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Understanding what constitutes high quality habitat is crucial for the conservation of species, especially those threatened with extinction. Habitat quality frequently is inferred by comparing the attributes of sites where a species is present with those where it is absent. However, species presence may not always indicate high quality habitat. Demographic parameters are likely to provide a more biologically relevant measure of quality, including a species’ ability to successfully reproduce. We examined factors believed to influence territory quality for the grey-crowned babbler (Pomatostomus temporalis), a cooperatively breeding woodland bird that has experienced major range contraction and population decline in south-eastern Australia. Across three broad regions, we identified active territories and determined the presence of fledglings and the size of family groups, as surrogates of territory quality. These measures were modelled in relation to habitat attributes within territories, the extent of surrounding wooded vegetation, isolation from neighbouring groups, and the size of the neighbourhood population. Fledgling presence was strongly positively associated with group size, indicating that helpers enhance breeding success. Surprisingly, no other territory or landscape-scale variables predicted territory quality, as inferred from either breeding success or group size. Relationships between group size and environmental variables may be obscured by longer-term dynamics in group size. Variation in biotic interactions, notably competition from the noisy miner (Manorina melanocephala), also may contribute. Conservation actions that enhance the number and size of family groups will contribute towards reversing declines of this species. Despite associated challenges, demographic studies have potential to identify mechanistic processes that underpin population performance; critical knowledge for effective conservation management. [ABSTRACT FROM AUTHOR]

The article presents a study regarding the effects of time since fire on birds in semiarid Eucalyptus shrublands in southeastern Australia. The study used surveys and nonlinear regression model for the probability of occurrence of bird species with time since fire. Results showed that bird species respond to postfire age from different fire events and that the shape of species' fire response was also influenced by the effect of fires on mortality of the species.

Agricultural environments have a critical role in the global conservation of biodiversity, but the persistence of forest and woodland-dependent species in these systems is often limited by insufficient habitat. Modified or semi-natural 'countryside' (matrix) vegetation is used by many species, but its value at the landscape scale is rarely tested. Do such habitats simply provide additional resources for populations sustained by remnant native vegetation in the landscape, or can they enhance populations over and above that sustained by natural vegetation cover? We surveyed woodland-dependent birds in all types of landscape element in 27 farmland mosaics (100 ha each) in south-eastern Australia. Four measures of wooded vegetation cover were quantified: native vegetation only; and combinations of native vegetation plus scattered trees and/or tree plantations. We used an information-theoretic approach to compare the responses of 30 species to each measure of vegetation cover. Woodland birds were well represented in agricultural mosaics (65% of the regional species-pool); however, almost half were recorded only in mosaics with >20% native vegetation cover. The incidence of 23 species was positively related to measures of wooded cover, indicating increased occurrence in mosaics with a greater cover of wooded vegetation. For 12 species, scattered trees and plantations provided supplementary habitat that enhanced their population status at the landscape scale, beyond that sustained by native vegetation cover. While native vegetation has a critical role for conservation in agricultural environments, careful management of wooded countryside elements (such as scattered trees, tree plantations) offers additional benefits to the woodland-dependent avifauna. [ABSTRACT FROM AUTHOR]

Managing fire to achieve hazard reduction while providing for biodiversity conservation is complex in fire-prone regions. This challenge is exacerbated by limited understanding of post-fire changes in habitat and fuel attributes over time-scales commensurate with their development, and a paucity of empirical research integrating the effects of fire on these attributes. We used a 110-year post-fire chronosequence to investigate temporal development in habitat resources used by fauna, and fuels for fire in semi-arid Mallee vegetation, south-eastern Australia. Fire-history mapping previously limited investigation to 35 years post-fire. The patterns of temporal change over 110 years for 13 variables, representing key attributes of habitat and fuel, were explored using nonlinear mixed models and data from 549 sites. Most habitat and fuel attributes exhibited changes in abundance and rate of development over extended periods, emphasizing the importance of documenting post-fire dynamics over long time-frames. Further, developmental patterns were mostly nonlinear, indicating that a shorter temporal perspective (e.g. 20-30 years post-fire) may obscure, or provide an inaccurate understanding of, long-term changes. There were striking differences in the post-fire dynamics of some habitat and fuel attributes. Leaf litter and spinifex grass Triodia scariosa, which function as both habitat and fuel, increased rapidly after fire followed by a plateau or slow decline after 20-30 years. In contrast, live tree stems were not predicted to develop hollows until 40 years, after which time the density of live hollow-bearing stems, an important habitat feature, increased steadily. Synthesis and applications. Fire affects the development and abundance of resources over substantially longer periods than can be examined using fire-mapping based on satellite imagery. Our results demonstrate that post-fire changes in mallee vegetation influence fire hazard and faunal habitat in different ways. Critically, the cover/abundance of most primary fuel sources did not increase substantially beyond around 30 years post-fire; whereas important habitat attributes changed in ways that affect faunal occurrence for over a century. Fire management must explicitly acknowledge the potential for fire to affect fauna and fuel differently, and for these effects to operate over time-frames that may extend well beyond current understanding. [ABSTRACT FROM AUTHOR]

