The effects of forest habitat, canopy light condition, vertebrate herbivory and species mean seed size on growth of tree seedlings were evaluated for six widely different species of North Queensland tropical rain forests. Two forest localities differing in size and rainfall intensity were used for the trial. In each forest, seedlings were transplanted three weeks after germination into small to medium-sized canopy gaps and into the forest interiors, with half protected by cages and the other half unprotected. Growth measurements were made over a period of 16 months. All growth parameters examined differed significantly between the six species. At the end of the study period, for most species, forest site and protection from vertebrates did not affect seedling biomass. For all species, growth was higher in gaps than in forest interior, but most biomass allocation patterns did not differ between the two habitats. This was attributed to the small difference in photosynthetically active radiation (PAR) levels between the two habitats (interior, 0.48–2.53% PAR; gap, 3.58–7.09% PAR). Between species, seedling growth in the forest interior and sensitivity to increasing light were significantly correlated with initial mean seed size. The growth ability of the six species in and out of canopy gaps is discussed in terms of regeneration status of forest tree species.

Length-mass relationships within an assemblage of tropical snakes are used to describe morphological groups. We report patterns of body size based on length and mass measurements of 603 individual snakes of 27 species captured at La Selva, Costa Rica from March 1982 through August 1984. This assemblage of snakes is composed of at least four morphological groups each of which consists of species with similar habitat preferences. These groups are heavy-bodied terrestrial forms, light-bodied arboreal forms, long-tailed leaf-litter forms, and forms of unextreme relative mass and tail length. This tropical snake assemblage is more diverse in species richness and morphological diversity than a temperate assemblage.

Habitat fragmentation is gradually altering tropical forests all around the globe (Wright 2005), as human populations convert large blocks of pristine forest habitats into permanently fragmented or human-modified landscapes (Tabarelli et al. 2004). Fragmentation processes apparently create opportunities for small sets of species, which proliferate across modified landscapes, while others are driven to extinction or remain as minimal populations (Tabarelli et al. 2010). This ‘winners vs. losers paradigm’ (sensu McKinney & Lockwood 1999) probably describes one of the most conspicuous rearrangements of tropical biotas in response to human disturbances (in addition to biomass collapse), with unanticipated consequences for ecosystem functioning and long-term biodiversity persistence (Lôbo et al. 2011). Despite such appeal, the ecological identity of proliferating organisms and the mechanisms underlying their high abundance levels remains poorly appreciated.

As the dry season progresses in arid and semi-arid ecosystems, rain-fed surface water sources become depleted, forcing most animals to concentrate in the immediate vicinity of the few remaining permanent sources of drinking water. This study investigates the temporal dynamics of use of water-holes by nine African large-herbivore species in the dry season in the semi-arid savanna of Hwange National Park, Zimbabwe, and particularly how annual rainfall influences this temporal dynamics. Two contrasting years in terms of annual rainfall were compared: 2003 (a drought – 362.6 mm) and 2004 (average rainfall – 695.8 mm). In 2003, water-holes were used far more intensively and the level of aggregation of herbivores at water-holes was significantly higher. The temporal dynamics of water-hole use in the dry season differed between the two years: in 2003, the peak of water-hole use started much earlier and lasted 3 mo. Elephants and grazers showed the largest difference in use of water-holes between 2003 and 2004 supporting the suggestion that browsers are less water dependent. This study suggests that annual rainfall should be taken into account when predicting the peak of the dry season.

Soil processes are essential in enabling forest regeneration in disturbed landscapes. Little is known about whether litterfall from dominating pioneer species in secondary rain forest is functionally equivalent to that of mixed rain-forest litter in terms of contribution to soil processes. This study used the litterbag technique to quantify the decomposition and nutrient dynamics of leaf litter characteristic of three wet tropical forest communities in the Paluma Range National Park, Queensland, Australia over 511 d. These were: undisturbed primary rain forest (mixed rain-forest species), selectively logged secondary rain forest (pioneer Alphitonia petriei) and tall open eucalypt forest (Eucalyptus grandis). Mass loss, total N, total P, K, Ca and Mg dynamics of the decaying leaves were determined, and different mathematical models were used to explain the mass loss data. Rainfall and temperature data were also collected from each site. The leaves of A. petriei and E. grandis both decomposed significantly slower in situ than the mixed rain-forest species (39%, 38% and 29% ash-free dry mass remaining respectively). Nitrogen and phosphorus were immobilized, with 182% N and 134% P remaining in E. grandis, 127% N and 132% P remaining in A. petriei and 168% N and 121% P remaining in the mixed rain-forest species. The initial lignin:P ratio and initial lignin:N ratio exerted significant controls on decomposition rates. The exceptionally slow decomposition of the pioneer species is likely to limit soil processes at disturbed tropical rain-forest sites in Australia.

