Pigeon homing: new airbag experiments to assess the role of olfactory information for pigeon navigation

Summary In three series of experiments we assessed the effects of olfactory and non-olfactory information collected en route or at the release site on the initial orientation of homing pigeons. In the first experiment, pigeons were transported in open crates to two sites located in opposite directions from the home loft. They were left at the site for 1 h, then put into airtight containers filled with air from that site and brought back to the loft. From there, controls were transported back to the original site. Experimentals were transported to the opposite site. Upon arrival at the site, the olfactory mucosae of both groups were anesthetized with Gingicain. Thus in this experiment, control and experimental pigeons were exposed to different olfactory as well as to different non-olfactory information during displacement and at the site. In the second series, controls and experimentals were treated as in the first experiment, except that they were enclosed in the airtight containers at the very beginning of the experiment and were ventilated with synthetic air until arrival at the final release site. This treatment excluded the possibility to perceive olfactory information en route or at the site. In this series, the two groups differed only with respect to non-olfactory information perceived during displacement and/or at the release site. In the third series, we exposed pigeons at the loft to air collected either at the later release site (controls) or to air collected at a site located in opposite direction of the home loft (experimentals). Here the two groups differed only with respect to their exposure to air of different origin. In all three series, the pooled controls showed a directional preference that was statistically indistinguishable from the home direction. All three experimental groups were disoriented. In the first two series, the differences in the initial orientation of control and experimental pigeons were highly significant. In the third experiment, there was only very weak statistical evidence for a difference between controls and experimentals. These results suggest that more than one factor is involved in the pigeons' navigation system. According to the present experiment with synthetic air, pigeons probably gather and process non-olfactory information during the first part of their transport from the home loft to the release site. Thus, some kind of, in this case non-olfactory, route reversal seems to be involved in the homing process. In addition, the experiment involving only manipulations of airborne information indicated some olfactory component. Previous experiments at our loft did not result in disorientation of the pigeons if either only the access to airborne information had been removed or when otherwise unmanipulated pigeons had been transported in detours to the final release site. Therefore, we assume that our pigeons' navigation system relies on several cues. Deletion of one cue can be compensated by other information. Often the initial orientation of our pigeons is disturbed only when at least one cue is removed and another one provides false information.     

Goldfish and oscars have comparable responsiveness to dipole stimuli

The relative roles of the fish lateral line and inner ear for the perception of hydrodynamic stimuli are poorly investigated. Here, we studied responsiveness to a 100 Hz vibrating sphere (dipole stimulus) of goldfish and oscars, two species that differ in peripheral lateral line morphology, inner ear morphology, mechanical linkage between inner ear and swim bladder, and inner ear sensitivity. We measured unconditioned dipole-evoked changes in breathing activity in still water and in the presence of a 5-cm s⁻¹ background flow. In still water, individuals from both species responded to sound pressure levels (SPLs) between 92 and 109 dB SPL re 1 μPa_RMS. Responsiveness was not affected by background flow or by temporary inactivation of the lateral line. The data suggest that fish with different lateral line and inner ear morphologies have similar sensitivities to vibrating sphere stimuli and can detect and respond to dipole sources equally well in still water and in moderate background flows. Moreover, behavioral responses were not dependent on a functional lateral line, suggesting that in this type of experiment, the inner ear is the dominant sense organ for the perception of hydrodynamic stimuli.     

Waste prevention for sustainable resource and waste management

Although the 2Rs (reduce and reuse) are considered high-priority approaches, there has not been enough quantitative research on effective 2R management. The purpose of this paper is to provide information obtained through the International Workshop in Kyoto, Japan, on 11–13 November 2015, which included invited experts and researchers in several countries who were in charge of 3R policies, and an additional review of 245 previous studies. It was found that, regarding policy development, the decoupling between environmental pressures and economy growth was recognized as an essential step towards a sustainable society. 3R and resource management policies, including waste prevention, will play a crucial role. Approaches using material/substance flow analyses have become sophisticated enough to describe the fate of resources and/or hazardous substances based on human activity and the environment, including the final sink. Life-cycle assessment has also been developed to evaluate waste prevention activities. Regarding target products for waste prevention, food loss is one of the waste fractions with the highest priority because its countermeasures have significant upstream and downstream effects. Persistent organic pollutants and hazardous compounds should also be taken into account in the situation where recycling activities are globally widespread for the promotion of a material-cycling society.     

