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1.
Adv Mar Biol ; 96: 85-114, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37980130

RESUMO

Little is known about the biology of pygmy (Kogia breviceps) and dwarf (K. sima) sperm whales as these animals are difficult to observe in the wild. However, both species strand frequently along the South African, Australian and New Zealand coastlines, providing samples for these otherwise inaccessible species. The use of DNA samples from tissue and DNA extracted from historical material, such as teeth and bone, allowed a first analysis of the population structure of both species in the Southern Hemisphere. A 279 base pair consensus region of the mitochondrial cytochrome b gene was sequenced for 96 K. breviceps (53 tissue and 43 teeth or bone samples) and 29 K. sima (3 tissue and 26 teeth or bone samples), and 26 and 12 unique haplotypes were identified, respectively. K. breviceps showed a higher nucleotide diversity of 0.82% compared to 0.40% in K. sima. Significant genetic differentiation was detected in the Southern Hemisphere between K. breviceps from South Africa and New Zealand (ФST = 0.042, p < 0.05). Mitochondrial control region sequences (505 bp) were available for 44 individuals (41 K. breviceps and 3 K. sima) for comparative purposes. A comprehensive global phylogenetic analysis (maternal lineage) of our sequences together with all available Kogia mtDNA sequences largely supported previously published phylogenetic findings, but highlighted some changed inferences about oceanic divergences within both species. The higher nucleotide diversity and low population differentiation observed in K. breviceps may result from its broad foraging ecology and wide distribution, which may indicate a more opportunistic feeding behaviour and tolerance towards a larger range of water temperatures than K. sima.


Assuntos
Cachalote , Baleias , Humanos , Animais , Filogenia , Austrália , DNA , Nucleotídeos
2.
Ecol Evol ; 4(15): 3060-71, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25247063

RESUMO

Previous assessments of wildlife road mortality have not used directly comparable methods and, at present, there is no standardized protocol for the collection of such data. Consequently, there are no internationally comparative statistics documenting roadkill rates. In this study, we used a combination of experimental trials and road transects to design a standardized protocol to assess roadkill rates on both paved and unpaved roads. Simulated roadkill were positioned over a 1 km distance, and trials were conducted at eight different speeds (20-100 km·h(-1)). The recommended protocol was then tested on a 100-km transect, driven daily over a 40-day period. This recorded 413 vertebrate roadkill, comprising 106 species. We recommend the protocol be adopted for future road ecology studies to enable robust statistical comparisons between studies.

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