scholarly journals Subfossil lemur discoveries from the Beanka Protected Area in western Madagascar

2019 ◽  
Vol 93 ◽  
pp. 187-203 ◽  
Author(s):  
David A. Burney ◽  
Haingoson Andriamialison ◽  
Radosoa A. Andrianaivoarivelo ◽  
Steven Bourne ◽  
Brooke E. Crowley ◽  
...  
Keyword(s):  
Human Activity ◽  
Protected Area ◽  
Avian Predators ◽  
Extant Species ◽  
Fossil Site ◽  
Pottery Sherds ◽  
Human Predation ◽  
Considerable Range ◽  
Prey Items ◽  
Prolemur Simus

AbstractA new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar.

Cranial morphology and systematics of an extraordinary sample of the Late Neogene dwarf tapir, Tapirus polkensis (Olsen)

2009 ◽  
Vol 83 (2) ◽  
pp. 238-262 ◽  
Author(s):  
Richard C. Hulbert ◽  
Steven C. Wallace ◽  
Walter E. Klippel ◽  
Paul W. Parmalee
Keyword(s):  
Single Species ◽  
Relative Strength ◽  
Cranial Morphology ◽  
Linear Measurements ◽  
Average Mass ◽  
Gray Fossil Site ◽  
Extant Species ◽  
Late Neogene ◽  
Fossil Site ◽  
Almost All

The previously poorly known “Tapiravus” polkensis Olsen, 1960 (Mammalia, Perissodactyla, Tapiridae) is now known from abundant, well preserved specimens from both the type area in central Florida and from the Gray Fossil Site (GFS) in eastern Tennessee. The latter has produced over 75 individuals, the greatest number of tapirids from a single fossil site, including many articulated skeletons. Almost all linear measurements taken on skulls, mandibles, and cheek teeth from GFS have coefficients of variation less than 10 (most between 3 and 7), indicating the presence of a single species. However, the sample reveals considerable intraspecific variation for a few key morphologic features, including development of the sagittal crest, outline shape of the nasals, and number and relative strength of lingual cusps on the P1. The Florida sample of T. polkensis is more limited, but has the same state as the GFS sample for all preserved characters of systematic significance, and while the Florida teeth are on average smaller (especially narrower lower cheek teeth), they fall either within or just below the observed range of the Gray Fossil Site population. The new material supports a reassignment of “Tapiravus” polkensis to the genus Tapirus, and demonstrates that the geologic age of the species is significantly younger than previously thought, Hemphillian rather than Barstovian. Tapirus polkensis is the smallest known North American Tapirus, and smaller than any of the extant species in the genus, with an estimated average mass of 125 kg.

scholarly journals Antarctica's wilderness has declined to the exclusion of biodiversity

2019 ◽  
Author(s):  
Rachel I. Leihy ◽  
Bernard W.T. Coetzee ◽  
Fraser Morgan ◽  
Ben Raymond ◽  
Justine D. Shaw ◽  
...  
Keyword(s):  
Surface Area ◽  
Human Activity ◽  
Protected Area ◽  
Human Impacts ◽  
Area Network ◽  
Natural Reserve ◽  
Wilderness Areas ◽  
Biogeographic Regions ◽  
The Antarctic ◽  
Specially Protected Areas

Recent assessments of the biodiversity value of Earth's dwindling wilderness areas have emphasized the whole of Antarctica as a crucial wilderness in need of urgent protection. Whole-of-continent designations for Antarctic conservation remain controversial, however, because of widespread human impacts and frequently used provisions in Antarctic law for the designation of specially protected areas to conserve wilderness values, species and ecosystems. Here we investigate the extent to which Antarctica's wilderness encompasses its biodiversity. We assembled a comprehensive record of human activity on the continent (~ 2.7 million localities) and used it to identify unvisited areas ≥ 10 000 km2 (i.e. Antarctica's wilderness areas) and their representation of biodiversity. We show that, at best, 7 770 000 km2 of wilderness remains, covering 56.9% of the continent's surface area, however it captures few important biodiversity features. Important Bird Areas, ice-free Antarctic Conservation Biogeographic Regions crucial for biodiversity and areas with verified biodiversity records are largely excluded. Our results demonstrate that Antarcticas wilderness has already declined to the exclusion of much of its biodiversity. But that on a continent set aside as a natural reserve, increased regulation of human activity and urgent expansion of the Antarctic specially protected area network could feasibly reverse this trend.

scholarly journals Interference coloration as an anti-predator defence

2015 ◽  
Vol 11 (4) ◽  
pp. 20150159 ◽  
Author(s):  
Thomas W. Pike
Keyword(s):  
Animal Groups ◽  
Exact Location ◽  
Avian Predators ◽  
Poor Understanding ◽  
Mechanistic Basis ◽  
Predator Defence ◽  
Prey Items

