The effect of food on growth and metamorphosis of paedomorphs in Triturus alpestris apuanus

The effect of food level on growth and metamorphosis of paedomorphs was examined in an experimental replicated design in Triturus alpestris apuanus. Paedomorphosis concerns the retention of larval characteristics in adult individuals. Newts that forgo metamorphosis and then retain gill and gill slits in the adult stage maintain an aquatic life but keep potential for undergoing metamorphosis. Paedomorphs metamorphosed later in treatments with food as a non-limiting factor than in stressful treatments where food was limited. Timing of metamorphosis did not differ between males and females. Food level greatly affected growth rates. These results confirm and extend optimality models that predict paedomorphosis under advantageous aquatic conditions (paedomorph advantage hypothesis) and metamorphosis in stressful aquatic habitats

Fin flickering and associated sounds in the cichlid fish Ophthalmotilapia ventralis: a preliminary study.

Fin flickering was defined as rapid movements of the fins. The behavioral function of such movements is however not well established. Depending on the species investigated, they were considered as comfort movements (e.g. removal of minor irritations) or alarm for young. In the cichlid Etroplus maculatus they allow homogenous repartition of eggs on the substrate. We studied visual and acoustical behavior of five Ophthalmotilapia ventralis (two males and three females) reared in a 240 l tank. Pectoral fin flickering associated with sound production was often observed, especially from fish that established a territory. With the exception of the butterflish Chaetodon mutlicinctus and gouramis, this aspect of fin flickering is generally overlooked in teleosts. First observations support the fact that sounds (peak frequency and pulse duration: 562±95 Hz and 14±5 ms, respectively) are not emitted during all kinds of fin movements but mainly during some caudo-rostral horizontal fin sweeps. In-depth studies are however required to better characterize the movements and understand what morphological traits are responsible for the sound production. Further investigations are also needed to determine if fin flickering has a role in O. ventralis social interaction

Effect of water temperature on the courtship behavior of the Alpine newt Triturus alpestris

peer reviewedTemperature is expected to have an effect on the behavioral patterns of all organisms, especially ectotherms. However, although several studies focused on the effect of temperature on acoustic displays in both insects and anurans, almost nothing is known about how environmental temperature may affect ectotherm visual courtship displays and sexual performance. The purpose of this study was to determine the effect of environmental temperature on the sexual behavior of Alpine newts (Triturus alpestris). We subjected T. alpestris to two different temperatures in controlled laboratory conditions. Temperature had a major effect on both male and female behaviors: at low temperature, the frequencies of several displays, including tail-raising during sperm deposition, are lowered. This variation is caused indirectly by temperature because it is due to female responsiveness, which is temperature-dependent. However, the fanning movement of the male's tail during its main courtship display is independent of female behavior: at lower temperatures, the tail beats at a lower rate, but for a longer time. The similar reproductive success (i.e. sperm transfer) at the two temperature ranges indicates that breeding in cold water is not costly but instead allows males and females to mate early in the season. This is particularly adaptive because, in many habitats, the reproductive period is shortened by drying or freezing conditions, which may impair survival of branchiate offspring. This study also demonstrates the necessity of considering environmental parameters when modeling optimality and characteristics of ectotherm behaviors

Essai d’estimation des dommages piscicoles engendrés par les prises d’eau industrielles et les turbines hydroélectriques dans les cours d’eau de la Province de Liège. Partie E. Chapitre 8. Les centrales hydro-électriques sur la Méhaigne, petit affluent de la Meuse dans le sous-bassin Meuse aval

Ce rapport à la Commission provinciale de Liège du Fonds piscicole de Wallonie est un dossier bibliographique qui analyse l’impact potentiel sur les populations de poissons des quatre centrales hydroélectriques (voir tableau A) installées sur la Méhaige, principal, petit affluent de la rive gauche de la Meuse, sous-bassin Meuse aval. L’impact de la production d’hydroélectricité sur les poissons de la Méhaigne concerne principalement le cours inférieur de la rivière où se succèdent sur une distance de 5,9 km trois micro-centrales qui utilisent un débit de 2-3 m3/s, pratiquement égal au module. L’utilisation d’un tel débit sur aussi petite rivière favorise un fort pourcentage d’entrainement de l’eau et des poissons dévalants dans l’installation de turbinage (turbine Kaplan, turbine Francis ou vis hydrodynamique). Dans ce cas, il faut envisager un effet cumulé de la cascade des trois microcentrales de la Basse Méhaigne

Synthesis of 3-Alkenyl-1-azaanthraquinones via Diels-Alder and Electron Transfer Reactions

