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Hadrosaur dinosaurs (Ornithischia: Hadrosauridae) were abundant in Late Cretaceous terrestrial environments of North America and Asia. Their derived dental and postcranial specializations for herbivory have led to the suggestion that these dinosaurs were analogous to modern ungulates in lifestyle. Ungulates display a suite of morphological features that are correlated with diet, habitat preference, and sexual dimorphism. In this paper we examine several of these same features in hadrosaurs in order to determine whether they display similar patterns under multivariate analysis. Initial results confirm the resemblances between hadrosaurs and ungulates but suggest that missing data may considerably affect the outcomes of statistical analyses. Using the hadrosaur dataset as a template, we artificially degrade the (previously complete) ungulate datasets and perform the same analyses. Results are consistent with earlier results and provide an opportunity to assess the impact of missing data on the original multivariate structure. Our results support the hypothesis that hadrosaurs were similar to ungulates in patterns of ecomorphology.
The aim of the study was to assess the diet composition of four carnivore species inhabiting the Gorce National Park (Western Carpathians, S Poland), i.e., grey wolf (Canis lupus), Eurasian lynx (Lynx lynx), red fox (Vulpes vulpes), and pine marten (Martes martes). The food analysis was based on scats collected between June 2016 and February 2017 along seven transects of a total length 96.13 km. Altogether 187 faeces were found, 95 of grey wolf, 20 of lynx, 49 of red fox, and 23 of pine marten, respectively. The dominant food category of wolf and lynx were ungulates, comprising respectively 98% and 95% of the consumed biomass. The trophic niche overlap between wolf and lynx was very high (Pianka’s index Ojk=0.99). However, there were differences in the consumed prey species. Wolves fed on red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa), while lynxes foraged equally on two ungulates, red deer and roe deer. Medium−sized carnivores showed greater variety in consumed food. Both pine marten and red fox had higher values of Levins’ index of the trophic niche breadth than larger carnivores and highly overlapped their diets (Ojk=0.96). Pine marten and red fox consumed mostly small mammals. Additionally, martens consumed frequently fruits, whereas red foxes foraged on carrion of ungulates. This might explain the fact that wolf and lynx overlapped their trophic niches more with red fox than with the pine marten.
Effects of ungulate pressure on the development of young generation of trees is one of the most important issues in ecology and forestry. Ungulate pressure influence on the development of natural regeneration has been also reported from several national parks. Our study on the effects of ungulate browsing on the young generation of trees was conducted on more than 500 sample plots controlled during one growing season. The overall browsing pressure ranged from 7.6% in seedlings to 20.3% in low saplings. The pressure of ungulates on the regeneration of Picea abies, the dominant species in the Tatra National Park, was by and large below 1%. Broadleaved species were browsed more frequently. The relationship between the plot altitudes and browsing intensity was statistically significant for seedlings and low saplings; at the higher altitudes, the browsing pressure was greater. There was also observed a statistically significant relationship between the type of former management and the browsing degree in seedlings; in the areas subjected to “landscape protection”, the intensity of browsing was higher when compared to strictly protected areas. Pressure exerted by ungulates on tree regeneration was very unevenly distributed, i.e. some plots were heavily browsed and many others - not browsed at all. The most affected tree species were Salix caprea and Sorbus aucuparia, although the percentage of browsed individuals rarely exceeded 50%. Other species favored by ungulates was Acer pseudoplatanus; despite the high browsing pressure, this species was present among seedlings and tall saplings, suggesting that it would be able to recruit to the tree layer. Abies alba was browsed less frequently than the deciduous trees; however, among the tall saplings it was the third most browsed species.
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