Explanation of the spatial distribution patterns in species richness, and especially those of small-ranged species (endemics), bears relevance for studies on evolution and speciation, as well as for conservation management. We test a geometric constraint model, the mid-domain effect (MDE), as a possible explanation for spatial patterns of species richness in Palearctic songbirds (Passeriformes), with an emphasis on the patterns of small-ranged species. We calculated species richness based on digitised distribution maps of phylogenetic species of songbirds endemic to the Palearctic region. Data were plotted and analyzed over a one degree equal area map of the Palearctic Region, with a grid cell area of 4062 km². The emergent biogeographic patterns were analysed with WORLDMAP software. Comparison of the observed richness pattern among 2401 phylogenetic taxa of songbirds in the Palearctic Region with the predictions of a fully stochastic bi-dimensional MDE model revealed that this model has limited empirical support for overall species richness of Palearctic songbirds. Major hotspots were located south of the area where MDE predicted the highest species- richness, while some of the observed coldspots were in the centre of the Palearctic Region. Although small-ranged species are often found in areas with the highest species richness, MDE models have a very restricted explanatory power for the observed species-richness pattern in small-ranged species. Regions with a high number of small-ranged species (endemism hotspots) may contain a unique set of environmental conditions, unrelated to the shape or size of the domain, allowing a multitude of species to co-exist.
Amphibia-Reptilia 30 (2009): 151-171 Biogeography of Chilean herpetofauna: distributional patterns of species richness and endemism Marcela A. Vidal 1,2 , ∗ , Eduardo R. Soto 2 , Alberto Veloso 2 Abstract. We analyze the geographic distribution pattern of Chilean amphibian and reptile species
pools that would also explain the high crustacean species endemism and richness there (Menu-Marque et al., 2000 ; De los Ríos-Escalante & Robles, 2013). The Branchinecta habitats in Chile are characterized by an absence of fish, and are nesting and feeding sites for aquatic birds such as swans
here (1) identify the major spatial and taxonomic gaps in the currently available knowledge in order to identify future research priorities, and (2) analyse patterns of species richness, endemism and main distribution types (i.e. groups of species with similar distribution patterns) for European
consider that, given their particular geological histories, mountain systems are generally centers of endemism and in most cases harbor a greater diversity than neighboring regions (Jingyun, Zehao and Haiting, 2004; Körner, 2004; Brehm et al., 2008; Kozak and Wiens, 2010; Hoorn et al., 2013; Graham et al
Introduction The Ryukyu Islands are the southernmost region of Japan and are a tropical marine region of high biodiversity and species endemism ( Hughes et al., 2002 ; Cowman et al., 2017 ; Reimer et al., 2019 ). It was estimated that a large part (70%) of the marine biodiversity in Japanese
; Crawford et al., 2010 ; Forrest et al., 2011 ). Recently, Bd has been recorded in Nicaraguan anurans (García-Roa et al., 2014 ). Although cloud forest-inhabiting Plethodontid salamanders like Bolitoglossa species on the Pacific versant of Nicaragua display a high level of endemism and have a high
.-J. Biotic affinities in a transitional zone between the Atlantic and the Mediterranean: a biogeographical approach based on sponges Journal of Biogeography 1995 22 89 110
Morrone J.J. On the identification of areas of endemism Systematic Biology 1994 43 438 441
Rosen B.R. From fossils to earth
A systematic revision of the genus Hylarana in the Western
Ghats-Sri Lanka biodiversity hotspot is presented. Species delineation in
Hylarana is complicated due to a lack of distinct colour
differences or striking morphological characters, leading to potential
misidentification. We conducted extensive surveys throughout the Western
Ghats-Sri Lanka biodiversity hotspot and performed multiple gene (16S, COI and
Cytb) barcoding using 103 samples collected from cultivated land and natural
habitats. Genetic distance comparisons and Neighbor Joining trees indicated the
presence of at least 14 candidate species in the region, supported by taxa
groupings for all three genetic markers. Utilising a combination of molecular
and morphological data, we describe seven new species, doubling the number of
Hylarana species previously known from this region. We
further demonstrate that H. temporalis, which
was originally described from Sri Lanka, was misidentified with the Western
Ghats endemic species for nearly 100 years. Conversely, H.
aurantiaca was originally described from the Western Ghats
and misidentified in Sri Lanka. Our study confirms that the distribution of
H. temporalis is restricted to Sri Lanka,
while H. aurantiaca is endemic to the Western
Ghats, and that there are no shared Hylarana species between
the two regions. Hylarana flavescens, H.
intermedius and H.
montanus, previously considered synonyms of
H. temporalis are confirmed as valid
species. Hylarana bhagmandlensis is removed from the synonymy
of H. aurantiaca and placed as a junior
subjective synonym of H. montanus. To
establish nomenclatural stability, H.
flavescens, H. malabarica
and H. temporalis are lectotypified and
H. intermedius is neotypified. Detailed
descriptions, diagnosis, morphological and genetic comparisons, illustrations
and data on distribution and natural history are provided for all species.
Phylogenetic analyses based on three mitochondrial markers (16S, COI and Cytb)
and a fragment of the nuclear Rag1 gene, show complete endemism of the Western
Ghats-Sri Lankan species. Four major groups in this region are identified as: 1
— the Hylarana aurantiaca group, endemic to the Western Ghats;
2 — the Hylarana flavescens group, endemic to the Western
Ghats; 3 — the Hylarana temporalis group, endemic to Sri Lanka;
and 4 — the Hylarana malabarica group from Sri Lanka and India.
The discovery of numerous morphologically cryptic Hylarana
species in this region further emphasizes the benefits of utilizing an
integrative taxonomic approach for uncovering hidden diversity and highlighting
local endemism in the Western Ghats-Sri Lanka biodiversity hotspot.