Imperial College London

DrJosephTobias

Faculty of Natural SciencesDepartment of Life Sciences (Silwood Park)

Reader in Biodiversity and Ecosystems
 
 
 
//

Contact

 

+44 (0)20 7594 1059j.tobias

 
 
//

Location

 

KennedySilwood Park

//

Summary

 

Publications

Publication Type
Year
to

98 results found

Stoddard MC, Sheard C, Akkaynak D, Yong EH, Mahadevan L, Tobias JAet al., 2019, Evolution of avian egg shape: underlying mechanisms and the importance of taxonomic scale, Ibis, Vol: 161, Pages: 922-925, ISSN: 0019-1019

Journal article

Santini L, Butchart SHM, Rondinini C, Benítez-López A, Hilbers JP, Schipper A, Cengic M, Tobias JA, Huijbregts MAJet al., 2019, Applying habitat and population-density models to land-cover time series to inform IUCN red list assessments, Conservation Biology, Vol: 33, Pages: 1084-1093, ISSN: 0888-8892

The IUCN Red List categories and criteria are the most widely used framework for assessing the relative extinction risk of species. The criteria are based on quantitative thresholds relating to the size, trends and structure of species' distributions and populations. However, data on these parameters are sparse and uncertain for many species and unavailable for others, potentially leading to their misclassification, or classification as Data Deficient. Here we propose an approach combining data on land-cover change and species-specific habitat preferences, population abundance and dispersal distance to estimate key parameters (extent of occurrence, maximum area of occupancy, population size and trend, and degree of fragmentation) and hence IUCN Red List categories. We demonstrate the applicability of our approach for non-pelagic birds and terrestrial mammals globally (∼15,000 species), generating predictions fairly consistent with published Red List assessments, but more optimistic overall. We predict 4.2% of species (467 birds and 143 mammals) to be more threatened than currently assessed, and 20.2% of Data Deficient species (10 birds and 114 mammals) to be at risk of extinction. However, incorporating the habitat fragmentation sub-criterion reduced these predictions 1.5-2.3% and 6.4-14.9% (depending on the quantitative definition of fragmentation) of threatened and Data Deficient species respectively, highlighting the need for improved guidance to Red List assessors on applying this aspect of the Red List criteria. Our approach can be used to complement traditional methods of estimating parameters for Red List assessments. Furthermore, it can readily provide an early warning system to identify species potentially warranting changes in their extinction risk category based on periodic updates of land cover information. Given that our method relies on optimistic assumptions about species distribution and abundance, all species predicted to be more at risk than cu

Journal article

Tobias JA, Pigot AL, 2019, Integrating behaviour and ecology into global biodiversity conservation strategies, PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 374, ISSN: 0962-8436

Journal article

Habel JC, Tobias JA, Fischer C, 2019, Movement ecology of Afrotropical birds: Functional traits provide complementary insights to species identity, BIOTROPICA, ISSN: 0006-3606

Journal article

Hatfield J, Barlow J, Joly CA, Lees AC, Parruco CF, Tobias J, Orme C, Banks-Leite Cet al., Mediation of area and edge effects by adjacent land use, Conservation Biology, ISSN: 0888-8892

Habitat loss, fragmentation and degradation have pervasive detrimental effects on tropical forest biodiversity, but the role of the surrounding land use (i.e. matrix) in determining the severity of these impacts remains poorly understood. We surveyed bird species across an interior-edge-matrix gradient to assess the effects of matrix type on biodiversity at 49 different sites with varying levels of landscape fragmentation in the Brazilian Atlantic Forest – a highly threatened biodiversity hotspot. Our findings revealed that both area and edge effects are more pronounced in forest patches bordering pasture matrix, while patches bordering Eucalyptus plantation maintained compositionally similar bird communities between the edge and the interior, in addition to exhibiting reduced effects of patch size. These results suggest that the type of matrix in which forest fragments are situated can explain a substantial amount of the widely-reported variability in biodiversity responses to forest loss and fragmentation.

