Olfaktorische Reize bei Raubkatzen als Beitrag zum Enrichment.
Fachbereich Ökologie und Evolution, Paris-Lodron-Universität Salzburg
Zoo Salzburg Gemeinnützige GmbH
Environmental Enrichments finden in Zoos und Tiergärten immer mehr Anklang. Die Idee, den Lebensraum von Zootieren durch Spielzeuge, verstecktes Futter oder verschiedene Düfte zu bereichern, kommt nicht von ungefähr.
Den Tieren im Zoo werden viele überlebenswichtige Aufgaben von den Pflegern abgenommen. Beispielsweise müssen sich die Tiere keine Sorgen um das Futter machen, also keine Beutetiere fangen oder Früchte sammeln. Außerdem fällt die Partnersuche für die Fortpflanzung weg. Zu guter Letzt brauchen die Tiere im Zoo nicht einmal ihr eigenes Revier abgrenzen. Nicht selten konnte man in Zoos beobachten, dass manche Tiere im Gehege auf und ab spazierten. Dieses stereotype Bewegungsmuster ist nicht natürlich und macht eine psychische Störung der Tiere sichtbar.
Was kann man also tun, damit derartige Verhaltensstörungen der Vergangenheit angehören? Die Antwort lautet "Enrichment". Enrichments können in mehrere verschiedene Kategorien eingeteilt werden. Um den Faktor des olfaktorischen Reizes zum Enrichment hinzuzufügen und dessen Wirkung beobachten zu können, wurden im Rahmen dieser Diplomarbeit zwei verschiedene ätherische Öle eingesetzt.
Um die Beobachtungen durchführen zu können, bediente man sich eines Lockstockes, auf dem ein Holzplättchen befestigt wurde. Täglich wurden diese Holzplättchen ausgewechselt und neu mit den ätherischen Ölen besprüht.
Insgesamt waren 72 Beobachtungen geplant, davon sollten 36 Beobachtungen auf die Jaguare und 36 Beobachtungen auf die Löwen fallen. Aufgrund äußerer Einflüsse, konnten die Beobachtungen bei den Löwen nicht zu hundert Prozent durchgeführt werden.
In der ersten Woche wurde die Nullprobe durchgeführt. Das heißt, sechs Tage lang wurden täglich neue Holzrohlinge, ohne Duft, am Lockstock montiert. In den darauf folgenden sechs Tagen wurde täglich ein Holzrohling mit ätherischem Minzöl besprüht und anschließend am Lockstock montiert. In der dritten Woche kam das ätherische Zitronenöl zum Einsatz. Um nichts dem Zufall zu überlassen, wurde ein zweiter Durchgang gestartet.
Die Ergebnisse zeigen, dass die Raubkatzen zum Teil sehr stark auf die ätherischen Öle reagiert haben. Die Resultate zeigen, dass die Raubkatzen unter dem Einfluss der ätherischen Öle bestimmte Verhaltensweisen deutlich öfter zeigten, als bei den Nullproben.
Weiters wird deutlich, dass die Reaktionen auf die ätherischen Öle nicht geschlechtsspezifisch zu sein scheinen. Trotzdem liegt die Vermutung nahe, dass Männchen und Weibchen ihr Interesse auf unterschiedliche Art und Weise zeigen.
Zu erkennen ist auch, dass die Jaguare deutlich aktiver waren als die Löwen und dementsprechend stärker auf die ätherischen Öle reagierten. Hinzu kommt, dass die Raubkatzen das Nanaminzöl gegenüber dem Zitronenöl präferierten.
Auch die Auswirkung des Mondes auf die Raubkatzen wurde untersucht. Bei abnehmendem Mond waren die Raubkatzen im Zoo Salzburg deutlich aktiver als bei zunehmendem Mond.
Environmental enrichments have grown in appeal for many zoos. The idea to enrich the habitat of captive animals with toys, hidden feed or various aromas is a meaningful strategy.
