scholarly journals The Dire Consequences of Specializing on Large Herbivores

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Branden T. Neufeld
Keyword(s):  
Canis Lupus ◽  
Prey Species ◽  
Niche Differentiation ◽  
Similar Species ◽  
Grey Wolf ◽  
Large Herbivores ◽  
The North ◽  
Extinction Event ◽  
Canis Dirus ◽  
Dire Wolf

Niche differentiation is a way in which similar species avoid competition. Some species do this by specializing in certain prey items. This review aims to determine why the dire wolf (Canis dirus) went extinct while its similar and less abundant relative, the grey wolf (Canis lupus) did not. Both species were present in North America during the Pleistocene, though only one went extinct during the Quaternary extinction event. Physiological differences existed between the two species, mostly due to a greater focus in hypercarnivory for dire wolves. Dire wolves had more robust frame and skull, greater bite strength, and larger carnasials and canines. These differences in dire wolf morphology all help it to handle and kill larger prey species, while the more lithe grey wolf is better adapted to switching to smaller alternative prey. Dire wolves at have been shown to consume mostly large herbivores while grey wolves can survive with lagomorphs as a primary food source. Larger carnivore body size means reduction in locomotor performance, which means that when many mega-herbivores went extinct at the end of the Pleistocene, dire wolves were not as well adapted to switch to smaller prey as grey wolves are. Their naturally larger body mass also means that they needed higher caloric input to maintain their body condition and fecundity. Overall, Canis dirus specialized in larger prey than Canis lupus, so when this prey became extinct, the dire wolf went extinct along with other hypercarnivores such as the North American lion, Smilodon, and short-faced bear.

scholarly journals Niches, rather than neutrality, structure a grassland pioneer guild

2005 ◽  
Vol 272 (1570) ◽  
pp. 1357-1364 ◽  
Author(s):  
Lindsay A Turnbull ◽  
Liz Manley ◽  
Mark Rees
Keyword(s):  
Seed Size ◽  
Adult Stage ◽  
Niche Differentiation ◽  
Competitive Dynamics ◽  
Similar Species ◽  
Adult Density ◽  
Pioneer Species ◽  
Trade Offs ◽  
Very High ◽  
Early Establishment

Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails.

scholarly journals The First Record of Echinococcus ortleppi (G5) Tapeworms in Grey Wolf (Canis lupus)

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 853
Author(s):  
Jacek Karamon ◽  
Małgorzata Samorek-Pieróg ◽  
Jacek Sroka ◽  
Ewa Bilska-Zając ◽  
Joanna Dąbrowska ◽  
...  
Keyword(s):  
Small Intestine ◽  
Molecular Identification ◽  
Canis Lupus ◽  
Sequence Comparison ◽  
First Record ◽  
Grey Wolf ◽  
South Eastern ◽  
Counting Technique ◽  
Small Intestines ◽  
First Time

The aim of this study is to confirm the presence and molecular identification of Echinococcus tapeworms in wolves from south-eastern Poland. An investigation was carried out on the intestines of 13 wolves from south-eastern Poland. The small intestines were divided into three equal segments. Each segment was separately examined using the sedimentation and counting technique (SCT). The detected Echinococcus tapeworms were isolated and identified by PCRs and sequencing (nad1 and cox1 genes). Additionally, DNA isolated from the feces of wolves positive for Echinococcus tapeworms was examined with two diagnostic PCRs. The intestines of one wolf were positive for E. granulosus s.l. when assessed by SCT; the intestine was from a six-year-old male wolf killed in a communication accident. We detected 61 adult tapeworms: 42 in the anterior, 14 in the middle, and 5 in the posterior parts of the small intestine. The PCRs conducted for cox1 and nad1 produced specific products. A sequence comparison with the GenBank database showed similarity to the deposited E. ortleppi (G5) sequences. An analysis of the available phylogenetic sequences showed very little variation within the species of E. ortleppi (G5), and identity ranged from 99.10% to 100.00% in the case of cox1 and from 99.04 to 100.00% in the case of nad1. One of the two diagnostic PCRs used and performed on the feces of Echinococcus-positive animals showed product specific for E. granulosus. This study showed the presence of adult E. ortleppi tapeworms in wolves for the first time.

First wolves in Luxembourg since 1893, originating from the Alpine and Central European populations

Mammalia ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Laurent Schley ◽  
Marianne Jacobs ◽  
Sebastian Collet ◽  
Alexander Kristiansen ◽  
Jan Herr
Keyword(s):  
Canis Lupus ◽  
Dna Analysis ◽  
Carcass Characteristics ◽  
Management Plan ◽  
Apex Predator ◽  
Grey Wolf ◽  
Melting Pot ◽  
Central European ◽  
The Past ◽  
Hard Evidence

