Nejvíce citovaný článek - PubMed ID 31380096
Measuring avian specialization
Environmental change is increasing worldwide and many animal species face anthropogenic threats, especially diet specialists. Yet the degree to which specialist species are currently impacted by environmental change remains poorly understood. We examine how anthropogenic pressures impact dietary specialist species. We calculated indices of diet specialization for mammal species, based on the Gini inequality coefficient, and combined these indices with human pressure data. We then used spatially explicit Mantel tests to examine global patterns in mammal diet specialization. We used a generalized linear mixed model to investigate correlations between the percentage of diet specialist species in mammal communities in an area and its total species richness, human pressure and protection status (mediated through an interaction with the continent). Findings revealed that areas with many diet specialists in mammal communities are also impacted by high human pressure. Additionally, we found that the global protected area system adequately covers habitat for many mammal diet specialists, but has lower effectiveness in South America, Oceania, North America and Europe compared with Africa and Asia. Finally, we identified potential reservoirs for specialist species-places containing many highly diet specialist species and that are subject to less human pressure-which may be important for conservation efforts.
- Klíčová slova
- biodiversity, community, diet specialization, human footprint, mammal species, protected areas network,
- MeSH
- antropogenní vlivy * MeSH
- biodiverzita MeSH
- dieta * MeSH
- ekosystém MeSH
- lidé MeSH
- savci * fyziologie MeSH
- zachování přírodních zdrojů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The biodiversity impacts of agricultural deforestation vary widely across regions. Previous efforts to explain this variation have focused exclusively on the landscape features and management regimes of agricultural systems, neglecting the potentially critical role of ecological filtering in shaping deforestation tolerance of extant species assemblages at large geographical scales via selection for functional traits. Here we provide a large-scale test of this role using a global database of species abundance ratios between matched agricultural and native forest sites that comprises 71 avian assemblages reported in 44 primary studies, and a companion database of 10 functional traits for all 2,647 species involved. Using meta-analytic, phylogenetic and multivariate methods, we show that beyond agricultural features, filtering by the extent of natural environmental variability and the severity of historical anthropogenic deforestation shapes the varying deforestation impacts across species assemblages. For assemblages under greater environmental variability-proxied by drier and more seasonal climates under a greater disturbance regime-and longer deforestation histories, filtering has attenuated the negative impacts of current deforestation by selecting for functional traits linked to stronger deforestation tolerance. Our study provides a previously largely missing piece of knowledge in understanding and managing the biodiversity consequences of deforestation by agricultural deforestation.
- MeSH
- biodiverzita * MeSH
- fylogeneze MeSH
- lesy MeSH
- zachování přírodních zdrojů * MeSH
- zemědělství MeSH
- Publikační typ
- časopisecké články MeSH
Nest boxes represent a popular tool to support secondary cavity-nesting species. Surprisingly, the benefits and limitations of nest boxes for target species in different environments are poorly understood. We performed a 3-years experimental study in two different Central European forests to evaluate nest box use and breeding performance of boreal owl (Aegolius funereus) - a species well known for its readiness to occupy nest boxes. Based on territorial vocalisation, two boreal owl populations 200 km apart were similarly abundant in their environments. However, only the boreal owl population in young restored Norway (Picea abies) and blue (Picea pungens) spruce-dominated forests on mountain plateaus readily occupied nest boxes with the occupancy reaching 8-15%. Nest boxes lost their supporting function for the boreal owl in mature Scots pine (Pinus sylvestris)-dominated forests in the lowland, where the nest box occupancy reached 0-1%. As a result, the population of boreal owls that used nest boxes in the young restored forests produced 10 times more fledglings than the population inhabiting mature Scots pine forests. We explain the differences by the contrasting availability of natural tree cavities between the two study areas being much higher in mature Scots pine forests. For the first time, this study documents differences in nest box use despite similar food availability and population size of the target species. The study provides the findings-related recommendations for deploying nest boxes for boreal owls and points out a general lack of practical guides.
- MeSH
- borovice lesní * MeSH
- lesy MeSH
- šlechtění rostlin MeSH
- smrk * MeSH
- Stringiformes * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Brood parasitism is a breeding strategy adopted by many species of cuckoos across the world. This breeding strategy influences the evolution of life histories of brood parasite species.In this study, we tested whether the degree on diet specialization is related to the breeding strategy in cuckoo species, by comparing brood parasite and nonparasite species. We measured the gradient of diet specialization of cuckoos, by calculating the Gini coefficient, an index of inequality, on the multiple traits describing the diet of species. The Gini coefficient is a measure of statistical dispersion on a scale between 0 and 1, reflecting a gradient from low to high specialization, respectively. First, we tested the strength of the phylogenetic signal of diet specialization index among cuckoo species worldwide. Then, we ran phylogenetic generalized least square (PGLS) models to compare diet specialization, distribution range, and body mass of parasitic and nonparasitic cuckoo species, considering the phylogenetic signal of data.After adjusting for the phylogenetic signal of the data and considering both, species distribution range and species body mass, brood parasitic cuckoos were characterized by higher diet specialization than nonbrood parasitic species. Brood parasitic species were also characterized by a larger breeding distribution range than nonparasitic species.The findings of this study provide an additional understanding of the cuckoos' ecology, relating diet and breeding strategies, information that could be important in conservation ecology.
- Klíčová slova
- brood parasitism, cuckoos, diet specialization, functional traits, generalist, phylogenetic signal,
- Publikační typ
- časopisecké články MeSH