¿Cómo influyen las limitaciones geométricas en las pautas de migración?

Null models exclusively invoking geometric constraints have recently been demonstrated to provide new insight as to what explains geographic patterns of species richness and range size distribution. Analyses of migration patterns have traditionally been conducted in the absence of appropriate simulations and analytical models. Here we present a null model exclusively invoking geometric constraints and a more advanced analytical model incorporating spread along a migration direction that allow investigation of the influence of physiographical and physiological boundaries for terrestria taxa, with ocean and sea as geometric constraints, in relation to observed patterns of migration. Our models take into account the low recovery probability of terrestrial taxa over sea. The null model was not found to explain any of the directional variation in the ring–recoveries, but when comparing the distribution of data modeled using a simple clock–and–compass model with distributions of ring–recoveries, geometric constraints were found to explain up to 22% of the variation in ring–recoveries. However, the assumed directional concentrations per step used in the model were much higher than expected, and the qualitative fit of the model was rather poor even when non–terrestrial sites of recoveries were excluded.Recientemente se ha demostrado que los modelos nulos que recurren exclusivamente a las limitaciones geométricas proporcionan nuevas aportaciones para explicar las pautas geográficas que definen la riqueza de las especies y la distribución por tamaños según el rango. Tradicionalmente, los análisis de pautas de migración se han realizado sin emplear simulaciones ni modelos analíticos apropiados. En este estudio presentamos un modelo nulo que se basa exclusivamente en limitaciones geométricas, así como un modelo analítico más avanzado que incorpora la dispersión y una dirección de migración, lo que permite investigar la influencia de los límites fisiográficos y fisiológicos en los taxones terrestres, tomando el océano y el mar como limitaciones geométricas, con relación a las pautas de migración observadas. Los modelos que hemos empleado tienen en cuenta la baja probabilidad de recuperación de los taxones terrestres en el mar. El modelo nulo no pudo explicar ninguna de las variaciones direccionales en las recuperaciones de anillas; sin embargo, al comparar la distribución de los datos modelados utilizando un modelo simple de reloj y brújula con distribuciones de recuperaciones de anillas, se constató que las limitaciones geométricas podían explicar hasta el 22% de la variación en las recuperaciones de anillas. Pese a ello, las concentraciones direccionales por pasos que se presupusieron en el modelo fueron muy superiores a lo previsto, y el ajuste cualitativo del mismo resultó bastante deficiente cuando se excluyeron los emplazamientos de recuperaciones no terrestres

A global mismatch in the protection of multiple marine biodiversity components and ecosystem services

The global loss of biodiversity threatens unique biota and the functioning and services of ecosystems essential for human wellbeing. To safeguard biodiversity and ecosystem services, designating protected areas is crucial; yet the extent to which the existing placement of protection is aligned to meet these conservation priorities is questionable, especially in the oceans. Here we investigate and compare global patterns of multiple biodiversity components (taxonomic, phylogenetic and functional), ecosystem services and human impacts, with the coverage of marine protected areas across a nested spatial scale. We demonstrate a pronounced spatial mismatch between the existing degree of protection and all the conservation priorities above, highlighting that neither the world’s most diverse, nor the most productive ecosystems are currently the most protected ecosystems. Furthermore, we show that global patterns of biodiversity, ecosystem services and human impacts are poorly correlated, hence complicating the identification of generally applicable spatial prioritization schemes. However, a hypothetical “consensus approach” would have been able to address all these conservation priorities far more effectively than the existing degree of protection, which at best is only marginally better than a random expectation. Therefore, a holistic perspective is needed when designating an appropriate degree of protection of marine conservation priorities worldwide

Adaptive radiation and the evolution of nectarivory in a large songbird clade

The accumulation of exceptional ecological diversity within a lineage is a key feature of adaptive radiation resulting from diversification associated with the subdivision of previously underutilized resources. The invasion of unoccupied niche space is predicted to be a key determinant of adaptive diversification, and this process may be particularly important if the diversity of competing lineages within the area, in which the radiation unfolds, is already high. Here, we test whether the evolution of nectarivory resulted in significantly higher rates of morphological evolution, more extensive morphological disparity, and a heightened build‐up of sympatric species diversity in a large adaptive radiation of passerine birds (the honeyeaters, about 190 species) that have diversified extensively throughout continental and insular settings. We find that a large increase in rates of body size evolution and general expansion in morphological space followed an ancestral shift to nectarivory, enabling the build‐up of large numbers of co‐occurring species that vary greatly in size, compared to related and co‐distributed nonnectarivorous clades. These results strongly support the idea that evolutionary shifts into novel areas of niche space play a key role in promoting adaptive radiation in the presence of likely competing lineages

