scholarly journals Trophic niche shifts and phenotypic trait evolution are largely decoupled in Australasian parrots

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Vicente García-Navas ◽  
Joseph A. Tobias ◽  
Manuel Schweizer ◽  
Daniel Wegmann ◽  
Richard Schodde ◽  
...  
Keyword(s):  
Trophic Niche ◽  
Phenotypic Trait ◽  
Dispersal Capacity ◽  
Trait Evolution ◽  
Wide Range ◽  
Niche Shifts ◽  
Dietary Niche ◽  
Evolutionary Trajectories ◽  
Best Fitting ◽  
Trophic Shifts

Abstract Background Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary trajectories of a wide range of vertebrate groups, yet their consequences for morphological disparity and species diversity differ among groups. Methods Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological traits such as body size, beak shape, and dispersal capacity. Results We found no evidence for an ‘early-burst’ scenario of lineage or morphological diversification. The best-fitting models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly toward adaptive peaks they have not yet reached. Conclusions This study adds to a growing body of evidence indicating that the relationship between avian morphology and feeding ecology may be more complex than usually assumed and highlights the importance of adding more flexible models to the macroevolutionary toolbox.

scholarly journals Trophic Niche Shifts and Phenotypic Trait Evolution are Largely Decoupled in Australasian Parrots

2021 ◽  
Author(s):  
Vicente García-Navas ◽  
Joseph A. Tobias ◽  
Manuel Schweizer ◽  
Daniel Wegmann ◽  
Richard Schodde ◽  
...  
Keyword(s):  
Trophic Niche ◽  
Phenotypic Trait ◽  
Dispersal Capacity ◽  
Trait Evolution ◽  
Wide Range ◽  
Niche Shifts ◽  
Dietary Niche ◽  
Evolutionary Trajectories ◽  
Best Fitting ◽  
Trophic Shifts

Abstract Background: Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary trajectories of a wide range of vertebrate groups, yet its consequences for morphological disparity and species diversity differs among groups. Methods: Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological traits such as body size, beak shape, and dispersal capacity. Results: Rates of lineage diversification appear to be constant over time and we find no evidence for an ‘early-burst’ scenario of morphological diversification. The best-fitting models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly toward adaptive peaks they have not yet reached. Conclusions: This study adds to a growing body of evidence indicating that the relationship between avian morphology and feeding ecology may be more complex than usually assumed and highlights the importance of adding more flexible models to the macroevolutionary toolbox.

scholarly journals Trophic Trait Evolution Explains Variation in Nutrient Excretion Stoichiometry among Panamanian Armored Catfishes (Loricariidae)

Diversity ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 88
Author(s):  
Eric K. Moody ◽  
Fernando Alda ◽  
Krista A. Capps ◽  
Oscar Puebla ◽  
Benjamin L. Turner
Keyword(s):  
Significant Variation ◽  
Trophic Position ◽  
Nutrient Recycling ◽  
Trophic Niche ◽  
Relative Importance ◽  
Closely Related Species ◽  
Trait Evolution ◽  
Nutrient Excretion ◽  
Nutrient Mineralization ◽  
Excretion Rates

Variation in nutrient excretion rates and stoichiometric ratios (e.g., nitrogen to phosphorus) by consumers can have substantial effects on aquatic ecosystem function. While phylogenetic signals within an assemblage often explain variation in nutrient recycling rates and stoichiometry, the phylogenetically conserved traits that underlie this phenomenon remain unclear. In particular, variation in nutrient excretion stoichiometry across a phylogeny might be driven by phylogenetic patterns in either diet or body stoichiometry. We examined the relative importance of these traits in explaining variation in nutrient recycling rates and stoichiometry in a diverse family of Neotropical-armored catfishes, Loricariidae, in Panamanian streams. We found significant variation in nutrient mineralization traits among species and subfamilies, but variation in nutrient excretion stoichiometry among species was best explained by trophic position rather than body stoichiometry. The variation in trophic position among Panamanian species was consistent with variation in the trophic niche of their genera across South America, suggesting that phylogenetic patterns underpin the evolution of trophic and nutrient excretion traits among these species. Such geographical variation in nutrient mineralization patterns among closely related species may be common, given that trophic variation in fish lineages occurs widely. These results suggest that information on trophic trait evolution within lineages will advance our understanding of the functional contribution of animals to biogeochemical cycling.

