Tropical Birds

The marine environment of the atolls of Scilly (Manuae) and Mopelia (Maupiha'a), located at the western end of French Polynesia, is still very little studied, as well as terrestrial and marine birds. An ornithological inventory of Scilly and Mopelia atolls has been carried out on part of a scientific mission conducted from 25 November to 8 December 2014.
The assembly of seabirds in these atolls is particularly diverse with respectively 9 and 11 species observed in Scilly and Mopelia, with 4 confirmed breeding species in Scilly and 10 in Mopelia in the 17 of the Society Island and in the 28 of French Polynesia. Many seabird colonies are located on the uninhabited motus (islet) and not exploited for coprah. The main motu of Mopelia houses a large Sooty Tern colony of about 110 000 pairs, while Vini peruviana, a protected species of category A, present on only a few atolls and classified as vulnerable on the IUCN Red List, is widespread on the two atolls. The absence of the black Rat and the relatively small predation threats of invasive or introduced species help to preserve the richness of avian heritage of these islands. These atolls are therefore important areas for bird conservation.

Le milieu marin des atolls de Scilly (Manuae) et Mopelia (Maupiha’a), situés à l’extrémité Ouest de la Polynésie française, est encore très peu étudié, de même que l’avifaune terrestre et marine. Un inventaire ornithologique des atolls de Scilly et Mopelia a été réalisé sur dans le cadre d’une mission scientifique menée du 25 novembre au 8 décembre 2014.
L’assemblage des oiseaux marins de ces atolls est particulièrement diversifié avec 9 et 11 espèces rencontrées respectivement à Scilly et Mopelia, pour 4 espèces reproductrices confirmées à Scilly et 10 à Mopelia, sur les 17 de la Société et les 28 de la Polynésie française. De nombreuses colonies d’oiseaux marins sont situées sur les motu inhabités et non exploités pour le coprah. Le motu principal de Mopelia abrite une importante colonie de Sterne fuligineuse d’environ 110 000 couples, tandis que le Vini peruviana, espèce protégée de catégorie A présente uniquement sur quelques atolls et classée vulnérable sur la liste rouge de l’UICN, est largement répandu sur les 2 atolls. L’absence du Rat noir et les menaces liées à la prédation d’espèces invasives ou introduites encore relativement réduites ont permis de préserver la richesse du patrimoine avien de ces îles. Ces atolls constituent donc des zones importantes pour la conservation des oiseaux.

A study on the communal roosting behaviour and patterns of roosting in birds to elucidate the factors controlling the communal roosting behaviour was carried out in Kerala, India. The study was initiated in the year December 2015 and the field data collection continued up to December 2017. The objectives of the project were 1. To study the roosting behaviour and patterns of birds in Kerala and 2. To elucidate the factors controlling the roosting behaviour of birds in Kerala.  The investigation was conducted in a tropical area and the main method was of direct observation and field surveys. Ten Districts in the State such as Thiruvananthapuram, Kollam, Alappuzha, Ernakulum, Thrissur, Malappuram, Palakkad, Kozhikode, Kannur and Kasaragod. were surveyed for locating and studying different aspects of communal roosts. Location of roosts, roosting trees and threats to roosts were studied. Factors affecting the communal roosts were analyzed to ascertain the reasons of shifting the roosts. Dependence on human presence was recorded in four type of roosts namely wetland birds, land birds, mixed species and also in the birds of prey roosts. A review of the published literature was carried out to gather the available data on the roosting sites. Forest areas in the highlands namely Idukki, Pathanamthitta, Kottayam and Wayanad Districts were not surveyed for this study. 

