Search results for "Territoriality"
showing 10 items of 46 documents
Predicting and Measuring Decision Rules for Social Recognition in a Neotropical Frog.
2022
AbstractMany animals use signals, such as vocalizations, to recognize familiar individuals. However, animals risk making recognition mistakes because the signal properties of different individuals often overlap due to within-individual variation in signal production. To understand the relationship between signal variation and decision rules for social recognition, we studied male golden rocket frogs, which recognize the calls of territory neighbors and respond less aggressively to a neighbor’s calls than to the calls of strangers. We quantified patterns of individual variation in acoustic properties of calls and predicted optimal discrimination thresholds using a signal detection theory mod…
Territoriality in the Sheet-Web Spider Linyphia triangularis (Clerck) (Araneae, Linyphiidae
2010
Zusammenfassung 1 Das adulte L. triangularis-♂ bleibt bis zu 2 Tagen im Netz eines ♀, betrachtliche Zeit verbringt es von Netz zu Netz wandernd. Wahrend der Zeit des gemeinsamen Netzaufenthaltes ist das ♂, ob das ♀ nun kopulationsbereit ist oder nicht, stets der dominante Teil des Paares. 2 Wenn mehrere ♂♂ im ♀-Netz zusammentreffen, zeigen sie Droh- und Kampfverhalten, in dem die vergroserten Chelizeren und Klauen benutzt werden. Mehrere Stufen des Kampfverhaltens werden beschrieben und als Aggressionsanzeiger betrachtet. 3 Netzreduktion durch das ♂ wird als Methode zur Verhinderung von Storungen wahrend der Kopulation betrachtet. Selektionsmechanismen, die die Evolution solchen Verhaltens …
Social behavior, chemical communication, and adult neurogenesis: Studies of scent mark function in Podarcis wall lizards
2011
Lacertid lizards have been hailed as a model system for the study of reptilian chemical communication. However, results obtained with the genus Podarcis, a diverse group of wall lizards with complex systematics, challenge emerging paradigms and caution against hasty generalizations. Here we review the available evidence on the role of chemical stimuli in male-female and male-male interactions in Iberian Podarcis. Males of several species can discriminate between chemicals left on substrates by females of their own or a different species, suggesting that differences in female chemical cues may underlie species recognition in this group. Females, on the other hand, do not respond differential…
Territorial defense, territory size, and population regulation.
2005
The carrying capacity of an environment is determined partly by how individuals compete over the available resources. To territorial animals, space is an important resource, leading to conflict over its use. We build a model where the carrying capacity for an organism in a given environment results from the evolution of territorial defense effort and the consequent space use. The same evolutionary process can yield two completely different modes of population regulation. Density dependence arises through expanding and shrinking territories if fecundity is low, breeding success increases gradually with territory size, and/or defense is cheap. By contrast, when fecundity is high, breeding suc…
Implantations, activités et relations des établissements d'assistance en Bourgogne à la fin du Moyen Age
2012
The study presented here is the conclusion of an inventory about hospitals having existed on the territory of some dioceses (Autun, Auxerre, Chalon-sur-Saône, Nevers and the south of that of Langres diocese) between XIIth and XVth centuries. Based on the data collected, an atlas of assistance and a directory of sources on medieval hospitals of the study area has been made. The compiled informations proved to be very different but also very heterogeneous. Nevertheless, reflexions were conducted about the characteristics of these hospitals and their relationships with their economic, religious, political and social environments. It revolves around three parts dealing by turns the influence of…
Alternative reproductive tactics and the propensity of hybridization
2009
One explanation for hybridization between species is the fitness benefits it occasionally confers to the hybridizing individuals. This explanation is possible in species that have evolved alternative male reproductive tactics: individuals with inferior tactics might be more prone to hybridization provided it increases their reproductive success and fitness. Here we experimentally tested whether the propensity of hybridization in the wild depends on male reproductive tactic in Calopteryx splendens damselflies. Counter to our expectation, it was males adopting the superior reproductive tactic (territoriality) that had greatest propensity to hybridize than males adopting the inferior tactics (…
The effect of male-male competition and ornament size on mean and variance of courtship intensity towards heterospecific and conspecific females
2015
Discrimination between hetero- and conspecifics is the elementary choice an individual performs when searching for potential mates. The level of selectivity and strength of species discrimination is modified by variance in the quality of females, level of the male’s reproductive investment, mate search costs, and the competitive environment. The effect of the competitive environment on both species discrimination and conspecific mate choice has seldom been studied simultaneously. We experimentally manipulated territorial competition ofCalopteryx splendensdamselfly males in the wild, and asked two questions. First, does increased competition influence the territorial males’ responses towards…
Fish welfare in aquaculture: From physiology to molecular activities and new tools for study innovative diets, social and spatial stress
2022
Guaranteeing a high quality of life for animals has recently become a matter of increasing concern. Welfare assessment has been well-developed for terrestrial species, mainly for those kept in captivity, but the current state of the art is less well-characterized for aquatic animals. The classical methodologies utilised to date, such as the kind of behavioural observation widely used for terrestrial animals, are not appropriate for improving our knowledge of the well-being of aquatic animals if used alone, mainly due to the large number of species and the difficulty of obtaining comparative results among the different taxa of interest. Among different approaches, the evaluation of internal …
Species-specific song convergence in a moving hybrid zone between two passerines
2003
Moving hybrid zones are receiving increasing attention. However, so far little is known about the proximate mechanisms underlying these movements. Signalling behaviour, by individuals engaged in interspecific sexual and aggressive interactions, may play a crucial role. In this study, we investigated song variation within a moving hybrid zone between two warblers, Hippolais polyglotta and H. icterina. In these species, song is involved in interspecific territoriality and, probably, in mixed pairings. We showed that allopatric populations of the two species are clearly acoustically differentiated. However, interspecific differences faded out in sympatry as a result of an overall pattern of co…
Interspecific aggression and character displacement in the damselfly Calopteryx splendens
2004
Problems in species recognition are thought to affect the evolution of secondary sexual characters mainly through avoidance of maladaptive hybridization. Another, but much less studied avenue for the evolution of sexual characters due to species recognition problems is through interspecific aggression. In the damselfly, Calopteryx splendens, males have pigmented wing spots as a sexual character. Large-spotted males resemble males of another species, Calopteryx virgo, causing potential problems in species recognition. In this study, we investigate whether there is character displacement in wing spot size and whether interspecific aggression could cause this pattern. We found first that wing …