Journal article

Cannon PG, Gilroy JJ, Tobias JA, Anderson A, Haugaasen T, Edwards DPet al., 2019, Land-sparing agriculture sustains higher levels of avian functional diversity than land sharing, Global Change Biology, Vol: 25, Pages: 1576-1590, ISSN: 1354-1013

The ecological impacts of meeting rising demands for food production can potentially be mitigated by two competing land-use strategies: off-setting natural habitats through intensification of existing farmland (land sparing), or elevating biodiversity within the agricultural matrix via the integration of 'wildlife-friendly' habitat features (land sharing). However, a key unanswered question is whether sparing or sharing farming would best conserve functional diversity, which can promote ecosystem stability and resilience to future land-use change. Focusing on bird communities in tropical cloud forests of the Colombian Andes, we test the performance of each strategy in conserving functional diversity. We show that multiple components of avian functional diversity in farmland are positively related to the proximity and extent of natural forest. Using landscape and community simulations, we also show that land-sparing agriculture conserves greater functional diversity and predicts higher abundance of species supplying key ecological functions than land sharing, with sharing becoming progressively inferior with increasing isolation from remnant forest. These results suggest low-intensity agriculture is likely to conserve little functional diversity unless large blocks of adjacent natural habitat are protected, consistent with land sparing. To ensure the retention of functionally diverse ecosystems, we urgently need to implement mechanisms for increasing farmland productivity whilst protecting spared land. This article is protected by copyright. All rights reserved.

Journal article

Kirschel ANG, Seddon N, Tobias JA, 2019, Range-wide spatial mapping reveals convergent character displacement of bird song, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 286, ISSN: 0962-8452

Journal article

Felice RN, Tobias JA, Goswami A, 2019, How Dietary Niche Shapes Macroevolution in the Avian Skull, Annual Meeting of the Society-for-Integrative-and-Comparative-Biology (SICB), Publisher: OXFORD UNIV PRESS INC, Pages: E68-E68, ISSN: 1540-7063

Conference paper

Mayhew RJ, Tobias JA, Bunnefeld L, Dent DHet al., 2019, Connectivity with primary forest determines the value of secondary tropical forests for bird conservation, Biotropica, Vol: 51, Pages: 219-233, ISSN: 0006-3606

Species extinctions caused by the destruction and degradation of tropical primary forest may be at least partially mitigated by the expansion of regenerating secondary forest. However, the conservation value of secondary forest remains controversial, and potentially underestimated, since most previous studies have focused on young, single-aged, or isolated stands. Here, we use point-count surveys to compare tropical forest bird communities in 20–120-year-old secondary forest with primary forest stands in central Panama, with varying connectivity between secondary forest sites and extensive primary forest. We found that species richness and other metrics of ecological diversity, as well as the combined population density of all birds, reached a peak in younger (20-year-old) secondary forests and appeared to decline in older secondary forest stands. This counter-intuitive result can be explained by the greater connectivity between younger secondary forests and extensive primary forests at our study site, compared with older secondary forests that are either (a) more isolated or (b) connected to primary forests that are themselves small and isolated. Our results suggest that connectivity with extensive primary forest is a more important determinant of avian species richness and community structure than forest age, and highlight the vital contribution secondary forests can make in conserving tropical bird diversity, so long as extensive primary habitats are adjacent and spatially connected.Abstract in Spanish is available with online material.

Journal article

Felice RN, Tobias JA, Pigot AL, Goswami Aet al., 2019, Dietary niche and the evolution of cranial morphology in birds, Proceedings of the Royal Society B: Biological Sciences, Vol: 286, ISSN: 1471-2954

Cranial morphology in birds is thought to be shaped by adaptive evolution for foraging performance. This understanding of ecomorphological evolution is supported by observations of avian island radiations, such as Darwin’s finches, which display rapid evolution of skull shape in response to food resource availability and a strong fit between cranial phenotype and trophic ecology. However, a recent analysis of larger clades has suggested that diet is not necessarily a primary driver of cranial shape and that phylogeny and allometry are more significant factors in skull evolution. We use phenome-scale morphometric data across the breadth of extant bird diversity to test the influence of diet and foraging behaviour in shaping cranial evolution. We demonstrate that these trophic characters are significant but very weak predictors of cranial form at this scale. However, dietary groups exhibit significantly different rates of morphological evolution across multiple cranial regions. Granivores and nectarivores exhibit the highest rates of evolution in the face and cranial vault, whereas terrestrial carnivores evolve the slowest. The basisphenoid, occipital, and jaw joint regions have less extreme differences among dietary groups. These patterns demonstrate that dietary niche shapes the tempo and mode of phenotypic evolution in deep time, despite a weaker than expected form–function relationship across large clades.

