Changes in avian species composition following surface mining and reclamation along a riparian forest corridor in southern Indiana

Data on the response of bird communities to surface mining and habitat modification are limited, with virtually no data examining the effects of mining on bird communities in and along riparian forest corridors. Bird community composition was examined using line transects from 1994 to 2000 at eight sites within and along a riparian forest corridor in southwestern Indiana that was impacted by an adjacent surface mining operation. Three habitats were sampled: closed canopy, riparian forest with no open water; fragmented canopy, riparian forest with flood plain oxbows; and reclaimed mined land with constructed ponds. Despite shifts in species composition, overall bird species richness, measured as the mean number of bird species recorded/transect route, did not differ among habitats and remained unchanged across years. More species were recorded solely on mined land than in either closed forest or forested oxbow habitats. Mined land provided stopover habitat for shorebirds and waterfowl not recorded in other habitats, and supported an assemblage of grassland-associated bird species weakly represented in the area prior to mining. A variety of wood warblers and other migrants were recorded in the forest corridor throughout the survey period, suggesting that, although surface mining reduced the width of the forest corridor, the corridor was still important habitat for movement of forest-dependent birds and non-resident bird species in migration. We suggest that surface mining and reclamation practices can be implemented near riparian forest and still provide for a diverse assemblage of bird species. These data indicate that even narrow (0.4 km wide) riparian corridors are potentially valuable in a landscape context as stopover habitats and routes of dispersal and movement of forest-dependent and migratory bird species.     

Habitat Use and Body Mass Regulation among Warblers in the Sahel Region during the Non-Breeding Season

Migratory birds face significant challenges across their annual cycle, including occupying an appropriate non-breeding home range with sufficient foraging resources. This can affect demographic processes such as over-winter survival, migration mortality and subsequent breeding success. In the Sahel region of Africa, where millions of migratory songbirds attempt to survive the winter, some species of insectivorous warblers occupy both wetland and dry-scrubland habitats, whereas other species are wetland or dry-scrubland specialists. In this study we examine evidence for strategic regulation of body reserves and competition-driven habitat selection, by comparing invertebrate prey activity-density, warbler body size and extent of fat and pectoral muscle deposits, in each habitat type during the non-breeding season. Invertebrate activity-density was substantially higher in wetland habitats than in dry-scrubland. Eurasian reed warblers Acrocephalus scirpaceus occupying wetland habitats maintained lower body reserves than conspecifics occupying dry-scrub habitats, consistent with buffering of reserves against starvation in food-poor habitat. A similar, but smaller, difference in body reserves between wet and dry habitat was found among subalpine warblers Sylvia cantillans but not in chiffchaffs Phylloscopus collybita inhabiting dry-scrub and scrub fringing wetlands. Body reserves were relatively low among habitat specialist species; resident African reed warbler A. baeticatus and migratory sedge warbler A. schoenobaenus exclusively occupying wetland habitats, and Western olivaceous warblers Iduna opaca exclusively occupying dry habitats. These results suggest that specialists in preferred habitats and generalists occupying prey-rich habitats can reduce body reserves, whereas generalists occupying prey-poor habitats carry an increased level of body reserves as a strategic buffer against starvation.     

Agricultural Intensification Exacerbates Spillover Effects on Soil Biogeochemistry in Adjacent Forest Remnants

Land-use intensification is a central element in proposed strategies to address global food security. One rationale for accepting the negative consequences of land-use intensification for farmland biodiversity is that it could ‘spare’ further expansion of agriculture into remaining natural habitats. However, in many regions of the world the only natural habitats that can be spared are fragments within landscapes dominated by agriculture. Therefore, land-sparing arguments hinge on land-use intensification having low spillover effects into adjacent protected areas, otherwise net conservation gains will diminish with increasing intensification. We test, for the first time, whether the degree of spillover from farmland into adjacent natural habitats scales in magnitude with increasing land-use intensity. We identified a continuous land-use intensity gradient across pastoral farming systems in New Zealand (based on 13 components of farmer input and soil biogeochemistry variables), and measured cumulative off-site spillover effects of fertilisers and livestock on soil biogeochemistry in 21 adjacent forest remnants. Ten of 11 measured soil properties differed significantly between remnants and intact-forest reference sites, for both fenced and unfenced remnants, at both edge and interior. For seven variables, the magnitude of effects scaled significantly with magnitude of surrounding land-use intensity, through complex interactions with fencing and edge effects. In particular, total C, total N, δ¹⁵N, total P and heavy-metal contaminants of phosphate fertilizers (Cd and U) increased significantly within remnants in response to increasing land-use intensity, and these effects were exacerbated in unfenced relative to fenced remnants. This suggests movement of livestock into surrounding natural habitats is a significant component of agricultural spillover, but pervasive changes in soil biogeochemistry still occur through nutrient spillover channels alone, even in fenced remnants set aside for conservation. These results have important implications for the viability of land-sparing as a strategy for balancing landscape-level conservation and production goals in agricultural landscapes.     

