Abstract: Learning to associate sensory cues with threats is critical for minimizing aversive experience. The ecological benefit of associative learning relies on accurate perception of predictive cues, but how aversive learning enhances perceptual acuity of sensory signals, particularly in humans, is unclear. We combined multivariate functional magnetic resonance imaging with olfactory psychophysics to show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after aversive conditioning, paralleling the spatial divergence of ensemble activity patterns in primary olfactory (piriform) cortex. Our findings indicate that aversive learning induces piriform plasticity with corresponding gains in odor enantiomer discrimination, underscoring the capacity of fear conditioning to update perceptual representation of predictive cues, over and above its well-recognized role in the acquisition of conditioned responses. That completely indiscriminable sensations can be transformed into discriminable percepts further accentuates the potency of associative learning to enhance sensory cue perception and support adaptive behavior.

Abstract: Pferdehaltungssysteme mit angrenzenden Ausläufen gelten als eine sehr tiergerechte
Haltungsform, da sie den Tieren eine gewisse Bewegungsmöglichkeit
bieten. Ziel der vorliegenden Untersuchung war es, zu erfassen, ob der angrenzende
Auslauf selbst einen ausreichenden Anreiz zur Bewegung darstellt und wie sich verschiedene
Bewegungs- und Platzangebote auf die Bewegungsaktivität von Pferden
in einer Gruppen-Auslaufhaltung auswirken. Zudem wurde ermittelt, welche Auswirkung
die Bewegungsform bzw. –intensität auf das Wohlbefinden der Tiere hat.
Der Großteil der in Deutschland gehaltenen Pferde verbringt die meiste Zeit des
Tages im Stall, obwohl mittlerweile bekannt ist, dass Pferde unter natürlichen
Haltungsbedingungen 12 bis 16 Stunden des Tages in Bewegung verbringen. Der
Optimierung der Stallhaltungssysteme gilt daher ein besonderes Interesse.
Zu diesem Zweck wurden von September 2004 bis Oktober 2005 Versuche mit 24
Warmblutstuten im Alter von 1½ bis 3½ Jahren in Einzel- und Gruppen-
Auslaufhaltungssystemen durchgeführt. Jeweils sechs Pferde bildeten eine Versuchsgruppe.
In jeder Gruppe fanden fünf Varianten von einer ca. dreiwöchigen
Dauer statt. Die Gruppenhaltung wurde dabei durch drei unterschiedliche Zusatzbewegungsangebote
(2 Std. Weide / Tag, 2 Std. unbegrünte Koppel / Tag, 1 Std. Freilauf-
Führanlage / Tag) ergänzt. In der Einzel-Auslaufhaltung (Box mit 45 m²-großem
angrenzenden Auslauf) und in einer Versuchsvariante der Gruppenhaltung bekamen
die Pferde hingegen keine zusätzliche Bewegung außerhalb des Stallhaltungssystems
angeboten. Das Gruppenhaltungssystem selbst war durch die räumliche
Trennung der Funktionsbereiche (Liegen, Fressen, Trinken, Bewegen) gekennzeichnet
und der angrenzende Auslauf war 270 m² groß. In einer zusätzlichen Versuchsphase
fand in der Gruppenhaltung eine Erweiterung des permanent zugänglichen
Auslaufs auf insg. 540 m² statt.
Die Bewegungsaktivität wurde mit Pedometern erfasst, die an jeweils einem Hinterbein
der Pferde befestigt wurden und ergänzend fand eine Analyse von Videoaufzeichnungen
statt. Zur Beurteilung der Stressbelastung fanden Messungen der Herz192
Zusammenfassung
frequenzvariabilität (Parameter HF und SD2) und der fäkalen Cortisolmetabolitenkonzentration
statt.