Journal article

Cooney CR, MacGregor HEA, Seddon N, Tobias JAet al., 2018, Multi-modal signal evolution in birds: re-examining a standard proxy for sexual selection, Proceedings of the Royal Society B: Biological Sciences, Vol: 285, ISSN: 1471-2954

Sexual selection is proposed to be an important driver of speciation and phenotypic diversification in animal systems. However, previous phylogenetic tests have produced conflicting results, perhaps because they have focused on a single signalling modality (visual ornaments), whereas sexual selection may act on alternative signalling modalities (e.g. acoustic ornaments). Here, we compile phenotypic data from 259 avian sister species pairs to assess the relationship between visible plumage dichromatism-a standard index of sexual selection in birds-and macroevolutionary divergence in the other major avian signalling modality: song. We find evidence for a strong negative relationship between the degree of plumage dichromatism and divergence in song traits, which remains significant even when accounting for other key factors, including habitat type, ecological divergence and interspecific interactions. This negative relationship is opposite to the pattern expected by a straightforward interpretation of the sexual selection-diversification hypothesis, whereby higher levels of dichromatism indicating strong sexual selection should be related to greater levels of mating signal divergence regardless of signalling modality. Our findings imply a 'trade-off' between the elaboration of visual ornaments and the diversification of acoustic mating signals, and suggest that the effects of sexual selection on diversification can only be determined by considering multiple alternative signalling modalities.

Journal article

Fecchio A, Bell JA, Collins MD, Farias IP, Trisos CH, Tobias JA, Tkach VV, Weckstein JD, Ricklefs RE, Batalha-Filho Het al., 2018, Diversification by host switching and dispersal shaped the diversity and distribution of avian malaria parasites in Amazonia, Oikos, Vol: 127, Pages: 1233-1242, ISSN: 0030-1299

Understanding how pathogens and parasites diversify through time and space is fundamental to predicting emerging infectious diseases. Here, we use biogeographic, coevolutionary and phylogenetic analyses to describe the origin, diversity, and distribution of avian malaria parasites in the most diverse avifauna on Earth. We first performed phylogenetic analyses using the mitochondrial cytochrome b (cyt b) gene to determine relationships among parasite lineages. Then, we estimated divergence times and reconstructed ancestral areas to uncover how landscape evolution has shaped the diversification of Parahaemoproteus and Plasmodium in Amazonia. Finally, we assessed the coevolutionary patterns of diversification in this host-parasite system to determine how coevolution may have influenced the contemporary diversity of avian malaria parasites and their distribution among Amazonian birds. Biogeographic analysis of 324 haemosporidian parasite lineages recovered from 4178 individual birds provided strong evidence that these parasites readily disperse across major Amazonian rivers and this has occurred with increasing frequency over the last five million years. We also recovered many duplication events within areas of endemism in Amazonia. Cophylogenetic analyses of these blood parasites and their avian hosts support a diversification history dominated by host switching. The ability of avian malaria parasites to disperse geographically and shift among avian hosts has played a major role in their radiation and has shaped the current distribution and diversity of these parasites across Amazonia.

Journal article

Chapman P, Tobias JA, Edwards DP, Davies RGet al., 2018, Contrasting impacts of land use change on phylogenetic and functional diversity of tropical forest birds, Journal of Applied Ecology, Vol: 55, Pages: 1604-1614, ISSN: 0021-8901

1. Biodiversity conservation strategies increasingly target maintaining evolutionary history and the resilience of ecosystem function, not just species richness (SR). This has led to the emergence of two metrics commonly proposed as tools for decision making: phylogenetic diversity (PD) and functional diversity (FD). Yet the extent to which they are interchangeable remains poorly understood. 2. We explore shifts in and relationships between FD and PD of bird communities across a disturbance gradient in Borneo, from old-growth tropical forest to oil palm plantation. 3. We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance (MNTD) from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance (MPD) is constrained by forest logging more than by conversion to oil palm, taking account of SR. 4. The decline in FD across the gradient is less severe than in PD, with all metrics indicating relatively high trait diversity in oil palm despite low SR, although functional redundancy is much reduced. Accounting for SR, levels of functional over- or under-dispersion of bird communities are strongly coupled to habitat disturbance level rather than to any equivalent phylogenetic metric. 5. Policy Implications. We suggest that while phylogenetic diversity (PD) is an improvement on species richness as a proxy for functional diversity (FD), conservation decisions based on PD alone cannot reliably safeguard maximal FD. Thus, PD and FD are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets.