Zookeepers have relieved animals in zoos of many duties which were essential for survival in the wild. For example the animals do not have to worry about food - they do not have to catch prey or collect fruit. In addition, searching for a partner for the purpose of reproduction has been eliminated. Finally, animals in zoos do not even have to define their own territories. In zoos, it has often been observed that some animals pace in their compounds. This behavior is unnatural and demonstrates a visible mental disorder.
What can be done in order to end such behavioral and mental problems so that they become a thing of the past? The answer is "environmental enrichment" which can be divided into several different categories such as social, physical habitat and sensory enrichments. In order to study the impact of olfactoric stimuli as an environmental enrichment, two different essential oils were used within the frame of this thesis.
In order to be able to conduct observations, experiments were performed using a lure - a wooden stake to which small square pieces of wood were fixed. These wooden pieces were sprayed with essential oils on a daily basis and rotated every six days.
All in all, 72 observations were planned, 36 of which to be done with jaguars and 36 with lions. Because of outside influences, the lion observations could not be completed in full.
During the first week, baseline observations were completed. For six days, new wooden pieces without any essential oils were fixed to the lure. In the following six days, essential mint oil was sprayed on the wooden pieces before they were attached to the lure. In the third week, essential lemon oil was used. In order to leave nothing to chance, a second round of observations were also completed using the same procedure.
The results indicate that the predatory cats reacted to some extent quite strongly to the essential oils. The final outcomes demonstrate that the animals displayed certain behaviors more frequently when under the influence of essential oils than during the control stage (without essential oils).
Of additional interest is the fact that the reactions to the essential oils do not appear to be related to the animals' sex. However it can be speculated that males and females exhibit their interests in different manners and forms.
It should also be recognized, that the jaguars were decidedly more active than the lions and subsequently reacted more strongly to the essential oils. In addtion, the predatory cats seemed to prefer the nana mint oil over the lemon oil.
The effect of the moon on the cats was also investigated. During a waning moon, the big cats were much more active than during a waxing moon.
Ethologische und hygienische Untersuchungen über die Haltungsbedingungen von Raubkatzen in zoologischen Gärten.
Dr. med. vet. Dissertation
Fachbereich Veterinärmedizin, Freie Universität Berlin
Neun Zoos in Deutschland
The aim of the present study was to obtain informations which help to define guidelines to improve the environmental conditions in enclosures for cats of prey. In order to assess the animales"welfare im their environment the hygienic, ethological and breeding aspects, as well as the death rate and the occurrence of diseases were studied. During 15 months nine zoos in the Federal Republic of Germany were visited. Data of the environmental conditions in 35 enclosures, where 266 animals (21 species) were kept, were collected. During five visits, each one for a period of three days, the following data were reported: relative humidity, temperature inside and outside of every stable, C02, ammonia, lung passing dust, concentration of airborn microorganism and their compound, ventilation of the air inside of every pen, light intensity and temperature of surfaces. To decide, if cats of prey are able to cope whith their surrounding environment, the behaviour of 33 lions, 30 tigers, 31 leopards and 20 cheethas was observed for a period of 10 days per animal. For each day the time was subdivided in two hlocks of ten minutes and five blocks of one minute. The enclosures' physical characteristics were recorded. The breeding records of all cats present in the zoos and the data of pathology since 1981 were collected. There was a large variation in indoor temperature relative humidity, concentration of airborn ammonia and microorganisms during the year. In vitrines (cages with a front glas and an average volume of 31mü) the temperature was higher and the relative humidity lower than in the othersystems (p < 0,01). The data depended on the seasons and ranged between 22.2 and 25.6 øC and 33.3 to 46.6% relative humidity. In stables for only a single species with an average volume of 116mü the parameters were between 11.8 and 21.8 øC and 51,5 to 63.8 % relative humidity. The large