Imperial College London

DrJosephTobias

Faculty of Natural SciencesDepartment of Life Sciences (Silwood Park)

Senior Lecturer in Biodiversity
 
 
 
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Contact

 

+44 (0)20 7594 1059j.tobias CV

 
 
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Location

 

KennedySilwood Park

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Summary

 

Publications

Publication Type
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80 results found

Chapman PM, 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, ISSN: 0021-8901

© 2018 British Ecological Society. 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. 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. We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance is constrained by forest logging more than by conversion to oil palm, taking account of SR. 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. 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 phylogenetic diversity alone cannot reliably safeguard maximal functional diversity. Thus, phylogenetic diversity and functional diversity are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets.

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

© 2018 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. 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.

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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 Biol, Vol: 16

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.

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Hatfield JH, Orme CDL, Tobias JA, Banks-Leite Cet al., 2018, Trait-based indicators of bird species sensitivity to habitat loss are effective within but not across data sets., Ecol Appl, 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 data sets 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 four to nine variables showed high explanatory power within a single study or data set, but none performed as strong predictors across all data sets. 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.

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Ulrich W, Banks-Leite C, De Coster G, Habel JC, Matheve H, Newmark WD, Tobias JA, Lens Let al., 2018, 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

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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 &ITDrosophila&IT, NATURE ECOLOGY & EVOLUTION, Vol: 1, ISSN: 2397-334X

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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

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

JOURNAL ARTICLE

Grether GF, Peiman KS, Tobias JA, Robinson BWet al., 2017, Causes and Consequences of Behavioral Interference between Species, TRENDS IN ECOLOGY & EVOLUTION, Vol: 32, Pages: 760-772, ISSN: 0169-5347

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

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

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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-+, ISSN: 0036-8075

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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: 0962-8452

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Waldron A, Miller DC, Redding D, Mooers A, Kuhn TS, Nibbelink N, Roberts JT, Tobias JA, Gittleman JLet al., 2017, Reductions in global biodiversity loss predicted from conservation spending, NATURE, Vol: 551, Pages: 364-+, ISSN: 0028-0836

JOURNAL ARTICLE

Bregman TP, Lees AC, MacGregor HEA, Darski B, de Moura NG, Aleixo A, Barlow J, Tobias JAet al., 2016, Using avian functional traits to assess the impact of land-cover change on ecosystem processes linked to resilience in tropical forests, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 283, ISSN: 0962-8452

JOURNAL ARTICLE

Bregman TP, Lees AC, MacGregor HEA, Darski B, de Moura NG, Aleixo A, Barlow J, Tobias JAet al., 2016, Using avian functional traits to assess the impact of land-cover change on ecosystem processes linked to resilience in tropical forests, Proceedings. Biological sciences, Vol: 283

© 2016 The Author(s). Vertebrates perform key roles in ecosystem processes via trophic interactions with plants and insects, but the response of these interactions to environmental change is difficult to quantify in complex systems, such as tropical forests. Here, we use the functional trait structure of Amazonian forest bird assemblages to explore the impacts of land-cover change on two ecosystem processes: seed dispersal and insect predation. We show that trait structure in assemblages of frugivorous and insectivorous birds remained stable after primary forests were subjected to logging and fire events, but that further intensification of human land use substantially reduced the functional diversity and dispersion of traits, and resulted in communities that occupied a different region of trait space. These effects were only partially reversed in regenerating secondary forests. Our findings suggest that local extinctions caused by the loss and degradation of tropical forest are non-random with respect to functional traits, thus disrupting the network of trophic interactions regulating seed dispersal by forest birds and herbivory by insects, with important implications for the structure and resilience of human-modified tropical forests. Furthermore, our results illustrate how quantitative functional traits for specific guilds can provide a range of metrics for estimating the contribution of biodiversity to ecosystem processes, and the response of such processes to land-cover change.