Journal article

McEntee JP, Tobias JA, Sheard C, Burleigh JGet al., 2018, Tempo and timing of ecological trait divergence in bird speciation., Nature Ecology and Evolution, Vol: 2, Pages: 1120-1127, ISSN: 2397-334X

Organismal traits may evolve either gradually or in rapid pulses, but the relative importance of these modes in the generation of species differences is unclear. Additionally, while pulsed evolution is frequently assumed to be associated with speciation events, few studies have explicitly examined how the tempo of trait divergence varies with respect to different geographical phases of speciation, starting with geographic isolation and ending, in many cases, with spatial overlap (sympatry). Here we address these issues by combining divergence time estimates, trait measurements and geographic range data for 952 avian sister species pairs worldwide to examine the tempo and timing of trait divergence in recent speciation events. We show that patterns of divergence in key ecological traits are not gradual, but instead seem to follow a pattern of relative stasis interspersed with evolutionary pulses of varying magnitude. We also find evidence that evolutionary pulses generally precede sympatry, and that greater trait disparity is associated with sympatry. These findings suggest that early pulses of trait divergence promote subsequent transitions to sympatry, rather than occurring after sympatry has been established. Incorporating models with evolutionary pulses of varying magnitude into speciation theory may explain why some species pairs achieve rapid sympatry whereas others undergo prolonged geographical exclusion.

Journal article

Pigot A, Jetz W, Sheard C, Tobias JAet al., 2018, The macroevolutionary dynamics of species coexistence in birds, Nature Ecology and Evolution, Vol: 2, Pages: 1112-1119, ISSN: 2397-334X

Ecological communities are assembled from the overlapping of species in geographic space, but the mechanisms facilitating or limiting such overlaps are difficult to resolve. Here, we combine phylogenetic, morphological and environmental data to model how multiple processes regulate the origin and maintenance of geographic range overlap across 1,115 pairs of avian sister species globally. We show that coexistence cannot be adequately predicted by either dispersal-assembly (that is, biogeographic) models or niche-assembly models alone. Instead, our results overwhelmingly support an integrated model with different assembly processes dominating at different stages of coexistence. The initial attainment of narrow geographic overlap is dictated by intrinsic dispersal ability and the time available for dispersal, whereas wider coexistence is largely dependent on niche availability, increasing with ecosystem productivity and divergence in niche-related traits, and apparently declining as communities become saturated with species. Furthermore, although coexistence of any individual pair of species is highly stochastic, we find that integrating assembly processes allows broad variation in the incidence and extent of coexistence to be predicted with reasonable accuracy. Our findings demonstrate how phylogenetic data coupled with environmental factors and functional traits can begin to clarify the multi-layered processes shaping the distribution of biodiversity at large spatial scales.

Journal article

Bovo AAA, Ferraz KMPMB, Magioli M, Alexandrino ER, Hasui É, Ribeiro MC, Tobias JAet al., 2018, Habitat fragmentation narrows the distribution of avian functional traits associated with seed dispersal in tropical forest, Perspectives in Ecology and Conservation, Vol: 16, Pages: 90-96, ISSN: 2530-0644

Land-use change influences biodiversity in non-random ways, affecting some species and functional groups more than others, with potential implications for the loss or degradation of important ecological processes, such as seed dispersal. Here we investigate the effect of patch-size reduction on the composition and functional richness (FRic) of avian communities in Atlantic Forest fragments, focusing on morphological traits associated with seed dispersal in frugivorous birds. We found that FRic of three key traits—hand-wing index, body mass and gape width—decreased with patch size reduction, because species with larger values for morphological traits were lost through local extinction. The relative absence of large-gaped and more-dispersive frugivores in small forest fragments has important implications because these species play a pivotal role in seed dispersal, carrying higher seed loads for longer distances, and consuming larger-sized seeds that cannot be dispersed by smaller-gaped frugivores. Our results highlight the importance of preserving large or interconnected habitat patches, and promoting habitat restoration of cleared areas, to ensure that sufficient avian functional diversity is maintained to supply the full range of seed dispersal services required by tropical forests, both currently and in future.

Journal article

Howard C, Stephens PA, Tobias JA, Sheard C, Butchart SHM, Willis SGet al., 2018, Flight range, fuel load and the impact of climate change on the journeys of migrant birds, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 285, ISSN: 0962-8452

Climate change is predicted to increase migration distances for many migratory species, but the physiological and temporal implications of longer migratory journeys have not been explored. Here, we combine information about species' flight range potential and migratory refuelling requirements to simulate the number of stopovers required and the duration of current migratory journeys for 77 bird species breeding in Europe. Using tracking data, we show that our estimates accord with recorded journey times and stopovers for most species. We then combine projections of altered migratory distances under climate change with models of avian flight to predict future migratory journeys. We find that 37% of migratory journeys undertaken by long-distance migrants will necessitate an additional stopover in future. These greater distances and the increased number of stops will substantially increase overall journey durations of many long-distance migratory species, a factor not currently considered in climate impact studies.