Local habitat complexity correlates with song complexity in a vocally elaborate honeyeater

Song complexity is an important behavioural trait in songbirds, subject to sexual selection. Elucidation of intraspecific variation in song complexity can provide insights into its evolution. In this study, we investigated song complexity variation in tūī (Prosthemadera novaeseelandiae), a vocally complex songbird endemic to New Zealand. At two separate nature reserves, we recorded male songs in two habitat types: forest remnants with high habitat complexity, and open habitats with lower habitat complexity. Analyses indicated strong evidence that song complexity was higher in forest habitats. Possible explanations for this divergence include: (i) competition between individuals results in higher quality, dominant males with more complex songs occupying forest habitats, and less competitive males occupying open habitat zones; (ii) forest habitats provide more abundant resources therefore higher tūī density, resulting in more complex songs; and (iii) a higher abundance of food in dense forest habitats may reduce nutritional stress during development resulting in full development of song nuclei. However, these hypotheses on the drivers of habitat effects on tūī song complexity remain to be tested.     

Seasonal variation in avian diversity and tolerance by migratory forest specialists of the patch-isolation gradient across a fragmented forest system

Forest-habitat loss and fragmentation reduce connectivity, presenting dispersal challenges for many forest-dependent species with deleterious effects on community structure and diversity. It is expected that avian forest specialists are vulnerable to fragmentation, yet seasonal migrants may be more resilient to isolation effects than sedentary specialists. We surveyed bird communities in 138 habitat patches of the critically endangered Indian Ocean Coastal Belt, South Africa, across a range of isolation distances from mainland forests during the breeding and non-breeding seasons. We quantified taxonomic and functional diversity per patch based on species’ traits and performed 26 generalized linear mixed-effects models on the effects of isolation and the amount of habitat in the surrounding matrix on avian trait-diversity measurements. We compared diversity measures between seasons for evidence of resilience to isolation effects for migrants and compared linear regressions of isolation-distance effects to segmented regressions at various isolation distances to explore dispersal limits of sedentary forest specialists. All avian diversity measures were higher during the breeding season. The amount of surrounding habitat was a positive driver of all diversity measures. Isolation-distance effects had the most negative effect during the breeding season, and on sedentary forest specialists, which were unable to disperse across isolation distances > 500 m. Sedentary forest specialists are a conservation priority given (a) their value in perpetuating ecosystem services and (b) their vulnerability to isolation effects. Migratory forest specialists exhibited resilience to the isolation effect during non-breeding; thus, certain specialized niches may be occupied given the vagility of migratory forest specialists.     

A global model of the response of tropical and sub-tropical forest biodiversity to anthropogenic pressures

Habitat loss and degradation, driven largely by agricultural expansion and intensification, present the greatest immediate threat to biodiversity. Tropical forests harbour among the highest levels of terrestrial species diversity and are likely to experience rapid land-use change in the coming decades. Synthetic analyses of observed responses of species are useful for quantifying how land use affects biodiversity and for predicting outcomes under land-use scenarios. Previous applications of this approach have typically focused on individual taxonomic groups, analysing the average response of the whole community to changes in land use. Here, we incorporate quantitative remotely sensed data about habitats in, to our knowledge, the first worldwide synthetic analysis of how individual species in four major taxonomic groups—invertebrates, ‘herptiles’ (reptiles and amphibians), mammals and birds—respond to multiple human pressures in tropical and sub-tropical forests. We show significant independent impacts of land use, human vegetation offtake, forest cover and human population density on both occurrence and abundance of species, highlighting the value of analysing multiple explanatory variables simultaneously. Responses differ among the four groups considered, and—within birds and mammals—between habitat specialists and habitat generalists and between narrow-ranged and wide-ranged species.     