buildings for cats of prey ( 3257mü) worked as an intermediate. In enclosures for tropical cats the data of relative humidity were not significantly higher than in the pens of the animals of the other climatic zones. In 55 to 78% of the cases the measured ammonia concentration was between 0 and 5 ppm. The area per animal, the temperature inside the stables and the amount of time, in which the animals left the houses, correlated negatively with the concentration of the disadvantage gas. The intensity of artificial light ranged on average from 18 to 1600 Ix and for daylight from 16 to 6892 Ix. In buildings reachable for visitors cages were brighter than those which were not (p e 0,01). The ascertained concentrations of airborn microorganism distinguished between the different housing systems and ranged between 7177.3 and 15834.2 KBE/mü. The concentration correlated negativly with the temperature outside of the buildings, while the amount of each compound, especially the gram positive cocci and rods, was influenced by the microclimate of the stables. The gram negative germs covered only 4.5 to 7.5%. Therefore the gram positive microorganisms were predominant. The further specification showed a wide range of different germs. Staphylococcus xylosus and lentus were the main cocci of the genus Staphyloccus. In the group of the Micrococcaceae Micrococcusa varians and luteus were dominant. 31% of the gram positve rods was classified as Rhodococcus equi. In the group of fungi members Penicillium and Aspergillusspecies were represented preferantiably. The part of the primary pathogen germs was low and amounted totaly below 1%. The analysis of the enclosures "physical characteristics showed that not all possibilities of design and construction were used in the best way. In only 48 2% of the outdoor cages the bottom was built with natural materials. In 20% of the indoor pens with concrete and tiles the ground was also covered with litter or sand. Mostly the development of the third dimension was mostly made available by boards; supplementary trees and artificial hills were insert. In only 20% of the indoorand 19% of the outdoor pens the structure of the room was assessed to be very good. In 22.5%(indoor) and 9.4% (outdoor) of the cases this rating was poor. The comparison between the ethograrms of the different species (lion, tiger, leopard, cheetha) showed a speciesspecific distribution of the observed parameters. Lions showed a longer resting period and they were more inactive than the other cats (p < 0 01 ). Cheethas and leopards did not sleep as long as the other big cats. Giving the opportunity all cats prefered higher resting places, but leopards used them more frequently (p < 0 01). This species prefered also concealments (holes, trees) for its resting period. Comparing the moving activities the males of the big cats walked for a longer period than the female ones (p < 0.05) . Leopards showed stereotypies more often than the others (63 3% of the active period) (p < 0 01), male leopards moved longer in astereotypic way than the females (male: 67 9 min; female: 34.9 min) (p < 0 05). Enclosures also influenced this behaviour. In pens below 200 mý animals showed stereotypies for longer periods than in larger ones (44 6 min /6 9 min) (p < 0 01). Most of the animals (85%) descented from breeding programs. There were no differences in successful breeding among the different species or zoos. But cats living in an area larger than 50 mý per animal gave birth to more cubs ( 8.4 cubs) than those in a smaller one (5.5 cubs) The type of building, in which he animals were kept, influenced the number of born and grown up animals. In the large buildings for cats of prey less animals were born (5.2) and grown up (3.0) than in houses for only one species (10.6 born and 7.3 juveniles) (p < 0.01). The noted data of the breeding records showed that 57% of the dead cubs were killed by their mother or father. This quota of the young animals died by occlusion comprised 24% of pathological data of the subadults. Not all the animals were available for pathological examination. Further analysis of the pathological data showed that infectious diseases were common for both groups -young and adult. Pneumonia followed by bronchopneumonia were the main respiratory problems - pulmonary diseases ranked on the third place as reason of death. In comparison with cats of the other regions cats from the tropic showed more often infections and pulmonary diseases.The ability of animals to adapt to different environmental conditions is limited. Therefore it is necessary to understand the animals" needs in order to offer good animal housing. As a kind of help to build adequate environments for cats of prey a catalogue of recommendations respectively demands for the housing were given.