Die Auswertung des Bewegungsverhaltens ergab, dass eine zusätzliche zweistündige
freie Bewegung der Pferdegruppe auf einer Weide zu einer deutlichen
Steigerung der durchschnittlichen Bewegungsaktivität (149,6 Min. / Tag) führt,
ebenso wie eine einstündige Bewegung in einer Führanlage (173,0 Min. / Tag). Eine
unbegrünte Koppel regte die Pferde der Gruppenhaltung hingegen nicht zu vermehrter
Bewegung an (131,6 Min. / Tag), sondern bewirkte z. T. sogar eine Abnahme
der Bewegungsaktivität. In der Gruppen-Auslaufhaltung ohne zusätzliches Bewegungsangebot
war die Bewegungsaktivität ebenfalls gering (125,8 Min / Tag) und
während der Einzel-Auslaufhaltung ohne Zusatzbewegung zeigten die Pferde die
geringste Bewegungsaktivität (102,3 Min. / Tag).
Bei der alleinigen Analyse der Bewegungszeit im Stallhaltungssystem war kein signifikanter
Einfluss der zusätzlichen Bewegung außerhalb des Stallsystems auf die
übrige Fortbewegung feststellbar.
Auch eine Vergrößerung des an den Stall angrenzenden Auslaufs im Gruppenhaltungssystem
hatte keinen steigernden Einfluss auf das Bewegungsverhalten der
Pferde.
Die Stressbelastung der Pferde war in den Varianten der Gruppenhaltung mit zweistündigem
Weidegang (SD2: 82,9 ms; Cortisolmetaboliten: 29,0 nmol / kg Kot) sowie
der einstündigen Bewegung in einer Freilauf-Führanlage (SD2: 99,2 ms; Cortisolmetaboliten:
27,7 nmol / kg Kot) am geringsten. Die Untersuchungen zeigten eine
Stresszunahme in der Gruppenhaltung mit zweistündigem Auslauf auf einer unbegrünten
Koppel ohne Futterangebot (SD2: 101,3 ms; Cortisolmetaboliten:
39,6 nmol / kg Kot) sowie in der Variante der Gruppenhaltung ohne zusätzliches Bewegungsangebot
(SD2: 113,3 ms; Cortisolmetaboliten: 38,4 nmol / kg Kot). Dem
Mittelwert der Gruppe nach zu folgern hatten die Pferde während der Einzelhaltung
ohne Zusatzbewegung eine sehr große Stressbelastung (SD2: 123,8 ms; Cortisolmetaboliten:
37,5 nmol / kg Kot). Ein Vergleich der Gruppen- und Einzelhaltung hinsichtlich
der Herzfrequenzvariabilität hat jedoch gezeigt, dass insg. 70 % der Pferde
während der Haltung in einer Gruppe weniger Stress empfinden. Es gab aber auch
Zusammenfassung 193
Pferde (30 %), die in der Einzelhaltung eine abnehmende Stressbelastung zeigten,
wobei hier der Einfluss der Rangordnung eine entscheidende Rolle zu spielen
scheint.
Durch die Auswertung mehrerer Messparameter (sowohl für Stress- als auch für Bewegungsverhalten)
werden gleichgerichtete Tendenzen bei den Versuchsvarianten
deutlich, allerdings ist eine eindeutige Gewichtung der Parameter nicht möglich.
Somit ist die methodische Vorgehensweise dieser Untersuchung sehr positiv und als
notwendig anzusehen, da die Messdaten auch immer gewissen Schwankungen
durch externe Einflüsse unterliegen.
Allgemein ist festzuhalten, dass Auslaufhaltungssysteme zwar eine gewisse
Anregung zur Bewegung bieten, aber mit maximal vier Stunden (insg. 62 – 248 Min.)
Bewegung pro Tag war der tägliche Anteil an Bewegung sehr viel geringer als
beispielsweise bei Pferden in freier Wildbahn oder ganzjähriger Weidehaltung. Somit
deckt ein Auslaufhaltungssystem trotz getrennter Funktionsbereiche und eines
großen Auslaufs nicht den Bewegungsbedarf der Pferde, wenn keine zusätzlichen
Bewegungsanreize und –möglichkeiten angeboten werden.
Eine zusätzliche Bewegung von Pferden ist nicht nur zur Gesunderhaltung des
Bewegungsapparates und der Körperfunktionen notwendig, sondern auch um das
Wohlbefinden und die Ausgeglichenheit der Pferde zu steigern.