Non-breeding season habitat quality mediates the strength of density-dependence for a migratory bird

Our understanding of when natural populations are regulated during their annual cycle is limited, particularly for migratory species. This information is needed for parametrizing models that can inform management and conservation. Here, we use 14 years of data on colour-marked birds to investigate how conspecific density and habitat quality during the tropical non-breeding period interact to affect body condition and apparent annual survival of a long-distance migratory songbird, the American redstart (Setophaga ruticilla). Body condition and survival of birds in high-quality mangrove habitat declined as density increased. By contrast, body condition improved and survival did not vary as density increased in adjacent, lower quality scrub habitat, although mean condition and survival were almost always lower than in mangrove. High rainfall enhanced body condition in scrub but not in mangrove, suggesting factors such as food availability outweighed consequences of crowding in lower quality habitat. Thus, survival of overwintering redstarts in mangrove habitat, disproportionately males, appears to be regulated by a crowding mechanism based on density-dependent resource competition. Survival of individuals in scrub, mostly females, appears to be limited by density-independent environmental factors but not regulated by crowding. The contrasting effects of density and food limitation on individuals overwintering in adjacent habitats illustrate the complexity of processes operating during the non-breeding period for migratory animals, and emphasize the need for long-term studies of animals in multiple habitats and throughout their annual cycles.     

High Bird Species Diversity in Structurally Heterogeneous Farmland in Western Kenya

Tropical ecosystems are globally important for bird diversity. In many tropical regions, land‐use intensification has caused conversion of natural forests into human‐modified habitats, such as secondary forests and heterogeneous agricultural landscapes. Despite previous research, the distribution of bird communities in these forest‐farmland mosaics is not well understood. To achieve a comprehensive understanding of bird diversity and community turnover in a human‐modified Kenyan landscape, we recorded bird communities at 20 sites covering the complete habitat gradient from forest (near natural forest, secondary forest) to farmland (subsistence farmland, sugarcane plantation) using point counts and distance sampling. Bird density and species richness were on average higher in farmland than in forest habitats. Within forest and farmland, bird density and species richness increased with vegetation structural diversity, i.e., were higher in near natural than in secondary forest and in subsistence farmland than in sugarcane plantations. Bird communities in forest and farmland habitats were very distinct and very few forest specialists occurred in farmland habitats. Moreover, insectivorous bird species declined in farmland habitats whereas carnivores and herbivores increased. Our study confirms that tropical farmlands can hardly accommodate forest specialist species. Contrary to most previous studies, our findings show that structurally rich tropical farmlands hold a surprisingly rich and distinct bird community that is threatened by conversion of subsistence farmland into sugarcane plantations. We conclude that conservation strategies in the tropics must go beyond rain forest protection and should integrate structurally heterogeneous agroecosystems into conservation plans that aim at maintaining the diverse bird communities of tropical forest‐farmland mosaics.     

How may agricultural matrix intensification affect understory birds in an Atlantic Forest landscape? A qualitative model on stochasticity and immigration

Understanding how different approaches of matrix management affect organisms that inhabit natural patches is crucial for biological conservation. Considering that great part of the tropical area is composed of agricultural land and that most of the land use is either intensified or on the verge to be, a relevant question is: how may agricultural intensification of the landscape matrix affect the population dynamics of understory birds? This paper describes a qualitative model based on the Qualitative Process Theory and implemented in Garp3 to provide answers to this question. We built a model using four species of endemic passerine birds in order to evaluate the case in an Atlantic Forest area, a biodiversity hotspot. The model describes a landscape composed of an extinction-resistant source patch and one target forest patch where stochastic events occur. If permeability of the matrix exceeds a given species-specific threshold, propagules coming from the source reach the target patch. Agriculture intensification affects the matrix spatial structure and reduces permeability to forest birds, thus reduces rescue effect. Additionally, we assume that some species may use the matrix as a supplementary habitat for feeding and that matrix management may affect the resource base for those species. Simulation results suggest that, if agriculture intensification continues to threat the Atlantic Forest biome, populations of sensitive species (Xiphorhynchus fuscus and Sclerurus scansor) that exist in the small forest patches (which is true for most forest remnants) will be highly susceptible to local extinctions and without further re-colonization.     