Twelve species of birds were found to roosts communally in Kerala and out of these eight species were wetland birds and four species land birds. The studies showed that the communal roosts were formed in four types, namely communal roosts of wetland species alone, land bird roost, mixed species roosts and communal roosts of birds of prey. A total of 258 communal roosts were recorded during the study and out of these 44 were communal roosts exclusively with wetland birds, 131 with land birds, 66 with mixed species and 11 with birds of prey species. Prominent communal roosting species were House crow (Corvus splendens), Common myna (Acridotheres tristis), Little cormorant (Phalacrocorax niger), Night heron (Nycticorax nycticorax), Pond heron (Ardeola grayii), Indian darter (Anhinga melanogaster), Brahminy kite (Haliastur indus) and Black kite (Milvus migrans). Highest number of communal roosts were recorded from Malappuram District followed by Ernakulum and Thrissur Districts. Highest number of wetland bird communal roosts were recorded from Palakkad and Thrissur Districts.
Most of the communal roosts were recorded from the coastal areas and mid lands. As a whole, 81% of the communal roost were within 15 m distance from the nearest road. Birds of prey were not depended on human presence in selecting the roosting sites. Ninety three per cent of the land birds were depending on human presence, for the protection of the roost from the predators, where as it was 82 per cent in the mixed species and 75 per cent in the wetland species. The communal roosts of wetland birds were near the prominent wetlands, streams or near paddy fields. Only 59 per cent of the roosts were within 15 m distance from the road. Apart from the locations near the human presence, wetland birds selected isolated islands also for establishing communal roosts. Wetland birds were communally breeding and roosting in same locations. Due to this, birds were bringing food materials, like fish to the communal roosting sites. The wasted fish lying on the ground and decaying fish produced bad and foul smell. This created hostility of local people towards the communal roosts.  They tried various methods to get rid of the roosting birds from the sites. Due to this, birds were never able to establish communal roost in the private properties. The owners always removed the trees or branches for threatening the birds. For this reason most of the communal roosts were established and maintained in public properties owned by the Government or other public agencies.
The case study of a communal roost of land birds at Mannuthy, Thrissur District (House crow and Common myna) showed that, after the complete felling of trees, on the first day the birds were clueless and they roosted on nearby bushes. But on the second day the birds vacated the nearby bushes and found new roosting trees near the area and some of the birds went to trees which were far away.

The study showed that, shifting of roosts is normal in wetland birds, even if trees are intact whereas the land birds never shifted the location from the preferred trees. On the removal of trees, the land birds shifted to another nearby roosts or to new selected trees. The communally roosting land birds, wetland birds and mixed species roosts selected the roosting sites mainly to avoid the predators. This is clear from the fact that the majority of the communal roosts of these species were in the locations where the presence of humans are available for twenty four hours. This was realized by establishing the roosts near the road sides, municipal parks, or in taxi stands. Wetland birds communally roosted away from the human location also, where they assured the protection from the predators by selecting Islands surrounded by water or in isolated mangrove patches encircled by water. Birds of prey being carnivores, never selected the sites with human presence because they were not in need of protection from predators and they defended themselves. The wetland birds and land birds preferred human protection for their communal roost.

  As people are not allowing roosting of birds in trees located in private properties, birds completely depended on the public places. The authorities have to give high attention to save the communal roosting trees of the public places otherwise birds depended on communal roosting will be threatened. For this the conflict with the local people and communal roosting birds should be addressed and solved. 
                                                                                                   
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Note: Book review (2001) uploaded here as a 2nd file.

Beni Biological Station Biosphere Reserve (1,353 km²) in north-central tropical lowland Bolivia includes three major biogeographic regions: mostly Amazon, and Cerrado and Chaco. About 70% is flooded seasonally. In a heterogeneous mosaic, 89% is forest (high dense, or riparian, or swamp); 2% open woodlands; 1% dry savanna and thorn scrub; and 8% wetlands. The rich biodiversity includes some 2,000 species of vascular plants, 100 spp. of mammals, 480 spp. of birds, 50+ spp. of reptiles and amphibians, and 210 spp. of fishes. Some 2,000 people (indigenous and immigrant) living in or adjacent to the BBR depend on the natural resources for hunting, fishing, gathering, craft production, subsistence agriculture, and cattle-ranching.