Journal article

Drury JP, Tobias JA, Burns KJ, Mason NA, Shultz AJ, Morlon Het al., 2018, Contrasting impacts of competition on ecological and social trait evolution in songbirds, PLoS Biology, Vol: 16, ISSN: 1544-9173

Competition between closely related species has long been viewed as a powerful selective force that drives trait diversification, thereby generating phenotypic diversity over macroevolutionary timescales. However, although the impact of interspecific competition has been documented in a handful of iconic insular radiations, most previous studies have focused on traits involved in resource use, and few have examined the role of competition across large, continental radiations. Thus, the extent to which broad-scale patterns of phenotypic diversity are shaped by competition remain largely unclear, particularly for social traits. Here, we estimate the effect of competition between interacting lineages by applying new phylogenetic models that account for such interactions to an exceptionally complete dataset of resource-use traits and social signaling traits for the entire radiation of tanagers (Aves, Thraupidae), the largest family of songbirds. We find that interspecific competition strongly influences the evolution of traits involved in resource use, with a weaker effect on plumage signals, and very little effect on song. Our results provide compelling evidence that interspecific exploitative competition contributes to ecological trait diversification among coexisting species, even in a large continental radiation. In comparison, signal traits mediating mate choice and social competition seem to diversify under different evolutionary models, including rapid diversification in the allopatric stage of speciation.

Journal article

Derryberry EP, Seddon N, Derryberry GE, Claramunt S, Seeholzer GF, Brumfield RT, Tobias JAet al., 2018, Ecological drivers of song evolution in birds: Disentangling the effects of habitat and morphology, Ecology and Evolution, Vol: 8, Pages: 1890-1905, ISSN: 2045-7758

Environmental differences influence the evolutionary divergence of mating signals through selection acting either directly on signal transmission ("sensory drive") or because morphological adaptation to different foraging niches causes divergence in "magic traits" associated with signal production, thus indirectly driving signal evolution. Sensory drive and magic traits both contribute to variation in signal structure, yet we have limited understanding of the relative role of these direct and indirect processes during signal evolution. Using phylogenetic analyses across 276 species of ovenbirds (Aves: Furnariidae), we compared the extent to which song evolution was related to the direct influence of habitat characteristics and the indirect effect of body size and beak size, two potential magic traits in birds. We find that indirect ecological selection, via diversification in putative magic traits, explains variation in temporal, spectral, and performance features of song. Body size influences song frequency, whereas beak size limits temporal and performance components of song. In comparison, direct ecological selection has weaker and more limited effects on song structure. Our results illustrate the importance of considering multiple deterministic processes in the evolution of mating signals.

Journal article

Hatfield JH, Orme CDL, Tobias JA, Banks-Leite Cet al., 2017, Trait-based indicators of bird species sensitivity to habitat loss are effective within but not across datasets., Ecological Applications, Vol: 28, Pages: 28-34, ISSN: 1051-0761

Species' traits have been widely championed as the key to predicting which species are most threatened by habitat loss, yet previous work has failed to detect trends that are consistent enough to guide large-scale conservation and management. Here we explore whether traits and environmental variables predict species sensitivity to habitat loss across two datasets generated by independent avifaunal studies in the Atlantic Forest of Brazil, both of which detected a similar assemblage of species, and similar species-specific responses to habitat change, across an overlapping sample of sites. Specifically, we tested whether 25 distributional, climatic, ecological, behavioral and morphological variables predict sensitivity to habitat loss among 196 bird species, both within and across studies, and when data were analysed as occurrence or abundance. We found that 4-9 variables showed high explanatory power within a single study or dataset, but none performed as strong predictors across all datasets. Our results demonstrate that the use of species traits to predict sensitivity to anthropogenic habitat loss can produce predictions that are species- and site-specific and not scalable to whole regions or biomes, and thus should be used with caution. This article is protected by copyright. All rights reserved.

