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6. MEASURING BEHAVIOUR

Measuring the animals behaviour is a practical, easy and inexpensive way to be sure of the real benefit of the enrichment.

Throughout a systematic study, we will be able to evaluate, if our hypothesis is true and the use of the enrichment to manage the behaviour we want to.

Several authors have measured behaviour to evaluate the adaptation of the animals to its captive habitat (Eyre 1997, Mc Grew et al 1986 and Wemelsfelder 1999), and some have measured behaviour in combination with physiological evaluation (Sheperdson 1994).

By explaining one study on the behaviour of captive coatis (Nasua nasua) I suggest a simple way to measure the effectiveness of the enrichment techniques, this based in methodology used by other authors.

Measuring Effect.

This study proposes to divide an enrichment project in six steps.

Choosing the species and the environmental enrichment devices

Designing an Ethogram

Choosing the sampling method and designing a checksheet

Collecting the data

Data Analysis

Results and conclusions

Experiment on the coatis

Methods.

First step: Choosing the species and the environmental enrichment devices

When designing an enrichment program, it is important to understand the necessities of the captive species and the type of enrichment they need, for this reason the knowledge of the natural history is vital to achieve good results.

This practical research was made on the Jersey Zoo group of coatis (Nasua nasua), and they were chosen because their opportunistic behaviour, they are always exploring and investigating, always on the move (Morris, 1964).Also, because their forage behaviour, the coatis forage both arboreally and terrestrially (Eisenberg, 1989) The coatis can be seen feeding on fruit high in the canopy of a tree, or searching the forest floor for animal prey by pocking their noses into crevices, turning over rocks, or ripping apart dead logs with their claws (Emmons, 1990).

These reasons make them a good species for manage behaviour with enrichment, also they can present abnormal behaviours if they are not provide with an enriched environment (see Meyer-Holzapfel, 1968).

The group of coatis in the Jersey Zoo includes five adult females, one adult male and three female cubs still dependant of their mothers' milk, reason why they were not included in the study. Their behaviour were measured indoors in their principal den, but they had free access to another den, where they were not visible.

The environmental enrichment devices used were some of the ones currently on use on the coati's enclosure in Jersey Zoo, and were chosen according with their location in the enclosure (ground level and elevated level) and the type of food that involve (mealworms and locusts).

The number of mealworms used were the double of the locusts considering the size and an expected difference in time of manipulation of the food, suggested by K. Cowan (Dep. Head, Jersey Zoo Mammal Department). Also were chosen for being a favoured food for the coatis.

Feeding Enrichment Devices

Mealworms scattered on ground: Number of mealworms: 120

Locusts scattered on ground: Number of locusts: 60

Activity balls with mealworms: Number of devices: 3. Number of mealworms: 120

Hanging coffee sacks with locusts: Number of devices: 3. Number of locusts: 60

Hanging food baskets with mealworms: Number of devices: 3. Number of mealworms: 120

Second step: Designing an Ethogram

A ethogram had to be designed in order to specify the behaviours that were going to be measured and that could be affected by the provision of the feeding enrichment device. According with Martin and Bateson, (1986) The criteria used to define a category of behaviour were unambiguously distinguished from other categories.

Research Question: Does the location placement of different environmental enrichment devices and the food placed on them, affect the proportion of time spend by the coatis in trees and on ground?

1. Locomotion on ground: (Loc) Any movement of the animal between an origin point to another point of the enclosure using only the ground

2. Foraging on ground: (Fog) Searching Behaviour intended to get food, including manipulation of feeding device.

3. Feeding on ground: (Feg) Consumption or ingestion of food on ground.

4. Foraging in tree: (Fot) Searching Behaviour intended to get food in trees, including manipulation of feeding device

5. Feeding in tree: (Fet) Consumption or ingestion of food in tree.

6. Climbing: (CL) Any movement of the animal between different points in a tree or different trees without using the ground.

7. Other: (OT) Animal performs any behaviour not already described.

8. Not Visible: (NV) Due to the location or position of the animal, it is impossible to accurately determine its behaviour.

Third Step: Choosing the sampling method and designing a checksheet

The sampling method used was scan sampling at thirty seconds intervals (Altmann 1974, in Mellen, Hayes and Sheperdson, 1998) to estimate the performance of the behaviours. This period of time between scans provides sufficient time space to find each animal in the enclosure and record its behaviour, and because the behaviours defined here are states, or ongoing behaviours (Washington Park Zoo, 1983)

The checksheet designed, include the names of the individuals each with two columns, which were filled with the behaviour showed and the level on which it was performed.

Also, in the checksheet there was place to explain some others conditions at the moment of the observations such as temperature and time, also to place the name of the observer, feeding enrichment device and place for notes about the behaviour of the animals, and changes in the environment, such as the presence or not of the infants in the enclosure.

A model of the Checksheet used is on appendix I.

Fourth step: Collecting the data

The observation periods last fifteen minutes or thirty scans starting at the time of offering the enrichment device time in which the devices receive more attention from the animals (personal observation.) .The behaviour of each animal according with the ethogram, was scored each scan, and the location choosed for the observer was in an a corner of the enclosure inside a safety porch where the coatis did not had access.