Interference coloration, in which the perceived colour varies predictably with the angle of illumination or observation, is extremely widespread across animal groups. However, despite considerable advances in our understanding of the mechanistic basis of interference coloration in animals, we still have a poor understanding of its function. Here, I show, using avian predators hunting dynamic virtual prey, that the presence of interference coloration can significantly reduce a predator's attack success. Predators required more pecks to successfully catch interference-coloured prey compared with otherwise identical prey items that lacked interference coloration, and attacks against prey with interference colours were less accurate, suggesting that changes in colour or brightness caused by prey movement hindered a predator's ability to pinpoint their exact location. The pronounced anti-predator benefits of interference coloration may explain why it has evolved independently so many times.

Iridescent blue and orange components contribute to the recognition of a multicomponent warning signal

Behaviour ◽  
2013 ◽  
Vol 150 (3-4) ◽  
pp. 321-336 ◽  
Author(s):  
Kimberly V. Pegram ◽  
Melissa J. Lillo ◽  
Ronald L. Rutowski
Keyword(s):  
Warning Signal ◽  
Animal Kingdom ◽  
Battus Philenor ◽  
Warning Signals ◽  
Long Wavelength ◽  
Avian Predators ◽  
Redundant Signal ◽  
Pipevine Swallowtail ◽  
Swallowtail Butterflies ◽  
Prey Items

Warning colouration functions to deter predators from attacking unprofitable (e.g., unpalatable or toxic) prey items. While warning colours are often characterized by long-wavelength components (e.g., orange, red or yellow), many distasteful animals across the animal kingdom display orange or red colour patches adjacent to or within a field of short-wavelength colouration such as blue (e.g., strawberry poison dart frogs, pipevine swallowtail and pyjama nudibranch), which yields a multicomponent visual warning signal. Here we show that, in such signals, blue and orange patches can function as redundant signal components; avian predators trained not to attack the intact blue and orange colouration of the pipevine swallowtail (Battus philenor) recognised the butterflies as distasteful even when the blue and orange were presented individually. Our results demonstrate that blue colouration and potential multiple, unimodal, signal components should be considered in research on visual warning signals, including in well-studied animals, such as dendrobatid frogs and swallowtail butterflies.

scholarly journals Increased and sex-selective avian predation of desert locusts Schistocerca gregaria treated with Metarhizium acridum

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244733
Author(s):  
Wim C. Mullié ◽  
Robert A. Cheke ◽  
Stephen Young ◽  
Abdou Baoua Ibrahim ◽  
Albertinka J. Murk
Keyword(s):  
Side Effects ◽  
Schistocerca Gregaria ◽  
Maximum Effect ◽  
Desert Locust ◽  
Metarhizium Acridum ◽  
Avian Predation ◽  
Avian Predators ◽  
Locust Control ◽  
The Impact ◽  
Prey Items

The entomopathogenic fungus Metarhizium acridum in oil-based formulations (Green Muscle® (GM)) is a biopesticide for locust control lacking side-effects on biodiversity, unlike chemical insecticides. Under controlled conditions, GM-treated locusts and grasshoppers attract predators, a complementary advantage in locust control. We assessed avian predation on a population of desert locusts in northern Niger aerially sprayed operationally with GM with 107 g viable conidia ha-1. Populations of adult locusts and birds and vegetation greenness were assessed simultaneously along two transects from 12 days before until 23 days after treatment. Common kestrels Falco tinnunculus and lanners F. biarmicus were the predominant avian predators. Regurgitated pellets and prey remains were collected daily beneath “plucking posts” of kestrels. Locusts started dying five days post-spray and GM had its maximum effect one-two weeks after the spray, with 80% efficacy at day 21. After spraying, bird numbers increased significantly (P<0.05) concurrent with decreasing desert locust densities. Locust numbers decreased significantly (P<0.001) with both time since spraying and decreasing greenness. Before spraying, kestrel food remains under plucking posts accounted for 34.3 ±13.4 prey items day-1, of which 31.0 ±11.9 were adult desert locusts (90.3%), reducing post-spray to 21.1 ±7.3 prey items day-1, of which19.5 ±6.7 were adult desert locusts (92.5%), attributable to decreased use of the plucking-posts by the kestrels rather than an effect of the spray. After spraying, kestrels took significantly (P<0.05) more larger female (75–80%) than smaller male (20–25%) locusts. Avian predation probably enhanced the impact of the GM on the desert locust population, especially by removing large adult females. No direct or indirect adverse side-effects were observed on non-target organisms including locust predators such as ants and birds. These substantial ecological advantages should also be considered when choosing between conventional chemical and biopesticide-based locust control.

