1 The dispersal mode adopted by a plant species is frequently associated with other attributes of the plant and its habitat. In this paper we review these associations and present a set of hypotheses which, when considered together, make a probabilistic prediction of the dispersal mode adopted by a plant species. When applied to a species list, the hypotheses can be used to generate a prediction of its dispersal spectrum, i.e. the percentages of different dispersal modes that have been adopted. 2 The formulation of such a set of hypotheses has several purposes: (i) to summarize existing knowledge about dispersal adaptations and their interrelations with other attributes of plants and their habitats; (ii) to couch that knowledge in such a way that falsifiable predictions can be made; (iii) to arrive at provisional conclusions about which factors are the most important in shaping the evolution of dispersal mode in different plants or different environments. 3 The review of relationships between dispersal mode and other attributes of plants and their habitats lead to the following provisional conclusions; (i) seeds larger than 100 mg tend to be adapted for dispersal by vertebrates while those smaller than 0.1 mg tend to be unassisted; most seeds, however, are between 0.1 and 100 mg, and in this range all of the dispersal modes are feasible; (ii) plant growth form and stature (sometimes in relation to the canopy height of the vegetation) seem to exclude certain dispersal modes; (iii) the availability of specific dispersal vectors seems rarely to be an important determinant of dispersal mode; (iv) attributes of the physical environment also seem rarely to be important, except indirectly through their influence on plant stature and seed size.

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Current predictions of how species will respond to climate change are based on coarse-grained climate surfaces or idealized scenarios of uniform warming. These predictions may erroneously estimate the risk of extinction because they neglect to consider spatially heterogenous warming at the landscape scale or identify refugia where species can persist despite unfavourable regional climate. To address this issue, we investigated the heterogeneity in warming that has occurred in a 10 km × 10 km area from 1972 to 2007. We developed estimates by combining long-term daily observations from a limited number of weather stations with a more spatially comprehensive dataset (40 sites) obtained during [2005][2006]. We found that the spatial distribution of warming was greater inland, at lower elevations, away from streams, and at sites exposed to the northwest (NW). These differences corresponded with changes in weather patterns, such as an increasing frequency of hot, dry NW winds. As plant species were biased in the topographic and geographic locations they occupied, these differences meant that some species experienced more warming than others, and are at greater risk from climate change. This species bias could not be detected at coarser scales. The uneven seasonal nature of warming (e.g. more warming in winter, minimums increased more than maximums) means that climate change predictions will vary according to which predictors are selected in species distribution models. Models based on a limited set of predictors will produce erroneous predictions when the correct limiting factor is not selected, and this is difficult to avoid when temperature predictors are correlated because they are produced using elevation-sensitive interpolations. The results reinforce the importance of downscaling coarse-grained (∼50 km) temperature surfaces, and suggest that the accuracy of this process could be improved by considering regional weather patterns (wind speed, direction, humidity) and topographic exposure to key wind directions. These predictions may erroneously estimate the risk of extinction because they neglect to consider spatially heterogenous warming at the landscape scale or identify refugia where species can persist despite unfavourable regional climate. To address this issue, we investigated the heterogeneity in warming that has occurred in a 10 km by 10 km area from 1972 to 2007. We developed estimates by combining long-term daily observations from a limited number of weather stations with a more spatially comprehensive dataset (40 sites) obtained during [2005][2006]. We found that the spatial distribution of warming was greater inland, at lower elevations, away from streams, and at sites exposed to the NW. These differences corresponded with changes in weather patterns, such as an increasing frequency of hot, dry NW winds.As plant species were biased in the topographic and geographic locations they occupied, these differences meant that some species experienced more warming than others, and are at greater risk f...

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r 2) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. SummaryTranslocating birds to a new area of habitat to restore or supplement depleted populations may pose a significant threat to the translocated individuals. While for many species, translocated individuals appear to move larger distances than resident animals, species with poor dispersal capacity may be restricted in movements and translocation methods may need to accommodate differences in movements to ensure success. In this study, designed to provide insights to inform our broader program of translocations in New South Wales, Australia, we investigated post-release movements in the endangered, semiflightless Eastern Bristlebird (Dasyornis brachypterus). We predicted that movements would be minimal, with few differences between males and females, similar to published information for a resident un-manipulated population. Following the release of 45 birds at a host location at Jervis Bay, NSW, over a three-year programme, we followed individuals for up to two weeks using radio-tracking. The translocated birds had larger maximum movements and moved through much larger home ranges than nontranslocated individuals from the resident population. Translocated birds moved 300 m further after release when conspecifics were present. Males moved further than females and tended to have l...

The absence of small birds from many suburban areas may be due to adverse garden characteristics, interspecific aggression or human behaviour such as supplementary food provisioning that encourages predators. We investigated the relationship between these factors and the presence of seven small bird species in Sydney through a community-based survey. The survey was conducted by participants over a 7-day period between 7 AM and 10 AM in November and early December 2000. Three dominant species, the noisy miner (Manorina melanocephala), pied currawong (Strepera graculina) and common myna (Acridotheres tristis) were each present in over 59% of gardens. Each small bird species was present in less than 40% of gardens. All small birds were negatively associated with noisy miners, but only the silvereye (Zosterops lateralis) was negatively associated with pied currawongs. None of the species of small birds was negatively associated with common mynas. Four species of small birds were associated with at least one habitat variable, notably the proportion of native vegetation. Although more birds were recorded in gardens in which meat was provided, there were significantly fewer small birds in these gardens. There were also more birds recorded in gardens where seed was provided, with red-browed finches (Neochmia temporalis) positively associated with seed provisioning in most regions of Sydney. The presence of dogs and cats was not related to the total abundance of birds overall or small birds in gardens. While garden characteristics may influence the presence of small birds to some degree, the presence of noisy miners, a species that are thought to aggressively exclude other species from their territories, is likely to be an important influence on these species in suburban areas. Furthermore, supplementary feeding by people is likely to negatively influence some small birds. The presence of carnivorous pets does not seem to influence the presence of small birds at the scale of the individual garden.