Eggshell colour is more strongly affected by maternal identity than by dietary antioxidants in a captive poultry system

1.Biologists have long puzzled over the apparent conspicuousness of blue-green eggshell coloration in birds. One candidate explanation is the sexual signalling hypothesis that the blue-green colour of eggshells can reveal an intrinsic aspect of females' physiological quality, with only high-quality females having sufficient antioxidant capacity to pigment their eggs with large amounts of biliverdin. Subsequent work has argued instead that eggshell colour might signal condition-dependent traits based on diet. 2.Using Araucana chickens that lay blue-green eggs, we explored (i) whether high levels of dietary antioxidants yield eggshells with greater blue-green reflectance, (ii) whether females differ from one another in eggshell coloration despite standardized environments, diets and rearing conditions, and (iii) the relative strength with which diet vs. female identity affects eggshell coloration. 3.We reared birds to maturity and then placed them on either a high- or low-antioxidant diet, differing fourfold in Vitamin E acetate and Vitamin A retinol. After 8 weeks, the treatments were reversed, such that females laid eggs on both diets in an order-balanced design. We measured the reflectance spectra of 545 eggs from 25 females. 4.Diet had a very limited effect on eggshell spectral reflectance, but individual females differed strongly and consistently from one another, despite having been reared under uniform conditions. However, predictions from avian visual modelling suggest that most of the egg colour differences between females, and nearly all of the differences between diets, are unlikely to be visually discriminable. 5.Our data suggest that eggshell reflectance spectra may carry information on intrinsic properties of the female that laid the eggs, but the utility of this coloration as a signal to conspecifics in this species may be limited by the sensitivity of a receiver to detect it.

The Pursuit of Tangible Happiness: Religion and Politics in a Japanese New, New Religion

The decline of traditional religions in Japan in the past century, and especially since the end of World War Two, has led to an explosion of so-called “new religions” (shin shūkyō 新宗教), many of which have made forays into the political realm. The best known—and most controversial—example of a “political” new religion is Sōka Gakkai 創価学会, a lay Buddhist movement originally associated with the Nichiren sect that in the 1960s gave birth to a new political party, Komeitō 公明党 (lit., Clean Government Party), which in the past several decades has emerged as the third most popular party in Japan (as New Komeitō). Since the 1980s, Japan has also seen the emergence of so-called “new, new religions” (shin shin shūkyō 新新宗教), which tend to be more technologically savvy and less socially concerned (and, in the eyes of critics, more akin to “cults” than the earlier new religions). One new, new religion known as Kōfuku-no-Kagaku 幸福の科学 (lit., Institute for Research in Human Happiness or simply Happy Science), founded in 1986 by Ōkawa Ryūho 大川隆法, has very recently developed its own political party, Kōfuku Jitsugentō 幸福実現党 (The Realization of Happiness Party). This article will analyse the political ideals of Kōfuku Jitsugentō in relation to its religious teachings, in an attempt to situate the movement within the broader tradition of religio-political syncretism in Japan. In particular, it will examine the recent “manifesto” of Kōfuku Jitsugentō in relation to those of New Komeitō and “secular” political parties such as the Liberal Democratic Party (Jimintō 自民党) and the Democratic Party (Minshutō 民主党).

Effects of Food Availability on Yolk Androgen Deposition in the Black-Legged Kittiwake (Rissa tridactyla), a Seabird with Facultative Brood Reduction

In birds with facultative brood reduction, survival of the junior chick is thought to be regulated primarily by food availability. In black-legged kittiwakes (Rissa tridactyla) where parents and chicks are provided with unlimited access to supplemental food during the breeding season, brood reduction still occurs and varies interannually. Survival of the junior chick is therefore affected by factors in addition to the amount of food directly available to them. Maternally deposited yolk androgens affect competitive dynamics within a brood, and may be one of the mechanisms by which mothers mediate brood reduction in response to a suite of environmental and physiological cues. The goal of this study was to determine whether food supplementation during the pre-lay period affected patterns of yolk androgen deposition in free-living kittiwakes in two years (2003 and 2004) that varied in natural food availability. Chick survival was measured concurrently in other nests where eggs were not collected. In both years, supplemental feeding increased female investment in eggs by increasing egg mass. First-laid ("A") eggs were heavier but contained less testosterone and androstenedione than second-laid ("B") eggs across years and treatments. Yolk testosterone was higher in 2003 (the year with higher B chick survival) across treatments. The difference in yolk testosterone levels between eggs within a clutch varied among years and treatments such that it was relatively small when B chick experienced the lowest and the highest survival probabilities, and increased with intermediate B chick survival probabilities. The magnitude of testosterone asymmetry in a clutch may allow females to optimize fitness by either predisposing a brood for reduction or facilitating survival of younger chicks.

“What Happens When Pollinators Get Sick? Behavioral Impacts of Honeybee Viruses”

Like all organisms on the planet, honeybees (Apis mellifera) are susceptible to infection with a wide variety of viruses. These viruses may produce infections with no visible symptoms or may have devastating consequences on both the individual bee and the entire hive. Deformed Wing Virus, a member of the Iflavirus group of viruses, has an RNA genome and has had a particularly important impact on bee health. It can be spread between bees in a several ways – bees can infect each other during feeding or grooming activities, drones can pass the virus to the queen during mating and queens can lay infected eggs. The primary and most devastating way that these viruses are transmitted within and between hives involves a parasitic mite, an animal known ominously as Varroa destructor. The talk will discuss the effect that viruses have on the health and behavior of honeybees and will outline the collaborative research activities of Drs. Evans and Pizzorno over the last 7 years.