Feeding ecology of Symbolophorus californiensis larvae (Teleostei: Myctophidae) in the southern transition region of the western North Pacific

2009 ◽  
Vol 90 (6) ◽  
pp. 1249-1256 ◽  
Author(s):  
Chiyuki Sassa
Keyword(s):  
Transition Region ◽  
North Pacific ◽  
Western North Pacific ◽  
Developmental Stages ◽  
Feeding Habits ◽  
Larval Growth ◽  
Trophic Niche ◽  
Size Class ◽  
Gut Contents ◽  
Wide Range

The feeding habits of myctophid larvae of Symbolophorus californiensis were examined in the southern transition region of the western North Pacific where the main spawning and nursery grounds of S. californiensis are formed. This species is a key component of the pelagic ecosystems of this region, and their larvae attain one of the largest sizes among myctophids. To analyse gut contents larvae, including most life history stages after yolk-sac absorption (3.7 to 22.2 mm body length (BL)), were collected in the upper 100 m layer in 1997 and 1998. Feeding incidence was higher during the day than at night (53.1–92.3% versus 0–5.6%), and daytime feeding incidence increased gradually with larval growth. Larvae fed mainly on copepods of various developmental stages. Larvae of S. californiensis showed an ontogenetic change in their diet: larvae ≤7.9 mm BL (i.e. preflexion stage) fed mainly on copepod eggs and nauplii, while the larvae ≥8 mm BL consumed mainly calanoid copepodites such as Pseudocalanus and Paracalanus spp. In the largest size-class (16–22.2 mm BL), the furcilia stage of euphausiids was also an important prey item. There was an increase in the average prey size with growth in larvae ≤11.9 mm BL, while the number of prey eaten positively correlated with growth in larvae ≥12 mm BL. The trophic niche breadth also increased with larval growth, which would ensure a wide range of available food resources for the larger size-class larvae.

scholarly journals Urban rats have less variable, higher protein diets

2018 ◽  
Vol 285 (1889) ◽  
pp. 20181441 ◽  
Author(s):  
E. Guiry ◽  
M. Buckley
Keyword(s):  
Urban Ecology ◽  
Rural Areas ◽  
Urban Areas ◽  
Conservation Strategies ◽  
Human Society ◽  
Animal Management ◽  
Wide Range ◽  
Brown Rat ◽  
Dietary Niche ◽  
Urban And Rural Areas

Over the past 1000 years, rats ( Rattus spp.) have become one of the most successful and prolific pests in human society. Despite their cosmopolitan distribution across six continents and ubiquity throughout the world's cities, rat urban ecology remains poorly understood. We investigate the role of human foods in brown rat ( Rattus norvegicus ) diets in urban and rural areas over a 100 year period ( ca AD 1790–1890) in Toronto, Canada using stable carbon ( δ 13 C) and nitrogen ( δ 15 N) isotope analyses of archaeological remains. We found that rat diets from urban sites were of higher quality and were more homogeneous and stable over time. By contrast, in rural areas, they show a wide range of dietary niche specializations that directly overlap, and probably competed, with native omnivorous and herbivorous species. These results demonstrate a link between rodent diets and human population density, providing, to our knowledge, the first long-term dietary perspective on the relative value of different types of human settlements as rodent habitat. This study highlights the potential of using the historical and archaeological record to provide a retrospective on the urban ecology of commensal and synanthropic animals that could be useful for improving animal management and conservation strategies in urban areas.

scholarly journals Distinct evolutionary trajectories of V1R clades across mouse species

2020 ◽  
Author(s):  
Caitlin H Miller ◽  
Polly Campbell ◽  
Michael J Sheehan
Keyword(s):  
Positive Selection ◽  
House Mouse ◽  
Gene Family Evolution ◽  
Specific Gene ◽  
Receptor Subtypes ◽  
Gene Repertoire ◽  
Social Signals ◽  
Functional Roles ◽  
Wide Range ◽  
Evolutionary Trajectories

