Implications of transformation to irregular silviculture for woodland birds: A stand wise comparison in an English broadleaf woodland

© 2018 Elsevier B.V. Woodland birds in Britain have undergone significant long term declines since the late 1960s, associated in particular with changes in woodland structure in general, and loss of early successional vegetation. Irregular, continuous canopy broadleaf management is a form of selective logging, very recently adopted in UK that produces woodlands with open canopies and substantial mid- and understorey growth. We examined spring and late winter bird densities, estimated using distance sampling, at 310 points in irregular, transitional (that being managed towards irregular), limited intervention, and coppice stands within a large working broad-leaf woodland in lowland southern Britain. Almost all understorey and canopy vegetation measures differed significantly across stand types. Ten of 20 species had highest spring abundance in irregular woodland, five in coppice, three in transitional, and just two in limited intervention. In winter, 5–6 species preferred each of limited intervention, irregular and transitional, while no species preferred coppice. Densities differed little across seasons except in Paridae where abundances increased in late winter during which limited intervention stands were used more by this group. Birds generally occupied similar niche positions and had similar niche breadths across seasons. Compared to under-managed woodlands, irregular silviculture in UK's broadleaf woodlands is likely to enhance habitat quality for woodland birds, including several species of conservation concern e.g. marsh tit Poecile palustris which was twice as abundant in irregular stands as in any other stand type

Comparisons of songbirds on sale across online and physical markets in Indonesia

Unsustainable wildlife trade is a leading threat to biodiversity, not least in Southeast Asia where serious overexploitation of songbirds has precipitated the ‘Asian Songbird Crisis’. While the nature of bird trade in physical markets is fairly well studied, the growing online trade in birds is far less understood, in terms of diversity and traits of birds on offer. Here, online trade, monitored across twelve broad spectrum Indonesian bird-selling Facebook groups over a period of six months in 2022, is compared to published data from physical markets, and from a machine learning web-scrape. Nearly 2,000 individuals of 190 Indonesian species were recorded from Facebook, with 9.5% of species being categorised as Threatened (IUCN 2022), 15.8% protected under Indonesian law, and 17.4% regarded as priority taxa according to the Asian Songbird Trade Specialist Group. These represent similar proportions of species to those from physical market surveys, although physical markets had more individuals of protected species than did Facebook groups. Bird family composition did not correlate between online and physical platforms, with the former dominated by Muscicapidae and the latter by Estrildidae. Controlling for trade volume, online groups had higher species richness than physical markets, although the difference was not significant. Bird ‘communities’ on offer in the individual Facebook groups were both similar to each other, and distinct from those in physical markets, although there was a geographical signature especially in the latter. Results highlight the importance of monitoring online trade as, while there are substantial differences in types of birds sold, it contains a similarly high number of species of conservation concern to physical markets

Spatial and seasonal variation in abundance within an insular grey parrot population

© 2017 John Wiley & Sons Ltd. Populations of Psittacidae are endangered by habitat loss and the international pet market. The grey parrot (Psittacus erithacus) is among the most traded species, yet little is known about densities and their variability in time and space. The population of grey parrots on the island of Príncipe (Gulf of Guinea) was estimated with distance sampling, in both pre- and postbreeding seasons. Abundance was related to a range of habitat features using generalized additive models. Densities averaged 48 ± 3 (SE) individuals km-2 in the prebreeding and 59 ± 4 in the postbreeding season, both extremely high compared to elsewhere in Africa and to other parrot species. Despite a population of 6000-8000 individuals over only 139 km2, parrots were patchily distributed, being unrecorded in ~25% of surveyed areas. Abundance varied seasonally, with densities being significantly higher in secondary compared to primary forest in the post- but not in the prebreeding season. Abundance was most tied to the presence of nest-tree species prior to breeding and to feeding-tree species and lightly sloping ground after breeding. These results highlight the need to preserve a matrix of habitat types to provide resources for parrots across seasons and ensure that surveys recognize seasonality in habitat use as a potential bias

Trapping method and quota observance are pivotal to population stability in a harvested parrot

Wildlife trade is currently regulated mainly in terms of ‘volume’, i.e. the number of individuals taken from the wild or numbers appearing on the market in a given year. To explore the possible effects of other factors such as capture methods, variability in annual harvest, and habitat, we built and validated a demographic model for a closed population of Grey Parrots Psittacus erithacus on Príncipe, and ran 50-year simulations for the population under different harvest scenarios. There was a fine line between capture volumes being robustly sustainable (11% harvested) and dramatically unsustainable (15%). Population trajectories were highly sensitive to changes in adult survivorship, such that the inclusion of even a small number of adults among the harvest had a far greater impact than a similar number of juveniles. High annual variation in capture rate (reflecting poor national management of trade) could make the difference between sustainability and non-sustainability if quotas were set around critical harvest volumes. While these patterns may be common to large traded parrots generally, sufficient habitat and secure nest sites exist on Príncipe to render the effects of habitat loss on the island less important than in most other situations. If trade in parrots is to continue sustainably it will require reliable demographic and harvest data and must eliminate instability in quota observance (exceeded quotas are not compensated by shortfalls in other years) and, especially, the indiscriminate capture of adults

Extreme and complex variation in range-wide abundances across a threatened Neotropical bird community

