Search results for "territorialit"
showing 10 items of 57 documents
A field test of behavioural flexibility in Zenaida doves (Zenaida aurita).
2010
7 pages; International audience; Animals' ability to adjust their behaviour when environmental conditions change can increase their likelihood of survival. Although such behavioural flexibility is regularly observed in the field, it has proven difficult to systematically quantify and predict inter-individual differences in free-living animals. We presented 24 Zenaida doves (Zenaida aurita) on 12 territories with two learning tests in their natural habitat in Barbados. The dove pairs showed high site fidelity and territoriality, allowing us to test individuals repeatedly while accounting for the effects of territorial chases and pair bonds on our learning measures. We used a foraging apparat…
THE INTENSITY OF SEXUAL SELECTION PREDICTS WEAPON SIZE IN MALE BOVIDS
2007
As a classical example of a sexually selected trait, the horns of male bovids offer a prime opportunity to identify predictors of the intensity of sexual selection. Here I use the comparative method to quantify sexual and natural selection pressures behind interspecific variation in horn length. I show that male horn length depends on factors proposed to affect the mean mate number per mating male, correlating positively with group size and negatively with male territoriality. This suggests that whereas group size increases the opportunity for sexual selection, territoriality reduces it because territorial males are unable to follow and monopolize female groups as effectively as males in no…
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…
Dalla “Sé-cattedrale” al “Sé-Nazione”. Sull’architettura della città e del territorio lusitano: chiavi di lettura storico-antropologiche
2010
La città è traccia architettonico-morfologica della storia che la produce. In pochi paesi l’urbe ha tracciata in sé, così chiaramente, l’evoluzione di questa storia, come in Portogallo, fra i più antichi per unità nazionale. L’articolo propone un percorso attraverso la formazione identitaria portoghese, dalla crescita economica, fasi coloniali, sino alla decadenza dell’economia marittima. Economia, questa, che anche attraverso l’urbe, come luogo privilegiato di sviluppo, decreta il vero inizio della globalizzazione planetaria. L’excursus storico si conclude con la crisi identitaria di fine Ottocento, per tracciare quello che è il profilo dell’immaginario nazionale portoghese, soprattutto co…