised in light of these reported effects on bird reproduction.

Morphometric traits of gizzard in relation to feeding habits of wild Sardinian partridges (Alectoris barbara barbara, Bonnaterre, 1790) with particular regard to clast selection.

Housing and feeding practices of wild birds for conservation management of biodiversity or restocking play a crucial role in determining the survival rates of animals when released into nature. Failure in coping with the environment might be one of the main flaws captive animals can experience when put into natural habitat. The present investigation aimed at exploring feeding habits and related morphometric traits of gizzard with respective content from wild partridges in comparison with captive ones. A total of 52 hunted wild Sardinian adult partridges (Alectoris barbara barbara Bonnaterre, 1790) were used. By comparison, 42 captive adult partridges reared in cages were enrolled. From each animal, the morphology of gizzard was investigated and respective content analysed for gross composition and taxonomical determination of fractions. Wet sieving analysis of each gizzard content was carried out (four-sieve towers with different mesh sizes: 1mm, 500μm, 250μm and 125μm), and relative and absolute weight of fresh filled and empty gizzards were recorded. Thickness of muscular layer of gizzard wall was measured by stereomicroscope. Carcass weight significantly (p<0.05) differed between captive vs. wild partridges (478±21 and 305±35g respectively). Post-mortem inspection highlighted gross morphological differences of gizzards between the two groups. Fresh weight of empty gizzards was 6.37±0.80 vs. 11.25±1.82g, with average pH values of digesta 4.97±0.11 vs. 4.38±0.28 in captive vs. wild partridges respectively. Gizzard content from wild partridges accounted a 61.7% vs. 38.3% of biological vs. non-biological material proportions (DM basis). The non-biological material was mostly represented by lithic fragments and minerals (quartz, feldspar, calcite and mica) with specific peculiarities in terms of granulometry and morphometry. Feeding the captive partridges should point to support morphological and functional adaptation of gizzards to the feeding stuffs naturally available in the environment.

Free and Esterified Carotenoids in Ornaments of an Avian Species: The Relationship to Color Expression and Sources of Variability

Many animal species show ornaments with yellow-orange-red colors produced by carotenoid pigments. Such traits have evolved as reliable signals of individual quality because of the costs inherent to their production or maintenance. In animal tissues, carotenoids are often found combined with free fatty acids, as carotenoid esters, which may confer more stability to coloration than free carotenoids. Surprisingly, the potential relevance of carotenoid esterification in the expression of animal sexual signals has been virtually ignored. Moreover, the sources of variability of esterified carotenoid levels are barely known, because most studies have not quantified their concentrations. Here, carotenoids in the ornaments (bill, eye rings, and legs) of red-legged partridges Alectoris rufa were quantified in their free and esterified forms. Carotenoid ester levels were the best predictors of leg color, whereas the redness of the other traits was better explained by free carotenoids. Nonetheless, total carotenoid levels (the sum of free and esterified forms) were always significantly correlated to redness. Young partridges had lower levels of free and esterified carotenids in the legs than did older individuals. Also, wild animals had higher ester levels and a higher proportion of carotenoids in esterified forms in all traits than did captive partridges. Probable physiological mechanisms explaining these patterns are discussed.

Molecular phylogeny and diversity of the Corsican red‐legged partridge: hybridization and management issues

The red-legged partridge, Alectoris rufa (Phasianidae), is a game bird hunted throughout its range (Italy, France with Corsica Island, Iberian Peninsula). The release into the wild of farmed birds of unknown origin coupled to the hybridization with the exotic chukar Alectoris chukar (East Mediterranean to East Asia) has led to the reduction of the spatial component of genetic variability and to the pollution of the genome of A. rufa, respectively. On the mainland, A. chukar genes occur according a decreasing gradient from Italy to the Iberian Peninsula. Corsica hosts a number of A. rufa×A. chukar hybrids, but at a much lower incidence than nearby Italy. We sampled 97 red-legged partridges in different habitats of Corsica [lower-Mediterranean: Desertu di l'Agriate; rural: Nessa-Felicetu; mountainous: Vivariu-Venacu and Fium'Orbu-Taravu (FT)]. We investigated kinship between Corsican and continental A. rufa populations by sequencing the mitochondrial DNA (mtDNA) Cytochrome-b gene in a subset (n=60) of island specimens as well as in 105 partridges sampled on mainland Europe. All 97 Corsican partridges were genotyped at eight microsatellite DNA loci in order to estimate intraspecific relationships at a finer scale. We also used microsatellite data from previous studies to compare the genotypes of A. rufa reared in the only island farm with those of wild conspecifics. Corsican partridges grouped in the only statistically reliable and diverging mtDNA clade. Microsatellites provided evidence for the genetic isolation of the FT mountain population, whose low level of hybridization with A. chukar had been unveiled in a former paper. Both mtDNA and microsatellite markers revealed that released captive partridges did not enter the wild breeding populations to any great extent. We suggested banning A. rufa translocation from Corsica to the continent to comply with the disclosed genetic kinship, and vice versa to contain the spreading of A. chukar genes in to the A. rufa population.

Captivity diets alter egg yolk lipids of a bird of prey (the American kestrel) and of a galliforme (the red-legged partridge).

The salient feature of the fatty acid profile of kestrel eggs collected in the wild was the very high proportion of arachidonic acid (15.2%+/-0.7% of fatty acid mass, n=5) in the phospholipid fraction of the yolk. Kestrels in captivity fed on day-old chickens produced eggs that differed from those of the wild birds in a number of compositional features: the proportion of linoleic acid was increased in all the lipid fractions; the proportion of arachidonic acid was increased in yolk phospholipid and cholesteryl ester; the proportion of alpha-linolenic acid was decreased in all lipid classes, and that of docosahexaenoic acid was decreased in phospholipid and cholesteryl ester. Partridge eggs from the wild contained linoleic acid as the main polyunsaturate of all the yolk lipid fractions. Captive partridges maintained on a formulated diet very rich in linoleic acid produced eggs with increased levels of linoleic, arachidonic, and n-6 docosapentaenoic acids in the phospholipid fraction; reduced proportions of alpha-linolenic acid were observed in all lipid classes, and the proportion of docosahexaenoic acid was markedly reduced in the phospholipid fraction. Thus, captive breeding of both the kestrel and the partridge increases the n-6/n-3 polyunsaturate ratio of the yolk lipids.

Effects of hand‐rearing on physiology and anatomy in the grey partridge

Artificial rearing may result in changes in the physiology and anatomy of gallinaceous birds. This may partially explain the poor survival of released birds. To study the effects of hand‐rearing on grey partridges Perdix perdix, we measured the anatomical and physiological characteristics of 14 wild and 15 hand‐reared partridges. Captive partridges were heavier, had relatively larger breast muscles but relatively lighter hearts and livers than wild birds. Wild birds had longer small intestines, longer caeca and relatively heavier gizzards than hand‐reared birds. They also had higher glycogen content and cytochrome‐c oxidase activity in the pectoral muscles, indicating their better flying endurance compared to hand‐reared birds. The results suggest that captivity results in altered anatomical and physiological characteristics, and hand‐reared partridges may therefore be poorly predisposed for an abrupt release into the wild.