This book presents main work since the BBS was established in 1982 (becoming a UNESCO Biosphere Reserve in 1986), including scientific research and general information, on vegetation, wildlife (mostly vertebrates, butterflies), ecology, indigenous and immigrant peoples, ethnobiology and ethnoecology, resource management and conservation. The five sections comprise 12 chapters in Spanish, 9 in English, with Spanish and English abstracts: (1) History and introduction to BBR, including overview of the area’s ecology and a book-integrating review for management; (2 & 3) Fundamental and/or applied research on soils, vegetation, floristics and fauna of the BBR and nearby areas; (4) Uses and management of resources by local communities; (5) Conservation: Biogeographic analyses and context of BBR and historical administrative review and summary of BBS and BBR projects.

Subjects in detail: (1) Evaluation and monitoring for adaptive management, with integration of all chapters; (2) BBS and BBR characteristics, history in context, and management; (3) Soils in BBR area; (4) Vegetation mapping from satellite data for habitat studies in Amazon lowlands, with new vegetation map of BBR; (5) BBR’s 27 vegetation formations, and their conservation importance; (6) Floristic composition and diversity of forested habitats in BBR; (7) Ecology and biogeography of BBR’s 12 palm species; (8) Fishes in BBR; (9) Amphibians and reptiles in BBR and Beni Dept.; (10) Ecology, biogeography and conservation of BBR forest-island faunas (mainly birds, butterflies); (11) Birds of nearby Sabana de Espíritu – diversity and ecology; (12) Wildlife diversity with selective logging of bigleaf mahogany (Swietenia macrophylla) in nearby Bosque Chimanes; (13) Consequences of subsistence hunting in BBR (especially reducing white-lipped peccary [Tayassu pecari] and black-faced black spider monkey [Ateles chamek]); (14) Census and conservation of Endangered Ateles chamek in BBR; (15) Forest regeneration after slash-and-burn agriculture at BBR; (16) Experimental pre-Hispanic-style raised-field cultivation, a better alternative to slash-and-burn; (17) Indigenous (Tsimane/Chimane) agriculture, hunting and fishing; (18) Traditional (indigenous and immigrant) knowledge of useful plants; (19) Biogeographic analyses and administrative development of BBR, and implications for protected area management and frontier regional planning.

The Lovely Fairy-Wren (Malurus amabilis) is endemic to the wet tropics of Australia and is one of 11 species in the genus Malurus. Despite the large number of studies on fairy-wrens, little is known about the Lovely Fairy-Wren. This study provides the first detailed description of its ecology, behaviour, and breeding biology. Lovely Fairy-Wrens displayed breeding behaviour characteristic of tropical birds, with groups maintaining territories and breeding year-round, small clutch size (two to three eggs), long juvenile dependence (2 months) and high adult breeder survival (86%). They breed cooperatively, and groups formed when male (but not female) offspring delayed dispersal and remained in their natal group as subordinates. Groups were typically small (2.5 ± 0.8 individuals), possibly because productivity was low: 29% of the monitored groups produced at least one fledgling per year. Males provided high levels of parental care and this, together with low extra-pair courtship and petal displays, suggests that this species may not be as promiscuous as other fairy-wrens. Unlike other Australian fairy-wrens, males maintained their brightly coloured adult plumage year-round after initial acquisition. This lack of seasonal moult into dull plumage, coupled with the unusually colourful plumage of females in this species, suggests that the impact of natural selection on the plumage colour of both sexes may be lower in this species than in their congeners. We discuss similarities and differences in life-history and morphological traits between the Lovely Fairy-Wren and other Malurus species.

