scholarly journals Birds associated with treefall gaps in a lowland forest in southwestern Brazilian Amazonia

2021 ◽  
Vol 51 (1) ◽  
pp. 42-51
Author(s):  
Jônatas LIMA ◽  
Edson GUILHERME
Keyword(s):  
Forest Canopy ◽  
Bird Species ◽  
Fragmented Landscape ◽  
Amazon Forest ◽  
Lowland Forest ◽  
Brazilian Amazonia ◽  
Vegetation Height ◽  
Treefall Gaps ◽  
Survival And Reproduction ◽  
Degree Of Association

ABSTRACT Natural communities are dynamic systems in time and space. The spatial distribution of plants and animals tends to coincide with the availability of resources needed for the survival and reproduction of each species. Natural treefall gaps offer a number of resources that influence the distribution of birds within the forest. We compared the understory bird assemblages of natural treefall gaps (15 sampling points) with those found in the adjacent forest (15 points) in the Humaitá Forest Reserve in southwestern Brazilian Amazonia. We used mist-nets to sample birds and obtained 700 captures of 105 species. Species richness, number of individuals, and species composition were all similar between gaps and forest, although six species presented some degree of association with the gaps, and nine with the forest. Nectarivores preferred gaps significantly over forest, whereas insectivores and frugivores were distributed equally between gaps and forest. Vegetation height and density differed between gaps and forest, and influenced the distribution of bird species in the two environments. Fruit availability was positively correlated with frugivore abundance in gaps. Overall, 33.3% of the birds associated with the treefall gaps are from lower forest canopy, while the others are understory species. We showed that the use of natural gaps by birds in a fragmented landscape of the Amazon forest contributes to the environmental heterogeneity and succession dynamics following natural events of habitat disturbance.

scholarly journals Prey, management and landscape requirements of an endangered population of the Woodlark Lullula arborea in Southwest Germany

2021 ◽  
Author(s):  
Verena Rösch ◽  
Pascal Aloisio ◽  
Martin H. Entling
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Ground Cover ◽  
Main Food ◽  
Vegetation Height ◽  
Endangered Population ◽  
Rhine Valley ◽  
Territory Selection ◽  
Main Food Source ◽  
Upper Rhine

AbstractVineyards can be valuable habitats for biodiversity conservation. For example, in Rhineland-Palatinate (Germany) over a third of the state’s critically endangered Woodlark (Lullula arborea) population breeds in vineyards along the western margin of the Upper Rhine Valley. We here aim to elucidate how local ground cover management, food availability and the proximity to settlements affect territory selection by this bird species in the region. As climate, site conditions and management differ greatly from more continental or Mediterranean wine-growing areas, conditions for Woodlark conservation may differ as well.We compared 26 Woodlark territories in vineyards with 26 nearby reference areas from which Woodlarks were absent. We recorded vineyard ground cover in the inter-rows (% cover) as well as vegetation height and composition (forbs vs. grasses). Arthropods were sampled using pitfall traps, since they are the main food resource of Woodlarks during the breeding season. In addition, the distance to built-up areas was measured. The vegetation in Woodlark territories was shorter (mean 14.2 vs. 19.6 cm) and more dominated by forbs (39% vs. 27% cover) than in absence areas. The vegetation cover in the inter-rows had no effect on Woodlark territory presence or absence. Woodlarks also favoured areas with a higher abundance of arthropods (mean abundance 69.1 vs. 57.5) and a greater distance to built-up areas (mean distance 554 vs. 373 m). We conclude that to promote the Woodlark in wine-growing areas, short, forb-rich swards should be created, facilitating arthropod detectability. This is likely to require low levels of nitrogen fertilization since fertilizers favour tall-growing grasses that outcompete forbs. Pesticide applications should be kept at a minimum to enhance arthropods as the main food source for Woodlarks and their chicks. In addition, the expansion of settlements into breeding areas of Woodlarks should be avoided.

The consequences of selective logging for Bornean lowland forest birds

1992 ◽  
Vol 335 (1275) ◽  
pp. 443-457 ◽  
Keyword(s):  
Population Dynamics ◽  
Bird Species ◽  
Selective Logging ◽  
Forest Birds ◽  
Primary Forest ◽  
Bird Conservation ◽  
Lowland Forest ◽  
Dipterocarp Forest ◽  
Logged Forest ◽  
Lowland Dipterocarp Forest

In lowland dipterocarp forest in Sabah, Malaysia, most primary forest bird species were present in areas selectively logged eight years previously. However, certain taxa, notably flycatchers, woodpeckers, trogons and wren-babblers, became comparatively rare. In contrast, nectarivorous and opportunistic frugivorous species were significantly more abundant. Few species appeared to change foraging height, but netting rates suggest that the activity of some species had increased, or that some birds ranged over larger areas after logging. Although there is still much to be learned about the survival of birds in logged forest, large areas of this habitat are important for bird conservation. However, the susceptibility of logged forest to fire, and our present incomplete understanding of bird behaviour and population dynamics in logged forests mean that they should not be considered by conservationists as alternatives to reserves of primary forest.

