scholarly journals Abundance and active patch selection modulate reproductive connectivity and fitness of pea crabs living on sand dollars

2021 ◽  
Author(s):  
Juliana de Andrade Souza
Keyword(s):  
Patch Selection ◽  
Sand Dollars

scholarly journals Abundance And Active Patch Selection Modulate Reproductive Connectivity And Fitness of Pea Crabs Living On Sand Dollars

2021 ◽  
Author(s):  
Juliana A. Souza ◽  
Augusto A. V. Flores
Keyword(s):  
Reproductive Potential ◽  
Population Level ◽  
Allee Effects ◽  
Sand Dollar ◽  
Patch Selection ◽  
Biological Organization ◽  
Individual Fitness ◽  
Offspring Production ◽  
Crab Abundance ◽  
Sand Dollars

Abstract Connectivity is paramount for population stability, but the mechanisms underlying the distribution of populated patches and how they affect reproductive connectivity and individual fitness remain elusive. Here, we mapped the distribution of sand dollars – as habitat patches for obligate-commensal pea crabs – at several sites. At occupied patches, we assessed whole-crab population structure and the fitness of ovigerous females. While sand-dollar supply did not limit the size of crab populations, overall crab abundance limited reproductive connectivity and the potential for offspring production. However, except for sites of extremely low and high connectivity, crab aggregations at sand-dollar clusters countervailed the overall random distribution of sand-dollar populations, greatly enhancing the reproductive potential of whole-crab populations. Crab interactions, likely controlled by larger females, added to reproductive connectivity by increasing the frequency of mating pairs in hosts. Differently from the population-level case, effects of crab abundance on individual fitness were dual and only detectable when abundance was lowest (positive) or highest (negative), so that fitness remained high at intermediate crab abundance, decreasing when it became either too low (e.g. Allee effects) or too high (e.g. energetic costs of intraspecific competition). This study indicates that connectivity may affect different levels of biological organization in specific ways.

MOLECULAR PHYLOGENY OF SAND DOLLARS (ECHINOIDEA: CLYPEASTEROIDA) WITH NEW DATA EXTRACTED FROM TAIWANESE SPECIES

2017 ◽  
Author(s):  
Jih-Pai Lin ◽  
◽  
Kwen-Shen Lee ◽  
Lo-Yu Chang ◽  
Shyh-Jye Lee
Keyword(s):  
Molecular Phylogeny ◽  
Sand Dollars

scholarly journals Foraging theory upscaled: the behavioural ecology of herbivore movement

2010 ◽  
Vol 365 (1550) ◽  
pp. 2267-2278 ◽  
Author(s):  
N. Owen-Smith ◽  
J. M. Fryxell ◽  
E. H. Merrill
Keyword(s):  
Seasonal Cycle ◽  
Large Scale ◽  
Diel Activity ◽  
Patch Selection ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Gps Collars ◽  
Activity Schedule ◽  
Spatio Temporal ◽  
Time And Energy

We outline how principles of optimal foraging developed for diet and food patch selection might be applied to movement behaviour expressed over larger spatial and temporal scales. Our focus is on large mammalian herbivores, capable of carrying global positioning system (GPS) collars operating through the seasonal cycle and dependent on vegetation resources that are fixed in space but seasonally variable in availability and nutritional value. The concept of intermittent movement leads to the recognition of distinct movement modes over a hierarchy of spatio-temporal scales. Over larger scales, periods with relatively low displacement may indicate settlement within foraging areas, habitat units or seasonal ranges. Directed movements connect these patches or places used for other activities. Selection is expressed by switches in movement mode and the intensity of utilization by the settlement period relative to the area covered. The type of benefit obtained during settlement periods may be inferred from movement patterns, local environmental features, or the diel activity schedule. Rates of movement indicate changing costs in time and energy over the seasonal cycle, between years and among regions. GPS telemetry potentially enables large-scale movement responses to changing environmental conditions to be linked to population performance.

Spatial variability in seed predation in Primula farinosa: local population legacy versus patch selection

Oecologia ◽  
2009 ◽  
Vol 160 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Didrik Vanhoenacker ◽  
Jon Ågren ◽  
Johan Ehrlén
Keyword(s):  
Spatial Variability ◽  
Seed Predation ◽  
Local Population ◽  
Patch Selection

Thyroid hormones determine developmental mode in sand dollars (Echinodermata: Echinoidea)

2004 ◽  
Vol 6 (6) ◽  
pp. 382-392 ◽  
Author(s):  
Andreas Heyland ◽  
Adam M. Reitzel ◽  
Jason Hodin
Keyword(s):  
Thyroid Hormones ◽  
Developmental Mode ◽  
Sand Dollars

scholarly journals Evolutionary origins for ecological patterns in space

2020 ◽  
Vol 117 (30) ◽  
pp. 17482-17490 ◽  
Author(s):  
Mark C. Urban ◽  
Sharon Y. Strauss ◽  
Fanie Pelletier ◽  
Eric P. Palkovacs ◽  
Mathew A. Leibold ◽  
...  
Keyword(s):  
Local Adaptation ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Keystone Species ◽  
Future Research ◽  
Evolutionary Divergence ◽  
Patch Selection ◽  
Fully Integrated ◽  
Evolutionary Origins ◽  
Ecological Patterns

Historically, many biologists assumed that evolution and ecology acted independently because evolution occurred over distances too great to influence most ecological patterns. Today, evidence indicates that evolution can operate over a range of spatial scales, including fine spatial scales. Thus, evolutionary divergence across space might frequently interact with the mechanisms that also determine spatial ecological patterns. Here, we synthesize insights from 500 eco-evolutionary studies and develop a predictive framework that seeks to understand whether and when evolution amplifies, dampens, or creates ecological patterns. We demonstrate that local adaptation can alter everything from spatial variation in population abundances to ecosystem properties. We uncover 14 mechanisms that can mediate the outcome of evolution on spatial ecological patterns. Sometimes, evolution amplifies environmental variation, especially when selection enhances resource uptake or patch selection. The local evolution of foundation or keystone species can create ecological patterns where none existed originally. However, most often, we find that evolution dampens existing environmental gradients, because local adaptation evens out fitness across environments and thus counteracts the variation in associated ecological patterns. Consequently, evolution generally smooths out the underlying heterogeneity in nature, making the world appear less ragged than it would be in the absence of evolution. We end by highlighting the future research needed to inform a fully integrated and predictive biology that accounts for eco-evolutionary interactions in both space and time.

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.

Sign in / Sign up

Export Citation Format

Share Document