Inconstancy in predator/prey ratios in Quaternary large mammal communities of Italy, with an appraisal of mechanisms

2007 ◽  
Vol 67 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Pasquale Raia ◽  
Carlo Meloro ◽  
Carmela Barbera
Keyword(s):  
Ecosystem Functioning ◽  
Strong Support ◽  
Ecological Research ◽  
Large Mammal ◽  
Predator Prey ◽  
Pleistocene Mammals ◽  
Animal Communities ◽  
Dispersal Events ◽  
Mammal Communities ◽  
Time Extinction

AbstractConstancy in predator/prey ratio (PPR) is a controversial issue in ecological research. Published reports support both constancy and inconstancy of the ratio in animal communities. Only a few studies, however, specifically address its course through time. Here we study the course of predator/prey ratio in communities of large Plio-Pleistocene mammals in Italy. After controlling for taphonomic biases, we find strong support for PPR inconstancy through time. Extinction, dispersal events, and differences in body size trends between predators and their prey were found to affect the ratio, which was distributed almost bimodally. We suggest that this stepwise dynamic in PPR indicates changes in ecosystem functioning. Prey richness was controlled by predation when PPR was high and by resources when PPR was low.

Applying Island Biogeographic Theory to an East African Reserve

1978 ◽  
Vol 5 (3) ◽  
pp. 191-195 ◽  
Author(s):  
Ronald I. Miller
Keyword(s):  
Human Activities ◽  
East African ◽  
Mammal Species ◽  
Community Interactions ◽  
Large Mammal ◽  
Northern Tanzania ◽  
Game Reserve ◽  
Animal Communities ◽  
Mammal Communities ◽  
Protected Animal

The isolation of nature reserves by encroaching civilization may provide significant changes in the structure and composition of protected animal communities. Recent models from applied island biogeographic theory provide a means of predicting the possible effects of isolation in the large-mammal community in the Mkomazi Game Reserve of northern Tanzania. A decrease in the number of large-mammal species inhabiting this preserve is predicted by all the models.The dynamic interdependence of the large-mammal communities of East African reserves is vital to their survival and yet is especially vulnerable to disruption from surrounding human activities. Knowledge of the effects of increasing isolation on the complex community interactions among the component ecosystems in East African reserves, will enhance conservationists' ability to minimize extirpation pressures in this region.

scholarly journals Ruminants reveal Eocene Asiatic palaeobiogeographical provinces as the origin of diachronous mammalian Oligocene dispersals into Europe

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bastien Mennecart ◽  
Manuela Aiglstorfer ◽  
Yikun Li ◽  
Chunxiao Li ◽  
ShiQi Wang
Keyword(s):  
Central Asia ◽  
New Taxa ◽  
Late Eocene ◽  
Eastern Asia ◽  
Large Mammal ◽  
Southern Province ◽  
The North ◽  
Grande Coupure ◽  
Dispersal Events ◽  
North And South

AbstractFaunal provincialism between the North and South parts of Eastern Asia is shown to have been in place since the late Eocene. This provincialism structured the mammalian dispersals across Eurasia for millions of years and provides insights into both palaeonvironments and palaeoclimate zonation. In addition, this study reveals the oldest record of a crown ruminant (Iberomeryx from Shinao, China). Ecologically, as well as economically, ruminant artiodactyls are one of the most important large mammal groups today. The revision of the ruminants from the Shinao Formation, from the Caijiachong marls and Xiaerhete, resulted in two new taxa and shows that the different provinces were populated by distinct taxa living in different environments, dominated by the monsoon in the South and drier conditions in the North. Evaluating this result in a Eurasian context demonstrates that the dispersals from Asia to Europe was complex. These results confirm that there were at least two dispersal events, distinct in space and time: the Grande-Coupure from Northern and Central Asia along the North ca. 34 Mya and the Bachitherium dispersal event from the Southern province along a southerly route ca. 31 Mya.

scholarly journals Is the scaling of swim speed in sharks driven by metabolism?

2015 ◽  
Vol 11 (12) ◽  
pp. 20150781 ◽  
Author(s):  
David M. P. Jacoby ◽  
Penthai Siriwat ◽  
Robin Freeman ◽  
Chris Carbone
Keyword(s):  
Body Size ◽  
Ecosystem Functioning ◽  
Foraging Ecology ◽  
Geometric Model ◽  
Predator Prey ◽  
Marine Systems ◽  
Movement Rates ◽  
Scaling Relationship ◽  
Model Predictions ◽  
Ecological Parameters