Response to Kruse-Plass et al. (2017) regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize events (MON810, Bt11 and 1507)

We respond to the paper of Kruse-Plass et al. (Environ Sci Eur 29:12, 2017), published in this journal, regarding the risk to non-target lepidopteran larvae exposed to pollen from one or more of three Bt maize events (MON810, Bt11 and 1507). We emphasise that what is important for environmental risk assessment is not the number of pollen grains per se, but the degree of exposure of a NT lepidopteran larva to Bt protein contained in maize pollen. The main text of this response deals with general issues which Kruse-Plass et al. have failed to understand; more detailed refutations of each of their claims are given in Additional file 1. Valid environmental risk assessment requires direct measurement of pollen on leaves at varying distances outside a source field(s); such measurements reflect the potential exposure experienced by an individual larva on a host plant. There are no new data in the Kruse-Plass et al. paper, or indeed any data directly quantifying pollen on actual host-plant leaves outside a maize field; only data gathered within or at the edge of maize crops were reported. Values quoted by Kruse-Plass et al. for deposition on host plants outside the field were estimates only. We reiterate the severe methodological criticisms made by EFSA [Relevance of a new scientific publication (Hofmann et al. 2016) for previous environmental risk assessment conclusions and risk management recommendations on the cultivation of Bt-maize events MON810, Bt11 and 1507. EFSA Supp Publ; EN-1070, 2016], which render this estimation procedure unreliable. Furthermore, criticisms of EFSA (EFSA J 2015(13):4127, 2015) and of EFSA [Relevance of a new scientific publication (Hofmann et al. 2016) for previous environmental risk assessment conclusions and risk management recommendations on the cultivation of Bt-maize events MON810, Bt11 and 1507. EFSA Supp Publ; EN-1070, 2016] made by Kruse-Plass et al. are shown in Additional file 1 to be without foundation. We therefore consider that there is no valid evidence presented by Kruse-Plass et al. to justify their conclusions.     

Determination of carbamazepine and 12 degradation products in various compartments of an outdoor aquatic mesocosm by reliable analytical methods based on liquid chromatography-tandem mass spectrometry

Environmental Science and Pollution Research - The aims of this work are to develop suitable analytical methods to determine the widely used anticonvulsant carbamazepine and 12 of its...     

Canister-Based Method for Monitoring Toxic VOCs in Ambient Air

The availability of reliable, accurate and precise monitoring methods for toxic volatile organic compounds (VOCs) is a primary need for state and local agencies addressing daily monitoring requirements related to odor complaints, fugitive emissions, and trend monitoring. The canister-based monitoring method for VOCs is a viable and widely used approach that is based on research and evaluation performed over the past several years. This activity has involved the testing of sample stability of VOCs in canisters and the design of time-integrative samplers. The development of procedures for analysis of samples in canisters, including the procedure for VOC preconcentration from whole air, the treatment of water vapor in the sample, and the selection of an appropriate analytical finish has been accomplished. The canister-based method was initially summarized in the EPA Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air as Method TO-14. Modifications and refinements are being added to Method TO-14 in order to obtain a Statement of Work for the Superfund Contract Laboratory Program for Air. This paper discusses the developments leading to the current status of the canisterbased method and provides a critique of the method using results obtained in EPA monitoring networks.     