[Horse husbandry systems with close-by discharge are considered to be a very livestock-
friendly housing form, as they offer a certain movement opportunity for the
animals. The aim of the present study was to examine how different movement and
space offerings affect the movement activities of horses in a group horse husbandry
with close-by discharge, and whether the discharge provides itself an adequate
incentive for movement. The impact that the form or rather intensity of movement has
on the wellbeing of the animals was also established.
Most of the horses held in Germany spend most of the day in the stable, although it is
meanwhile known that horses under natural housing conditions are 12 to 16 hours of
the day in motion. Therefore the improvement of stable housing systems applies a
special interest.
For this purpose, 24 warmblood mares, aged from 1½ to 3½ years, were studied in
single and group discharge husbandry systems from September 2004 until October
2005. Six horses formed an experimental group. In every group five variants of approximately
three weeks were proceeded. Thereby the group husbandry was supplemented
with three different additional movement opportunities (2 h pasture / day,
2 h non-grassy pasture land / day, 1 h free range horse walker / day). In the single
discharge husbandry (single box with 45 sq. m-large close-by discharge) and in one
experimental variant of the group husbandry got the horses, however, offered no additional
movement outside the husbandry system. The group husbandry system itself
was marked by the spatial division of the functional areas (lying, eating, drinking,
moving) and the close-by discharge measured 270 sq. m. In an additional phase of
the study, and expansion of the permanently accessible close-by discharge to
540 sq. m was found.
The movement activity was documented with pedometers attached respectively to
one hind leg of the horse and a supplementary analysis of video documentation. To
evaluate the stress exposure measurements of heart frequency variability (parameters
HF and SD2) and of the faecal cortisol metabolite concentration were performed.
Summary 195
The interpretation of the movement behaviour showed that additional two hours of
free movement on a pasture led to a significant increase in the average movement
activity (149.6 min / day), as well as one hour movement in a horsewalker did
(173.0 min / day). The non-grassy pasture land, however, didn’t inspire the horses of
the group husbandry to increased movement (131.6 min / day), but sometimes even
caused a decrease in movement activity. In the group discharge husbandry without
additional movement opportunities the movement activity was also low
(125.8 min / day), and during the single discharge husbandry without additional
movement the horses showed the least movement activity (102.3 min / day).
In analysing only the movement time in the stable system was no significant impact
of the additional movement outside the housing system to the rest of locomotion
ascertainable.
As well an expansion of the close-by stable discharge in the group husbandry system
had no increasing influence on the movement behaviour of the horses.
The stress exposure of the horses was least in the variations of group husbandry
with two hours on a pasture (SD2: 82.9 ms; cortisol metabolites: 29.0 nmol / kg faeces)
as well as one hour of movement in a free range horse walker (SD2: 99.2 ms;
cortisol metabolites: 27.7 nmol / kg faeces). The studies showed a rise in stress in
group husbandry with two hours of movement on a non-grassy pasture land without
feeding opportunity (SD2: 101.3 ms; cortisol metabolites: 39.6 nmol / kg faeces) as
well as in the variation of the group husbandry without additional movement offerings
(SD2: 113.3 ms; cortisol metabolites: 38.4 nmol / kg faeces). Judging from the mean
of the group the horses had a very high stress exposure in the variation of the single
husbandry without additional movement offerings (SD2: 123.8 ms; cortisol metabolites:
37.5 nmol / kg faeces). But a comparison of the group and single husbandry in
terms of the heart frequency variability showed that alltogether 70 % of the horses
experienced less stress if hold in a group. However, some horses (30 %) showed
reducing stress in the single husbandry, whereas here the influence of social hierarchy
seems to play a decisive role.
196 Summary
In consequence of the examination of several measuring parameters (both for stressand
for movement behaviour) parallel aligned tendencies become apparent in the
experimental variants, however, is a unique weighting of the parameters not possible.
Thus, the methodological approach of this study is to be regarde as very positive and
necessary, since the data always vary with some fluctuations by external influences.
