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Lead (Pb) poisoning via ingestion of shot pellets is a frequent cause of death in wild birds and also has a wide range of subclinical effects. Here we report on the sublethal effects Pb exposure has on the breeding performance of red-legged partridges (Alectoris rufa). We studied the effects of Pb exposure on sperm quality, reproductive success, egg properties, laying performance, antioxidant levels, and carotenoid-based coloration. Birds were exposed by oral gavage to one or three No. 6 Pb shot pellets (2.8 mm in diameter, mean mass ± SD 109 ± 7.97 mg). We show that exposure to three pellets (330 mg) reduced the hatching rate of females and decreased the acrosome integrity and sperm motility of males. In addition, females exposed to 1 pellet (110 mg) produced heavier eggs and chicks, whereas males exposed to 1 pellet presented an increase in sperm vigor. Sperm viability, concentration, progressiveness or fecundation rate were not affected by Pb treatment. Pb exposure increased circulating antioxidant levels in males, whereas the percentage of carotenoidpigmented eye-ring area decreased in exposed females. Several sperm parameters showed positive relationships with coloration and antioxidant levels, suggesting that males displaying redder ornaments may be more capable of protecting sperm from oxidative stress in the event of sublethal Pb exposure. © 2016 American Chemical Society.

This article documents the addition of 112 microsatellite marker loci and 24 pairs of single nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Agelaius phoeniceus, Austrolittorina cincta, Circus cyaneus, Circus macrourus, Circus pygargus, Cryptocoryne · purpurea Ridl. nothovar. purpurea, Mya arenaria, Patagioenas squamosa, Prochilodus mariae, Scylla serrata and Scytalopus speluncae. These loci were cross-tested on the following species: Cryptocoryne · purpurea nothovar. purpurea, Cryptocoryne affinis, Cryptocoryne ciliata, Cryptocoryne cordata var. cordata, Cryptocoryne elliptica, Cryptocoryne griffithii, Cryptocoryne minima, Cryptocoryne nurii and Cryptocoryne schulzei. This article also documents the addition of 24 sequencing primer pairs and 24 allele-specific primers or probes for Aphis glycines.

1. Among the commonest sexual signals of birds are the red-yellow traits pigmented by carotenoids, but how they reliably advertise individual quality remain poorly understood. Here we tested the hypothesis that carotenoid-based signalling is enhanced by testosterone but reduced by parasites, and that the dual action of testosterone on ornament expression and parasite resistance ensures reliable signalling. 2. Tetraonid birds such as the red grouse Lagopus lagopus scoticus have bright red combs pigmented by carotenoids, which function in intra- and inter-sexual selection. In separate experiments, we manipulated a main nematode parasite, Trichostrongylus tenuis (using deparasitation and re-infection) and testosterone (using testosterone or combined Flutamide/ATD treatments) in free-living males and investigated effects on plasma carotenoids and comb colour. 3. In untreated males, comb redness positively correlated with plasma carotenoids, testosterone concentration and condition. Plasma carotenoids and comb redness both negatively correlated with T. tenuis abundance. 4. Plasma carotenoids decreased in response to a challenge from T. tenuis, but increased when parasites were reduced. Testosterone enhanced comb redness, but tended to deplete plasma carotenoids. Combined Flutamide and ATD treatment had no significant effects on comb colour or plasma carotenoids, indicating that testosterone effects might be direct. 5. Our experiments show contrasted effects of testosterone and nematode parasites on carotenoid-based ornamentation. Testosterone and parasites have well documented interactions in the study model. These, together with the opposite effects that testosterone and parasites have on carotenoid availability and use, would shape optimal levels of signalling, depending on individual quality, and might ensure reliable signalling. 6. Carotenoid-based and testosterone-dependent traits have rarely been linked. Our study provides such a connection and shows that investiga

Among the most familiar sexual signals are red, yellow, and orange sexual traits pigmented by carotenoids. Many birds can detect near-ultraviolet (UV) light, and UV signals can play key roles in mate choice. Grouse (Tetraonidae) exhibit bright carotenoid-dependent sexual ornaments, their supra-orbital combs, which to humans appear orange-red. Combs also reflect in the UV, which is not visible to humans but is likely to be visible to grouse. In male red grouse Lagopus lagopus scoticus, we show that comb UV reflectance decreases with increasing comb size and redness. By removing the epidermis of combs, where carotenoid pigments are, we show that the UV reflectance is a property of the dermis, underneath the red pigmented epidermis. Carotenoid pigmentation of combs acted as a mask to reduce reflectance by the dermis in the range 400–550 nm and in the UV, 300–400 nm. Patagium skin (non-ornamental skin under the wing) also reflects in the UV, but epidermis removal on this bare part tended to reduce UV reflectance, whereas removal of the red epidermis of combs increased UV reflectance. Males in better condition (greater body mass relative to size) had bigger and redder combs, but with less UV. Thus, carotenoid pigments of grouse combs are deposited on a white background with significant UV reflectance, which can influence how the signal is perceived by conspecifics. Carotenoid-based traits exhibit UV reflectance in a number of species, but how UV reflectance and carotenoid pigmentation influence colour remains little known for integumentary ornaments compared to plumage traits. UV vision is not uncommon in birds and other animals, so future studies should investigate how UV reflectance influences the perception of carotenoid-based signals of quality.

There are costs and benefits to individuals of having high levels of circulating testosterone, and the costs can be particularly apparent outside the breeding season. Unlike many birds, red grouse have high testosterone levels in autumn and in this study we explored the consequences of variation in autumn testosterone levels, in terms of survival and breeding success. We caught 123 male grouse in September, from six sites in Scotland and England, U.K. Grouse were given either testosterone or control implants, then fitted with radiotransmitters and released. Control males tended to survive better, but the difference was not statistically significant. During the first 3 months, cause of mortality varied with treatment, with birds of prey killing only testosterone-implanted birds. In spring, females paired with testosterone-implanted males had larger combs (sexual ornaments) than those with controls, suggesting that they might have been better-quality individuals. Testosterone-implanted birds were more likely to be paired and to be bigamous, and each bird alive in spring produced on average 2.5 more offspring than control birds. The benefits of investing in elevated levels of testosterone are clearly high for those males that survive the winter. However, these benefits are reduced by overwinter mortality and the reproductive success of all males alive at the start of the experiment did not vary statistically with treatment. We discuss the longer-term consequences of high testosterone levels, which are likely to be very different to short-term ones