Geology topics

Frederick Kraus

Publications and source records attributed to Frederick Kraus.

5 recordsLinked to original sources

USGS2023

Skinks of Oceania, New Guinea, and Eastern Wallacea: An underexplored biodiversity hotspot

Context: Skinks comprise the dominant component of the terrestrial vertebrate fauna in Oceania, New Guinea, and Eastern Wallacea (ONGEW). However, knowledge of their diversity is incomplete, and their conservation needs are poorly understood. Aims: To explore the diversity and threat status of the skinks of ONGEW and identify knowledge gaps and conservation needs. Methods: We compiled a list of all skink species occurring in the region and their threat categories designated by the International Union for Conservation of Nature. We used available genetic sequences deposited in the National Center for Biotechnology Information’s GenBank to generate a phylogeny of the region’s skinks. We then assessed their diversity within geographical sub-divisions and compared to other reptile taxa in the region. Key results: Approximately 300 species of skinks occur in ONGEW, making it the second largest global hotspot of skink diversity following Australia. Many phylogenetic relationships remain unresolved, and many species and genera are in need of taxonomic revision. One in five species are threatened with extinction, a higher proportion than almost all reptile families in the region. Conclusions: ONGEW contain a large proportion of global skink diversity on <1% of the Earth’s landmass. Many are endemic and face risks such as habitat loss and invasive predators. Yet, little is known about them, and many species require taxonomic revision and threat level re-assessment. Implications: The skinks of ONGEW are a diverse yet underexplored group of terrestrial vertebrates, with many species likely facing extreme risks in the near future. Further research is needed to understand the threats they face and how to protect them.

Pacific Conservation Biology↗

USGS2022

Cryptic extinction risk in a western Pacific lizard radiation

Cryptic ecologies, the Wallacean Shortfall of undocumented species’ geographical ranges and the Linnaean Shortfall of undescribed diversity, are all major barriers to conservation assessment. When these factors overlap with drivers of extinction risk, such as insular distributions, the number of threatened species in a region or clade may be underestimated, a situation we term ‘cryptic extinction risk’. The genus Lepidodactylus is a diverse radiation of insular and arboreal geckos that occurs across the western Pacific. Previous work on Lepidodactylus showed evidence of evolutionary displacement around continental fringes, suggesting an inherent vulnerability to extinction from factors such as competition and predation. We sought to (1) comprehensively review status and threats, (2) estimate the number of undescribed species, and (3) estimate extinction risk in data deficient and candidate species, in Lepidodactylus . From our updated IUCN Red List assessment, 60% of the 58 recognized species are threatened (n = 15) or Data Deficient (n = 21), which is higher than reported for most other lizard groups. Species from the smaller and isolated Pacific islands are of greatest conservation concern, with most either threatened or Data Deficient, and all particularly vulnerable to invasive species. We estimated 32 undescribed candidate species and linear modelling predicted that an additional 18 species, among these and the data deficient species, are threatened with extinction. Focusing efforts to resolve the taxonomy and conservation status of key taxa, especially on small islands in the Pacific, is a high priority for conserving this remarkably diverse, yet poorly understood, lizard fauna. Our data highlight how cryptic ecologies and cryptic diversity combine and lead to significant underestimation of extinction risk.

Biodiversity and Conservation↗

USGS2021

Who’s your daddy? On the identity and distribution of the paternal hybrid ancestor of the parthenogenetic gecko Lepidodactylus lugubris (Reptilia: Squamata: Gekkonidae)

The widespread parthenogenetic gecko Lepidodactylus lugubris is comprised of several clonal lineages, at least one of which has been known for some time to have originated from hybridization between its maternal ancestor, Lepidodactylus moestus , and a putatively undescribed paternal ancestor previously known only from remote islands in the Central Pacific. By integrating new genetic sequences from multiple studies on Lepidodactylus and incorporating new genetic sequences from previously sampled populations, we recovered a phylogenetic tree that shows a close genetic similarity between the generally hypothesized paternal hybrid ancestor and a recently described species from Maluku (Indonesia), Lepidodactylus pantai . Our results suggest that the paternal hybrid ancestor of at least one parthenogenetic clone of L. lugubris is conspecific with L. pantai and that the range of this species extends to Palau, the Caroline Islands, the Kei Islands, Wagabu, and potentially other small islands near New Guinea. Deeper genetic structure in the western (Palau, Maluku) versus eastern (eastern Melanesia, Micronesia, Polynesia) part of this species’ range suggests that the western populations likely dispersed via natural colonization, whereas the eastern populations may be the result of human-mediated dispersal. The potential taxonomic affinities and biogeographic history should be confirmed with further morphological and genetic analyses, including research on L. woodfordi from its type locality, which would have nomenclatural priority if found to be conspecific with L. pantai . We recommend referring to the wide-ranging sexual species as Lepidodactylus pantai until such a comparison can be made.

Zootaxa↗

USGS2021

Conservation status of the world’s skinks (Scincidae): Taxonomic and geographic patterns in extinction risk

Our knowledge of the conservation status of reptiles, the most diverse group of terrestrial vertebrates, has improved dramatically over the past decade, but still lags behind that of the other tetrapod groups. Here, we conduct the first comprehensive assessment (~92% of the world’s ~1,714 described species) of the conservation status of skinks (Scincidae), the most speciose reptile family worldwide. Using IUCN criteria, we found that ~20% of species are threatened with extinction, and nine species are Extinct or Extinct in the Wild. The highest levels of threat are evident in Madagascar, and the Neotropics, and in the subfamilies Mabuyinae, Eugongylinae and Scincinae. The vast majority of threatened skink species were listed based primarily on their small geographic ranges (Criterion B, 83%; Criterion D2, 13%). Although the population trend of 42% of species were stable, 14% were found to have declining populations. The key threats to skinks are habitat loss due to agriculture, invasive species, and biological resource use. Distributions of 61% of species did not overlap with protected areas. Despite our improved knowledge of the conservation status of the world’s skinks, 8% of species remain to be assessed and 221 species (14%) are listed as Data Deficient. The conservation status of almost a quarter of the world’s skink species thus remains unknown. We use our updated knowledge of the conservation status of the group to develop and outline the priorities for the conservation assessment and management of the world’s skink species.

Biological Conservation↗

USGS2001

Newly emergent and future threats of alien species to Pacific birds and ecosystems

Although the devastating effects of established alien species to Pacific birds and ecosystems are generally well recognized by the avian conservation community, we raise the under appreciated issue of effects of incipient and future invasions. Although special attention to Pacific bird species “on the brink” is to a certain extent appropriate and necessary, a comparable focus on stopping new invasions appears desperately needed. All indications suggest that introductions will escalate with the trend toward ever increasing commerce and unrestricted trade unless stronger preventative measures are implemented very soon. The threat to Pacific island avifaunas from the brown tree snake ( Bniga irregularis ) is well-known, but as many as several hundred of the world’s snake species, some of which are repeatedly smuggled illegally as pets, might have similar impacts on native birds if transported to Pacific islands. We touch upon a sampling of obviously severe potential future threats, with the hope of raising awareness and resolve to fix the current woefully inadequate system for prevention of and rapid response to new invasions.

Studies in Avian Biology↗