A convenient route to 3-alkenyl-1-azaanthraquinones via a hetero Diels-Alder reaction between an azadiene and naphthoquinone, a free radical chlorination and an electron transfer reaction is reported

Is the black grouse (Lyrurus tetrix) an indirect victim of the sylvatic rabies eradication by fox vaccination?

peer reviewedINTRODUCTION Since 2017, a reinforcement program was developed to save the last, endangered, Belgian population of black grouse (Lyrurus tetrix), in the High Fens Natural Park. To improve the success of this program, an analysis of past data of this population was undertaken to understand the causes of its past decline. Climate models, applied in previous studies to explain these population trends in the High Fens, failed to describe this major modification in this population’s dynamic and its recent decline. MATERIAL AND METHODS A time series analysis was applied on the core population to understand the causes of its past decline, using annual spring male census data recorded between 1967 and 2016. RESULTS AND DISCUSSION In the period 1967–1993, there was a fluctuation around an equilibrium of a population of ca. 40–45 males. After 1993, the population dynamic changed drastically, decreasing continuously until finally reaching quasi-extinction. On average, the population lost 15.4% of its size each year. Red fox (Vulpes vulpes) populations in Western Europe experienced a significant decline and stabilized at lower densities than observed in the past due to an outbreak of sylvatic rabies. In early 1990s, a fox demographic explosion followed a massive vaccination campaign, and fox populations became larger than had been observed before the epizootic. The eradication of the rabies was not the direct cause of this demographic explosion, as rabies-free areas experienced it also (but earlier). The causes are more to be sought in environmental modifications induced by humans. CONCLUSIONS Around 1993, the remarkable synchronicity between the beginning of the Black Grouse population decline in High Fens and the fox demographic explosion suggests a significant increase in predation on this bird species. If the fox is singled out for this change in Black grouse dynamics, it should not be concluded that it is entirely responsible for this decline. It is quite possible that other factors have added up, such as the arrival or increase of other predators (the raccoon in particular, but also the wild boar, and better health of the populations of large raptors), deer overgrazing, and other subtle habitat changes and in climate

Post-release acclimation of translocated Black Grouse (Lyrurus tetrix): a multi-time scale analysis using telemetry

peer reviewedINTRODUCTION Translocation of living individuals is a conservation strategy used to reinforce declining populations. However, failures are not uncommon, notably due to factors such as high mortality or unexpected behaviors (e.g. absence of reproductive behavior, tendency to leave the release area, etc.). We translocated 88 Black Grouse (Lyrurus tetrix) from Sweden to Belgium to reinforce the last population occurring in the country. We tracked 58% of them by GPS telemetry and analyzed their movements to see if an acclimation in the release area was noticeable, but also to gain insights on the pattern of activity of the Grouse (a) right after a translocation event and (b) over the course of the year. MATERIAL AND METHODS The translocated Black Grouse were captured in Kårböle (Sweden) in late April 2017, 2018 and 2019 and 2022. Trapping took place on the leks, using fall traps. Individuals were then ringed, measured and placed in individual boxes to be transported to the ‘Hautes Fagnes’ Nature Reserve (Belgium), in which they were released circa 30 hours after capture. Spatial data was collected via solar-powered GPS-GSM backpack transmitters deployed on 51 individuals. Analyses were conducted using QGIS and RStudio. RESULTS AND DISCUSSION We noticed a high inter-individual variability, probably related to different stress-coping mechanisms and personalities. However, it is noteworthy that the longest movements, including explorations out of the reserve, are performed during the first 3 weeks post-release. All grouse then returned to the reserve and only moved over short distances for 3-4 months, until a second peak of higher activity in October. Although some grouse died during their long-distance movements, it was not an inevitable fatality. CONCLUSIONS Except the 3 weeks post-release, the general activity pattern detected is in line with the behavior of non- translocated Black Grouse, suggesting that translocated individuals need a short (but critical) period of acclimation to their new environment, then behave normally and have therefore the potential to thrive

Evaluation de la qualité biologique des rivières wallonnes sur base des indices biologiques poissons. Support technique aux inventaires 2014.

Ce rapport final présente les résultats des inventaires piscicoles effectués en juin-juillet et en septembre-octobre 2014 ainsi que le calcul des indices biologiques « poissons » (IBIP et EFI)

Evaluation de la qualité biologique des rivières wallonnes sur base des indices biologiques poissons. Support technique aux inventaires 2012.

Ce rapport a pour objectif l’évaluation de la qualité biologique des eaux de surface basée sur les indices biologiques « poissons » dans un certain nombre de cours d’eau de Wallonie. Il résulte d’une convention entre le Service public de Wallonie et l’Université de Liège