1. This report describes the first phase of studies on the impact on the bird community of silvicultural trials carried out by the Forest Planning and Management Project (FPMP) of the Belize Forest Department in the Chiquibul Forest Reserve and the Rio Bravo Conservation and Management Area. The FPMP seeks to make better use of Belize’s forest resources than is achieved through traditional selective logging. This study aims to provide forest managers with information on silvicultural impacts on birds, so that biodiversity issue can be considered, along with forestry issues, in management decisions.
2. The study is designed to answer the following questions: a) What impact do the FPMP silvicultural trials have on forest habitat structure; b) What impact do the silvicultural trials have on the forest-bird community; c) Does the impact on forest structure cause increases in bird species typical of treefall gaps in unlogged forest or of open areas such as along roads; cause decreases in species that prefer undisturbed forest; and/or cause existing species in the forest to adapt behaviorally to accommodate the changes in forest structure?
3. To answer these questions we must: 1) compare forest structure and bird communities at the sites of the silvicultural trials before and after timber extraction; (2) compare those bird communities with birds typical of treefall gaps and along roads; and (3) document how species respond behaviorally to the changes in vegetation structure. In this report we describe the results of pre-trial studies of the vegetation structure and avifauna of the trial plots, forest gaps, and roadsides.
4. The study took place in subtropical moist forests in the Chiquibul Forest Reserve and the Rio Bravo Conservation and Management Area (Hill Bank). The silvicultural treatment sites were 300×600 m (18-ha) forest plots installed by the FPMP, four at Chiquibul and two at Hill Bank. Two of the Chiquibul plots were in deciduous seasonal forest and two in deciduous semi-evergreen seasonal forest. One-half (nine contiguous hectares) of each plot was randomly selected for extraction of all merchantable trees, the other half to be an undisturbed control. Gap study sites were within the 18-ha trial plots. Roadside plots were seven 800-m segments near the Las Cuevas Research Station. Gaps and roadsides were not studied at Hill Bank.
5. We measured forest canopy height, canopy openness, and small stem density in each plot, and located and measured the area of all treefall gaps. We measured vegetation height along the road study areas.
6. In each of the silvicultural treatment plots we made point counts of birds three times at each of 12 points in each of the plots (Fig. 1). Birds were also mist-netted and released unharmed at 24 points in each plot. Additionally, we systematically plotted territories or bird locations in the plots on at least three days and recorded location and behavior of these birds and others in studies in forest gaps and along roadsides.
7. The four Chiquibul plots were significantly different from one another in terms of canopy height, canopy openness, and stem density. But large sample sizes make statistical comparisons highly sensitive to small differences in vegetation structure that may not be biologically meaningful. There were few differences between deciduous seasonal forest and deciduous semi-evergreen seasonal forest. Due to the great spatial heterogeneity of the vegetation within each of the four Chiquibul plots, the two treatment halves of each plot were structurally different from each other in most comparisons. Nonetheless, the comparative design of the silvicultural trial is robust because the logging treatment will undoubtedly produce a much greater contrast than existed before treatment between the logged and unlogged plot halves and in pre- and post-treatment comparisons of the logged half.
8. A total of 139 bird species were recorded on the Chiquibul forest plots in censusing, mist-netting, or opportunistic observations. Point counts in the treatment plots detected 1021 individual birds in 109 species, while 359 individual birds in 45 species were caught in mist-nets. Emberizids (sparrows and allies, warblers, tanagers, and orioles), flycatchers, wrens, vireos, and hummingbirds were the more common families detected in censuses, whereas emberizids, woodcreepers, flycatchers, wrens, and manakins dominated the mist-net samples. In terms of foraging guilds, small insectivores and small omnivores dominated the point-count and mist-net data, whe rleaarsge insectivores and nectiavrores were less abundant. Migrants made up between 11.8 and 18.8% of the birds censused and between 21.6 and 29.2% of birds netted.
9. Comparisons among the four Chiquibul sites indicate significant differences in relative abundances of individuals, species, and families of birds, according to point-count data, but only for individuals, according to mist-net data. There was no difference in the bird species richness or diversity between deciduous seasonal forest and deciduous semi-evergreen seasonal forest types, although there were some differences between forest types in relative abundances of some bird species. This suggests the two forest types contain similar bird communities. Censusing and mist-net results revealed some significant differences between treatment halves of the silvicultural plots. Birds foraging in treefall gaps differed little from those in the forest interior.
10. Point counts from the forest plots were combined those from roadside plots to evaluate the degree of habitat specialization in bird species. Species were categorized as to whether they were observed both in the forest interior and along the roadsides (both habitats), observed only in the forest interior (only interior), or only along roadsides (only roadsides). The combined list included 147 species, 79 of which occurred in both habitats, 31 in only interior, and 37 in only roadsides. The relatively high proportions of large omnivores and large insectivores in the forest interior specialists and the high numbers of small omnivores and the low numbers of small insectivores and nectivorous species among roadside specialists stands out. Most of the small insectivores used both habitats. Neotropical migrants made up 20.7% of the individuals in the species using both habitats, a remarkable 36.3% of the individuals in the species only detected in the roadside counts, but only 1.5% of the individuals in the species found in the interior. Although relative abundances of species differed significantly between forest interior and roadsides, only 8% of species seen in forest plots were never recorded in gaps or along roads. Birds in the forest interior and in gaps are more often observed foraging than birds along roadsides, which are relatively more frequently engaged in other behaviors, such as vocalizing or watching for predators.
11. As at Chiquibul, at Hill Bank there were pre-treatment differences in forest structure between the two silvicultural plots. Most comparisons of the bird community showed little differences between plots; however there were some significant differences between plots in abundance of certain species. Both census and mist-net data indicated little difference in the pre-treatment bird communities of treatment and control halves of the plots.
12. These results enable us to make several predictions concerning the effects of the silvicultural treatments on the forest-bird community. If disturbance to the forest by the logging treatment is similar to increasing the number of treefalls, it may have little effect on bird-species composition and numbers. But if the forest is opened dramatically the birds may encounter a significant change in the foraging substrates available and be more vulnerable to aerial predators, and species composition and/or abundances could shift significantly. Most of the species that appear to prefer the forest interior, and may be most at risk to disturbance, are tropical residents. These include trogons, motmots, cotingids, woodpeckers, woodcreepers, and hummingbirds may be adversely affected. However, most species in the forest (small insectivores in the Emberizidae) may adjust ably to or even do better (such as Neotropical migrants) in a modestly disturbed forest habitat.
13. In the short-term, because birds do move about the landscape, adversely affected species will recolonize habitats as they recover the necessary habitat features. If silvicultural management is mindful of maintaining good forest habitat for source populations and allowing the treated areas to recover critical forest characteristics sufficiently between harvests, the managed forests will be recolonized and should maintain most if not all the avian biodiversity in the landscape.

