Behaviour

Fernö, Anders

doi: 10.1163/156853987X00189pmid: N/A

<jats:sec><jats:title>Abstract</jats:title><jats:p>Territorial mosaics of A. burtoni were studied in the laboratory. A difference in rank between neighbouring territorial fish was usually found, with the male with higher rank exhibiting more offensive behaviour and the opponent resisting more passively. A role asymmetry in boundary disputes was found in both high- and low-intensity aggression. Linear rank orders were formed. High rank was associated with a high aggressive and sexual activity towards non-territorial fish and a high mating succes". Territorial size was larger in superior males. A superior did not, however, generally expand his territory towards an inferior. This could be due to the involvement of escalated aggression with the reduction of territory. Most males of low rank did, however, eventually lose their territories. Establishing and losing territories were correlated with a low level of low-intensity aggression. Escalated fighting seldom occurred in spite of a strong competition for females, and aggression was usually limited to Frontal display and low-intensity aggression. Frontal display also played a key role for de-escalation of physical aggression. A. burtoni seems to follow the strategy "Honest", using a honestly graded display with few escalations.</jats:p> </jats:sec>

Fernö, Anders

doi: 10.1163/156853987x00189pmid: N/A

AbstractTerritorial mosaics of A. burtoni were studied in the laboratory. A difference in rank between neighbouring territorial fish was usually found, with the male with higher rank exhibiting more offensive behaviour and the opponent resisting more passively. A role asymmetry in boundary disputes was found in both high- and low-intensity aggression. Linear rank orders were formed. High rank was associated with a high aggressive and sexual activity towards non-territorial fish and a high mating succes". Territorial size was larger in superior males. A superior did not, however, generally expand his territory towards an inferior. This could be due to the involvement of escalated aggression with the reduction of territory. Most males of low rank did, however, eventually lose their territories. Establishing and losing territories were correlated with a low level of low-intensity aggression. Escalated fighting seldom occurred in spite of a strong competition for females, and aggression was usually limited to Frontal display and low-intensity aggression. Frontal display also played a key role for de-escalation of physical aggression. A. burtoni seems to follow the strategy "Honest", using a honestly graded display with few escalations.

Baur, Bruno

doi: 10.1163/156853987X00198pmid: N/A

<jats:sec><jats:title>Abstract</jats:title><jats:p>In the field hatchlings of the land snail Arianta arbustorum have been observed devouring eggs from sib as well as non-sib clutches. In the laboratory newly hatched A. arbustorum were tested for their ability to distinguish between eggs of different degrees of relatedness. In these experiments hatchlings did not discriminate between sib, other kin and non-kin eggs. Snails from three populations showed the same egg preferences, but they differed in their propensity for cannibalism. Despite the apparent lack of sib and kin recognition, egg cannibalism in A. arbustorum may be adaptive, even among siblings, because of the nutritional and energetic benefits.</jats:p> </jats:sec>

Baur, Bruno

doi: 10.1163/156853987x00198pmid: N/A

AbstractIn the field hatchlings of the land snail Arianta arbustorum have been observed devouring eggs from sib as well as non-sib clutches. In the laboratory newly hatched A. arbustorum were tested for their ability to distinguish between eggs of different degrees of relatedness. In these experiments hatchlings did not discriminate between sib, other kin and non-kin eggs. Snails from three populations showed the same egg preferences, but they differed in their propensity for cannibalism. Despite the apparent lack of sib and kin recognition, egg cannibalism in A. arbustorum may be adaptive, even among siblings, because of the nutritional and energetic benefits.

Anthouard, Michel

doi: 10.1163/156853987X00206pmid: N/A

<jats:sec><jats:title>Abstract</jats:title><jats:p>juvenile Dicentrarchus labrax having achieved good or poor performance in a task involving pushing a lever to obtain food served as demonstrators for conspecifics naive to the task. The results show that fish exposed to good demonstrators were subsequently more likely to engage in the same operant act than same-aged fish that observed poor demonstrators. Thus the development of traditions is shown to be possible in small groups of fish of the same age, originating in the appearance of a novel, adaptive behaviour by certain innovative individuals.</jats:p> </jats:sec>

Anthouard, Michel

doi: 10.1163/156853987x00206pmid: N/A

Abstractjuvenile Dicentrarchus labrax having achieved good or poor performance in a task involving pushing a lever to obtain food served as demonstrators for conspecifics naive to the task. The results show that fish exposed to good demonstrators were subsequently more likely to engage in the same operant act than same-aged fish that observed poor demonstrators. Thus the development of traditions is shown to be possible in small groups of fish of the same age, originating in the appearance of a novel, adaptive behaviour by certain innovative individuals.

