Can starling eggs be useful as a biomonitoring tool to study organohalogenated contaminants on a worldwide scale?

Large-scale international monitoring studies are important to assess emission patterns and environmental distributions of organohalogenated contaminants (OHCs) on a worldwide scale. In this study, the presence of OHCs was investigated on three continents (Europe, North America and Australasia), using eggs of starlings (Sturnus vulgaris and Sturnus unicolor) to assess their suitability for large-scale monitoring studies. To the best of our knowledge, this is the first study using bird eggs of the same species as a biomonitor for OHCs on an intercontinental scale. We found significant differences in OHC concentrations of the eggs among sampling locations, except for hexachlorocyclohexanes (HCHs). Mean concentrations of sum polychlorinated biphenyls (PCBs) in eggs ranged from 78 ± 26 ng/g lipid weight (lw) in Australia to 2900 ± 1300 ng/g lw in the United States. The PCB profile was dominated by CB 153 and CB 138 in all locations, except for New Zealand, where the contribution of CB 95, CB 101 and CB 149 was also high. The highest mean sum polybrominated diphenyl ether (PBDE) concentrations were found in Canada (4400 ± 830 ng/g lw), while the lowest mean PBDE concentrations were measured in Spain (3.7 ± 0.1 ng/g lw). The PBDE profile in starling eggs was dominated by BDE 47 and BDE 99 in all countries, but in Belgium, the higher brominated PBDEs had a higher contribution compared to other countries. For the organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethanes (DDTs) ranged from 110 ± 16 ng/g lw in France to 17,000 ± 3400 ng/g lw in New Zealand, while HCHs and hexachlorobenzene were generally in low concentrations in all sampling locations. Chlordanes were remarkably high in eggs from the United States (2500 ± 1300 ng/g lw). The OCP profile in all countries was largely dominated by p,p′-DDE. In general, the worldwide trends we observed in starling eggs were in accordance with the literature on human and environmental OHC data, which suggests that there is potential for using starling eggs as a biomonitoring tool on a large geographical scale

The dispersal of vascular plants in a forest mosaic by a guild of mammalian herbivores

Endozochorous seed dispersal by herbivores can affect plant spatial dynamics and macroecological patterns. We have investigated the number and species composition of viable seeds deposited in faeces of a full guild of macroherbivores (four deer and two lagomorph species) in a forest in eastern Britain. One hundred and one plant species germinated from faecal pellet material, 85 of which were among the 247 vascular plant species recorded in the forest. However, three species – Chenopodium album, Urtica dioica and Agrostis stolonifera – comprised 56% of the seedlings recorded. Of the species recorded in faecal samples, 36% had no recognised dispersal mechanism, while very few (7%) were adapted to endozoochorous dispersal (fleshy fruit or nut). The number of species dispersed by the herbivores was ranked Cervus elaphus and Dama dama (96) > Capreolus capreolus (40) > Muntiacus reevesi (31) > Oryctolagus cuniculus (21) > Lepus europaeus (19), with the other taxa dispersing subsets of those dispersed by C. elpahus and D. dama. The invasive M. reevesi deposited the fewest seeds per gram of faecal pellet material (0.4 g−1) and hence fewer seeds per unit area than other deer species despite their numerical dominance, while C. elaphus/D. dama deposited the most (0.43 seeds m−2 year−1). Due to differences in faecal seed density among habitats combined with the ranging behaviour of animals, more seeds were deposited in younger stands, enhancing the potential contribution of macroherbivores to population persistence by dispersal and colonisation in a successional mosaic

Feralisation - The Understudied Counterpoint to Domestication

Feralisation is a complex process that occurs when a domestic population is returned to the wild. It impacts species invasion biology, speciation, conservation and hybridisation and can be thought of as the reverse of domestication. Domestication has been an area of intense interest and study ever since Darwin, and useful as a model for evolution and the effects of strong directional selection. Despite domestication being used to study genes affecting a large number of traits that change with selection, little is known about the genomic changes associated with feralisation. Much of the current work on the genetics of feralisation has focused on the detection of early hybrids (F1 or F2) between wild and domestic populations. Feralisation can lead to large changes in morphology, behaviour and many other traits, with the process of feralisation involving the sudden return of both natural and sexual selection. Such evolutionary forces influence predatory, foraging and male choice decisions and exert strong effects on once domesticated, now feral, individuals. As such, feralisation provides a unique opportunity to observe the genomic and phenotypic responses to selection from a known (domesticated) standpoint and identify the genes underlying these selective targets. In this review, we summarise what is known in particular regarding the genomics of feralisation, and also the changes that feralisation has induced on brain size and behaviour.https://nsuworks.nova.edu/cnso_bio_facbooks/1026/thumbnail.jp