Trophic ecology of adult male Odonata. I. Dietary niche metrics by foraging guild, species, body size, and location

2017 ◽  
Vol 43 (1) ◽  
pp. 1-14 ◽  
Author(s):  
LENIN D. CHARI ◽  
SYDNEY MOYO ◽  
NICOLE B. RICHOUX
Keyword(s):  
Body Size ◽  
Adult Male ◽  
Trophic Ecology ◽  
Dietary Niche ◽  
Niche Metrics ◽  
Foraging Guild

The influence of food availability, quality and body size on patch selection of coexisting grazer ungulates in western Serengeti National Park

2019 ◽  
Vol 46 (1) ◽  
pp. 54 ◽  
Author(s):  
John Bukombe ◽  
Andrew Kittle ◽  
Ramadhan B. Senzota ◽  
Hamza Kija ◽  
Simon Mduma ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Niche Overlap ◽  
Wildlife Habitat ◽  
Management Tool ◽  
Conservation Strategies ◽  
Patch Selection ◽  
Wet Season ◽  
Serengeti Ecosystem ◽  
Dietary Niche

Context Differences in body size and mouth morphologies influence dietary resource separation among savanna ungulates, and this influences their distribution across landscape. Aim The aim was to understand the influence of body size and mouth morphology differences on both diet and patch selection by ungulate species in western Serengeti. Two hypotheses were tested: (1) for ungulate species, the relative body sizes and muzzle widths (mean muzzle width range: 3.1- 9.85) relate directly to food biomass, and to quality of diets selected in the wet season when food is abundant; (2) in the wet season, if food is not limiting, similar-sized species should exhibit greater dietary niche overlap than ungulate species that differ greatly in body size and muzzle width; moreover, similar-sized species exhibit less dietary niche overlap than ungulate species that differ greatly in body size. Methods In the western Serengeti ecosystem, road transects and direct observation were used to obtain data on the distribution and diet of five ungulate species namely buffalo, zebra, wildebeest, topi and impala; which have of varying sizes (range: 70–630kg) feeding in three different vegetation types. Grassland biomass, structure, nutrient content and ungulate use were measured at sites along transects. Key Results Results indicated that large-bodied ungulates utilised patches of greater food abundance compared with those of smaller ungulates. Body mass was also negatively correlated with diet quality, so that smaller animals ate higher protein and lower-fibre foods, as predicted. Diet niche overlap (niche similarity) showed a strong positive relationship with body mass differences among ungulate species, in support of the second of the two predictions from this hypothesis, namely that dissimilarly sized species could eat the same food. Conclusion Overall, the results suggest that in this savanna system, variation in ungulate body size influences resource separation even in the food-abundant wet season, and that this helps multiple species to co-exist. Implications Implementing more focused conservation strategies will improve wildlife habitat quality by integrating fire as a forage management tool with grazing preferences to promote forage heterogeneity in protected areas.

Optimal foraging constrains macroecological patterns: body size and dietary niche breadth in lizards

2008 ◽  
Vol 17 (5) ◽  
pp. 670-677 ◽  
Author(s):  
Gabriel C. Costa ◽  
Laurie J. Vitt ◽  
Eric R. Pianka ◽  
Daniel O. Mesquita ◽  
Guarino R. Colli
Keyword(s):  
Body Size ◽  
Optimal Foraging ◽  
Niche Breadth ◽  
Dietary Niche

Body size and trophic divergence of two large sympatric elapid snakes (Notechis scutatus and Austrelaps superbus) (Serpentes:Elapidae) in Tasmania

2012 ◽  
Vol 60 (3) ◽  
pp. 159 ◽  
Author(s):  
S. Fearn ◽  
J. Dowde ◽  
D. F. Trembath
Keyword(s):  
Body Size ◽  
High Frequency ◽  
Field Data ◽  
Trophic Ecology ◽  
Competitive Exclusion ◽  
Head Size ◽  
Large Prey ◽  
Potential Prey ◽  
Island State ◽  
Species Being

Tiger snakes (Notechis scutatus) and lowland copperheads (Austrelaps superbus) are both large viviparous elapid snakes confined to the cooler, mesic regions of southern Australia. In spite of both species being common and widespread in the island state of Tasmania, no quantified studies on the trophic ecology of these two snakes from the main island has been published. During a two-year period we collected field data from 127 adult A. superbus and 74 adult N. scutatus from throughout eastern Tasmania. For both species, males were larger than females with respect to all measured parameters, including mass and head size. Reproduction in females was strongly seasonal and clutch size was not related to maternal body size. N. scutatus has a larger head than A. superbus and consequently ingests both small and large prey. N. scutatus in our study displayed the most catholic diet of any Australian elapid studied to date and consumed mammals (possum, bandicoot, antechinus, rats, mice), birds (fairy wrens), fish (eel, trout) and frogs. A. superbus shows a more specialist diet of large volumes of predominately ectothermic prey (frogs, lizards, snakes) even at maximal sizes and was more likely to contain ingested prey than specimens of N. scutatus. Distinctive rodent bite scars were common on N. scutatus but rare on A. superbus. The high frequency of rodent bite scars on N. scutatus further supports our findings of a primarily endothermic diet for mature specimens. We suggest that significant differences in head size, and hence diet, as well as a taxonomically diverse suite of potential prey in Tasmania allow both these large snakes to coexist in sympatry and avoid interspecific competitive exclusion.