scholarly journals Long-Term Impacts of Selective Logging on Amazon Forest Dynamics from Multi-Temporal Airborne LiDAR

2019 ◽  
Vol 11 (6) ◽  
pp. 709 ◽  
Author(s):  
Ekena Rangel Pinagé ◽  
Michael Keller ◽  
Paul Duffy ◽  
Marcos Longo ◽  
Maiza dos-Santos ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Forest Canopy ◽  
Binary Classification ◽  
Forest Degradation ◽  
Selective Logging ◽  
Ecological Impacts ◽  
Airborne Lidar ◽  
Classification Model ◽  
Amazon Forest ◽  
Gap Formation

Forest degradation is common in tropical landscapes, but estimates of the extent and duration of degradation impacts are highly uncertain. In particular, selective logging is a form of forest degradation that alters canopy structure and function, with persistent ecological impacts following forest harvest. In this study, we employed airborne laser scanning in 2012 and 2014 to estimate three-dimensional changes in the forest canopy and understory structure and aboveground biomass following reduced-impact selective logging in a site in Eastern Amazon. Also, we developed a binary classification model to distinguish intact versus logged forests. We found that canopy gap frequency was significantly higher in logged versus intact forests even after 8 years (the time span of our study). In contrast, the understory of logged areas could not be distinguished from the understory of intact forests after 6–7 years of logging activities. Measuring new gap formation between LiDAR acquisitions in 2012 and 2014, we showed rates 2 to 7 times higher in logged areas compared to intact forests. New gaps were spatially clumped with 76 to 89% of new gaps within 5 m of prior logging damage. The biomass dynamics in areas logged between the two LiDAR acquisitions was clearly detected with an average estimated loss of −4.14 ± 0.76 MgC ha−1 y−1. In areas recovering from logging prior to the first acquisition, we estimated biomass gains close to zero. Together, our findings unravel the magnitude and duration of delayed impacts of selective logging in forest structural attributes, confirm the high potential of airborne LiDAR multitemporal data to characterize forest degradation in the tropics, and present a novel approach to forest classification using LiDAR data.

Fig-eating by birds in a Malaysian lowland rain forest

1989 ◽  
Vol 5 (4) ◽  
pp. 401-412 ◽  
Author(s):  
Frank Lambert
Keyword(s):  
Rain Forest ◽  
Bird Species ◽  
Peninsular Malaysia ◽  
Forest Site ◽  
Lowland Forest ◽  
Lowland Rain Forest

ABSTRACTSixty bird species ate the figs of 29 Ficus taxa at a lowland forest site in Peninsular Malaysia. Although most bird-eaten figs were brightly coloured, four Ficus species produced dull-coloured ripe fruits. Whilst there was tremendous overlap in the sizes of figs eaten by different bird species, data presented show that the fig resource was partitioned by birds. Large birds were commoner visitors to large-fruited Ficus, but small birds tended to eat small figs. Within two avian genera, the Treron pigeons and Megalaima barbets, there was distinct partitioning of figs consumed according to fig size.

Analysis of an Instaneous Census Method for Heathland Birds

1983 ◽  
Vol 10 (3) ◽  
pp. 521 ◽  
Author(s):  
GH Pyke
Keyword(s):  
Frequency Distribution ◽  
Bird Species ◽  
Time Of Day ◽  
Vegetation Height ◽  
Time Of Year

Birds were censused from the top of a 2.5-m ladder positioned at the centre of circles of radius 20 m. Every 1 min the observer visually scanned one half of a circle, recording the identity of and the distance to every bird seen. This procedure was carried out for about eight scans and then repeated for the complementary semicircle. Birds tended to be repulsed from the observer and/or ladder. Consequently the census method cannot be used to estimate absolute densities. However, the frequency distribution of bird-observer distances was found to be independent of time of day, time of year, and bird species. The method can, therefore, be used at a particular location to compare different bird species and different times. Vegetation height affected the frequency distribution of bird-observer distances and so the method cannot provide accurate comparisons of bird densities in different areas. Fewer birds were seen per scan when the census was carried out 4-6 h after sunrise. The two observers in the study saw the same average number of birds per scan.

scholarly journals Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability

2014 ◽  
Vol 9 (12) ◽  
pp. 124021 ◽  
Author(s):  
Matthew O Jones ◽  
John S Kimball ◽  
Ramakrishna R Nemani
Keyword(s):  
Forest Canopy ◽  
Light Availability ◽  
Amazon Forest

scholarly journals Habitat and population estimates of some threatened lowland forest bird species in Tambopata, south-east Peru