The observer had been cleaning the enclosure and feeding the coatis for a week, before the study, so the animals did not paid too much attention to his presence in the enclosure during the sampling, and which allowed a very good location from which observe the individuals. It is important to easily recognise each individual in a given enclosure before start any behavioural research in a group of captive animals. Each day an different device was placed in the enclosure an approximately the same hour, between 10: 30 and 11: 30 a.m. and similar temperature 17 - 19 degrees Celsius.

Fifth step: Data Analysis

Once the data was collected, the following step was to turn all the checksheet data into a easy readable form, counting how many times each behaviour was performed by each individual during the sampling. For example one of the females, "Tonta" was recorded performing foraging behaviour on ground 9 times or scans when the locusts were offered scattered on ground.

Once all the behaviours were counted they were turned into a percentage of the total time of the sampling, thirty scans represent the cent per cent of the time, so the time percentage of this behaviour was 30. This is made for every behaviour and on each individual of the group.

Following this, the general average of the behaviour in the group was calculated to provide the necessary information to build pie charts that explain easy the results of the research. These pie charts can be compared between each other and provide information about which device is better encouraging what behaviour.

The information collected is not statistically representative, but shows clearly that a simply research like this can generate information about managing behaviour under controlled situations.

Sixth step: Results and conclusions

Figure 1.

Locusts scattered on ground: When this device was offered the coatis spent most of the time foraging on ground (31%), suggesting that the foraging behaviour on ground was encouraged. The Not Visible wedge represents 29 % of the scan time which means that the animals were not in the observation room for long time and they had prefer to get into the adjacent den. Feeding behaviour was recorded only in 4 % of the times suggesting that the locusts are ingested rapidly.

Figure 2.

The No Visible wedge represents 44% which means that near half of the sampling time the coatis moved onto the adjacent den. However, the behaviours on the ground were encouraged (foraging, locomotion, other and feeding) representing 44 % of the observations in comparison with the behaviours in trees 12 %.

Figure 3.

Taking only the first 15 scans of the observations in the Mealworms scattered on ground technique, it is obvious that the first half of the observations have a higher content of foraging on ground category and lower of Not Visible category. This suggests that the technique is reliable in terms of encouraging foraging on ground category but the intensity of the animal's reaction declines rapidly, affecting the final results of the observations. This concludes that in some environmental enrichment techniques could exist differences in the intensity of the response of the animal through time and this have to be studied.

Figure 4.

Activity balls with mealworms: Foraging on ground were the category most observed using this device, showing that this category were encouraged. The Not visible category was not recorded suggesting that this device encouraged the coatis to stay in the observation den., were the balls were placed.

Figure 5.

Hanging coffee sacks with locusts: The behaviour categories located in trees were more observed under this technique representing 70 % of the observation time in comparison with the categories occurred on ground 16 %. This shows that the device was successful attracting the coatis to the level it was placed.

Figure 6.

Hanging food baskets with mealworms: These baskets contained an activity ball inside, where the mealworms where placed in. The results show that the most observed category were Not Visible (43 %) followed by foraging on ground. Having in mind that the device was placed in trees the categories encouraged should be the ones at the same level, but this device when manipulated by one individual, causes the mealworms to fall down to the floor were other animals can forage for them. This could be used in hierarchical species were the dominant individual could be busy manipulating the device while the others feed themselves, possibly avoiding aggressions.

The results show that are differences between enrichment devices, some encourage behaviours in trees and some on ground, some encourage the animals to stay in the observation den and others not. The food placed on each device seemed to affect some behaviours since the time spent by the coatis foraging for locusts were higher at least in were offered in the same way (Scattered on ground). This even offering twice number of mealworms than locusts.

The devices more effective encouraging behaviours in ground were Activity balls with mealworms and locusts scattered on ground. This shows that this devices encouraged the coatis to stay on the ground, and can be used for this purposes. For categories at tree level, Hanging coffee sacks with locusts, showed to be the most effective.

Some devices can produce different results of what was expected, like Hanging food baskets with mealworms. This device was placed in trees but encouraged behaviours on ground.

The intensity and duration of the effectiveness in each device can differ. While some have high intensity and low duration like mealworms scattered on ground, others have high duration like Activity balls with mealworms.

This simple study shows that some devices are more effective than others and not always what expected is what happens, and that some behaviour categories can be easily managed by encouraging or discouraging them with environmental enrichment.

Only by implementing this or more elaborated kind of studies the people involved in

environmental enrichment can have a feedback and improve their techniques.

The amount of data collected was not statistically representative due to the size of the sample also in this case there was not baseline study to compare the data. This research was intended to demonstrate the change in same behaviours when using different enrichment devices.

I can suggest that more repetitions of data collection should be made in order to provide a statistically representative sample and that a baseline study of the animal and the behaviour to be changed should be conducted before offering the enrichment device. Where an active attempt is intended to manipulate behaviour the baseline data will be easier to collect as a starting point for the work.

A null hypothesis relating to the effect of enrichment should be proposed and may be proved or disproved statistically by comparing expected and observed patterns of behaviour.

The most common statistic employed to test a hypotheses or compare the means of two samples is the T-test. (Cooperrider, Boyd and Stuart, 1986)

Managing Animal Behaviour through Environmental Enrichment

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