Helbig, Andreas J.; Orth, Gerlinde; Laske, Volker; Wiltschko, Wolfgang

doi: 10.1163/156853987x00215pmid: N/A

AbstractMeadow pipit migration and orientation was studied by (1) watching visible migration and measuring flight directions with a compass in NW-Germany (1980-1985) and (2) conducting orientation experiments with caged migrants in radial-perch cages (MERKEL & FROMME, 1958). Free-flying pipits migrated SW in autumn and NE in spring in sunny and overcast weather, but on average there was less migration under overcast. In the field migration peaked in the first two morning hours and was almost over by the end of October. Strong migration always corresponded to a minimal scatter of flight directions. In the orientation cages the birds oriented SW in autumn and NNW in spring, but only in sunny weather during the first three morning hours. Activity decreased markedly later in the day (spring), in November compared to September/October and under overcast compared to sunny skies. The more active the birds were, the better was their orientation with respect to the overall mean direction. In general, meaningful orientation in the cages occurred only when migration intensity in the field was maximal. A lack of well-oriented behaviour in the cage is not necessarily caused by an inability to orient, but may be a consequence of low motivation to migrate. A six hour clockshift of experimental birds did not lead to a clear shift of their directional choices, but produced an axial NE-SW orientation in autumn and disorientation is spring. This result does not support the assumption that diurnal migrants orient primarily by means of a sun compass.

Orth, Gerlinde; Helbig, Andreas J.; Laske, Volker; Wiltschko, Wolfgang

doi: 10.1163/156853987X00215pmid: N/A

<jats:sec><jats:title>Abstract</jats:title><jats:p>Meadow pipit migration and orientation was studied by (1) watching visible migration and measuring flight directions with a compass in NW-Germany (1980-1985) and (2) conducting orientation experiments with caged migrants in radial-perch cages (MERKEL &amp; FROMME, 1958). Free-flying pipits migrated SW in autumn and NE in spring in sunny and overcast weather, but on average there was less migration under overcast. In the field migration peaked in the first two morning hours and was almost over by the end of October. Strong migration always corresponded to a minimal scatter of flight directions. In the orientation cages the birds oriented SW in autumn and NNW in spring, but only in sunny weather during the first three morning hours. Activity decreased markedly later in the day (spring), in November compared to September/October and under overcast compared to sunny skies. The more active the birds were, the better was their orientation with respect to the overall mean direction. In general, meaningful orientation in the cages occurred only when migration intensity in the field was maximal. A lack of well-oriented behaviour in the cage is not necessarily caused by an inability to orient, but may be a consequence of low motivation to migrate. A six hour clockshift of experimental birds did not lead to a clear shift of their directional choices, but produced an axial NE-SW orientation in autumn and disorientation is spring. This result does not support the assumption that diurnal migrants orient primarily by means of a sun compass.</jats:p> </jats:sec>

Turner, George F.

doi: 10.1163/156853987X00224pmid: N/A

<jats:sec><jats:title>Abstract</jats:title><jats:p>The paper investigates the occurrence of submission in relation to the courtship of the biparental sexually dimorphic convict cichlid, Cichlasoma (Archocentrus) nigrofasciatum. It was found that submission by females was not necessary for courtship to proceed and such behaviour was found only in a similar context to fleeing behaviour. The presence of an intruding male, while generally invoking courtship activities, did not reduce the aggressiveness of a resident female towards other conspecifics. Thus any inhibition of aggression was specific to the potential mate only. Similarly intruding males did not attack aggressive resident females, even though no symbolic inferiority was performed. It is suggested that inhibition of aggression towards the partner can occur in the absence of symbolic inferiority and proposed that a new terminology be adopted. Particular activities involved should be named according to postural elements, and the functional category referred to as Partner Attack Inhibition (PAI).</jats:p> </jats:sec>

Turner, George F.

doi: 10.1163/156853987x00224pmid: N/A

AbstractThe paper investigates the occurrence of submission in relation to the courtship of the biparental sexually dimorphic convict cichlid, Cichlasoma (Archocentrus) nigrofasciatum. It was found that submission by females was not necessary for courtship to proceed and such behaviour was found only in a similar context to fleeing behaviour. The presence of an intruding male, while generally invoking courtship activities, did not reduce the aggressiveness of a resident female towards other conspecifics. Thus any inhibition of aggression was specific to the potential mate only. Similarly intruding males did not attack aggressive resident females, even though no symbolic inferiority was performed. It is suggested that inhibition of aggression towards the partner can occur in the absence of symbolic inferiority and proposed that a new terminology be adopted. Particular activities involved should be named according to postural elements, and the functional category referred to as Partner Attack Inhibition (PAI).