JOURNAL ARTICLE

Collar NJ, Fishpool LDC, del Hoyo J, Pilgrim JD, Seddon N, Spottiswoode CN, Tobias JAet al., 2016, Toward a scoring system for species delimitation: a response to Remsen, JOURNAL OF FIELD ORNITHOLOGY, Vol: 87, Pages: 104-110, ISSN: 0273-8570

JOURNAL ARTICLE

Cooney CR, Seddon N, Tobias JA, 2016, Widespread correlations between climatic niche evolution and species diversification in birds, JOURNAL OF ANIMAL ECOLOGY, Vol: 85, Pages: 869-878, ISSN: 0021-8790

JOURNAL ARTICLE

Pigot AL, Bregman T, Sheard C, Daly B, Etienne RS, Tobias JAet al., 2016, Quantifying species contributions to ecosystem processes: a global assessment of functional trait and phylogenetic metrics across avian seed-dispersal networks, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 283, ISSN: 0962-8452

JOURNAL ARTICLE

Pigot AL, Tobias JA, Jetz W, 2016, Energetic Constraints on Species Coexistence in Birds, PLoS Biology, Vol: 14, ISSN: 1544-9173

© 2016 Pigot et al. The association between species richness and ecosystem energy availability is one of the major geographic trends in biodiversity. It is often explained in terms of energetic constraints, such that coexistence among competing species is limited in low productivity environments. However, it has proven challenging to reject alternative views, including the null hypothesis that species richness has simply had more time to accumulate in productive regions, and thus the role of energetic constraints in limiting coexistence remains largely unknown. We use the phylogenetic relationships and geographic ranges of sister species (pairs of lineages who are each other’s closest extant relatives) to examine the association between energy availability and coexistence across an entire vertebrate class (Aves). We show that the incidence of coexistence among sister species increases with overall species richness and is elevated in more productive ecosystems, even when accounting for differences in the evolutionary time available for coexistence to occur. Our results indicate that energy availability promotes species coexistence in closely related lineages, providing a key step toward a more mechanistic understanding of the productivity–richness relationship underlying global gradients in biodiversity.

JOURNAL ARTICLE

Pigot AL, Trisos CH, Tobias JA, 2016, Functional traits reveal the expansion and packing of ecological niche space underlying an elevational diversity gradient in passerine birds, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 283, ISSN: 0962-8452

JOURNAL ARTICLE

Seddon N, Mace GM, Naeem S, Tobias JA, Pigot AL, Cavanagh R, Mouillot D, Vause J, Walpole Met al., 2016, Biodiversity in the Anthropocene: prospects and policy, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 283, ISSN: 0962-8452

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Ulrich W, Lens L, Tobias JA, Habel JCet al., 2016, Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments, PLOS ONE, Vol: 11, ISSN: 1932-6203

JOURNAL ARTICLE

Bath E, Wigby S, Vincent C, Tobias JA, Seddon Net al., 2015, Condition, not eyespan, predicts contest outcome in female stalk-eyed flies, Teleopsis dalmanni, ECOLOGY AND EVOLUTION, Vol: 5, Pages: 1826-1836, ISSN: 2045-7758

JOURNAL ARTICLE

Bregman TP, Lees AC, Seddon N, MacGregor HEA, Darski B, Aleixo A, Bonsall MB, Tobias JAet al., 2015, Species interactions regulate the collapse of biodiversity and ecosystem function in tropical forest fragments, ECOLOGY, Vol: 96, Pages: 2692-2704, ISSN: 0012-9658

JOURNAL ARTICLE

Matthews TJ, Sheard C, -Jones HEWC, Bregman TP, Tobias JA, Whittaker RJet al., 2015, Ecological traits reveal functional nestedness of bird communities in habitat islands: a global survey, OIKOS, Vol: 124, Pages: 817-826, ISSN: 0030-1299

JOURNAL ARTICLE

Pigot AL, Tobias JA, 2015, Dispersal and the transition to sympatry in vertebrates, PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, Vol: 282, ISSN: 0962-8452

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Tobias JA, 2015, BIODIVERSITY Hidden impacts of logging, NATURE, Vol: 523, Pages: 163-164, ISSN: 0028-0836

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Bregman TP, Sekercioglu CH, Tobias JA, 2014, Global patterns and predictors of bird species responses to forest fragmentation: Implications for ecosystem function and conservation, BIOLOGICAL CONSERVATION, Vol: 169, Pages: 372-383, ISSN: 0006-3207

JOURNAL ARTICLE

Edwards DP, Tobias JA, Sheil D, Meijaard E, Laurance WFet al., 2014, Maintaining ecosystem function and services in logged tropical forests, TRENDS IN ECOLOGY & EVOLUTION, Vol: 29, Pages: 511-520, ISSN: 0169-5347

JOURNAL ARTICLE

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