The movement rates of sharks are intrinsically linked to foraging ecology, predator–prey dynamics and wider ecosystem functioning in marine systems. During ram ventilation, however, shark movement rates are linked not only to ecological parameters, but also to physiology, as minimum speeds are required to provide sufficient water flow across the gills to maintain metabolism. We develop a geometric model predicting a positive scaling relationship between swim speeds in relation to body size and ultimately shark metabolism, taking into account estimates for the scaling of gill dimensions. Empirical data from 64 studies (26 species) were compiled to test our model while controlling for the influence of phylogenetic similarity between related species. Our model predictions were found to closely resemble the observed relationships from tracked sharks, providing a means to infer mobility in particularly intractable species.

scholarly journals Mitochondrial genomes and thousands of ultraconserved elements resolve the taxonomy and historical biogeography of the Euphonia and Chlorophonia finches (Passeriformes: Fringillidae)

The Auk ◽  
2020 ◽  
Vol 137 (3) ◽  
Author(s):  
Tyler S Imfeld ◽  
F Keith Barker ◽  
Robb T Brumfield
Keyword(s):  
Divergence Time ◽  
Strong Support ◽  
Species Level ◽  
Mitochondrial Genomes ◽  
South American ◽  
Isthmus Of Panama ◽  
Eastern Hemisphere ◽  
Biogeographic History ◽  
Dispersal Events ◽  
South American Origin

Abstract Relationships of the Neotropical finches in the genera Euphonia and Chlorophonia (Fringillidae: Euphoniinae) have been clarified by recent molecular studies, but species-level relationships within this group have not been thoroughly addressed. In this study, we sampled specimens representing every recognized species of these genera, in addition to 2 outgroup taxa, and used target enrichment to sequence thousands of ultraconserved element (UCE) loci, as well as mitochondrial DNA reconstructed from off-target reads, from each specimen to infer these relationships. We constructed both concatenation and coalescent-based estimates of phylogeny from this dataset using matrices of varying levels of completeness, and we generated a time-scaled ultrametric tree using a recently published fossil-based external calibration. We found uniformly strong support for a monophyletic subfamily Euphoniinae and genus Chlorophonia, but a paraphyletic Euphonia across UCEs and mitochondrial genomes. Otherwise, our inferred relationships were largely concordant with previous studies. Our time-tree indicated a stem divergence time of 13.8 million years ago for this lineage, followed by a relatively young crown age of only 7.1 myr. Reconstructions of biogeographic history based on this tree suggest a South American origin for crown Euphoniinae, possibly resulting from a transoceanic dispersal event from the Eastern Hemisphere, followed by 2 dispersal events into the Caribbean and as many as 6 invasions of North America coinciding with recent estimates of the age at which the Isthmus of Panama had completely formed. We recommend splitting Euphonia and resurrecting the genus Cyanophonia for the 3 blue-hooded species more closely related to Chlorophonia. Based on our results, we suspect that there is undescribed species-level diversity in at least one, possibly many, widespread and phenotypically diverse species.

Phase Dependence and Population Cycles in a Large-Mammal Predator-Prey System

Ecology ◽  
2002 ◽  
Vol 83 (11) ◽  
pp. 2997 ◽  
Author(s):  
Eric Post ◽  
Nils Chr. Stenseth ◽  
Rolf O. Peterson ◽  
John A. Vucetich ◽  
Alicia M. Ellis
Keyword(s):  
Population Cycles ◽  
Phase Dependence ◽  
Large Mammal ◽  
Predator Prey ◽  
Prey System

Plio-Pleistocene decline of African megaherbivores: No evidence for ancient hominin impacts

Science ◽  
2018 ◽  
Vol 362 (6417) ◽  
pp. 938-941 ◽  
Author(s):  
J. Tyler Faith ◽  
John Rowan ◽  
Andrew Du ◽  
Paul L. Koch
Keyword(s):  
Evolutionary History ◽  
Homo Sapiens ◽  
Top Down ◽  
Large Mammal ◽  
Meat Eating ◽  
The Past ◽  
History Of ◽  
Mammal Communities ◽  
Herbivore Communities

It has long been proposed that pre-modern hominin impacts drove extinctions and shaped the evolutionary history of Africa’s exceptionally diverse large mammal communities, but this hypothesis has yet to be rigorously tested. We analyzed eastern African herbivore communities spanning the past 7 million years—encompassing the entirety of hominin evolutionary history—to test the hypothesis that top-down impacts of tool-bearing, meat-eating hominins contributed to the demise of megaherbivores prior to the emergence ofHomo sapiens. We document a steady, long-term decline of megaherbivores beginning ~4.6 million years ago, long before the appearance of hominin species capable of exerting top-down control of large mammal communities and predating evidence for hominin interactions with megaherbivore prey. Expansion of C4grasslands can account for the loss of megaherbivore diversity.

Sign in / Sign up

Export Citation Format

Share Document