Influence of habitat complexity and landscape configuration on pollination and seed-dispersal interactions of wild cherry trees

Land-use intensification is a major cause for the decline in species diversity in human-modified landscapes. The loss of functionally important species can reduce a variety of ecosystem functions, such as pollination and seed dispersal, but the intricate relationships between land-use intensity, biodiversity and ecosystem functioning are still contentious. Along a gradient from forest to intensively used farmland, we quantified bee species richness, visitation rates of bees and pollination success of wild cherry trees (Prunus avium). We analysed the effects of structural habitat diversity at a local scale and of the proportion of suitable habitat around each tree at a landscape scale. We compared these findings with those from previous studies of seed-dispersing birds and mammals in the same model system and along the same land-use gradient. Bee species richness and visitation rates were found to be highest in structurally simple habitats, whereas bird species richness—but not their visitation rates—were highest in structurally complex habitats. Mammal visitation rates were only influenced at the landscape scale. These results show that different functional groups of animals respond idiosyncratically to gradients in habitat and landscape structure. Despite strong effects on bees and birds, pollination success and bird seed removal did not differ along the land-use gradient at both spatial scales. These results suggest that mobile organisms, such as bees and birds, move over long distances in intensively used landscapes and thereby buffer pollination and seed-dispersal interactions. We conclude that measures of species richness and interaction frequencies are not sufficient on their own to understand the ultimate consequences of land-use intensification on ecosystem functioning.     

Birds,Cattle, and Bracken Ferns: Bird Community Responses to a Neotropical Landscape Shaped by Cattle Grazing Activities

Large areas of tropical moist forests have been converted to cattle pastures, generating complex landscapes where different habitats are represented by small patches with an uneven spatial distribution. Here, we describe how bird communities respond to the different elements present in a livestock landscape that was originally dominated by tropical moist forest. We surveyed six habitats: open pastures, pastures with shrubs, early‐ and middle‐secondary forests, mature forest, and pastures invaded by bracken ferns (Pteridium aquilinum). Bird diversity was high in secondary and mature forests, and low in fern‐invaded sites and open pastures. Fern‐dominated sites had the lowest bird species richness, and trophic guild diversity of all habitats. Habitat structure affected both bird species richness and densities in similar ways. Tree species richness was the habitat attribute that had a bigger positive effect on bird species richness. Bird community structure varied among sampled habitats, separating habitats in two major groups (forests and pastures). Our data indicate that bracken fern‐invaded pastures were the worst habitat condition for avian communities. To increase bird diversity, we recommend to eliminate or manage bracken fern and to increase shrub and tree cover in open pastures to provide food resources and shelter for birds. Finally, we encourage the maintenance of secondary and mature forest remnants as a strategy to conserve resident birds within a landscape dominated by livestock activities.     

Competition and Habitat Quality Influence Age and Sex Distribution in Wintering Rusty Blackbirds

Bird habitat quality is often inferred from species abundance measures during the breeding and non-breeding season and used for conservation management decisions. However, during the non-breeding season age and sex classes often occupy different habitats which suggest a need for more habitat-specific data. Rusty Blackbird (Euphagus carolinus) is a forested wetland specialist wintering in bottomland hardwood forests in the south-eastern U. S. and belongs to the most steeply declining songbirds in the U.S. Little information is available to support priority birds such as the Rusty Blackbird wintering in this threatened habitat. We assessed age and sex distribution and body condition of Rusty Blackbirds among the three major habitats used by this species in the Lower Mississippi Alluvial Valley and also measured food availability. Overall, pecan groves had the highest biomass mainly driven by the amount of nuts. Invertebrate biomass was highest in forests but contributed only a small percentage to overall biomass. Age and sex classes were unevenly distributed among habitats with adult males primarily occupying pecan groves containing the highest nut biomass, females being found in forests which had the lowest nut biomass and young males primarily staying in forest fragments along creeks which had intermediate nut biomass. Males were in better body condition than females and were in slightly better condition in pecan groves. The results suggest that adult males occupy the highest quality habitat and may competitively exclude the other age and sex classes.     

Identifying core habitat before it’s too late: the case of Bombina variegata,an internationally endangered amphibian

Impending land-use change, including agricultural intensification, is increasingly threatening biodiversity in traditional rural landscapes. To ensure the persistence of species that are vulnerable to land-use change it is necessary to identify and protect high quality habitat before species start to decline. Given that many potentially vulnerable species are still widespread in traditional rural landscapes, it is difficult to identify particularly important locations for such species. Presence–absence data on a given species may have limited application in such cases. As an alternative to presence–absence data, we investigated the influence of environmental variables on the physiological body condition of Bombina variegata (yellow-bellied toad) in a traditional rural landscape in Transylvania, Romania. The species is internationally endangered but remains common throughout our study area. Based on body condition measurements of 550 toads from 60 ponds, we found that toads in forest ponds had significantly better body condition than those in pasture ponds, indicating that forest landscapes provided particularly high quality habitat. We suggest that measures such as body condition—in addition to distribution data—could have considerable application in identifying high quality habitat for other species that are still widespread in traditional landscapes, but have declined in modernised, but otherwise similar landscapes.     