Abstract BACKGROUND: Many animals rely heavily on olfaction to navigate their environment. Among rodents, olfaction is crucial for a wide range of social behaviors. The vomeronasal olfactory system in particular plays an important role in mediating social communication, including the detection of pheromones and recognition signals. In this study we examine patterns of vomeronasal type-1 receptor (V1R) evolution in the house mouse and related species within the genus Mus . We report the extent of gene repertoire turnover and conservation among species and clades, as well as the prevalence of positive selection on gene sequences across the V1R tree. By exploring the evolution of these receptors, we provide insight into the functional roles of receptor subtypes as well as the dynamics of gene family evolution. RESULTS: We generated transcriptomes from the vomeronasal organs of 5 Mus species, and produced high quality V1R repertoires for each species. We find that V1R clades in the house mouse and relatives exhibit distinct evolutionary trajectories. We identify putative species-specific gene expansions, including a large clade D expansion in the house mouse. While gene gains are abundant, we detect very few gene losses. We describe a novel V1R clade and highlight candidate receptors for future study. We find evidence for distinct evolutionary processes across different clades, from largescale turnover to highly conserved repertoires. Patterns of positive selection are similarly variable, as some clades exhibit abundant positive selection while others display high gene sequence conservation. Based on clade-level evolutionary patterns, we identify receptor families that are strong candidates for detecting social signals and predator cues. Our results reveal clades with receptors detecting female reproductive status are among the most conserved across species, suggesting an important role in V1R chemosensation. CONCLUSION: Analysis of clade-level evolution is critical for understanding species’ chemosensory adaptations. This study provides clear evidence that V1R clades are characterized by distinct evolutionary trajectories. As receptor evolution is shaped by ligand identity, these results provide a framework for examining the functional roles of receptors.

Review of Data on Diets of Beaked Whales: Evidence of Niche Separation and Geographic Segregation

2003 ◽  
Vol 83 (3) ◽  
pp. 651-665 ◽  
Author(s):  
C.D. MacLeod ◽  
M.B. Santos ◽  
G.J. Pierce
Keyword(s):  
Prey Species ◽  
Stomach Contents ◽  
Published Data ◽  
Niche Separation ◽  
Beaked Whale ◽  
Important Prey ◽  
Wide Range ◽  
Dietary Niche ◽  
Beaked Whales ◽  
Fish Remains

This study reviewed published data on dietary preferences of beaked whales (Ziphiidae) from stomach contents analysis. Detailed data were only available for three of the six beaked whale genera (Hyperoodon, Mesoplodon and Ziphius). Stomach samples of these three beaked whale genera primarily contained cephalopod and fish remains, although some also contained crustaceans. Mesoplodon spp. were found to contain the most fish, with some species containing nothing but fish remains, while the southern bottlenose whale (Hyperoodon planifrons) and Cuvier's beaked whale (Ziphius cavirostris) rarely, if ever, contained fish. Of cephalopods identified, Histioteuthid, Gonatid, Cranchiid and Onychoteuthid species usually contributed most to prey numbers and biomass for all beaked whale genera. There was a wide range of species and families of cephalopods recorded from stomach contents, with no obvious preference for bioluminescent prey species, vertical migrating prey species or prey species with specific body compositions. Whales of the genus Mesoplodon generally contained smaller prey, such as cephalopods under 500 g in weight, compared with other beaked whales. Hyperoodon and Ziphius frequently contained much larger cephalopods with many important prey species having a mean weight of over 1000 g. This suggests that Mesoplodon occupies a separate dietary niche from Hyperoodon and Ziphius, which may be an example of niche segregation. In contrast, Hyperoodon and Ziphius appear to occupy very similar dietary niches but have geographically segregated distributions, with Hyperoodon occupying cold-temperate to polar waters and Ziphius occupying warm-temperate to tropical waters.

scholarly journals A food spectrum analysis of three bufonid species (Anura: Bufonidae) from Uttarakhand region of the western Himalaya, India

2019 ◽  
Vol 11 (13) ◽  
pp. 14663-14671
Author(s):  
Vivekanand Bahuguna ◽  
Ashish Kumar Chowdhary ◽  
Shurveer Singh ◽  
Gaurav Bhatt ◽  
Siddhant Bhardwaj ◽  
...  
Keyword(s):  
Spectrum Analysis ◽  
Western Himalaya ◽  
Amphibian Conservation ◽  
Food Spectrum ◽  
Ecological Diversity ◽  
Gut Content ◽  
Wide Range ◽  
Dietary Niche ◽  
Index Of Relative Importance ◽  
Terrestrial Insects

The ecological diversity of insects and its predators like amphibians are important determinants in ecological balance.  A total of 1,222 prey items in 84 specimens were examined to contribute the understanding of the diets of three Duttaphrynus species, viz., himalayanus, melanostictus, and stomaticus from Uttarakhand, the western Himalaya, India.  Gut content analysis of three bufonids revealed acceptance of a wide range of terrestrial insects and other invertebrates as their food.  The index of relative importance indicated that the most important preys were Formicidae, Coleoptera and Orthoptera.  Duttaphrynus melanostictus had the broadest dietary niche breadth, followed by D. himalaynus and D. stomaticus.  The wide prey spectrum well indicates that these species are the generalist and opportunist invertebrate feeder.  Information pertaining to the food spectrum analysis contributes to understanding the ecological roles and used as a baseline data for future successful amphibian conservation and management programs in the Himalayan ecosystem.

