Cat legislation that avoids or educates about the contentious issue of cat-free zones should receive solid community support.

No abstract

Chitons of the genus Ischnochiton are found predominantly on the undersurfaces of boulders, compared with other intertidal or subtidal habitats. They therefore appear to be habitat-specialists at this scale. This, combined with the fact that boulder fields are relatively sparse compared with other intertidal habitats, makes these animals vulnerable to natural and anthropogenic disturbances. In addition, many species of Ischnochiton are relatively rare and appear to have very patchy abundances, making them likely to have very specific requirements for habitat. We need to understand the habitat requirements in order to manage, conserve and restore disturbed habitats. The present study was carried out at three intertidal boulder fields separated along approximately 200 km of the coast of New South Wales, Australia, centred around Sydney. The boulder fields were representative of those found in this region. The boulders were made of different materials: shale in the north, sandstone in Sydney and quartzitic sandstone in the south. Some boulders in each boulder field were covered by up to 0.4 m of water during low tide. The study showed that the seven species examined were overdispersed among boulders in each of these three intertidal boulder fields. Most boulders did not have associated chitons, but there were very large abundances on a very small number of boulders. Chitons were also overdispersed among boulders that they occupied. These patterns were consistent among shores and among species, even though patterns of abundance were extremely different among different species. These species appear therefore to show specific requirements for habitat at a small spatial scale, using only a small proportion of potential patches of habitat (i.e. boulders) in any place. Extremely patchy patterns of dispersion can be caused by variation in patterns of recruitment, mortality or behavioural responses to habitat or other species. Before performing experiments to investigate such processes, it is useful to test hypotheses of association with habitat using mensurative experiments to identify environmental correlates that might explain the observed patterns. In the present study, sizes of boulders and the associated sessile and mobile assemblages were proposed as mechanisms that could affect dispersion of chitons among boulders. None of these factors, however, showed strong associations with abundances of chitons. The lack of support of these models rules out some features of habitat to which species of Ischnochiton might respond, thereby precluding manipulative experiments involving these features, which are unlikely to be involved in the very patchy patterns of dispersion of species of Ischnochiton .

While it is undeniable that both feral cats and owned domestic cats prey on native wildlife, evidence that this is a threat to the viability of wildlife populations is contentious, particularly in the suburbs. Where uncertainty is great or the risks are high, the precautionary principle is a guide as to whether or not action should be taken to regulate domestic cats. This involves an evaluation of the available evidence and the extent of uncertainty, as well as consideration of the viewpoints of major stakeholders. Applying this approach leads to the conclusion that wildlife can be protected while improving cat welfare. Containing cats at night not only separates cats and nocturnal wildlife, but minimises trauma from both cat fights and road accidents while reducing nuisance to neighbours from caterwauling and fighting. Desexed cats no longer contribute toward unwanted stray and feral cat populations that depredate native wildlife populations and are often less of a nuisance to neighbours and themselves as spraying and fighting are reduced. Cats with identification can be returned to their owners should they be found lost or injured, while problem cats can be identified. Therefore, the cat welfare issue is the key to a successful precautionary approach because it achieves wildlife protection while respecting the interests of cat owners.

Using data from 57 sites across suburban Perth we tested the influence of Cat Density on species richness and community composition of passerine birds as well as on the presence/absence of 15 common passerine species. Cat Density was not a significant predictor of any of the dependent variables. Instead, passerine species richness declined with increasing Distance to Bushland and with increasing Housing Density, but increased proportionately with the Size of, Nearest Bushland > 5ha. Together, these predictors explained approximately half the variability in bird species richness (adjusted R 2 for the complete data set = 0.414). Passerine community composition was significantly affected by Housing Density, Distance to, and Size of, Nearest Bushland >5ha. These environmental variables, especially Housing Density, appeared to act principally by their effect on the number of small and medium sized insectivores. Attempts to predict the presence/absence of 15 common passerines did not yield clear results, although Housing Density appeared the most likely predictor. While cat predation might be significant adjacent to remnant bushland or other areas of conservation significance, blaming cats for bird conservation issues in long-established suburbs may be a scapegoat for high residential densities, inappropriate landscaping at a range of scales or poor conservation of remnant bushland.