Search results for "megafauna"

Assessing the role of megafauna in tropical forest ecosystems and biogeochemical cycles - the potential of vegetation models

2018

21 pages; International audience; Megafauna (terrestrial vertebrate herbivores > 5 kg) can have disproportionate direct and indirect effects on forest structure, function, and biogeochemical cycles. We reviewed the literature investigating these effects on tropical forest dynamics and biogeochemical cycles in relation to ecology, paleoecology, and vegetation modelling. We highlight the limitations of field‐based studies in evaluating the long‐term consequences of loss of megafauna. These limitations are due to inherent space‐time restrictions of field‐studies and a research focus on seed dispersal services provided by large animals. We further present evidence of a research gap concerning t…

Continuous wildlife monitoring using blimps as an aerial platform: a case study observing marine megafauna

2020

ABSTRACT Aerial surveys are a powerful means of collecting ecological data in terrestrial and marine systems that may otherwise be difficult to acquire. Increasingly aerial observations are made with Unmanned Aerial Vehicles (UAVs), such as drones. As this technology has improved in reliability and affordability it has replaced the traditional use of fixed-wing aircraft and helicopters. Drones do, however, have limitations; primarily in their limited flight duration, potential to disturb wildlife and concerns over safety. Here we introduce an aerostat, a ground tethered blimp, as a logistically simple and economical alternative to drones and other aircraft. Blimps differ from drones by usin…

Benthic megafauna distribution in two different algal assemblages of the Ustica Island rocky infralittoral (NW Mediterranean)

2011

Early cave art and ancient DNA record the origin of European bison

2016

The two living species of bison (European and American) are among the few terrestrial megafauna to have survived the late Pleistocene extinctions. Despite the extensive bovid fossil record in Eurasia, the evolutionary history of the European bison (or wisent, Bison bonasus) before the Holocene (<11.7 thousand years ago (kya)) remains a mystery. We use complete ancient mitochondrial genomes and genome-wide nuclear DNA surveys to reveal that the wisent is the product of hybridization between the extinct steppe bison (Bison priscus) and ancestors of modern cattle (aurochs, Bos primigenius) before 120 kya, and contains up to 10% aurochs genomic ancestry. Although undetected within the fossil re…

Doom of the elephant-dependent trees in a Congo tropical forest.

2013

9 pages; International audience; In an evergreen lowland rain forest of the Cuvette Centrale, DR Congo, at the LuiKotale Max-Planck research site, forest elephants (Loxodonta cyclotis) are close to extinction. Between January 2009 and June 2011 we investigated the influence of elephant decline on sustainability of elephant-dispersed tree populations. For this, we explored how trees with the megafaunal syndrome reproduce without seed dispersal by elephants and how does this affect the demography and spatial distribution of these tree species. We studied alternative partners for functional replacement of the elephant. Overall, 18 tree species presenting the megafaunal syndrome were identified…

Modelling prey-predator interactions in Messina beachrock pools

2020

Abstract The Strait of Messina (Sicily, Italy) attracts the interest of marine ecologists for the presence of a large variety of habitat and mutually-interacting communities. Among them, beachrock formations, despite their wide geographic distribution, which also includes the Mediterranean area, have been poorly investigated from the biotic viewpoint. In this paper, the spatial and seasonal variability of benthic megafauna from the Messina microtidal beachrock is described. Combining in situ collected data (measurements of abiotic parameters and underwater visual census) with theoretical post-processing analyses (analysis of similarity percentages and cluster analysis), we deduced the possi…

The macro- and megabenthic fauna on the continental shelf of the eastern Amundsen Sea, Antarctica.

2013

11 pages; International audience; In 2008 the BIOPEARL II expedition on board of RRS James Clark Ross sailed to the eastern Amundsen Sea Embayment and Pine Island Bay, one of the least studied Antarctic continental shelf regions due to its remoteness and ice cover. A total of 37 Agassiz trawls were deployed at depth transects along the continental and trough slopes. A total of 5469 specimens, belonging to 32 higher taxonomic groups and more than 270 species, were collected. Species richness per station varied from 1 to 55. The benthic assemblages were dominated by echinoderms and clearly different to those in the Ross, Scotia and Weddell seas. Here we present the macro- and megafaunal assem…

Interazioni e trofodinamica della megafauna bentonica associata a due stati stabili alternativi dell'infralitorale superiore roccioso del Mediterrane…

2011

Phylogeography of lions (Panthera leossp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversity

2009

Lions were the most widespread carnivores in the late Pleistocene, ranging from southern Africa to the southern USA, but little is known about the evolutionary relationships among these Pleistocene populations or the dynamics that led to their extinction. Using ancient DNA techniques, we obtained mitochondrial sequences from 52 individuals sampled across the present and former range of lions. Phylogenetic analysis revealed three distinct clusters: (i) modern lions, Panthera leo; (ii) extinct Pleistocene cave lions, which formed a homogeneous population extending from Europe across Beringia (Siberia, Alaska and western Canada); and (iii) extinct American lions, which formed a separate popula…

Large herbivore population and vegetation dynamics 14,600–8300 years ago in central Latvia, northeastern Europe

2019

Abstract This study seeks to explain how the large herbivore (large vertebrate, megafauna – terrestrial taxa with adults > 45 kg) population density changed during abrupt postglacial climate and environmental change. The Lateglacial and Early Holocene (14,600–8300 years ago) were represented by various environmental and climate changes and a transition from a cold to a warm climate, with subsequent changes in flora and fauna. Using Lake Āraisi as a case study (Latvia, northeastern Europe), local to regional vegetation was reconstructed by analyzing plant macroremains and pollen from the lake sediment profile. Here, we present the first dung fungus spore-based qualitative reconstruction of l…