Endocrine disrupting nonyl- and octylphenol in infant food in Germany: considerable daily intake of nonylphenol for babies

Nonylphenol and octylphenol are persistent endocrine disrupters that are priority substances of the European Union Water Framework Directive. Their presence in the environment has caused increasing concern about their impact to human health. Infants are more sensitive to hormonal impacts of environmental chemicals than adults. The results of the present study indicate that nonylphenol is ubiquitous in foodstuffs for babies and toddlers commercially available in Germany, while octylphenol could only be determined in 80% of all food samples. The daily intakes based on consumption studies in μg nonylphenol kg⁻¹ body weight per day for high consumers in the baby category (0.23-0.65 μg kg⁻¹ bw d⁻¹) were relatively high. This could lead to a higher risk especially for babies.     

Pigeon homing: sun compass use in the southern hemisphere

Although the sun compass of birds is based on learning the sun's arc during development, it was unclear whether birds can use the sun when its apparent movement is reversed, in particular, whether northern birds that have been introduced into the southern hemisphere can use the southern sun. To answer this question, clock-shift experiments were performed with local homing pigeons in Auckland, New Zealand (37°S). In three fast-shift tests and two slow-shift tests, the experimental birds showed deflections from the untreated controls that were the mirror images of those observed in the northern hemisphere. These results clearly show that homing pigeons in New Zealand use a sun compass that is adapted to the situation in the southern hemisphere. The learning processes establishing the compensation mechanisms thus appear to be free of constraints concerning the direction of the sun's movement. Differences from recent findings with migratory birds, where the direction of celestial rotation proved of crucial importance for establishing the migratory direction, are discussed: the differences may arise from the different orientation tasks, in particular, from the involvement of innate information in establishing the migratory direction. Received: 13 November 1997 / Accepted after revision: 28 February 1998     

Magnetic compass orientation in the yellow-faced honeyeater,Lichenostomus chrysops,a day migrating bird from Australia

Summary In Australia, the southern populations of the yellow-faced honeyeater, Lichenostomus chrysops (Meliphagidae), perform annual migrations, with routes following the eastern coastline. In order to assess the role of magnetic cues in the migratory orientation of this diurnal migrant, its directional behaviour was recorded in recording cages under natural and experimentally manipulated magnetic-field conditions. During autumn the birds tested indoors in the local geomagnetic field showed a directional change from north initially to northwest later in the season (Fig. 1 a, b), which corresponds well with the general pattern of movement of this species in the field. Deflecting magnetic north to ESE resulted in a clockwise shift of the mean direction by 77° and 71°, respectively (Fig. 1 c, d), while no significant directional tendencies were observed in a magnetic field with a compensated horizontal component (Fig. 1 e, f; see Table 1). In outdoor tests in spring, the birds preferred southerly directions when tested in the local geo-magnetic field. In a magnetic field with a reversed vertical component (i.e. with an inclination pointing down instead of upwards) the birds reversed their directional tendencies and oriented northward (Fig. 2, Table 2). These results clearly show: (1) that yellow-faced honeyeaters can use the magnetic field for direction finding, and (2) that their magnetic compass functions as an inclination compass, as has been shown for several holarctic migrants.Correspondence to: W. Wiltschko     

Detour experiments with homing pigeons: information obtained during the outward journey is included in the navigational process

Summary To test the hypothesis that information on the route of the outward journey is involved in the orientation of displaced homing pigeons, we compared the behavior of control pigeons that had been displaced by the most direct route with that of experimental pigeons that had been transported along detours to the same release sites. At distances of 40 km we found no consistent effect. At distances between 75 and 130 km, however, deviations to the left of the direct route induced deflections to the left, while deviations to the right induced deflections to the right, i.e. the deflections of the vanishing bearings tended to compensate for the initial detour of the outward journey. The deflections were smaller than the deviations of the routes; they were not related to the routes themselves or the location of the release sites. A significant correlation emerged with the vector length of the controls, as longer vectors were associated with smaller deflections. This suggests that information on the route of the outward journey is used together with local map information in the navigational process, the significance of the route-specific information apparently depending on quality and reliability of the available local information. The nature of factors controlling the detour effect is still open.Correspondence to: R. Wiltschko