We estimated population sizes of parrots in a large (Sooretama/Linhares) and a small (Porto Seguro) lowland Atlantic forest reserve, and examined their habitat associations within the reserves, and their use of forest fragments. In Sooretama, most species had estimated populations between 1000 and 20,000 individuals, but in the smaller reserve population densities were low and all but one species had population estimates <500. Two Amazons, including the`Endangered' Amazona rhodocorytha, were strongly linked to primary forests whereas the`Vulnerable' Pyrrhura cruentata was associated with non-pristine forest. There was considerable movement of parrots between the Sooretama reserve and the surrounding country with Amazona species tending to¯y into the reserve during the mornings, and the macaw Propyrrhura maracana¯ying out. Other species, notably P. cruentata and P. leucotis, were never recorded away from the reserve. Most parrot populations in the region are likely to be small, and the substantial populations around Sooretama make this reserve a parrot stronghold. It is crucial that ®re, illegal logging and parrot capture are adequately controlled within Sooretama, and there is a strong argument for extending conservation management eorts to areas immediately outside the reserve. #

Summary1. Godwits of the Limosa l. limosa race have declined throughout northern Europe because of changing agricultural practices. The relict UK population is now mostly confined to two reserves within flood-defence structures, and numbers have declined at one of these. This study diagnosed the cause of this decline and evaluated options for remedial management. 2. Re-nesting models showed that productivity varied among sites and years in relation to flooding patterns. Floods caused breeding failure by forcing godwits to nest on nearby arable fields where nest and chick survival rates were low. 3. A population model showed that flood-dependent variations in productivity were sufficient to explain the contrasting population trends at the two sites. 4. The relative merits of various options for mitigating the effect of floods on godwits were investigated using a combination of hydrological, re-nesting and population models. 5. Models assuming a closed population resulted in numbers of godwit pairs at one site, the Ouse Washes in eastern England, declining and becoming extirpated within 30 years under current conditions. Some management options improved productivity, population growth and persistence likelihood, but the chances of extirpation were still high and conservation targets would not be met. 6.Models assuming an open population showed that target populations would only be achieved within 30 years if all of the available flood mitigation options were combined. However, habitat creation outside the Ouse Washes resulted in comparable productivity and population growth at a fraction of the cost. 7. Synthesis and applications. Provision of compensatory habitat is likely to be a more parsimonious means of conserving black-tailed godwits at the Ouse Washes than flood mitigation. However, reliance on the creation of new habitat is a more risky strategy as the godwits may continue to use traditional arable fields in favour of grassland alternatives, and because their productivity on created grassland is unknown.

No abstract

Marsden, S. J. and Whiffin, M. 2003. The relationship between population density, habitat position and habitat breadth within a neotropical forest bird community. -Ecography 26: 385-392.We examined the relationship between local abundance, habitat position and habitat breadth across bird species in a large Atlantic forest reserve in Brazil. This appears to be the first such study for any rainforest taxon. Habitat position for a species was its mean foraging height, along with the mean scores on three principal habitat axes for census stations at which it was recorded. Habitat breadth was the standard deviation of recorded foraging heights and the standard deviations of ''positive'' station scores on the habitat axes. We also examined differences in habitat position and breadth between endemic and wide-ranging taxa and amongst dietary groups. Amongst 31 species for which density estimation was possible, there were no correlations between local abundance and breadth of habitat use on any of the habitat axes. Breadth of habitat used did not vary with degree of endemism, but herbivores used a greater breadth of habitats on the axis describing canopy closure than did omnivores. Habitat position did not vary with endemic status, but herbivores preferred higher-biomass habitats than faunivores, and higher foraging heights than either faunivores or omnivores. Local abundance was linked weakly to habitat position with commoner species tending to forage in the lower strata of opencanopied areas. The 31 most commonly recorded species tended to occupy ''middlerange'' habitat positions, while 28 rarer species occupied habitats toward one or other end of the vegetation axes. These results suggest an association between the local abundance of a species and its habitat position, and especially its preference for common or mid-range habitats, rather than with its ability to utilise a wide range of habitats.

It is crucial for biodiversity conservation that protected areas are large and effective enough to support viable populations of their original species. We used a point count distance sampling method to estimate population sizes of a range of bird species in three Atlantic forest protected areas of size 5600, 22,500, and 46,050 ha. Population sizes were generally related to reserve area, although in the mid-sized reserve, there were many rare species reflecting a high degree of habitat heterogeneity. The proportions of forest species having estimated populations >500 ranged from 55% of 210 species in the largest reserve to just 25% of 140 species in the smallest reserve. All forest species in the largest reserves had expected populations >100, but in the small reserve, 28% (38 species) had populations <100 individuals. Atlantic forest endemics were no more or less likely to have small populations than widespread species. There are 79 reserves (>1000 ha) in the Atlantic forest lowlands. However, all but three reserves in the north of the region (Espı´rito Santo and states north) are smaller than 10,000 ha, and we predict serious levels of local extinction from these reserves. Habitat heterogeneity within reserves may promote species richness within them, but it may also be important in determining species loss over time by suppressing populations of individual species. We suggest that most reserves in the region are so small that homogeneity in the habitat/altitude within them is beneficial for maintenance of their (comparatively small) original species compliment. A lack of protection in the north, continued detrimental human activity inside reserves, and our poor knowledge of how well the reserve system protects individual taxa, are crucial considerations in biodiversity management in the region.