Journal article

Tobias JA, Waldron A, Tobias JA, 2017, Reductions in global biodiversity loss predicted from conservation spending, Nature, Vol: 551, Pages: 364-367, ISSN: 0028-0836

Halting global biodiversity loss is central to the Convention on Biological Diversity and United Nations Sustainable Development Goals1,2, but success to date has been very limited3,4,5. A critical determinant of success in achieving these goals is the financing that is committed to maintaining biodiversity6,7,8,9; however, financing decisions are hindered by considerable uncertainty over the likely impact of any conservation investment6,7,8,9. For greater effectiveness, we need an evidence-based model10,11,12 that shows how conservation spending quantitatively reduces the rate of biodiversity loss. Here we demonstrate such a model, and empirically quantify how conservation investment between 1996 and 2008 reduced biodiversity loss in 109 countries (signatories to the Convention on Biological Diversity and Sustainable Development Goals), by a median average of 29% per country. We also show that biodiversity changes in signatory countries can be predicted with high accuracy, using a dual model that balances the effects of conservation investment against those of economic, agricultural and population growth (human development pressures)13,14,15,16,17,18. Decision-makers can use this model to forecast the improvement that any proposed biodiversity budget would achieve under various scenarios of human development pressure, and then compare these forecasts to any chosen policy target. We find that the impact of spending decreases as human development pressures grow, which implies that funding may need to increase over time. The model offers a flexible tool for balancing the Sustainable Development Goals of human development and maintaining biodiversity, by predicting the dynamic changes in conservation finance that will be needed as human development proceeds.

Journal article

Ulrich W, Banks-Leite C, De Coster G, Habel JC, Matheve H, Newmark WD, Tobias JA, Lens Let al., 2017, Environmentally and behaviourally mediated co-occurrence of functional traits in bird communities of tropical forest fragments, Oikos, Vol: 127, Pages: 274-284, ISSN: 0030-1299

Two major theories of community assembly - based on the assumption of 'limiting similarity' or 'habitat filtering', respectively - predict contrasting patterns in the spatial arrangement of functional traits. Previous analyses have made progress in testing these predictions and identifying underlying processes, but have also pointed to theoretical as well as methodological shortcomings. Here we applied a recently developed methodology for spatially explicit analysis of phylogenetic meta-community structure to study the pattern of co-occurrence of functional traits in Afrotropical and Neotropical bird species inhabiting forest fragments. Focusing separately on locomotory, dietary, and dispersal traits, we tested whether environmental filtering causes spatial clustering, or competition leads to spatial segregation as predicted by limiting similarity theory. We detected significant segregation of species co-occurrences in African fragments, but not in the Neotropical ones. Interspecific competition had a higher impact on trait co-occurrence than filter effects, yet no single functional trait was able to explain the observed degree of spatial segregation among species. Despite high regional variability spanning from spatial segregation to aggregation, we found a consistent tendency for a clustered spatial patterning of functional traits among communities in fragmented landscapes, particularly in non-territorial species. Overall, we show that behavioural effects, such as territoriality, and environmental effects, such as the area of forest remnants or properties of the landscape matrix in which they are embedded, can strongly affect the pattern of trait co-occurrence. Our findings suggest that trait-based analyses of community structure should include behavioural and environmental covariates, and we here provide an appropriate method for linking functional traits, species ecology and environmental conditions to clarify the drivers underlying spatial patterns of species c

Journal article

Thaxter CB, Buchanan GM, Carr J, Butchart SHM, Newbold T, Green RE, Tobias JA, Foden WB, O'Brien S, Pearce-Higgins JWet al., 2017, Bird and bat species' global vulnerability to collision mortality at wind farms revealed through a trait-based assessment, Proceedings of the Royal Society B: Biological Sciences, Vol: 284, ISSN: 1471-2954

Mitigation of anthropogenic climate change involves deployments of renewableenergy worldwide, including wind farms, which can pose a significantcollision risk to volant animals. Most studies into the collision risk betweenspecies and wind turbines, however, have taken place in industrializedcountries. Potential effects for many locations and species therefore remainunclear. To redress this gap, we conducted a systematic literature reviewof recorded collisions between birds and bats and wind turbines withindeveloped countries. We related collision rate to species-level traits and turbinecharacteristics to quantify the potential vulnerability of 9538 bird and888 bat species globally. Avian collision rate was affected by migratory strategy,dispersal distance and habitat associations, and bat collision rates wereinfluenced by dispersal distance. For birds and bats, larger turbine capacity(megawatts) increased collision rates; however, deploying a smaller numberof large turbines with greater energy output reduced total collision risk perunit energy output, although bat mortality increased again with the largestturbines. Areas with high concentrations of vulnerable species were alsoidentified, including migration corridors. Our results can therefore guidewind farm design and location to reduce the risk of large-scale animal mortality.This is the first quantitative global assessment of the relative collisionvulnerability of species groups with wind turbines, providing valuable guidancefor minimizing potentially serious negative impacts on biodiversity.