Bats and birds carry out most of the seed dispersal in the Neotropics (Galindo-Gonzáles et al. 2000), and are crucial for the dynamics and regeneration of tropical forests (Whittaker & Jones 1994). However, only a few details are known about the interactions in particular bat–fruit systems. Most frugivorous bats are highly mobile (Bernard & Fenton 2003), and do not harm seeds (Fleming & Sosa 1994), suggesting that they are legitimate and effective seed dispersers (sensu Fleming & Sosa 1994).

Tropical forests can recover after anthropogenic disturbances of light to moderate intensity (Aide et al. 1995, 1996, 2000; Uhl 1987, Uhl et al. 1988); however, severe disturbances (e.g. compaction or loss of soil) often result in conditions that prevent forest recovery. These degraded sites are often dominated by grasses (Aide & Cavelier 1994, Cabin et al. 2002, Cavelier et al. 1998, Uhl et al. 1988) and ferns (Cohen et al. 1995, García et al. 1994, Slocum et al. 2000, Walker & Boneta 1995) that can impose barriers for tree regeneration and arrest the succession process. Important barriers for tree regeneration include: (1) competition with grasses and ferns for soil moisture, nutrients and light (Aide & Cavelier 1994, Guimarães-Vieira et al. 1994, Holl et al. 2000, Nepstad et al. 1996, Russell et al. 1998, Walker 1994, Zimmerman et al. 2000), and (2) dispersal limitation given that grasses and fernlands offer few resources that attract seed dispersers (Guevara & Laborde 1993, Holl et al. 2000, McDonnell & Stiles 1983, Slocum & Horvitz 2000, Zimmerman et al. 2000).

Resource partitioning between elephant, giraffe, kudu and impala was assessed. This was to address concerns that elephant population increase adversely affects other species through depleting their food in key areas close to permanent water. Resources considered were woody species browsed, height browsed and plant parts browsed. Animals were observed as they browsed and the plant species, browsing heights and plant parts browsed were recorded. Observations were made over 1 y and the data were divided between wet and dry season. Schoener's index of resource use overlap was calculated for plant species, browsing heights and plant parts eaten and differences in overlap between wet and dry season were tested. Levin's measure of niche breadth in plant species utilized by the different browsers was calculated. Woody species identity was the main separator between food resources that elephant used and those giraffe, impala and kudu used. Giraffe, kudu and impala mainly browsed the same species and plant parts but browsed at different heights. There was no difference in resource use overlap between seasons with different resource availability. Since elephant browsed different woody species from those browsed by the others, it is unlikely that the increasing elephant population will deplete food resources for the other browsers.

Mistnets were set at ground level and 11–30 m above ground in lowland rainforest at Kuala Lompat in peninsular Malaysia, and Sepilok in Sabah, to compare the abundance of fruit bats in the subcanopy and at ground level. Capture rates in the subcanopy were up to 100 times greater than at ground level, averaging 3–7 bats per net-night. Species diversity was higher in the subcanopy than forest understorey. Two species that were frequently captured in the subcanopy, Megaerops wetmorei and Dyacopterus spadiceus, were previously thought to be rare. The abundance of Old World fruit bats in the subcanopy indicates that their roles in pollination and seed dispersal of Malaysian forest trees may be greater than previously recognized. Further research on foraging ranges, food selection and roosting habits is required to determine the overall importance of fruit bats in forest regeneration through seed dispersal, and the adequacy of existing reserves for their conservation.

The annual flood pulses of central Amazonian rivers inundate marginal forests to 10 m depth or more (Furch & Otto 1987, Junk et al. 1989). The regularity of this flooding seems to have promoted the development of a complex relationship between forest plants and fishes that consume their seeds (Goulding 1980). Several fish species migrate into the flooded forests to feed on buoyant fruits and seeds, and many plant species reach their fruiting peak during the flood season. Fruits and seeds have been reported to have adaptive features related to water (hydrochory) and/or fish (ichthyochory) dispersal (Araújo-Lima & Goulding 1998, Gottsberger 1978, Goulding 1980, Kubitzki & Ziburski 1994, Scarano 1998, Williamson 1999, Williamson & Costa 2000). Strong multicuspidate teeth in frugivorous fishes, fruit/seed buoyancy (Goulding 1980) and chemical signs released by fallen fruit to attract fish (Araújo-Lima & Goulding 1998) are mechanisms for the seed dispersal of the flooded forest community.

The habit, shade-tolerance and dispersal agent of 19 bromeliad species were studied in a rainforest community in order to relate specific traits to the spatial occurrence of the species. Highest density was found in riparian forest (RF), followed by restinga scrub (RE), rocky shore (RS) and dense canopy forest (DF). Terrestrial bromeliads occurred in open sites (RE and RS), epiphytes were absent in RS and facultative species occupied all four habitats. Bird-dispersed bromeliads occurred in the upper canopy, whereas those dispersed by mammals were low in the forest profile. Bromeliads which are dispersed by similar fauna fruit sequentially through the year. Differences in traits may allow the sharing of habitats and strata among species.

