Genome scans and elusive candidate genes: detecting the variation that matters for speciation

Next‐generation sequencing is providing us with vast amounts of genetic data, yet we are currently struggling in our attempts to make sense of them. In particular, it has proven difficult to link phenotypic divergence and speciation to genome level divergence. In the current issue of Molecular Ecology, Ruegg et al. ( 2014 ) present new empirical results from two closely related bird taxa. They use a promising approach combining genome scan and candidate gene analysis. Their results suggest that we may have been looking in vain for candidate speciation genes by focusing only on genes found within genomic islands of divergence. This is because genes important in divergence and speciation may not be detected by genome scans and because features of the genomic architecture per se may have a large effect on the pattern of genome divergence.     

The New Zealand falcon and wind farms: a risk assessment framework

Abstract

Internationally, birds of prey are often reported as being relatively prone to collision with wind turbines in comparison to other groups of birds. However, as yet it is unclear to what extent New Zealand's only endemic bird of prey, the New Zealand falcon (Falco novaeseelandiae), is at risk. In this paper we summarise the potential for wind farms to impact New Zealand falcon, evaluate the efficacy of a range of risk assessment and post-consent monitoring practices, and present options for mitigating and/or offsetting any residual effects. We conclude that the lack of knowledge on the effects of wind farms on New Zealand falcon is the result of inconsistency in the assessment methods thus far employed and the absence of a coordinated approach to monitoring methods and the dissemination of results. To remedy this we present a risk assessment framework that, if adopted, will provide the information necessary to ensure alternative energy targets can be met without compromising the conservation of this threatened species.     

睾酮对鸟类繁殖影响研究进展

类固醇激素睾酮是影响鸟类繁殖最重要的性激素之一,与鸟类的繁殖行为的各个方面息息相关。睾酮通过影响鸟类的羽色、鸣声等来影响鸟类的配偶选择,同时睾酮可以调节配偶选择和繁殖投入之间的平衡。睾酮水平影响出雏数、出飞数、孵化率成功率等繁殖成效。睾酮还对个体的免疫活性和个体的存活率等产生影响。目前关于睾酮对鸟类繁殖影响的研究大多是通过外源性植入睾酮的方式来改变个体睾酮的浓度,其研究结果也常出现相互矛盾之处,对于自然状态下影响睾酮水平变化的因素尚缺乏了解,睾酮对雌雄鸟在繁殖过程中的影响也不尽相同,有必要继续深入研究。     

Factors influencing Cinnamon Teal nest attendance patterns

Patterns of nest attendance in birds result from complex behaviours and influence the success of reproductive events. Incubation behaviours vary based on individual body condition, energy requirements and environmental factors. We assessed nest attendance patterns in Cinnamon Teal Spatula cyanoptera breeding in the San Luis Valley of Colorado in 2016–2017 using trail and video cameras to observe behaviours throughout incubation. We evaluated the effect of temporal, life‐history and environmental covariates on the frequency and duration of incubation recesses as well as the incubation constancy. There was considerable model uncertainty among the models used to evaluate recess frequency. Recess duration varied according to the interaction between nest age and a quadratic effect of time of day, with hens on older nests taking longer recesses in the afternoon and hens on nests earlier in incubation taking longer recesses in the morning and evening. Incubation constancy decreased with higher ambient temperatures in the study area. This study provides evidence that Cinnamon Teal modify their behaviour during incubation according to the age of the nest and the time of day. These results improve our knowledge of Cinnamon Teal breeding ecology and shed light on the behaviours that fast‐lived species may use to cope with environmental factors during nesting.     

A place to land: spatiotemporal drivers of stopover habitat use by migrating birds

Migrating birds require en route habitats to rest and refuel. Yet, habitat use has never been integrated with passage to understand the factors that determine where and when birds stopover during spring and autumn migration. Here, we introduce the stopover‐to‐passage ratio (SPR), the percentage of passage migrants that stop in an area, and use 8 years of data from 12 weather surveillance radars to estimate over 50% SPR during spring and autumn through the Gulf of Mexico and Atlantic coasts of the south‐eastern US, the most prominent corridor for North America’s migratory birds. During stopovers, birds concentrated close to the coast during spring and inland in forested landscapes during autumn, suggesting seasonal differences in habitat function and highlighting the vital role of stopover habitats in sustaining migratory communities. Beyond advancing understanding of migration ecology, SPR will facilitate conservation through identification of sites that are disproportionally selected for stopover by migrating birds.     

Hydroxylation of quinocetone and carbadox is mediated by CYP1As in the chicken (Gallus gallus)

Quinoxaline derivatives (quinoxalines) comprise a class of drugs that have been widely used as animal antimicrobial agents and feed additives. Although the metabolism of quinoxaline drugs has been mostly studied using chicken liver microsomes, the biochemical mechanism of biotransformation of these chemicals in the chicken has yet to be characterized. In this study, using bacteria produced enzymes, we demonstrated that both CYP1A4 and CYP1A5 participate in the oxidative metabolism of quinoxalines. For CYP1A5, three hydroxylated metabolites of quinocetone were generated. In addition, CYP1A5 is able to hydroxylate carbadox. For CYP1A4, only one hydroxylated product of quinocetone on the phenyl ring was identified. Neither CYP1A5 nor CYP1A4 showed hydroxylation activity towards mequindox and cyadox. Our results suggest that CYP1A4 and CYP1A5 have different and somewhat overlapping substrate specificity in quinoxaline metabolism, and CYP1A5 represents a crucial enzyme in hydroxylation of both quinocetone and carbadox.