Journal article

Grether GF, Peiman KS, Tobias JA, Robinson BWet al., 2017, Causes and Consequences of Behavioral Interference between Species., Trends in Ecology and Evolution, Vol: 32, Pages: 760-772, ISSN: 1872-8383

Behavioral interference between species, such as territorial aggression, courtship, and mating, is widespread in animals. While aggressive and reproductive forms of interspecific interference have generally been studied separately, their many parallels and connections warrant a unified conceptual approach. Substantial evidence exists that aggressive and reproductive interference have pervasive effects on species coexistence, range limits, and evolutionary processes, including divergent and convergent forms of character displacement. Alien species invasions and climate change-induced range shifts result in novel interspecific interactions, heightening the importance of predicting the consequences of species interactions, and behavioral interference is a fundamental but neglected part of the equation. Here, we outline priorities for further theoretical and empirical research on the ecological and evolutionary consequences of behavioral interference.

Journal article

Stoddard MC, Yong EH, Akkaynak D, Sheard C, Tobias JA, Mahadevan Let al., 2017, Avian egg shape: Form, function, and evolution, Science, Vol: 356, Pages: 1249-1254, ISSN: 0036-8075

Avian egg shape is generally explained as an adaptation to life history, yet we currently lack a global synthesis of how egg-shape differences arise and evolve. Here, we apply morphometric, mechanistic, and macroevolutionary analyses to the egg shapes of 1400 bird species. We characterize egg-shape diversity in terms of two biologically relevant variables, asymmetry and ellipticity, allowing us to quantify the observed morphologies in a two-dimensional morphospace. We then propose a simple mechanical model that explains the observed egg-shape diversity based on geometric and material properties of the egg membrane. Finally, using phylogenetic models, we show that egg shape correlates with flight ability on broad taxonomic scales, suggesting that adaptations for flight may have been critical drivers of egg-shape variation in birds.

Journal article

Cooney CR, Tobias JA, Weir JT, Botero CA, Seddon Net al., 2017, Sexual selection, speciation and constraints on geographical range overlap in birds, Ecology Letters, Vol: 20, Pages: 863-871, ISSN: 1461-023X

The role of sexual selection as a driver of speciation remains unresolved, not least because we lack a clear empirical understanding of its influence on different phases of the speciation process. Here, using data from 1306 recent avian speciation events, we show that plumage dichromatism (a proxy for sexual selection) does not predict diversification rates, but instead explains the rate at which young lineages achieve geographical range overlap. Importantly, this effect is only significant when range overlap is narrow (< 20%). These findings are consistent with a ‘differential fusion’ model wherein sexual selection reduces rates of fusion among lineages undergoing secondary contact, facilitating parapatry or limited co-existence, whereas more extensive sympatry is contingent on additional factors such as ecological differentiation. Our results provide a more mechanistic explanation for why sexual selection appears to drive early stages of speciation while playing a seemingly limited role in determining broad-scale patterns of diversification.

Journal article

Bath E, Bowden S, Peters C, Reddy A, Tobias JA, Easton-Calabria E, Seddon N, Goodwin SF, Wigby Set al., 2017, Sperm and sex peptide stimulate aggression in female Drosophila, Nature Ecology and Evolution, Vol: 1, ISSN: 2397-334X

Female aggression towards other females is associated with reproduction in many taxa, and traditionally thought to be related to the protection or provisioning of offspring, such as through increased resource acquisition. However, the underlying reproductive factors causing aggressive behaviour in females remain unknown. Here we show that female aggression in the fruit fly Drosophila melanogaster is strongly stimulated by the receipt of sperm at mating, and in part by an associated seminal fluid protein, the sex peptide. We further show that the post-mating increase in female aggression is decoupled from the costs of egg production and from post-mating decreases in sexual receptivity. Our results suggest that male ejaculates can have a surprisingly direct influence on aggression in recipient females. Male ejaculate traits thus influence the female social competitive environment with potentially far-reaching ecological and evolutionary consequences.