PM2.5 Assessment in 21 European Study Centers of ECRHS II: Method and First Winter Results

Abstract

The follow-up of a cohort of adults from 29 European centers of the former European Community Respiratory Health Survey (ECRHS) I (1989–1992) will examine the long-term effects of exposure to ambient air pollution on the incidence, course, and prognosis of respiratory diseases, in particular asthma and decline in lung function. The purpose of this article is to describe the methodology and the European-wide quality control program for the collection of particles with 50% cut-off size of 2.5 µm aerodynamic diameter (PM_2.5 ) in the ECRHS II and to present the PM_2.5 results from the winter period 2000–2001.

Because PM_2.5 is not routinely monitored in Europe, we measured PM_2.5 mass concentrations in 21 participating centers to estimate background exposure in these cities. A standardized protocol was developed using identical equipment in each center (U.S. Environmental Protection Agency Well Impactor Ninety-Six [WINS] and PQ167 from BGI, Inc.). Filters were weighed in a single central laboratory. Sampling was conducted for 7 days per month for a year.

Winter mean PM_2.5 mass concentrations (November 2000–February 2001) varied substantially, with Iceland reporting the lowest value (5 µg/m³) and northern Italy the highest (69 µg/m³). A standardized procedure appropriate for PM_2.5 exposure assessmnt in a multicenter study was developed. We expect ECRHS II to have sufficient variation in exposure to assess long-term effects of air pollution in this cohort. Any bias caused by variation in the characteristics of the chosen monitoring location (e.g., proximity to traffic sources) will be addressed in later analyses. Given the homogenous spatial distribution of PM_2.5 , however, concentrations measured near traffic are not expected to differ substantially from those measured at urban background sites.     

Heat map visualization of complex environmental and biomarker measurements

Over the past decade, the assessment of human systems interactions with the environment has permeated all phases of environmental and public health research. We are invoking lessons learned from the broad discipline of Systems Biology research that focuses primarily on molecular and cellular networks and adapting these concepts to Systems Exposure Science which focuses on interpreting the linkage from environmental measurements and biomonitoring to the expression of biological parameters. A primary tool of systems biology is the visualization of complex genomic and proteomic data using “heat maps” which are rectangular color coded arrays indicating the intensity (or amount) of the dependent variable. Heat maps are flexible in that both the x-axis and y-axis can be arranged to explore a particular hypothesis and allow a fast overview of data with a third quantitative dimension captured as different colors. We are now adapting these tools for interpreting cumulative and aggregate environmental exposure measurements as well as the results from human biomonitoring of biological media including blood, breath and urine. This article uses existing EPA measurements of environmental and biomarker concentrations of polycyclic aromatic hydrocarbons (PAHs) to demonstrate the value of the heat map approach for hypothesis development and to link back to stochastic and mixed effects models that were originally used to assess study results.     

Mirror,mirror on the wall: the predictive value of mirror tests for measuring aggression in fish

The behaviour of animals towards their mirror image (“mirror test”) is routinely used as a proxy to measure aggression levels, especially in fish. The lack of evidence for visual self-recognition in fish supports this method. However, recent work points towards different hormonal and gene expression responses when fish are exposed either to conspecific opponents or to their mirror image, urging for validation of this widespread method. Here, we test the predictive value of mirror tests in three sympatric cichlid species from Lake Tanganyika: the cooperative breeder Neolamprologus pulcher, the polygamous shell brooder Telmatochromis vittatus and the monogamous, biparental piscivore Lepidiolamprologus elongatus. In particular, we compare differences in restrained and overt aggression levels for individuals of each species when confronted with a mirror or a live conspecific. The three species differed in response to the two contest situations. While in N. pulcher both aggressive responses were correlated between the mirror test and the live opponent fight, there was no such relationship in T. vittatus and L. elongatus. Thus, the mirror test appears to be a suitable surrogate for intraspecific aggression in N. pulcher, while aggression against a mirror image has limited predictive value for intraspecific aggression in the other two species. These results underline the importance of validating the mirror test’s predictive value in a study species before drawing conclusions from mirror tests about aggressiveness under natural, social conditions.