In general it can be established that discharge husbandry systems offer some incentive
for the horse to move, but with a maximum of four hours (overall 62 – 248 min) of
movement per day, the daily proportion of movement was much less than, for example,
in the case of wild horses or year-round pasture keeping. Thus, if no additional
movement incentives and possibilities are offered, the discharge husbandry system
doesn’t cover the movement needs of the horse despite separate functional areas
and a large outside discharge.
Additional movement is not only necessary to keep the musculoskeletal system and
bodily functions of the horse healthy, but also to ensure the horse’s well being and
mental balance.]

Abstract: Socially acquired predator avoidance is a phenomenon in which individuals acquire an avoidance response towards an initially neutral stimulus after they have experienced it together with the antipredator signals of social companions. Earlier research has established that alarm calls used for intraspecific communication are effective stimuli for triggering acquisition. However, animals produce a large range of other antipredator responses that might engage antipredator learning. Here, I examine the effects of conspecific distress calls, a signal that is produced by birds when restrained by a predator, and that appears to be directed towards predators, rather than conspecifics, on predator avoidance learning in Indian mynahs, Acridotheres tristis. Distress calls reflect high levels of alarm in the caller and should, therefore, mediate robust learning. Experiment 1 revealed that subjects performed higher rates of head movements in response to a previously unfamiliar avian mount after it had been presented simultaneously with playbacks of conspecific distress vocalizations. Experiment 2 revealed that increased rates of head saccades resembled the spontaneous response evoked by a novel stimulus more closely than it resembled the response evoked by a perched raptor, suggesting that distress calls inculcated a visual exploratory response, rather than an antipredator response. While it is usually thought that the level of acquisition in learners follows a simple relationship with the level of alarm shown by demonstrators, the present results suggest that this relationship may be more complex. Antipredator signals with different functions may have differential effects on learners.

Abstract: Dogs can learn effectively to detour around a V-shaped fence after observing a demonstration from either an unfamiliar human or dog demonstrator. We found earlier that there is substantial individual variation between the dogs' performance, even when using the same experimental conditions. Here, we investigate if the subjects' relative dominance rank with other dogs had an effect on their social learning performance. On the basis of the owners' answers to a questionnaire, subjects from multi-dog homes were sorted into groups of dominant and subordinate dogs. In Experiment 1, dominant and subordinate dogs were tested without demonstration and we did not find any difference between the groups-they had similarly low detour performances on their own. In Experiment 2 and 3, dogs from single dog and multi-dog households were tested in the detour task with demonstration by an unfamiliar dog, or human, respectively. The results showed that social learning performance of the single dogs fell between the dominant and subordinate multi-dogs with both dog and human demonstration. Subordinate dogs displayed significantly better performance after having observed a dog demonstrator in comparison to dominant dogs. In contrast, the performance of dominant and subordinate dogs was almost similar, when they observed a human demonstrator. These results suggest that perceived dominance rank in its own group has a strong effect on social learning in dogs, but this effect seems to depend also on the demonstrator species. This finding reveals an intricate organization of the social structure in multi-dog households, which can contribute to individual differences existing among dogs.

Abstract: The aim of this study was to determine the extent to which the classical properties of social dominance describe the pattern of feeder-related displacements with groups of cattle. We also compared the advantages and disadvantages of three dominance indices for describing the competitive success at the feeder. We observed displacements at the feeder within six groups of 12 lactating dairy cows over 72 h per group. We demonstrated that the cattle in our experiment established a quasi-linear hierarchy at the feeder where many dominance relationships were bi-directional (52.0 +/- 5.9%); namely, dominance relationships were significantly linear (P < 0.05 in five of the six groups) but contained many circular triads (45.0 +/- 5.6%). Dominance rank influenced the milk production (r = 0.36, P = 0.002) and the time budget of the animals: high-ranking cows were found spending more time at the feeder during the 120 min following provision of fresh food than low-ranking cows (P = 0.022), but dominance indices based on the occurrence of displacements at the feeder did not correlate with actual time spent at the feeder. The presence of numerous circular triads and bi-directional relationships suggests that the classical properties of social dominance do not correspond to the pattern of displacements that occur at feeders within small groups of cattle. Instead, the competitive success may also be affected by motivation or persistence by the animal to gain access to the food resource.