Search results for "10.03"

Dental microwear texture reflects dietary tendencies in extant Lepidosauria despite their limited use of oral food processing

2019

Lepidosauria show a large diversity in dietary adaptations, both among extant and extinct tetrapods. Unlike mammals, Lepidosauria do not engage in sophisticated mastication of their food and most species have continuous tooth replacement, further reducing the wear of individual teeth. However, dietary tendency estimation of extinct lepidosaurs usually rely on tooth shape and body size, which allows only for broad distinction between faunivores and herbivores. Microscopic wear features on teeth have long been successfully applied to reconstruct the diet of mammals and allow for subtle discrimination of feeding strategies and food abrasiveness. Here, we present, to our knowledge, the first de…

Oogenesis and reproductive investment of Atlantic herring are functions of not only present but long-ago environmental influences as well

2017

Following general life history theory, immediate reproductive investment (egg mass × fecundity/body mass) in oviparous teleosts is a consequence of both present and past environmental influences. This clarification questions the frequent use of season-independent (general) fecundity formulas in marine fish recruitment studies based on body metrics only. Here we test the underlying assumption of no lag effect on gametogenesis in the planktivorous, determinate-fecundity Atlantic herring (Clupea harengus) displaying large plasticity in egg mass and fecundity, examining Norwegian summer–autumn spawning herring (NASH), North Sea autumn-spawning herring (NSAH), and Norwegian spring-spawning herri…

Tri-axial accelerometry shows differences in energy expenditure and parental effort throughout the breeding season in long-lived raptors

2021

Cutting-edge technologies are extremely useful to develop new workflows in studying ecological data, particularly to understand animal behavior and movement trajectories at the individual level. Although parental care is a well-studied phenomenon, most studies have been focused on direct observational or video recording data, as well as experimental manipulation. Therefore, what happens out of our sight still remains unknown. Using high-frequency GPS/GSM dataloggers and tri-axial accelerometers we monitored 25 Bonelli’s eagles Aquila fasciata during the breeding season to understand parental activities from a broader perspective. We used recursive data, measured as number of visits and resi…

Using latent variable models to identify large networks of species‐to‐species associations at different spatial scales

2015

Summary We present a hierarchical latent variable model that partitions variation in species occurrences and co-occurrences simultaneously at multiple spatial scales. We illustrate how the parameterized model can be used to predict the occurrences of a species by using as predictors not only the environmental covariates, but also the occurrences of all other species, at all spatial scales. We leverage recent progress in Bayesian latent variable models to implement a computationally effective algorithm that enables one to consider large communities and extensive sampling schemes. We exemplify the framework with a community of 98 fungal species sampled in c. 22 500 dead wood units in 230 plot…

2020

Hypothermic Stunning in Juvenile Green Turtles (Chelonia mydas) in Uruguayan Coastal Waters: Learning for Future Events

2017

Abstract Chelonia mydas in temperate areas exhibits behavioral changes for adapting to sea temperature fluctuations; however, prolonged exposure to cold temperatures can lead to hypothermia and thus hypothermic stunning events. Here we report an unusual stranding event of 90 green turtles recorded in a 12-d period in July 2012 in southeastern Uruguay, analyzing the event in an oceanographic and meteorological context. Monitoring such events provides a unique opportunity to understand the impact of hypothermic stunning on juvenile green turtle stocks that spend the entire year in this temperate region of the southwestern Atlantic Ocean.

Otolith-based age and growth of the Lessepsian species Fistularia commersonii (Osteichtyes: Fistulariidae) in South of Sicily (Central Mediterranean …

2016

During spring–summer 2013, 23 specimens of the Lessepsian Fistularia commersonii Rüppell, 1838 were studied through occasional catches by artisanal and coastal trawler fisheries in the South of Sicily (Mediterranean Sea). The total lengths (TL, cm, without filament) and weight (W, g) ranged between 69.0 and 104.0 cm and 155 and 798 g, respectively. The estimated sex-combined parameters of the length–weight relationship (k = 9*10–9; b = 3.6) suggested a positive allometry. All pairs of sagittae were examined under a stereomicroscope and the age estimated by counting the complete translucent zones, both as whole and thin sections, with ages from 3 to 5 years. Growth parameters (von Bertalanff…

Das phylogenetische System

2003

Arten konnen im Lauf der Zeit als Linien aufgefast werden, die durch Aufspaltungsereignisse gegeneinander abgegrenzt sind. Anhand der Abfolge solcher Aufspaltungen lassen sich Arten in einem hierarchischen System, dem phylogenetischen System, zusammenfassen. Nachfolgend werden wir uns zunachst mit dieser Hierarchie der Arten und ihren Einheiten befassen. Dann werden wir uns naher mit dem Gedanken zur Artbildung durch Hybridisierung auseinandersetzen, weil er die konsequ ent hierarchische Struktur des phylogenetischen Systems in Frage stellt.

Urania sloanus (Cramer, 1779) (Lepidoptera: Uraniidae), an Enigmatic Extinct Species in Polish Museum Collections

2019

Urania sloanus is an endemic species in Jamaica. The species probably became extinct at the end of the 19th century or the beginning of the 20th century. During the work on combining the collections of exotic butterflies in the Upper Silesian Museum in Bytom, one specimen of this taxon was found. The discovery of this species in the Museum of Upper Silesia in Bytom led us to search for entomological collections in other Polish museums. As a result of our search, we found three additional specimens: two specimens in the collection of the Museum of Natural History of the University of Wrocław and one at the Zoological Museum of the Polish Academy of Sciences in Warsaw. In total, in the Polish…

A revision of the new world species of Gymnoclasiopa Hendel (Diptera, Ephydridae)

2012

Species of the shore-fly genus Gymnoclasiopa Hendel from the New World are revised, including G. grecorum, sp. n. (Alaska. Juneau: Gastineau Channel, Thane Road (S Juneau; 58°16.9’N, 134°22.4’W)) and G. matanuska, sp. n. (Alaska. Matanuska-Susitna: Palmer (Matanuska River; 61°36.5’N, 149°04.1’W)). We also clarify the status of previously described species, including those now discovered to have Holarctic distributions and/or for which sexual dimorphism was not appreciated and the species was described twice, including G. montana (Cresson) as a syn. n. of G. bohemanni (Becker). Two species, G. bella (Mathis), comb. n., and G. chiapas (Mathis), comb. n., are transferred from Ditrichophora to …