Journal article

Hosner PA, Tobias JA, Braun EL, Kimball RTet al., 2017, How do seemingly non-vagile clades accomplish trans-marine dispersal? Trait and dispersal evolution in the landfowl (Ayes: Galliformes), Proceedings of the Royal Society B: Biological Sciences, Vol: 284, ISSN: 0962-8452

Dispersal ability is a key factor in determining insular distributions and island community composition, yet non-vagile terrestrial organisms widely occur on oceanic islands. The landfowl (pheasants, partridges, grouse, turkeys, quails and relatives) are generally poor dispersers, but the Old World quail (Coturnix) are a notable exception. These birds evolved small body sizes and high-aspect-ratio wing shapes, and hence are capable of trans-continental migrations and trans-oceanic colonization. Two monotypic partridge genera, Margaroperdix of Madagascar and Anurophasis of alpine New Guinea, may represent additional examples of trans-marine dispersal in landfowl, but their body size and wing shape are typical of poorly dispersive continental species. Here, we estimate historical relationships of quail and their relatives using phylogenomics, and infer body size and wing shape evolution in relation to trans-marine dispersal events. Our results show that Margaroperdix and Anurophasis are nested within the Coturnix quail, and are each ‘island giants’ that independently evolved from dispersive, Coturnix-like ancestral populations that colonized and were subsequently isolated on Madagascar and New Guinea. This evolutionary cycle of gain and loss of dispersal ability, coupled with extinction of dispersive taxa, can result in the false appearance that non-vagile taxa somehow underwent rare oceanic dispersal.

Journal article

Fecchio A, Svensson-Coelho M, Bell J, Ellis VA, Medeiros MC, Trisos CH, Blake JG, Loiselle BA, Tobias JA, Fanti R, Coffey ED, De Faria IP, Pinho JB, Felix G, Braga EM, Anciaes M, Tkach V, Bates J, Witt C, Weckstein JD, Ricklefs RE, Farias IPet al., 2017, Host associations and turnover of haemosporidian parasites in manakins (Aves: Pipridae), Parasitology, Vol: 144, Pages: 984-993, ISSN: 0031-1820

Parasites of the genera Plasmodium and Haemoproteus (Apicomplexa: Haemosporida) are a diverse group of pathogens that infect birds nearly worldwide. Despite their ubiquity, the ecological and evolutionary factors that shape the diversity and distribution of these protozoan parasites among avian communities and geographic regions are poorly understood. Based on a survey throughout the Neotropics of the haemosporidian parasites infecting manakins (Pipridae), a family of Passerine birds endemic to this region, we asked whether host relatedness, ecological similarity and geographic proximity structure parasite turnover between manakin species and local manakin assemblages. We used molecular methods to screen 1343 individuals of 30 manakin species for the presence of parasites. We found no significant correlations between manakin parasite lineage turnover and both manakin species turnover and geographic distance. Climate differences, species turnover in the larger bird community and parasite lineage turnover in non-manakin hosts did not correlate with manakin parasite lineage turnover. We also found no evidence that manakin parasite lineage turnover among host species correlates with range overlap and genetic divergence among hosts. Our analyses indicate that host switching (turnover among host species) and dispersal (turnover among locations) of haemosporidian parasites in manakins are not constrained at this scale.

Journal article

Mason NA, Burns KJ, Tobias JA, Claramunt S, Seddon N, Derryberry EPet al., 2017, Song evolution, speciation, and vocal learning in passerine birds, Evolution, Vol: 71, Pages: 786-796, ISSN: 0014-3820

Phenotypic divergence can promote reproductive isolation and speciation, suggesting a possible link between rates of phenotypic evolution and the tempo of speciation at multiple evolutionary scales. To date, most macroevolutionary studies of diversification have focused on morphological traits, whereas behavioral traits─including vocal signals─are rarely considered. Thus, although behavioral traits often mediate mate choice and gene flow, we have a limited understanding of how behavioral evolution contributes to diversification. Furthermore, the developmental mode by which behavioral traits are acquired may affect rates of behavioral evolution, although this hypothesis is seldom tested in a phylogenetic framework. Here, we examine evidence for rate shifts in vocal evolution and speciation across two major radiations of codistributed passerines: one oscine clade with learned songs (Thraupidae) and one suboscine clade with innate songs (Furnariidae). We find that evolutionary bursts in rates of speciation and song evolution are coincident in both thraupids and furnariids. Further, overall rates of vocal evolution are higher among taxa with learned rather than innate songs. Taken together, these findings suggest an association between macroevolutionary bursts in speciation and vocal evolution, and that the tempo of behavioral evolution can be influenced by variation in developmental modes among lineages.

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00860179&limit=30&person=true