Abstract Considering the spread of the grey wolf (Canis lupus) in Europe over the past 30 years, Luxembourg took some measures to prepare for the return of this apex predator, including the establishment of a management plan that notably addresses the issue of wolf depredation on livestock. Here we present the results of genetic analyses of putative wolf saliva, hair and scat samples collected from or near prey carcasses between 2015 and 2020. In two cases, the wolf was confirmed via DNA analysis: in July 2017 near Garnich and in April 2020 near Niederanven, both assigned to category C1 (hard evidence). A third case was classified as C2 (confirmed observation) based on prey carcass characteristics, while genetic analysis yielded no result. These are the first confirmed records of wolves in Luxemburg since 1893. Moreover, the two C1-cases originated from the Alpine (Garnich) and Central European (Niederanven) populations. Given similar developments in the neighboring countries and regions, we conclude that the area including the Benelux countries as well as Rhineland-Palatinate, Saarland and Northern France may well become a melting pot for wolves of the two aforementioned populations in the coming years and decades.

scholarly journals Gray Wolves, Canis lupus, Killed by Cougars, Puma concolor, and a Grizzly Bear, Ursus arctos, in Montana, Alberta, and Wyoming

2008 ◽  
Vol 122 (1) ◽  
pp. 76 ◽  
Author(s):  
Michael D. Jimenez ◽  
Valpa J. Asher ◽  
Carita Bergman ◽  
Edward E. Bangs ◽  
Susannah P. Woodruff
Keyword(s):  
United States ◽  
Canis Lupus ◽  
Ursus Arctos ◽  
Puma Concolor ◽  
Western United States ◽  
Grizzly Bear ◽  
Grey Wolf ◽  
Gray Wolves ◽  
Large Predators

Four cases where large predators caused Grey Wolf (Canis lupus) mortality are recorded. We describe two incidents of Cougars (Puma concolar) killing Wolves in Montana and one incident of a Cougar killing a Wolf in Alberta. We report the first recorded incident of a Grizzly Bear (Ursus arctos) killing a Wolf in the western United States.

The quest for chron E23r at Partridge Island, Bay of Fundy, Canada: CAMP emplacement postdates the end-Triassic extinction event at the North American craton

2011 ◽  
Vol 48 (8) ◽  
pp. 1282-1291 ◽  
Author(s):  
M.H.L. Deenen ◽  
W. Krijgsman ◽  
M. Ruhl
Keyword(s):  
Magnetic Polarity ◽  
Bay Of Fundy ◽  
Long Distance ◽  
The North ◽  
Extinction Event ◽  
Maritime Canada ◽  
North American Craton ◽  
Geomagnetic Polarity ◽  
Central Atlantic ◽  
Geomagnetic Polarity Time Scale

The Partridge Island stratigraphic section at the Bay of Fundy, Maritime Canada, reveals a continental sedimentary succession with the end-Triassic mass extinction level closely followed by basalts of the Central Atlantic Magmatic Province (CAMP). New Paleomagnetic data show that a short reverse magnetic polarity chron, correlative to E23r of the Newark Geomagnetic Polarity Time Scale (GPTS), is present below the extinction event. Organic carbon isotope data and basalt geochemistry further indicate that the onset of CAMP emplacement in the Bay of Fundy was roughly synchronous with emplacement in the Newark basin, but slightly postdates the oldest CAMP volcanism in Morocco by ∼20 ka. These results confirm the potential for long-distance CAMP correlations based on geochemical trace elements, indicate substantiate provincialism of latest Triassic palynoflora, and suggest a very concise period (<<100 ka) of CAMP emplacement in the northern Atlantic region.

scholarly journals Niche differentiation and regeneration in the seasonally flooded Melaleuca forests of northern Australia

2007 ◽  
Vol 23 (4) ◽  
pp. 457-467 ◽  
Author(s):  
Donald C. Franklin ◽  
Peter S. Brocklehurst ◽  
Dominique Lynch ◽  
David M. J. S. Bowman
Keyword(s):  
Basal Area ◽  
Niche Differentiation ◽  
Floodplain Forests ◽  
Northern Australia ◽  
Closely Related Species ◽  
The North ◽  
Wide Range ◽  
Using Data ◽  
Seasonally Flooded ◽  
Burnt Areas

Gallery and floodplain forests in monsoonal northern Australia are mostly sclerophyllous and dominated by five closely related species of Melaleuca (Myrtaceae) amongst which niche differentiation is unclear. We present a floristic and environmental analysis of ‘the flooded forest’ using data from 340 plots distributed across 450 000 km2 of the Top End of the Northern Territory. Melaleuca argentea was confined to streams and occurred on sandier substrates, whereas M. cajuputi mostly occurred in the near-coastal lowlands on clay soils. The greater basal area of M. cajuputi suggests an association with productive sites. Melaleuca dealbata, M. viridiflora and M. leucadendra occurred on a wide range of soils. More deeply floodprone sites were occupied by M. argentea and M. leucadendra along streams and by M. leucadendra and M. cajuputi on floodplains and in swamps. A general deficiency but occasional abundance of Melaleuca seedlings suggests that regeneration is episodic. Seedlings were more frequent in recently burnt areas and especially where fires had been severe. We propose that Melaleuca forests occur where disturbance by fire and/or floodwater is too great for rain forest to persist, rendering them the wetland analogue to the eucalypts that dominate well-drained portions of the north Australian environment.

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