Tropical forest destruction and fragmentation of habitat patches may reduce population persistence at the landscape level. Given the complex nature of simultaneously evaluating the effects of these factors on biotic populations, statistical presence/absence modelling has become an important tool in conservation biology. This study uses logistic regression to evaluate the independent effects of tropical forest cover and fragmentation on bird occurrence in eastern Guatemala. Logistic regression models were constructed for 10 species with varying response to habitat alteration. Predictive variables quantified forest cover, fragmentation and their interaction at three different radii (200, 500 and 1000 m scales) of 112 points where presence of target species was determined. Most species elicited a response to the 1000 m scale, which was greater than most species’ reported territory size. Thus, their presence at the landscape scale is probably regulated by extra-territorial phenomena, such as dispersal. Although proportion of forest cover was the most important predictor of species’ presence, there was strong evidence of area-independent and -dependent fragmentation effects on species presence, results that contrast with other studies from northernmost latitudes. Species’ habitat breadth was positively correlated with AIC model values, indicating a better fit for species more restricted to tropical forest. Species with a narrower habitat breadth also elicited stronger negative responses to forest loss. Habitat breadth is thus a simple measure that can be directly related to species’ vulnerability to landscape modification. Model predictive accuracy was acceptable for 4 of 10 species, which were in turn those with narrower habitat breadths.