Distance and Regional Effects on the Value of Wild Bee Conservation

Many wild bee species are threatened across Europe, and with them the pollination function they provide. While numerous studies have assessed the value of bees as pollinators of crops, little is known about the non-marked value of bees. Using a choice modelling experiment, we examine these non-market values in Germany by identifying citizens’ willingness to pay (WTP) for wild bee conservation initiatives in four states. Effects of distance, state and regional affiliation are scrutinised, as previous research found these to affect respondents’ choices. Random parameter logit and latent class models are used to capture preference heterogeneity. Overall, we find strong support of wild bee conservation and a clear preference for improvement relative to the status quo, particularly in natural areas and for rare or endangered species. The yearly WTP for conservation initiatives ranges from 227 to 447€ per household. Our results show distance and regional effects on WTP. Initiatives in respondents’ home states are preferred, and increasing distance to initiatives in other states result in a slightly reduced WTP. Additionally, we observe regional preferences within an eastern and a western home region. These preferences are not explainable by socio-demographic characteristics, home state or distance and probably linked to social and cultural affiliations. We conclude that for widespread support in society and effective conservation initiatives, policy proposals must address this spatial heterogeneity from distance and regional effects. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.The authors thank the anonymous reviewers for their extensive and valuable comments on this manuscript. The authors would further like to thank Julian Sagebiel from the Swedish University of Agricultural Sciences for his support in the analysis of the survey data. They thank Alice Rogowski, Bennet Bergmann, Helena Leinweber, Jan Peters, Jean Paul Moreaux, Thomas Prossliner, as well as the focus groups participants for their valuable comments on the early version of the questionnaire. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. C.M., B.D. and C.R. thank the Danish National Research Foundation for its support of the Center for Macroecology, Evolution and Climate (Grant No. DNRF96)

Determinants Of Bird Species Richness, Endemism, And Island Network Roles In Wallacea And The West Indies: Is Geography Sufficient Or Does Current And Historical Climate Matter?

Island biogeography has greatly contributed to our understanding of the processes determining species' distributions. Previous research has focused on the effects of island geography (i.e., island area, elevation, and isolation) and current climate as drivers of island species richness and endemism. Here, we evaluate the potential additional effects of historical climate on breeding land bird richness and endemism in Wallacea and the West Indies. Furthermore, on the basis of species distributions, we identify island biogeographical network roles and examine their association with geography, current and historical climate, and bird richness/endemism. We found that island geography, especially island area but also isolation and elevation, largely explained the variation in island species richness and endemism. Current and historical climate only added marginally to our understanding of the distribution of species on islands, and this was idiosyncratic to each archipelago. In the West Indies, endemic richness was slightly reduced on islands with historically unstable climates; weak support for the opposite was found in Wallacea. In both archipelagos, large islands with many endemics and situated far from other large islands had high importance for the linkage within modules, indicating that these islands potentially act as speciation pumps and source islands for surrounding smaller islands within the module and, thus, define the biogeographical modules. Large islands situated far from the mainland and/or with a high number of nonendemics acted as links between modules. Additionally, in Wallacea, but not in the West Indies, climatically unstable islands tended to interlink biogeographical modules. The weak and idiosyncratic effect of historical climate on island richness, endemism, and network roles indicates that historical climate had little effects on extinction-immigration dynamics. This is in contrast to the strong effect of historical climate observed on the mainland, possibly because surrounding oceans buffer against strong climate oscillations and because geography is a strong determinant of island richness, endemism and network roles. We evaluate the potential additional effects of historical climate on native breeding land bird species richness, endemism and island network roles in Wallacea and the West Indies. We find that island geography, especially island area but also isolation and elevation, largely explained the variation in island species richness and endemism, and that island network roles are tightly linked to geography and endemism. The weak and idiosyncratic effect of historical climate on island richness, endemism and network roles indicates that historical climate had little effects on extinction-immigration dynamics in Wallacea and the West Indies. This is in contrast to the strong effect of historical climate observed on the mainland, possibly because surrounding oceans buffer against strong climate oscillations and because geography is a strong determinant of island richness, endemism and network roles

Range and extinction dynamics of the steppe bison in Siberia : A pattern-oriented modelling approach

Aim To determine the ecological processes and drivers of range collapse, population decline and eventual extinction of the steppe bison in Eurasia. Location Siberia. Time period Pleistocene and Holocene. Major taxa studied Steppe bison (Bison priscus). Methods We configured 110,000 spatially explicit population models (SEPMs) of climate-human-steppe bison interactions in Siberia, which we ran at generational time steps from 50,000 years before present. We used pattern-oriented modelling (POM) and fossil-based inferences of distribution and demographic change of steppe bison to identify which SEPMs adequately simulated important interactions between ecological processes and biological threats. These "best models" were then used to disentangle the mechanisms that were integral in the population decline and later extinction of the steppe bison in its last stronghold in Eurasia. Results Our continuous reconstructions of the range and extinction dynamics of steppe bison were able to reconcile inferences of spatio-temporal occurrence and the timing and location of extinction in Siberia based on hundreds of radiocarbon-dated steppe bison fossils. We showed that simulating the ecological pathway to extinction for steppe bison in Siberia in the early Holocene required very specific ecological niche constraints, demographic processes and a constrained synergy of climate and human hunting dynamics during the Pleistocene-Holocene transition. Main conclusions Ecological processes and drivers that caused ancient population declines of species can be reconstructed at high spatio-temporal resolutions using SEPMs and POM. Using this approach, we found that climatic change and hunting by humans are likely to have interacted with key ecological processes to cause the extinction of the steppe bison in its last refuge in Eurasia.Peer reviewe

Phylogenetic signals in the climatic niches of the world’s amphibians

The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species are also ecologically similar has often been made, although the prevalence of such a phylogenetic signal in ecological niches remains heavily debated. Here, we provide a global analysis of phylogenetic niche relatedness for the world's amphibians. In particular, we assess which proportion of the variance in the realised climatic niches is explained on higher taxonomic levels, and whether the climatic niches of species within a given taxonomic group are more similar than between taxonomic groups. We found evidence for phylogenetic signals in realised climatic niches although the strength of the signal varied among amphibian orders and across biogeographical regions. To our knowledge, this is the first study providing a comprehensive analysis of the phylogenetic signal in species climatic niches for an entire clade across the world. Even though our results do not provide a strong test of the niche conservatism hypothesis, they question the alternative hypothesis that niches evolve independently of phylogenetic influences