Aim: Understanding patterns and drivers of variation in abundance across full species ranges is crucial in conservation science, but our knowledge of these forms and pro-cesses is limited, especially in the tropics. This study aims to: (1) identify patterns in variation of abundance across sites; (2) examine congruence of abundance hotspots across species and spatial autocorrelation of abundance within species; and (3) assess the nature and strength of environmental correlates of abundance (topography, habi-tat and human pressure).Location: Twenty- six sites across the full ranges of 14 dry forest bird species in north-ern Peru.Methods: Study sites in this patchy habitat were selected within strata derived from species distribution models, while also ensuring geographic representation. Species abundance data from variable- width transects were compared across sites and across range core versus edge; relationships between abundance and environmental varia-bles were examined using GAMs, and spatial autocorrelation was examined with mul-tivariate Mantel tests.Results: Although most species were recorded at most sites, local abundance varied by one or two orders of magnitude. Several species showed a humped rather than the classic skewed abundance distribution, with abundance not necessarily highest at the centre of species’ ranges. Spatial autocorrelation in species’ local abundance was evi-dent only at distances less than 55 km. Sites of maximum abundance for individual species did not coincide—nine different sites held highest densities of at least one species. Relationships between local abundance and almost all environmental corre-lates were non- linear.Main conclusions: The extreme variation in species abundances and the complexity in their relationships with environmental variables have important implications, both for design of conservation- motivated surveys for which we offer some recommendations, and for the need for multiple reserves to capture high local abundances of key species

The effects of tourist and boat traffic on parrot geophagy in lowland Peru

© 2017 The Association for Tropical Biology and Conservation. Ecotourism generates important revenue in many developing economies, but poorly regulated ecotourism can threaten the long-term viability of key biological resources. We determined the effects of tourism, boat traffic, and natural disturbances on parrot geophagy (soil consumption) across seven riverine claylicks in the lowlands of Madre de Dios, Peru. Claylick use significantly decreased when visitors did not follow good practice guidelines and tourist numbers exceeded the capacity of the observation blinds. Otherwise, tourist presence and natural disturbance did not have a significant effect. However, large macaws, particularly Red-and-green Macaws (Ara chloropterus), avoided visiting claylicks during periods of peak tourist numbers. Where parrots had multiple geophagy sites to choose from, they preferred sites further from tourist groups. The effect of boat disturbance was greatest on a narrow river with infrequent boat events. On a wider river with heavier traffic, boat disturbance had less of an effect and this effect was inversely proportional to the distance of boats from the claylick. Where visitors followed good-practice tourism guidelines, they had a low overall negative effect on parrot geophagy. We recommend that visitors respect the claylick observation guidelines to minimize anthropogenic disturbance on parrots and maintain these sites for the benefit of wildlife and humans alike

Irregular silviculture positively influences multiple bat species in a lowland temperate broadleaf woodland

Changing economics in the 20th century led to losses and fragmentation of semi-natural woodland in Britain and to a reduction in active woodland management with many becoming increasingly neglected, even-aged and with closed canopy. Lack of woodland management is known to contribute to declines in some taxonomic groups, for example birds. However, the response of bats to changes in woodland structure are poorly understood. We compared two measures of bat activity, derived from static acoustic recorders across 120 sample plots in coppice, irregular high forest (uneven-aged, continuous cover) and limited intervention (under-managed, even-aged) management stands, within a large tract of ancient woodland in southern England. Bat species richness was highest in irregular high forest stands, and there were significant differences in occupancy rates for most bat species across stand management types. Coppice recorded low activity of several bat species and irregular high forest showed high occupancy rates, including for Barbastelle Barbastella barbastellus, which is IUCN listed as near threatened. The occupancy rates in stand management types differed for some bat species between mid- and late summer counts, suggesting seasonal variation in habitat use. Within stands, most bat species were associated with opened canopy, lower growing stocks and reduced densities of understorey, and to a lesser extent, with large-girthed trees and presence of deadwood snags. In some cases, species responded to a given habitat variable similarly across the three stand management types, whereas in others, the response differed among stand management types. For example, increased numbers of large-girthed trees benefitted a number of bat species within coppice where these were least common, but not in irregular stands. Irregular silviculture high forest appears to provide many of the structural attributes that positively influence occupancy of several woodland bat species, including Barbastella barbastellus

A new vertebrate for Europe: the discovery of a range-restricted relict viper in the western Italian Alps

We describe Vipera walser, a new viper species from the north-western Italian Alps. Despite an overall morphological resemblance with Vipera berus, the new species is remarkably distinct genetically from both V. berus and other vipers occurring in western Europe and shows closer affinities to species occurring only in the Caucasus. Morphologically, the new species appear to be more similar to V. berus than to its closest relatives occurring in the Caucasus, but can be readily distinguished in most cases by a combination of meristic features as confirmed by discriminant analysis. The extant population shows a very low genetic variability measured with mitochondrial markers, suggesting that the taxon has suffered a serious population reduction/bottleneck in the past. The species is extremely range-restricted (less than 500 km2) and occurs only in two disjunct sites within the high rainfall valleys of the Alps north of Biella. This new species should be classified as globally ‘endangered’ due to its small and fragmented range, and an inferred population decline. The main near-future threats to the species are habitat changes associated with reduced grazing, along with persecution and collecting