Experimental evidence for extreme dispersal limitation in tropical forest birds

Movements of organisms between habitat remnants can affect metapopulation structure, community assembly dynamics, gene flow and conservation strategy. In the tropical landscapes that support the majority of global biodiversity and where forest fragmentation is accelerating, there is particular urgency to understand how dispersal across habitats mediates the demography, distribution and differentiation of organisms. By employing unique dispersal challenge experiments coupled with exhaustive inventories of birds in a Panamanian lacustrine archipelago, we show that the ability to fly even short distances (< 100 m) between habitat fragments varies dramatically and consistently among species of forest birds, and that this variation correlates strongly with species' extinction histories and current distributions across the archipelago. This extreme variation in flight capability indicates that species' persistence in isolated forest remnants will be differentially mediated by their respective dispersal abilities, and that corridors connecting such fragments will be essential for the maintenance of avian diversity in fragmented tropical landscapes.     

The Effect of Local and Landscape-Level Characteristics on the Abundance of Forest Birds in Early-Successional Habitats during the Post-Fledging Season in Western Massachusetts

Many species of mature forest-nesting birds (“forest birds”) undergo a pronounced shift in habitat use during the post-fledging period and move from their forest nesting sites into areas of early-successional vegetation. Mortality is high during this period, thus understanding the resource requirements of post-fledging birds has implications for conservation. Efforts to identify predictors of abundance of forest birds in patches of early-successional habitats have so far been equivocal, yet these previous studies have primarily focused on contiguously forested landscapes and the potential for landscape-scale influences in more fragmented and modified landscapes is largely unknown. Landscape composition can have a strong influence on the abundance and productivity of forest birds during the nesting period, and could therefore affect the number of forest birds in the landscape available to colonize early-successional habitats during the post-fledging period. Therefore, the inclusion of landscape characteristics should increase the explanatory power of models of forest bird abundance in early-successional habitat patches during the post-fledging period. We examined forest bird abundance and body condition in relation to landscape and habitat characteristics of 15 early-successional sites during the post-fledging season in Massachusetts. The abundance of forest birds was influenced by within-patch habitat characteristics, however the explanatory power of these models was significantly increased by the inclusion of landscape fragmentation and the abundance of forest birds in adjacent forest during the nesting period for some species and age groups. Our findings show that including factors beyond the patch scale can explain additional variation in the abundance of forest birds in early-successional habitats during the post-fledging period. We conclude that landscape composition should be considered when siting early-successional habitat to maximize its benefit to forest birds during the post-fledging period, and should also be included in future investigations of post-fledging habitat use by forest birds.     

Shifts from native to invasive small mammals across gradients from tropical forest to urban habitat in Borneo

Urbanization has paved the way for the spread of commensal rodents at global scale. However, it is largely unknown how these species use tropical anthropogenic landscapes originally covered with forests and inhabited by diverse small mammal assemblages. We surveyed non-flying small mammals in various urban and suburban habitat types and adjacent forest in the tropical town of Kota Kinabalu in Borneo. We used occupancy and polynomial regression models to determine variation in species occurrences along gradients of land-use intensity. Müller’s sundamys (Sundamys muelleri) was the only native small mammal species found in urban and suburban landscapes with a continuous decrease in occurrence probability from forests to urban habitats. The invasive Asian black rat (Rattus rattus species complex) and the invasive Asian house shrew (Suncus murinus) had the highest occurrence probabilities in habitats of intermediate land-use intensity, but Asian black rats are also likely to occasionally invade forested habitats and occupied urban habitats in sympatry with the Norway rat (Rattus norvegicus). In urban and suburban habitats, fallow land possibly favoured the occurrence of S. muelleri and S. murinus. Other native small mammal species (Muridae, Sciuridae, Tupaiidae) were found only in forested areas. Our study shows that native small mammals found in forest are largely replaced by invasive species in urban and suburban habitats. Due to their occurrence in habitats of various land use intensities, S. muelleri and R. rattus comprise central links between forest wildlife and urban species, an association that is important to consider in studies of parasite and disease transmission dynamics.     