scholarly journals Quantifying and interpreting nestedness of bryophytes in the Zhoushan Archipelago, China

2019 ◽  
Author(s):  
Jing Yu ◽  
Dandan Li ◽  
Lin Shen ◽  
Busheng Zhuo ◽  
Shuiliang Guo
Keyword(s):  
Habitat Types ◽  
Long Distance ◽  
Dispersal Capacity ◽  
Moss Species ◽  
Spore Size ◽  
Ideal System ◽  
Wide Range ◽  
Continental Islands ◽  
Zhoushan Archipelago ◽  
Selective Extinction

Abstract Background: Detecting nestedness distribution and understanding their origin are important for biological conservation. Although previous studies on nestedness covered a wide range of taxa, discrepancies still exist on the prevalence of nestedness among biotas, and on the mechanisms to form nested distribution. Because bryophytes are poikilohydric, highly sensitive to habitats, and have a long-distance dispersal capacity, together with the fact that continental islands highly varied in area, elevation and habitat types, bryophytes on continental archipelago are thus an ideal system for the settlement of relevant disputes on nested distribution. However, few studies have been conducted on nestedness of bryophytes. To quantify nestedness level of different bryophyte categories on continental islands and possible mechanisms, we complied a presence/absence matrix of 446 species of bryophytes in 66 islands of the Zhoushan Archipelago, China. We also recorded spore sizes of 319 moss species based on available literature. By using the matrix temperature and the NODF metrics, as well as a conservative null model, we evaluated the nestedness levels of 18 bryophyte categories. We further explored possible mechanisms to form nested distribution by using partial Spearman rank correlations based on island area, elevation, habitat types and spore size of moss species. Results : We found that all 18 categories of bryophytes exhibited a high degree of nestedness. Nestedness level was higher for mosses than liverworts, higher for acrocarpous mosses than pleurocarpous mosses，and varied among different bryophyte 13 families. The nested distribution of bryophytes in the archipelago was not due to passive sampling, but mainly due to nested habitats and selective-extinction. Spore size might be a factor linked to selective-colonization accounting for nestedness of some moss categories. Conclusions : Nested habitats, selective-extinction, and partial selective-colonization resulted in a high level of nestedness for bryophytes in continental islands. Although the nestedness of bryophyte distribution in the Zhoushan Archipelago was statistically significant, such a nestedness was not perfect. Conservation of bryophytes should not only focus on the species-richest islands.

Colonization of a novel depauperate habitat leads to trophic niche shifts in three desert lizard species

Oikos ◽  
2015 ◽  
Vol 125 (3) ◽  
pp. 343-353 ◽  
Author(s):  
Simone Des Roches ◽  
Luke J. Harmon ◽  
Erica B. Rosenblum
Keyword(s):  
Trophic Niche ◽  
Lizard Species ◽  
Niche Shifts ◽  
Desert Lizard

scholarly journals Rates of ecomorphological trait evolution in passerine bird clades are independent of age

2020 ◽  
Vol 129 (3) ◽  
pp. 543-557
Author(s):  
Anna G Phillips ◽  
Till Töpfer ◽  
Katrin Böhning-Gaese ◽  
Susanne A Fritz
Keyword(s):  
Passerine Bird ◽  
Evolutionary Patterns ◽  
Trait Evolution ◽  
Best Fitting ◽  
Adaptive Radiations ◽  
Divergence Pattern ◽  
Patterns And Processes ◽  
The Relationship ◽  
Fitting Model ◽  
Key Innovations

Abstract Although the links between species richness and diversification rates with clade age have been studied extensively, few studies have investigated the relationship between the rates of trait evolution and clade age. The rate of morphological trait evolution has repeatedly been shown to vary through time, as expected, for example, for adaptive radiations, but the strength and sources of this variation are not well understood. We compare the relationship between the rates of trait evolution and clade age across eight monophyletic clades of passerine birds by investigating ecomorphological traits, i.e. morphological traits that influence the ecology of the species directly. We study the ecomorphological divergence pattern using analyses of the disparity through time and determine the best-fitting model of evolution for each trait in each clade. We find no support for a consistent dependence of evolutionary rates on clade age across wing, tail, tarsus and beak shape in our eight clades and also show that early burst models of trait evolution are rarely the best-fitting models within these clades. These results suggest that key innovations or adaptive radiations might be less common evolutionary patterns and processes than generally thought or might depend on the taxonomic level investigated.

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