Title: “The behavioural ecology and ethno-ornithology of the forest birds of Fiji”
A short biography:
Alivereti Naikatini is an experienced Fijian ecologist currently serving as the Director of Research & Development at Fiji’s Ministry of Forestry. Holding a Master of Science in Environmental Studies, he specializes in Fijian flora, terrestrial vegetation ecology, and forest-dwelling bird species. Previously, he dedicated over two decades as a senior technician at the South Pacific Regional Herbarium, with professional experience spanning Fiji, Vanuatu, and the Solomon Islands.
ABSTRACT:
Although Fiji’s forest birds have been well identified, there remain important knowledge gaps for individual species, particularly native species. This study looks at the behavioural ecology and ethno-ornithology of selected species of Fiji’s native forest birds. Four main research questions are asked: (1) What are the effects of habitat type on patterns of diversity, endemism, and conservation status? (2) Is there evidence for niche partitioning within and across foraging guilds in forest habitat? (3) Does habitat type and elevation affect the intensity of response to defend a territory from a simulated intruder? (4) What is the current status of forest bird indigenous knowledge (ethno-ornithological knowledge) in indigenous iTaukei communities in Fiji?
Firstly, different habitats were surveyed and tested for consistency in avian (bird) diversity, abundance, foraging guild, and distribution status (endemic, native, introduced) over a five-year period (2016-2020). The Point Count Method was used with a 100 m radius and a 7-minute observation period per site. A one-way Analysis of Similarities (ANOSIM) showed significant differences in species composition and bird abundance between the forested habitats and grassland habitats. A general linear model (GLM) showed significant differences in foraging guild composition and distribution status between forested and grassland habitats. There were no significant differences between the three forested habitats (primary montane forest, secondary old-growth forest, old-growth Mahogany plantations), while grassland habitats (mid and low elevation) had flux in species composition. Forest cover, irrespective of whether these forests are of primary or secondary nature, plays a significant role in maintaining the native and endemic forest bird species and other biodiversity in oceanic islands like Viti Levu, Fiji.
Secondly, the foraging niche and interspecific overlap in Fiji’s forest birds were explored, addressing these two questions: 1) Is there vertical stratification of foraging behavior? and 2) Is there evidence of interspecific competition driving the differences in foraging behaviour? To investigate the effect of interspecific competition, the foraging heights of the Orange-breasted Myzomela (Myzomela jugularis) honeyeater on Viti Levu Island (where it coexists with two other honeyeater species) and Leleuvia Island (no other honeyeater species) was compared. On Viti Levu, evidence for vertical niche partitioning within each foraging guild was observed. On Leleuvia, the Orange-breasted Myzomela occupied broader vertical foraging niche than on Viti Levu. This result supports the idea that vertical foraging height can be shaped by interspecific competition. The findings of this study provide empirical evidence for Robert MacArthur’s’ theory of niche differentiation in Fiji’s forest birds for every foraging guild measured and adds to the understanding of the significance of interspecific competition and niche divergence for patterns of ecological speciation on tropical islands.
Thirdly, the response of forest birds to intruders was tested and two questions are addressed: (1) Are endemic forest bird species territorial, defending their territory from intruders of the same species? (2) Do endemic forest birds species show increased territorial defense at a higher elevation when compared to low elevation forest habitats? The birdsong playback method was used, where pre-recorded bird songs were broadcasted at the study sites and the responses of the conspecific at three different elevations (low, mid, and high elevation forest) was recorded. Principal Components Analysis (PCA) was used to create a derived variable for the behavioural responses to the playback. To assess for the effect of native (non-endemic vs. endemic) species to playback response at different elevations, Independent-Samples T-test was used and the Generalised Linear Mixed Model (GLMM) Regression Analysis was used to test for the effect of elevation on the behavioral responses of the four targeted species. The results of the statistical analysis failed to show any significant differences between the endemic and non-endemic species response to the conspecific playback songs at the three different elevation categories. The only significant difference recorded in the statistical analysis was between the endemic and non-endemic insectivore species at high elevation forest where the endemic species responded more aggressively to the conspecific compared to the native species. The results suggest that in general, forest birds in Fiji show weak response to the conspecific playback song at the lowland and mid elevation forests compared to high elevation forest.
Fourthly, the indigenous knowledge of forest birds on two communities were studied where the following questions are addressed: (1) Do the indigenous (iTaukei) people of Viti Levu Island have cultural or spiritual connection with birds based on totemic belief and traditional knowledge? (2) Is there any difference in the indigenous iTaukei knowledge of birds between the male and female community members? (3) What is the knowledge level difference between community members in three age categories (elders, middle aged and youth)? The traditional knowledge data was obtained from two sources, from available literature, and from questionnaire interviews, which were then analysed statistically using the SPSS software. The results showed a significant difference in the bird knowledge between the two genders with the males recording a higher bird knowledge score. There was also a significant difference in the bird knowledge between the different age groups (elders, middle-aged and youth). The possible factors that could cause this difference in knowledge level are discussed but the main outcome highlighted is: how in future this type of traditional knowledge can be effectively passed down to the next generation given the behavioural changes now occurring within iTaukei communities?
Overall, the current study provides new information that contributes substantially to the national priority area of, the conservation of native birds in Fiji.
