Communication acoustique chez le cheval de Przewalski (Equus przewalski poliakov, 1881) réintroduit dans le Parc National de Hortobagy, Hongrie
; ; Huynen, Marie-Claude et al
in Cahiers d'Ethologie (2007), 22Detailed reference viewed: 58 (4 ULg)
Le tétras lyre dans les Hautes-Fagnes : quarante ans de suivis – dix ans d’actions.
Poncin, Pascal ; ; Loneux, Michèle et al
Article for general public (2007)Detailed reference viewed: 92 (3 ULg)
La reproduction : de la biologie à l’informatique – Introduction générale.
in Bulletin de la Société Royale des Sciences de Liège (2007)Detailed reference viewed: 19 (2 ULg)
Study of shoals by computerized video-tracking systems: development of a new multi-tracking system
Delcourt, Johann ; Becco, Christophe ; Ylieff, Marc et al
Conference (2006, September)Detailed reference viewed: 20 (6 ULg)
Brown trout fry move inshore at night: a choice of water depth or velocity?
; Poncin, Pascal ;
in Ecology of Freshwater Fish (2006), 15(3), 309-314
The instream positions of brown trout fry differ between daylight and darkness. According to field and laboratory observations, recently emerged 0+ brown trout use shallow and slow-flowing areas close to ... [more ▼]
The instream positions of brown trout fry differ between daylight and darkness. According to field and laboratory observations, recently emerged 0+ brown trout use shallow and slow-flowing areas close to the bank at night and tend to move off-shore during daylight. In laboratory channels, we tested whether the use of habitats close to the river bank could be attributed to a choice of either water depth or velocity. In two complementary experiments, emerging brown trout alevins were given the choice of using shallow-slow or deep-swift habitats (experiment 1), and deep-slow or shallow-swift habitats (experiment 2). At night, a persistent preference for the shallow habitats was displayed, regardless of velocity. It was concluded that swim-up brown trout fry respond to shallowness rather than ambient low water velocity when selecting habitats close to the bank at night. The behavioural significance of this result and implications for river management are discussed. [less ▲]Detailed reference viewed: 31 (4 ULg)
Ecological and ethological aspects of two natural hybrids involving common bream, Abramis brama (L.), of the River Meuse basin (Belgium).
; Ovidio, Michaël ; Poncin, Pascal et al
Conference (2006, June)Detailed reference viewed: 22 (4 ULg)
Experimental evidences of a structural and dynamical transition in fish school
Becco, Christophe ; Vandewalle, Nicolas ; Delcourt, Johann et al
in Physica A: Statistical Mechanics and its Applications (2006), 367
We have developed a video tracking system in order to determine all the trajectories of young fish (Oreochromis niloticus L.) within a school. Both individual and collective behaviours have been studied ... [more ▼]
We have developed a video tracking system in order to determine all the trajectories of young fish (Oreochromis niloticus L.) within a school. Both individual and collective behaviours have been studied as a function of the number of fish per unit area. By studying distributions of distances between fish and distributions of relative orientations, structural effects and cooperative motions have been evidenced. Signatures of a phase transition have been found, as predicted by some numerical models. This work opens new perspectives in the study of collective phenomena in biological systems since it is the first time that such measurements are possible. [less ▲]Detailed reference viewed: 154 (46 ULg)
Comparing the EthoVision 2.3 system and a new computerized multitracking prototype system to measure the swimming behavior in fry fish
Delcourt, Johann ; Becco, Christophe ; Ylieff, Marc et al
in Behavior Research Methods (2006), 38
Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The ... [more ▼]
Coming from the framework of unmarked fry tracking, we compared the capacities, advantages, and disadvantages of two recent video tracking systems: EthoVision 2.3 and a new prototype of multitracking. The EthoVision system has proved to be impressive for tracking a fry using the detection by gray scaling. Detection by subtraction has given less accurate results. Our video multitracking system is able to detect and track more than 100 unmarked fish by gray scaling technique. It permits an analysis at the group level as well as at the individual level. The multitracking program is able to attribute a number to each fish and to follow each one for the whole duration of the track. Our system permits the analysis of the movement of each individual, even if the trajectories of two fish cross each other. This is possible thanks to the theoretical estimation of the trajectory of each fish, which can be compared with the real trajectory (analysis with feedback). However, the period of the track is limited for our system (about 1 min), whereas EthoVision is able to track for numerous hours. In spite of these limitations, these two systems allow an almost continuous automatic sampling of the movement behaviors during the track. [less ▲]Detailed reference viewed: 92 (27 ULg)
Facteurs influençant l'efficacité des repeuplements. In: Vers une nouvelle politique des rempoissonnements.