Nestedness in biota as a function of species richness — biota of depauperate assemblages being non-random subsets of richer biotas — has been widely documented in recent years (see Wright et al. 1998, Oecologia 113: 1-20). Ordering sites by richness maximizes nestedness indices; however, ordering by other criteria such as area or isolation may be more ecologically interpretable. We surveyed birds in true fragments (35 in all), and in "reference areas" in large extant forest blocks (30 locations), of the same range of areas (10, 20, 40, 80 ha). The avifauna was divided into "bush birds" — species dependent on forest and woodland, and "open country" species. We looked at nestedness in four data sets: "bush birds" in fragments and reference areas, and "all birds" in fragments and in reference areas. All data sets were significantly nested. Ordering by area in all cases was not significantly less nested than ordering by richness. Ordering by area in fragments was significantly greater than in reference areas, but the differences in standardized nestedness indices were small (<15%). We identified those birds that had distributions among fragments that conformed strongly with area, those that were more randomly distributed and some species that were more likely to occupy the smallest fragments. Among the latter was a hyperaggressive, invasive, colonial native species (noisy miner Manorina melanocephala). A suite of small, insectivorous birds was more likely to strongly conform with expected distributions in relation to area, which was consistent with observations of their vulnerability to the effects of the noisy miner in smaller fragments. [ABSTRACT FROM AUTHOR]

Abstract: Managing fire regimes for conservation of biodiversity is a global challenge. We examined the responses of birds to fire mosaics (4-km diameter landscapes) comprising different compositions of fire age-classes, and used these results to evaluate the relative value of four contemporary strategies for fire management. These were: (1) promoting a diverse range of age-classes; (2) promoting particular age-classes for fire-sensitive species; (3) preventing reserve-scale wildfire; and (4) burning a fixed percentage (e.g. 5%) of the landscape annually. None of the 28 species examined was positively associated with landscapes with extensive recently burned (<10years) vegetation. One species was associated with landscapes with a greater diversity of age-classes while two species, including the endangered Black-eared Miner (Manorina melanotis), were associated with less diverse landscapes. Landscapes with extensive older (>35years since fire) vegetation were favoured by three species; while two species preferred those with extensive mid-age (11–35years since fire) vegetation. Our findings suggest that in semi-arid mallee ecosystems, management that results in large proportions of recently burned vegetation (e.g. by burning 5% of the landscape annually or permitting reserve-scale wildfires), or a high local diversity of age-classes, will negatively affect more bird species than they would aid. Management strategies that promote particular age-classes (i.e. mid-age and older vegetation) are likely to benefit bird species. Species-specific knowledge from a landscape perspective can refine management strategies to assist in defining the characteristics of ‘desirable’ fire mosaics for maintaining biodiversity. [Copyright &y& Elsevier]

Abstract: Tree hollows are a critical, yet potentially limiting habitat resource for many animal species. Fire influences hollow availability, and the associated indirect effects on fauna can threaten the persistence of hollow-dependent species in fire-prone systems. We investigated the influence of two temporal aspects of fire regimes (time-since-fire, inter-fire interval) on hollow occurrence in a semi-arid, fire-prone region in south-eastern Australia. Empirical data on the characteristics of hollow-bearing eucalypt stems and fire-history attributes were compiled for 581 study sites. Mixed models were used to examine the relative influence of time-since-fire and inter-fire interval on hollow occurrence. Time-since-fire and inter-fire interval both affected the probability of hollow occurrence, but in different ways. Time-since-fire influenced the occurrence of hollows in live and dead stems. As time-since-fire increased, so too did the probability of live and dead stems containing hollows. Live stems did not provide hollows before 40years post-fire, while the probability of dead stems containing hollows peaked at 50–60years. Inter-fire interval influenced the availability of hollows in dead stems. Longer inter-fire intervals resulted in an increased density of dead hollow-bearing stems. In this region, hollow-dependent fauna will benefit from increased fire-free periods, both in terms of individual fire events and the intervals between repeated fires. These results highlight the complex way in which fire affects the availability of faunal habitat resources, and the extended time periods over which such influences operate. Understanding the effects of fire regimes on slow-developing habitat resources over long time-frames is imperative for sound ecological fire management. [Copyright &y& Elsevier]