Pelvic bone structures in free-ranging Eurasian lynx (Lynx lynx) from Switzerland: a radiological pelvimetry study

Morend, F.; Lang, J.; Vidondo, B.; Ryser-Degiorgis, M.-P.

doi:10.1101/646935

Home/Archive/bioRxiv

bioRxiv · 10.1101/646935

Pelvic bone structures in free-ranging Eurasian lynx (Lynx lynx) from Switzerland: a radiological pelvimetry study

Morend, F.·Lang, J.·Vidondo, B.·Ryser-Degiorgis, M.-P.

View original source ↗Export metadata ↓

Abstract

The observation of severe pelvic malformations in Eurasian lynx (Lynx lynx) from a population reintroduced to Switzerland raised the question as to whether inbreeding may contribute to the development of congenital pelvic malformations. We aimed at providing baseline data on the pelvic morphology of Eurasian lynx from the reintroduced populations in Switzerland, at assessing potential differences in pelvic conformation between the two main Swiss populations, among age classes and between sexes, and at detecting pelvic anomalies. We performed measurements of 10 pelvic parameters on the radiographs of 57 lynx of both sexes and different ages taken from 1997-2015. We calculated two ratios (vertical diameter/acetabula; sagittal diameter/transversal diameter) and two areas (pelvic outlet and inlet) to describe the shape of the pelvis. Our results showed that the Eurasian lynx is a mesatipelvic species, with a pelvis length corresponding to approximatively 20% of the body length. We found no statistically significant differences between the two examined populations but observed growth-related pelvis size differences among age groups. Sexual dimorphism was obvious in the adult age group only: two parameters reflecting pelvic width were larger in females, likely to meet the physiological requirements of parturition. By contrast, pelvis length, conjugata vera, diagonal conjugata, vertical diameter and sagittal diameter were larger in males, in agreement with their larger body size. Accordingly, the ratio between the sagittal and transversal diameters was significantly larger in males, i.e. adult males have a different pelvic shape than adult females. Furthermore, pelvimetry highlighted one adult individual with values outside the calculated reference range, suggesting a possible congenital or developmental pathological morphology of the internal pelvis. Our work generated baseline data of the pelvic morphology including growth and sexual dimorphism of the Eurasian lynx. These data could also be useful for estimating age and sex in skeletal remains.

Explore related subjects

zoology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Morend, F., Lang, J., Vidondo, B., Ryser-Degiorgis, M.-P.. 2019-05-23. Pelvic bone structures in free-ranging Eurasian lynx (Lynx lynx) from Switzerland: a radiological pelvimetry study. https://doi.org/10.1101/646935

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A baseline for aquatic parasite diversity in West African mangroves: host-parasite records, DNA barcodes, and an experimental design for future use

Macroparasites represent a major fraction of biodiversity and biomass in marine ecosystems, yet remain substantially underrepresented in ecological surveys and food-web models, particularly in the Global South. This study addresses this geographic bias by providing the first comprehensive ecological survey of macroparasite communities of fishes in a West African Marine Protected Area (MPA) and adjacent Open-Access Area (OAA) characterised by mangrove forests. We collected 5,020 parasite specimens from 10 fish and one crab species in the Saloum Delta, Senegal, identifying 27 parasite species across all major taxa. Our findings include 15 new records for Senegal of which 11 are also new for West Africa. Additionally, 64% of host-parasite combinations constitute new host records. We provide 208 DNA barcodes, offering the first molecular data for 31% of these species globally and establishing a reference library for future DNA metabarcoding efforts in the region. Using sample size-corrected biodiversity indices and mixed-model analyses, we detected significant variations in parasite infracommunities and component communities between the MPA and OAA, demonstrating the feasibility of using comparative study designs to monitor fisheries impacts on parasite diversity in the Saloum Delta. Furthermore, the identification of trophically transmitted parasites provided evidence of unstudied food-web connections, e.g. predator-prey linkages between fishes and higher-trophic-level definitive hosts including birds and elasmobranchs. By integrating morphological identification, molecular data, and archiving of voucher specimens into publicly accessible, curated collections, this study establishes a new baseline for marine parasite biodiversity in West Africa and provides a methodological blueprint for surveying understudied regions.

zoology↗

bioRxiv2026

Sea slugs unplugged: Review of subpopulation sampling in phylogeographic studies of nudibranchs and their allies

Nudibranchs and other sea slugs include many cryptic species groups with unknown phenotypic and ecological diversity. How broadly and deeply should researchers sample those cryptic species pairs to capture the genetic variation within each species and potential adaptive differences between species? Fast and inexpensive surveys of genetic diversity that sample a single well-known locus across the geographical range ("phylogeography unplugged") have long been used to identify structured populations and guide choice of sampling localities for subsequent comparative genomic or phenotypic studies of the same species. Results from such studies might also be used to better understand the expected relationships between sampling and population structure in future comparative studies in other species (including many marine gastropods) for which an unplugged phylogeographic survey is not available or impractical. We reviewed analyses of molecular variance that used mitochondrial barcode sequences from marine sea slugs, and we asked whether there are characteristic patterns of subpopulation sampling that are associated with the magnitude and geographical scale of differentiation. We found wide variation in sampling designs: studies with both many and few samples discovered significant population differentiation or broadly similar distribution of haplotypes on both large and small spatial scales, in species from different higher taxonomic groups and oceans. We found two significant associations between sampling variables and population genetic variables, and we suggest using those associations to help guide (or understand the consequences of) sampling design in future studies.

zoology↗

bioRxiv2026

A novel methodology for assessing reinforcement choice in primates under human care

Positive Reinforcement Training is a technique commonly employed in zoological collections to elicit a desired behaviour from an animal under human care. Typically, a food item is offered as a reward for performing that behaviour. Three non-human primate species (Mandrillus sphinx, Pan troglodytes, and Hylobates lar) were offered four different foods (banana, grape, apple, and sweet potato) in a series of choice experiments. Latent variable models were employed to investigate which foods were the best selection to use as reinforcement items. Results show that food preference varies between the three primate species. Pan troglodytes and H. lar showed strong preferences for grape and banana, whereas M. sphinx showed a very strong preference for sweet potato. This study indicates that foraging ecology might play an important part in fruit selection and preference in primates. The findings highlight that understanding a species' natural behaviour and dietary preferences is key to informing reinforcement and training decisions.

zoology↗