This study provides the first quantitative description of vertical stratification in calling heights of ensiferan species constituting most of the dry-season nocturnal acoustic community of an evergreen forest in Kudremukh National Park in south-west India. Calling heights of an average of 26 individuals of each of the 20 ensiferan species were measured and subjected to an analysis of variance to test for differences in mean calling height between species and a cluster analysis to check for the presence of discontinuous calling height layers. There were significant differences in mean calling heights between species. Calling heights of different gryllid and tettigoniid species ranged from the ground to the canopy. More gryllid than tettigoniid species occupied the ground and herb layer. Our study revealed vertical stratification of calling heights, with discrete layers corresponding to the canopy, understorey and the ground layer. These clusters emerged from the raw data of calling heights of individuals without a priori distinction of layers. We found no significant correlation between the calling heights of species and call features, including mean dominant frequency of narrow band calls, mean syllable rate and mean duty cycle.

Data on the pollination biology of neotropical aroids are still scarce and concern only a few species (Beath 1999, Croat 1997, Gibernau et al. 1999, 2000; Mayo et al. 1997 and references cited therein). It appears from these studies that Anthurium, Monstera and Spathiphyllum are on the whole pollinated mainly by bees (but see Kraemer & Schmitt 1999), whereas Dieffenbachia, Homalomena, Syngonium, Philodendron and Xanthosoma are generally beetle-pollinated. Although araceous inflorescences may be visited by several insect taxa (Madison 1979), only a few are the legitimate pollinators for each species (Seres & Ramirez 1995, Valerio 1984, Young 1986).

Habitat degradation affects mixed-species bird flocks (flock hereafter) through two mechanisms – changes in the bird community from which flocks are drawn and changes in the propensities of species to flock. We determined the relative influence of these two mechanisms by examining variation in flocks across nine rain-forest fragments (range 11–2600 ha) in a plantation landscape in the Western Ghats, India. We found differences between fragments in average number of species (range 10.8–15.2) and individuals (range 19.0–37.6) per flock, number of species that participated in flocks (range 34–59), encounter rates (range 0.5–2.4 flocks h−1) and flock composition. Multiple regression and randomization tests revealed that different mechanisms contributed to this variation. Three flock variables (open-forest individuals per flock, total open-forest species that participated in flocks in a fragment, flock composition) mainly reflected changes in the bird communities of fragments. Habitat structure strongly influenced three flock variables (open-forest species per flock, total and rain-forest individuals per flock) and flock composition to a lesser extent. Finally, flock encounter rate was strongly related to fragment area, but not to abundance of flock participants indicating habitat degradation-induced changes in propensities of species to flock.

The dependence of tree seedling survival and growth on light availability was evaluated over 15 mo in three second-growth, wet forest stands (15–18 y old) in north-eastern Costa Rica. Seedlings of four canopy tree species (Dipteryx panamensis, Hyeronima alchorneoides, Virola koschnyi and Vochysia guatemalensis) were planted into four canopy treatments in three replicated stands and in a pasture site, spanning a nearly complete gradient of light availability. Survival and growth of all species increased in response to increasing light availability, but species differed in survival in shaded microsites (6–20% light transmittance) and in growth increments per light increase. Hyeronima showed the highest mortality at low light levels and the highest relative height growth increase per light increase. In contrast, Virola showed high survival at low and moderate light, but showed the lowest leaf area and above-ground biomass per light increase among all species. Dipteryx and Vochysia maintained relatively high rates of survival and growth across the entire light gradient. Hyeronima and Virola showed trade-offs between growth and survival responses to light, unlike Dipteryx and Vochysia. Differences among species in seedling survival at low light may be determined by a variety of physiological and morphological traits that may or may not be mechanistically linked to growth responses.

Spatial patterns presented by the opossums Caluromys philander, Philander frenata and Micoureus demerarae were studied, through radio-tracking, in a landscape composed of eight small (1.3–13.3 ha) forest fragments surrounded by a matrix of open vegetation in south-eastern Brazil. Sixteen individuals were fitted with radio-collar transmitters and monitored for 2–8 mo. Fixes were obtained by the ‘homing-in on the animal’ technique. Numbers of locations of each individual varied from 6 to 117. Home ranges sizes ranged from 2.5–7.0 ha for C. philander, 0.6–7.4 ha for P. frenata and 0.8–1.7 ha for M. demerarae. Fragments, both edges and interiors, were used more often than the matrix; they are the primary habitat for these marsupials in the landscape. The matrix was used for foraging by P. frenata and C. philander, and traversed in five movements between fragments by P. frenata. Ability to use fragment edges and the matrix is important in explaining how these marsupials are able to persist in the landscape.