Search results for "systematics."

Studies on the genus Capparis L. (Capparaceae) in Lao PDR. II: A new species from the Khammouan karst

2017

A new species of Capparis, Capparis lanceolatifolia, is described and illustrated from central Lao PDR, where it is known from a single limestone doline in the Hinboun District, Khammouan Province. The new species is characterized by narrowly lanceolate leaves, racemose inflorescence bearing trifid bracts and small size of flower. Its affinities with related taxa and conservation status are discussed.

2019

Predation risk and food: opposite effects on overwintering survival and onset of breeding in a boreal rodent

2012

1. In seasonal environments, optimal onset of breeding and survival plays major roles in individual fitness. Many physiological and behavioural factors related to breeding increase the risk of predation; thus, breeding decisions should be based on current risks and benefits. According to life-history theory, if current predation risk is high and breeding itself increases the risk, it may be beneficial to postpone breeding. 2. During winter in northern hemispheres, food availability is limited and is at its lowest just prior to the onset of breeding in spring. Food constraint may lead to poor condition and reduced ability to start breeding. 3. We studied the effects of food and predation ris…

Temporal variability in offspring quality and individual reproductive output in a broadcast-spawning marine fish

2017

Abstract The protracted spawning period of broadcast-spawning marine fishes has potential to generate considerable variability in metrics of individual reproductive output. We undertook a temporally detailed genetic study of larvae produced by Atlantic cod (Gadus morhua) from two spatially proximate populations spawning under controlled semi-natural conditions over 94 days. Based on daily samples of larvae (n = 4489 in total), we document fine-scaled temporal changes in, and correlates of, offspring phenotype and reproductive output (egg batches produced or fertilized). Larval length and standardized yolk-sac volume declined 11 and 49% over the spawning period, respectively. The adaptive si…

The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

2020

Abstract Aim: Nest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes …

Examining nonstationarity in the recruitment dynamics of fishes using Bayesian change point analysis

2017

Marine ecosystems can undergo regime shifts, which result in nonstationarity in the dynamics of the fish populations inhabiting them. The assumption of time-invariant parameters in stock–recruitment models can lead to severe errors when forecasting renewal ability of stocks that experience shifts in their recruitment dynamics. We present a novel method for fitting stock–recruitment models using the Bayesian online change point detection algorithm, which is able to cope with sudden changes in the model parameters. We validate our method using simulations and apply it to empirical data of four demersal fishes in the southern Gulf of St. Lawrence. We show that all of the stocks have experience…

Multiple‐batch spawning as a bet‐hedging strategy in highly stochastic environments: An exploratory analysis of Atlantic cod

2021

Stochastic environments shape life‐history traits and can promote selection for risk‐spreading strategies, such as bet‐hedging. Although the strategy has often been hypothesised to exist for various species, empirical tests providing firm evidence have been rare, mainly due to the challenge in tracking fitness across generations. Here, we take a ‘proof of principle’ approach to explore whether the reproductive strategy of multiple‐batch spawning constitutes a bet‐hedging. We used Atlantic cod (Gadus morhua) as the study species and parameterised an eco‐evolutionary model, using empirical data on size‐related reproductive and survival traits. To evaluate the fitness benefits of multiple‐batc…

Mechanisms of reciprocity and diversity in social networks: a modeling and comparative approach

2018

Individual-based computer models show that different mechanisms, proximity-based or emotional bookkeeping, can lead to reciprocation. By comparing social networks from different computer models with those of empirical data, we show that the models’ social networks bear limited resemblance with some features of the observed social networks. This indicates that additional social processes (third-party awareness) may be needed in these models to represent more accurately the social behavior and interaction patterns observed in group-living animals.

Population abundance, structure and movements of the European pond turtle, Emys orbicularis (Linnaeus 1758) based on capture-recapture data in a Veni…

2021

A freshwater turtle monitoring programme along the inland margins of the Venice lagoon was initiated in 2019 in collaboration with the World Wild Fund for Nature (WWF-Italy). From a total of 336 European pond turtles (Emys orbicularis) captured and marked, 97 freshwater turtles were recaptured at least once (28.9% return rate) providing important information on population size, structure and movements of mature individuals within the study area. The population size was estimated with capture-recapture method (Capture-Mark-Recapture-CMR) at 1009.4 ± 365.2 pond turtles, with a mean density of 252.3 ± 91.3 ind./ha. The analysis of the movements showed that the average distance covered intra-wa…

Epizoic Algae Distribution on the Carapace and Plastron of the European Pond Turtle (Emys orbicularis, Linnaeus, 1758): A Study from the Camargue, Fr…

2016

12 pages; International audience; We investigated epizoic algal assemblages on the shell of European pond turtles (Emys orbicularis) during two years (2013–2014). A total of 60 Emys orbicularis were captured in the three shallow Mediterranean wetlands located in Camargue. Epizoic algae on the plastron (below the shell) and carapace (above the shell) were sampled, identified and counted. Seventy-seven epizoic algal species were identified on the carapace and plastron and comprised in 51 Bacillariophyta, 11 Chlorophyta, 7 Cyanophyta, 6 Euglenophyta, 1 Dinophyta and1Xanthophyta taxa. Our findings indicated a distinct distribution of epizoic algae according to taxonomical group density; Chlorop…