Combining archive territory mapping data and aerial photography to investigate bird–habitat relationships: a case study from the Lincolnshire coast

Capsule Habitat associations of breeding birds in a complex coastal environment are clear, interpretable and mostly consistent between years.

Aims To match archive territory mapping data with historical aerial photographs and develop data handling and analytical techniques for the study of bird–habitat relationships.

Methods Bird registrations were digitized from archive British Trust for Ornithology Common Birds Census maps and habitat characteristics from contemporaneous aerial photographs. The resulting maps were overlaid and ranks of habitat preference for 15 species calculated using compositional analysis. Similarity analysis identified species with consistent habitat profiles across years. Cluster analysis identified groups of species with similar patterns of habitat use.

Results A total of 5400 registrations of 15 species in 14 habitats were analysed. Of these, 13 species showed stable patterns of habitat association across survey years. Clear differences and similarities in habitat preferences among the species were identified. The results may be used to inform conservation and management programmes in this and similar environments.

Conclusions Extensive archives of bird survey data can be used to study bird–habitat relationships and to measure the effects of natural and anthropogenic environmental change if contemporaneous aerial photographs can be sourced.     

A resource-based conceptual model of plant diversity that reassesses causality in the productivity–diversity relationship

Biogeographical studies frequently reveal positive correlations between species richness and estimates of environmental water and/or energy. A popular interpretation of this relationship relates the supply of water and energy to productivity, and then, in turn, to richness. Productivity–diversity theories are now legion, yet none has proved sufficiently intuitive to gain broad acceptance. Like productivity, heterogeneity is known to influence diversity at fine spatial scales, yet the possibility that richness might relate to water–energy dynamics at coarse spatial scales via a heterogeneity‐generating mechanism has received little attention. In this paper we outline such a conceptual model for plants that is internally consistent and testable. We believe it may help to explain the capacity of environments receiving different inputs of water and energy to support variable numbers of species at a range of spatial scales, the pervasive correlation between productivity and richness, some exceptions to the productivity–diversity relationship, the form of productivity–diversity curves and the link between richness and environmental ‘harshness’. The model may also provide an answer to one of the most venerable puzzles in the field of diversity studies: why high inputs of water and energy correspond to more species rather than simply more individuals.     

The presence of polyriboadenylic acid sequences in calf lens messenger RNA

The presence of poly(rA) sequences in lens RNA has been demonstrated by the isolation of RNase A and T₁-resistant fragments of approximately 50 nucleotide residues. These poly(rA)-rich sequences, obtained from lenses incubated for six hours in organ culture with [³H]adenosine, are located at the 3′ termini of mRNA as determined by 3′ exoribonuclease digestion. Limited digestion of the [³H]adenosine-labeled mRNA with the enzyme led to the abolition of binding to poly(rU)-filters and a concomitant loss of template activity with avian myeloblastosis virus RNA-dependent DNA polymerase. Furthermore, after incubation of lenses in organ culture with 3′-deoxyadenosine, the isolated polysomal RNA was unable to function as a template in an avian myeloblastosis virus RNA-dependent DNA polymerase-catalyzed reaction system.     

The reliability of palatability estimates obtained from rumen contents analysis and a field-based index of diet selection

Understanding herbivore foraging behaviour is often limited by not knowing the palatability of food items. Electivity indices can overcome this challenge by relating the consumption of food items to their relative abundance in the environment. We compare eight widely used electivity indices to relate the level of consumption of 48 food items in the rumen contents of 402 red deer Cervus elaphus in New Zealand to the environmental availability of food items. Additionally, we derive a field-based index of palatability from observed browse damage recorded during vegetation surveys at our site. Electivity indices were positively correlated with each other and with the browse survey index, which was also positively correlated with electivity indices from other studies. Thus, the choice of electivity index is unimportant when making comparisons of relative palatability among food items. Our analyses suggest that quantitative measures of palatability may be reliably inferred from observed browse damage in the field, which is quicker and less destructive to estimate than electivity indices. As a result, we demonstrate a useful technique for predicting herbivore diet selection.     

The reactivity to N-ethyl maleimide of the subunits of cytochrome oxidase.

Beef heart cytochrome oxidase (EC 1.9.3.1) prepared in this laboratory consistently presents 10 Coomassie blue staining zones on SDS-polyacrylamide gel electrophoresis. At pH 7.0 only two of these polypeptides (III and VIa) are labelled by radioactive N-ethyl maleimide (NEM). The labelling of VIa is variable and correlates with activity of particular oxidase preparations. When cytochrome oxidase is isolated from alkylated membranes, either mitochrondria or electron transport particles, polypeptide VIa is found not to be labelled; polypeptide III is more strongly labelled than when isolated oxidase is alkylated, and label now appears in polypeptide I which is not alkylated upon treatment of isolated oxidase with NEM.     