2004 ◽  
Vol 14 (4) ◽  
pp. 261-277 ◽  
Author(s):  
HUW LLOYD
Keyword(s):  
Bird Species ◽  
Selective Logging ◽  
Floodplain Forest ◽  
Primary Forest ◽  
Population Estimates ◽  
Lowland Forest ◽  
Density Estimates ◽  
Forest Bird ◽  
Madre De Dios ◽  
Forest Habitats

Surveys of threatened lowland forest bird species and forest habitats were conducted during a 21-month census of lowland bird communities in Tambopata, Department of Madre de Dios, south-east Peru. A combination of distance sampling census methods and direct counts was used for the census in five sites located along the Rio Madre de Dios and Rio Tambopata. All five sites consisted of different forest types with significantly different habitat components. Three of these sites were classified as primary forest habitats whilst the remaining two were classified as disturbed forests. Population densities were calculated for eight of the threatened species recorded during the census. Density estimates of non-bamboo specialists were higher in primary forest habitats than in disturbed forest habitats. Density estimates of most bamboo specialists were higher in primary Old Floodplain forest with extensive bamboo understorey than in primary Middle/Upper Floodplain forest with smaller, patchy areas of bamboo understorey. Calculation of regional population estimates based on the amount of forest cover from satellite photographs shows that only two of the threatened bird species have substantial populations currently protected by the Parque Nacional Bahuaja-Sonene and Reservada Nacional de Tambopata. Selective logging operations that reduce overall tree biomass and remove a large proportion of palm tree species from primary forest habitats will have an adverse affect on local populations of four of the threatened bird species in the region.

scholarly journals The birds of Korup National Park and Korup Project Area, Southwest Province, Cameroon

1994 ◽  
Vol 4 (1) ◽  
pp. 1-68 ◽  
Author(s):  
Paul G. Rodewald ◽  
Pierre-André Dejaifve ◽  
Arthur A. Green
Keyword(s):  
National Park ◽  
Bird Species ◽  
Montane Forest ◽  
Lowland Forest ◽  
Separate Species ◽  
Forest Reserve ◽  
Project Area ◽  
Forest Bird ◽  
Korup National Park ◽  
First Time

A total of 390 bird species are known to occur in the Korup National Park (KNP) and the surrounding Korup Project Area (KPA). Although the avifauna of KNP is incompletely known, it is already among the most ornithologically diverse lowland forest sites i n Africa. The avian diversity of the KPA is increased by the montane forest bird species of the Rumpi Hills Forest Reserve (RHFR) and the Nta Ali Forest Reserve (NAFR). The lowland and montane forests of the KNP/KPA are very important to the conservation of African forest birds. Four species found in the Korup area are considered globally threatened, and four are considered near-threatened. In addition, 40 species were considered for threatened status, some of which are likely future additions to the threatened list. Twelve of Korup's 36 montane forest bird species are endemic to the montane areas of western Cameroon, eastern Nigeria, and Bioko (Fernando Po). The RHFR is especially important as a refuge for montane birds because much of the montane forest elsewhere in western Cameroon has been cleared for agriculture. Breeding phenology data are provided for many lowland forest species. Additionally, this report provides information on many rarely recorded species for western Cameroon, including several species not previously documented in the region. Kemp's Longbill Macrosphenus ketnpi was recorded for the first time in Cameroon. Because it is sympatric with the Yellow Longbill M. flavicans in Korup, additional evidence now exists for the contention that M. ketnpi and M.flavicans are separate species. The Yellow-chested Apalis Apalisflavidawas also documented for the first time in Cameroon.

scholarly journals Conservation status of birds on Mindoro, Philippines

1992 ◽  
Vol 2 (4) ◽  
pp. 303-325 ◽  
Author(s):  
Guy C. L. Dutson ◽  
Tom D. Evans ◽  
Thomas M. Brooks ◽  
Desiderio C. Asane ◽  
Robert J. Timmins ◽  
...  
Keyword(s):  
Forest Cover ◽  
Conservation Status ◽  
Bird Species ◽  
Concerted Action ◽  
Medium Term ◽  
Lowland Forest ◽  
Risk Of Extinction ◽  
Forest Remnants ◽  
The Status

SummaryFour weeks of fieldwork in the forests of Mindoro, Philippines, in 1991 has elucidated the status of the six bird species endemic to the island. Of these, Ducula mindorensis and Otus mindorensis are high-altitude species with restricted ranges and in need of active conservation in the medium term. Three of the four lowland species, Gallicolumba platenae, Centropus steerü and Penelopides mindorensis are under immediate threat of extinction through forest clearance and fragmentation, while the fourth, Dicaeum retrocinctum, s i not under immediate threat but is certainly at risk of extinction in the long term. Whilst deforestation is an enormous problem across the entire Philippines, Mindoro is the smallest centre of endemism with the least forest cover after the Sulu Islands. Extinctions are believed inevitable within the next 10 years unless concerted action is urgently taken. The Halcon range must receive attention in order to conserve the montane species, but more urgent by far is the preservation of lowland forest remnants, concentrating on central-west Mindoro.

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