Asymmetric carabid beetle spillover between calcareous grasslands and coniferous forests

Central European calcareous grasslands are considered biodiversity hotspots, but are severely threatened by the change in land-use and by habitat fragmentation. Coniferous forests are typical adjacent habitats to calcareous grasslands, as abandoned calcareous grasslands are often afforested or develop into coniferous forests by succession. To investigate spillover between calcareous grasslands and coniferous forests, a total of 144 pitfall traps for carabid beetles were placed at three different distances (1, 5, 20 m) from the edge in both habitats at eight locations from April to late August. We found that both habitats had a distinct species assemblage and a decrease in spillover with increasing distance from the habitat edge into the adjacent habitat. Calcareous grasslands were more affected by spillover from the adjacent coniferous forests than vice versa because more forest specialists penetrated into calcareous grasslands than grassland specialists penetrated into coniferous forests. We conclude that spillover into small and isolated habitats can severely change species assemblages, which has to be considered in conservation measures. The protection of large sites with small edge-interior ratios can reduce negative effects on species assemblages in endangered calcareous grasslands.     

Carry-Over Effects of Nonbreeding Habitat on Start-to-Finish Spring Migration Performance of a Songbird

For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina). We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration) obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI) as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI) would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration distances were associated with the wettest areas (the highest quality habitats) of the Wood Thrush non-breeding range. This supports the theory that high-quality habitats offset the costs of farther migration, resulting in a leap-frog migration pattern.     

How resilient are Andean montane forest bird communities to habitat degradation?

The threatened forest habitats of the tropical Andes are reportedly being modified and destroyed 30% faster than their lowland tropical counterparts, but impacts on the hyper-diverse resident avifauna have received little systematic study. We present a baseline analysis of the effects of habitat modification on birds in a lower montane forest landscape in Ecuador, comparing avian community composition in landscape elements subjected to different levels of human modification: primary forest, secondary forest, edge habitat and agricultural land. We use data from a point count survey of 300 counts at 150 sites to test whether community composition and density of birds with different reported habitat preferences and foraging strategies change among landscape elements. Species richness and diversity were lowest in agricultural land, but on some measures, equally low in primary forest. Richness and diversity peaked in secondary forest and edge habitat, but ordination and density analysis revealed clear differences in their species composition. While secondary forest contained mostly forest-preferring species, edge habitat harboured a mix of forest and open-land birds. There was a clearly structured gradient in species composition across landscape elements, with densities of habitat specialists, foraging guilds and families varying considerably from primary forest to agricultural land. Agricultural land was characterised by an assemblage of widespread, abundant species very different from that in core forest habitats. As such, while the majority of montane forest birds appear resilient to a certain level of habitat modification, they cannot persist, and are displaced, where forest has been cleared outright. We argue that, for Andean montane forests, preservation of mature secondary forest offers flexibility in supplementing preserved primary forest areas to provide sufficient habitat for the persistence of this incredibly diverse but severely threatened bird community.     

Old rural parks support higher biodiversity than forest remnants

One of the main challenges in biodiversity conservation is to curb a further degradation and loss of high-quality habitats. In agricultural matrix landscapes, the detection of alternative habitats for habitat specialists may be a solution. Historic old parks or landscape gardens around manor houses and castles are cultural heritage of nobles, but their value in harbouring biodiversity is poorly acknowledged. Therefore we evaluated the potential of old rural parks to serve as a habitat for nemoral forest species. We recorded stand structure and the presence of forest biodiversity indicators in 74 closed-canopy stands of historic parks and compared them with 93 neighbouring mature forest remnants on ancient forest land. We estimated the importance of stand structure in relation to habitat type on biodiversity indicators. Finally we suggest single-value indicator-complexes for the cost-efficient assessment of the conservation value of forests and forest-like habitats. Park stands outclassed reference forests in several individual structural characteristics, and in combined indicators of habitat quality and biodiversity. Forests had higher estimates for the combined indicator of dead wood, but large-diameter dead wood types were more abundant in parks. Woodpeckers, several old-growth indicator epiphytes and forest herbs had successfully become established in planted forest-like park fragments. Old rural parks resemble high-conservation-value forests more than the best preserved contemporary forest remnants. After the century needed to overcome immigration delay, old parks do provide a refugium for temperate deciduous forest species. Consequently, biodiversity-targeted management should retain and enhance old-growth attributes in forests and on the peripheries of parks: e.g. preserving old trees to provide service for epiphytes, hollow trees and an understorey mosaic for birds and bats; dead wood elements for saproxylic insects and fungi; limited mowing frequency and increased cutting height for forest herbs. Forestry should enhance the recovery of mixed deciduous stands and avoid conifer plantations.