Genetic signatures of population change in the British golden eagle (<Emphasis Type="Italic">Aquila chrysaetos</Emphasis>)

The golden eagle (Aquila chrysaetos) was once widely distributed in the uplands of the British Isles, but is now extinct in Ireland, and largely confined to the highlands and islands of Scotland. As the precise extent and severity of the reduction in population size are unclear, it is important to understand how the population was affected by the decline. We therefore genotyped 13 polymorphic microsatellite loci in 172 individuals from the contemporary British population and compared their genetic diversity to 70 British and 9 Irish museum specimens. Despite the recent population decline, there is only slight evidence for a concomitant loss of genetic variation. Instead, two likelihood-based Bayesian methods provided evidence for a severe ancient genetic bottleneck, possibly caused by the fragmentation of a large mainland European population and/or the founding effects of colonising the British Isles. As the population persisted despite this ancient bottleneck, our conclusion is that there is limited need for intervention to augment the present-day genetic diversity. The main short-term objective of conservation measures should be to increase population sizes by continuous safeguarding of individuals and habitat management. Finally, we also confirmed that, for management purposes, the species should be considered a single population unit and that the extinct Irish population was not differentiated from the British one.     

Re-Examining Mortality Sources and Population Trends in a Declining Seabird: Using Bayesian Methods to Incorporate Existing Information and New Data

The population of flesh-footed shearwaters (Puffinus carneipes) breeding on Lord Howe Island was shown to be declining from the 1970''s to the early 2000''s. This was attributed to destruction of breeding habitat and fisheries mortality in the Australian Eastern Tuna and Billfish Fishery. Recent evidence suggests these impacts have ceased; presumably leading to population recovery. We used Bayesian statistical methods to combine data from the literature with more recent, but incomplete, field data to estimate population parameters and trends. This approach easily accounts for sources of variation and uncertainty while formally incorporating data and variation from different sources into the estimate. There is a 70% probability that the flesh-footed shearwater population on Lord Howe continued to decline during 2003–2009, and a number of possible reasons for this are suggested. During the breeding season, road-based mortality of adults on Lord Howe Island is likely to result in reduced adult survival and there is evidence that breeding success is negatively impacted by marine debris. Interactions with fisheries on flesh-footed shearwater winter grounds should be further investigated.     

Synthesis of delta crystallin from embryonic chick lens messenger ribonucleoprotein complex

A single, major 21 S messenger ribonucleoprotein (mRNP complex) was isolated and purified by sucrose gradient centrifugation after EDTA treatment of high salt washed polysomes from 15 day embryonic chick lenses. A 17 S mRNA was released from the 21 S mRNP. The 21 S mRNP complex coded for a 50 000 molecular weight protein identical to the subunit of delta crystallin. Similar results were obtained with the 17 S mRNA released from the 21 S mRNP complex.     

Climate change alters the trophic niche of a declining apex marine predator

Changes in the world's oceans have altered nutrient flow, and affected the viability of predator populations when prey species become unavailable. These changes are integrated into the tissues of apex predators over space and time and can be quantified using stable isotopes in the inert feathers of historical and contemporary avian specimens. We measured δ¹³C and δ¹⁵N values in Flesh‐footed Shearwaters (Puffinus carneipes) from Western and South Australia from 1936–2011. The Flesh‐footed Shearwaters more than doubled their trophic niche (from 3.91 ± 1.37 ‰² to 10.00 ± 1.79 ‰²), and dropped an entire trophic level in 75 years (predicted δ¹⁵N decreased from +16.9 ‰ to + 13.5 ‰, and δ¹³C from ?16.9 ‰ to ?17.9 ‰) – the largest change in δ¹⁵N yet reported in any marine bird, suggesting a relatively rapid shift in the composition of the Indian Ocean food web, or changes in baseline δ¹³C and δ¹⁵N values. A stronger El Niño‐Southern Oscillation results in a weaker Leeuwin Current in Western Australia, and decreased Flesh‐footed Shearwater δ¹³C and δ¹⁵N. Current climate forecasts predict this trend to continue, leading to increased oceanic ‘tropicalization' and potentially competition between Flesh‐footed Shearwaters and more tropical sympatric species with expanding ranges. Flesh‐footed Shearwater populations are declining, and current conservation measures aimed primarily at bycatch mitigation are not restoring populations. Widespread shifts in foraging, as shown here, may explain some of the reported decline. An improved understanding and ability to mitigate the impacts of global climactic changes is therefore critical to the long‐term sustainability of this declining species.