Biogeography of Pleistocene conifer species from the Ziegler Reservoir fossil site, Snowmass Village, Colorado

2014 ◽  
Vol 82 (3) ◽  
pp. 567-574 ◽  
Author(s):  
Dane M. Miller ◽  
Ian M. Miller ◽  
Stephen T. Jackson
Keyword(s):  
Morphological Characters ◽  
Picea Engelmannii ◽  
Western North America ◽  
Conifer Species ◽  
Picea Pungens ◽  
Morphological Studies ◽  
Extant Species ◽  
Fossil Site ◽  
Mis 5E ◽  
Cone Scale

AbstractPleistocene biogeography of conifer species is poorly known in much of western North America. We conducted morphological studies on 201 conifer cones and cone fragments recovered from Pleistocene sediments at the Ziegler Reservoir fossil site (2705 m) near Snowmass Village, Colorado. The basin, formed ~155–130 ka, contains fossil-bearing lacustrine, palustrine, and colluvial sediments spanning approximately 85 ka. Using a suite of morphological characters, particularly cone-scale bracts, we differentiated species of Abies, Picea, and Pseudotsuga. All fossil Abies specimens were assignable based on bract morphology to Abies concolor, which is currently absent from central Colorado (nearest populations are 160 km southwest of the site). A. concolor occurs only in sediments of MIS 5d and 5c. Pseudotsuga menziesii and Picea engelmannii cones occurred in sediments corresponding to MIS 5e, 5d, 5c, and 5a. A fourth conifer species, occurring in sediments of MIS 5e, 5d, 5c, and 5a, is difficult to assign to any extant species. Bract morphology is similar to Picea pungens, which grows near the site today, but scale morphology is unlike P. pungens. These fossils may represent ancestral P. pungens, an extinct variant, or an extinct sister species.

scholarly journals Soil trampling in an Antarctic Specially Protected Area: tools to assess levels of human impact

2009 ◽  
Vol 21 (3) ◽  
pp. 229-236 ◽  
Author(s):  
P. Tejedo ◽  
A. Justel ◽  
J. Benayas ◽  
E. Rico ◽  
P. Convey ◽  
...  
Keyword(s):  
Human Activity ◽  
Protected Area ◽  
South Shetland Islands ◽  
Free Living ◽  
Research Personnel ◽  
Antarctic Soils ◽  
Shetland Islands ◽  
Livingston Island ◽  
Current Advice ◽  
Arthropod Abundance

AbstractResearch in extremely delicate environments must be sensitive to the need to minimize impacts caused simply through the presence of research personnel. This study investigates the effectiveness of current advice relating to travel on foot over Antarctic vegetation-free soils. These are based on the concentration of impacts through the creation of properly signed and identified paths. In order to address these impacts, we quantified three factors - resistance to compression, bulk density and free-living terrestrial arthropod abundance - in areas of human activity over five summer field seasons at the Byers Peninsula (Livingston Island, South Shetland Islands). Studies included instances of both experimentally controlled use and natural non-controlled situations. The data demonstrate that a minimum human presence is sufficient to alter both physical and biological characteristics of Byers Peninsula soils, although at the lowest levels of human activity this difference was not significant in comparison with adjacent undisturbed control areas. On the other hand, a limited resilience of physical properties was observed in Antarctic soils, thus it is crucial not to exceed the soil's natural recovery capability.

Occurrence and biogeographic significance of Heliaster (Echinodermata: Asteroidea) from the Pliocene of southwest Florida

1988 ◽  
Vol 62 (01) ◽  
pp. 126-132 ◽  
Author(s):  
Douglas S. Jones ◽  
Roger W. Portell
Keyword(s):  
Central American ◽  
Eastern Pacific ◽  
Whole Body ◽  
Marine Fauna ◽  
Western Atlantic ◽  
Southwest Florida ◽  
Extant Species ◽  
Geologic Record ◽  
Central American Isthmus

Whole body asteroid fossils are rare in the geologic record and previously unreported from the Cenozoic of Florida. However, specimens of the extant species,Heliaster microbrachiusXantus, were recently discovered in upper Pliocene deposits. This marks the first reported fossil occurrence of the monogeneric Heliasteridae, a group today confined to the eastern Pacific. This discovery provides further non-molluscan evidence of the close similarities between the Neogene marine fauna of Florida and the modern fauna of the eastern Pacific. The extinction of the heliasters in the western Atlantic is consistent with the pattern of many other marine groups in the region which suffered impoverishment following uplift of the Central American isthmus.

Performance-based validation of the human activity profile

2007 ◽  
Author(s):  
Luci Fuscaldi Teixeira-Salmela ◽  
Sandra J. Olney ◽  
Revathy Devaraj
Keyword(s):  
Human Activity ◽  
Activity Profile
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