Loss of function of the non-genomic estrogen receptor GPR30 causes increased body size, percent body fat, and bone mass in adult male mice

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S62-S63
Author(s):  
J. Ford ◽  
A. Hajibeigi ◽  
M. Getachew ◽  
J. Liu ◽  
D. Clegg ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Body Size ◽  
Bone Mass ◽  
Body Fat ◽  
Adult Male ◽  
Percent Body Fat ◽  
Male Mice ◽  
Loss Of Function

scholarly journals Body-size Scaling is Related to Gut Microbial Diversity, Metabolism and Dietary Niche of Arboreal Folivorous Flying Squirrels

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Po-Yu Liu ◽  
An-Chi Cheng ◽  
Shiao-Wei Huang ◽  
Hsiao-Pei Lu ◽  
Tatsuo Oshida ◽  
...  
Keyword(s):  
Body Size ◽  
Microbial Diversity ◽  
Flying Squirrels ◽  
Size Scaling ◽  
Dietary Niche

scholarly journals A tiny ornithodiran archosaur from the Triassic of Madagascar and the role of miniaturization in dinosaur and pterosaur ancestry

2020 ◽  
Vol 117 (30) ◽  
pp. 17932-17936 ◽  
Author(s):  
Christian F. Kammerer ◽  
Sterling J. Nesbitt ◽  
John J. Flynn ◽  
Lovasoa Ranivoharimanana ◽  
André R. Wyss
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Evolutionary History ◽  
Trophic Ecology ◽  
Upper Triassic ◽  
Important Group ◽  
Size Evolution ◽  
Stem Lineage ◽  
Body Size Evolution

Early members of the dinosaur–pterosaur clade Ornithodira are very rare in the fossil record, obscuring our understanding of the origins of this important group. Here, we describe an early ornithodiran (Kongonaphon kelygen. et sp. nov.) from the Mid-to-Upper Triassic of Madagascar that represents one of the smallest nonavian ornithodirans. Although dinosaurs and gigantism are practically synonymous, an analysis of body size evolution in dinosaurs and other archosaurs in the context of this taxon and related forms demonstrates that the earliest-diverging members of the group may have been smaller than previously thought, and that a profound miniaturization event occurred near the base of the avian stem lineage. In phylogenetic analysis,Kongonaphonis recovered as a member of the Triassic ornithodiran clade Lagerpetidae, expanding the range of this group into Africa and providing data on the craniodental morphology of lagerpetids. The conical teeth ofKongonaphonexhibit pitted microwear consistent with a diet of hard-shelled insects, indicating a shift in trophic ecology to insectivory associated with diminutive body size. Small ancestral body size suggests that the extreme rarity of early ornithodirans in the fossil record owes more to taphonomic artifact than true reflection of the group’s evolutionary history.

scholarly journals Isotopic niche reflects stress-induced variability in physiological status

2018 ◽  
Vol 5 (2) ◽  
pp. 171398 ◽  
Author(s):  
Agnes M. L. Karlson ◽  
Martin Reutgard ◽  
Andrius Garbaras ◽  
Elena Gorokhova
Keyword(s):  
Body Size ◽  
Stable Isotope ◽  
Trophic Ecology ◽  
Physiological Stress ◽  
Isotope Composition ◽  
Stress Factors ◽  
Physiological Status ◽  
Isotopic Niche ◽  
Control Groups ◽  
Oxygen Conditions

The isotopic niche has become an established concept in trophic ecology. However, the assumptions behind this approach have rarely been evaluated. Evidence is accumulating that physiological stress can affect both magnitude and inter-individual variability of the isotopic signature in consumers via alterations in metabolic pathways. We hypothesized that stress factors (inadequate nutrition, parasite infestations, and exposure to toxic substances or varying oxygen conditions) might lead to suboptimal physiological performance and altered stable isotope signatures. The latter can be misinterpreted as alterations in isotopic niche. This hypothesis was tested by inducing physiological stress in the deposit-feeding amphipod Monoporeia affinis exposed to either different feeding regimes or contaminated sediments. In the amphipods, we measured body condition indices or reproductive output to assess growth status and δ 13 C and δ 15 N values to derive isotope niche metrics. As hypothesized, greater isotopic niche estimates were derived for the stressed animals compared to the control groups. Moreover, the δ 15 N values were influenced by body size, reproductive status and parasite infestations, while δ 13 C values were influenced by body size, oxygen conditions and survival. Using regression analysis with isotope composition and growth variables as predictors, we were able to discriminate between the amphipods exposed to nutritionally or chemically stressful conditions and those in the control groups. Thus, interpretation of isotopic niche can be confounded by natural or anthropogenic stressors that may induce an apparent change in isotopic niche. These findings stress the importance of including measures of growth and health status when evaluating stable isotope data in food web studies.

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