; Poncin, Pascal
in Vers une nouvelle politique de rempoissonnement (2006)Detailed reference viewed: 27 (6 ULg)
Factors affecting black grouse numbers : an overview of the part of predators. European conference, black grouse endangered species,
Loneux, Michèle ; ; et al
in PLUMMER, Ron (Ed.) European Conference 'Cynhadledd Ceiliog Y Rhos' Black Grouse Endangered Species (2005, December)Detailed reference viewed: 21 (2 ULg)
Courtship behavior in the Alpine newt Triturus alpestris at two different densities of males
Denoël, Mathieu ; ; Poncin, Pascal
in Herpetologica (2005), 61(4), 373-379
The aim of this laboratory experiment was to examine courtship behavior and reproductive success under two different perceived male densities ill the Alpine newt (Triturus alpestris). Male behavioral ... [more ▼]
The aim of this laboratory experiment was to examine courtship behavior and reproductive success under two different perceived male densities ill the Alpine newt (Triturus alpestris). Male behavioral patterns were similar at unbiased and male-biased operational sex ratios (OSR). Although the exhibition of hiring behaviors is risky in the presence of other males, no difference in the frequencies of displays was found at the two male, densities. Similarly, the responsiveness of females towards males and the Success rate of the encounters (i.e. spermatophore transfer) were not explained by file OSR. Our results show that courting Alphine newts do not change their courtship patterns when other males are present and do not interact directly. However they are not necessarily opposed to those of previous experiments showing sexual interference awl ,female aversion in male-biased OSR with possibility of interactions. These observations suggest that the evolution of courtship behavior may not be driven by the risk of sexual interference with other males prior to potential physical contact and that the benefits of breeding regardless of OSR can overcome the risk of Competition at male-biased OSR. [less ▲]Detailed reference viewed: 192 (15 ULg)
Impact implantation of a transmitter on Sarpa salpa behaviour: study with a computerized video tracking system
; Donnay, Annick ; Ylieff, Marc et al
in Journal of Fish Biology (2005), 67(2), 589-595
Two transmitter masses (2 and 6% of the fish's mass) were selected to examine the interference of tags with the behaviour of Sarpa salpa using a computerized video tracking system based on digital imaging ... [more ▼]
Two transmitter masses (2 and 6% of the fish's mass) were selected to examine the interference of tags with the behaviour of Sarpa salpa using a computerized video tracking system based on digital imaging techniques. The study demonstrated that light transmitters had no effect on the behavioural variables studied, and a substantial bias in behaviour is introduced if heavier (6%) tags are used. (c) 2005 The Fisheries Society of the British Isles. [less ▲]Detailed reference viewed: 75 (14 ULg)
Effect of water temperature on the courtship behavior of the Alpine newt Triturus alpestris
Denoël, Mathieu ; ; Poncin, Pascal
in Behavioral Ecology and Sociobiology (2005), 58(2), 121-127
Temperature 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 ... [more ▼]
Temperature 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. [less ▲]Detailed reference viewed: 176 (25 ULg)
A new automatic video multitracking system able to follow a large school.
Delcourt, Johann ; ; Vandewalle, Nicolas et al
Poster (2005)Detailed reference viewed: 4 (1 ULg)
Factors affecting black grouse numbers : an overview of the part of predators.
Loneux, Michèle ; ; et al
Conference (2005)Detailed reference viewed: 2 (0 ULg)
Evolution des populations de tétras lyres (Tetrao tetrix) sur le plateau des Hautes-Fagnes en regard des modifications des paramètres écologiques du milieu.
; ; Poncin, Pascal et al
in AVES (2005), 42/1-2Detailed reference viewed: 18 (4 ULg)
The spawning behaviour of the endangered freshwater fish Ladigesocypris ghigii (Gianferrari, 1927)
Poncin, Pascal ; ; et al
in Journal of Applied Ichthyology (2005), 21(3), 225-228
Ladigesocypris ghigii (Gianferrari, 1927), commonly called gizani, is an endangered freshwater fish endemic to the Greek island of Rhodes. The spawning behaviour of gizani was studied in aquaria, to ... [more ▼]
Ladigesocypris ghigii (Gianferrari, 1927), commonly called gizani, is an endangered freshwater fish endemic to the Greek island of Rhodes. The spawning behaviour of gizani was studied in aquaria, to develop an artificial breeding technique for this endangered species. Spawning in captivity was recorded over 41 spawning days between 15 February and 14 July 2001, under constant temperature (18 or 21 degrees C) and photoperiod 14L/10D. The number of spawning acts in a day was 82 +/- 28. No aggressiveness and no territoriality were developed. The mating system of the fish was polygamous, with females spawning more than once. In captivity, eggs are laid either on aquatic plants or on gravel, while in nature fish spawn mainly on algae and plants. The latter suggests that, as far as breeding substrate is concerned, gizani is an opportunistic species using different substrates when necessary. [less ▲]Detailed reference viewed: 18 (1 ULg)
Morphological changes of the nucleolus during oogenesis in oviparous teleost fish, Barbus barbus (L.).
Thiry, Marc ; Poncin, Pascal
in Journal of Structural Biology (2005), 152(1), 1-13
In fishes, like in amphibians, it is well established that variations in rRNA activity occur during oogenesis. Contrary to amphibians, however, little is known about the ultrastructural changes of the ... [more ▼]
In fishes, like in amphibians, it is well established that variations in rRNA activity occur during oogenesis. Contrary to amphibians, however, little is known about the ultrastructural changes of the nucleolus during fish oogenesis. Evolution of the nucleolus has been followed during oogenesis in the teleost fish Barbus barbus (L.) using light and transmission electron microscopies. We show that the behaviour of the nucleolus during B. barbus oogenesis resembles that reported in amphibians but also presents several peculiarities. The most striking feature is the marked vacuolization of nucleoli occurs at the beginning of the growth during previtellogenesis. The results obtained by means of the in situ terminal deoxynucleotidyl transferase-immunogold method for detecting DNA seem further to indicate that the chromatin cap becomes integrated into developing nucleoli during previtellogenesis and then segregate at the periphery of nucleoli at the end of glycoproteinic vitellogenesis. Our study also shows that the nucleoli of germ cells, like that of follicle cells, are devoid of fibrillar centre but comprise a fibrillar and a granular component whatever the oogenetic stage. Ultrastructural detection of DNA and nucleolar proteins (AgNOR proteins, fibrillarin, and pp135) supports further the view that the Barbus nucleolus is a bipartite structure. [less ▲]Detailed reference viewed: 52 (7 ULg)