Budgerigar Case Study

Figure 1. The proportion of time the parakeets spent performing each set of behaviours under control (a), horizontal (b) and vertical (c) conditions

Figure 2. The proportion of time the cockatiels spent performing each set of behaviours under control (a), horizontal (b) and vertical (c) conditions. Although a large amount of time was spent perching, it can be seen here that preening was a dominant behaviour during the control conditions for the cockatiels. This is seen to reduce as the perch arrangement changes.
Figure 3. The proportion of time the budgerigars spent performing each set of behaviours under control (a), horizontal (b) and vertical (c) conditions. This appears to remain similar between arrangements.

Figure 7. The number
The number of new locations made by the cockatiels. It appears that there are no obvious changes in the species as a whole in the number of new locations, but individual movements varied widely between experiments, particularly in cockatiels 1, 3, 4, 5 and 6 where an increase in new locations is seen in the horizontal and vertical arrangements.
Figure 9. The number of new locations made by the budgerigars. It can be seen in budgerigars 1, 2 and 4 that new locations were decreased during the horizontal arrangement and then increased during the vertical. However, for budgerigars 3, 5 and 6 the opposite has occurred.
Figure 10. The number of aggressive behaviour expressed by each species during each arrangement. It can be seen that a decrease in aggressive behaviour was expressed by all three species during the horizontal and vertical arrangements in comparison to the
Dominance hierarchies have a large influence on behaviour, yet are necessary to maintain relationships. McGowen et al. (2006) discussed dominance and roosting position in a captive flock of long-tailed tits, indicating that the most subordinate individuals would have to perch on the outer positions of the roost. This has also been seen in the red-winged blackbird where the roosts are structured according to dominance (Weatherhead and Hoysak, 1984). Dominance may also play an important role in aggression. Aggression in birds, especially in captivity, can create welfare issues for keepers and owners if allowed to elevate to situations where birds are getting injured regularly. However, aggression should be understood as a normal element of a bird 's social interactions and can be related to the instinct of natural behaviours such as attracting mates (Ophir and Galef, 2002). However, the costs of aggressive behaviour can be high, such as higher injury risk which may reduce survival (Wingfield et al., 2001), so such behaviour is regulated and used only when a necessity. Aggression may be a natural response to several factors, including hormonal changes through seasons (Marasco et al., 2011), breeding density (Yoon et al., 2012), territory (Hannon and Eason, 1995), resource availability (Vahl and Kingma, 2007), and kinship (Toth et al.,