INTRODUCTION
The Maluku Islands, Indonesia, located in the Wallacea region, support endemic bird species, such as the Moluccan megapode, through various habitat types (Yuni & Yuda 2020). Tropical forests provide complex habitats rich in composition and structure of vegetation for shelter, foraging, roosting or sheltering, and breeding (Baldeck et al. 2012; Bu et al. 2014; Velasques-Trujillo et al. 2021). Therefore, the composition and diversity of habitat vegetation support the diversity of endemic, rare, threatened, and endangered wild birds (Sodhi et al. 2011; Rocha et al. 2015; Devenish‐Nelson et al. 2019; Feng et al. 2020). The structure of a bird’s habitat, which includes vertical structure and floristic composition, is an essential component of its habitat. Vegetation structure and floristic composition have been used to predict the presence and diversity of bird species for a long time. Some bird taxa are influenced by vegetation structural factors (e.g., the complexity of stand configuration or architecture), while others are influenced by vegetation composition factors (e.g., vegetation type) (Tews et al. 2004; Tassicker et al. 2006; Gao et al. 2014; Rutten et al. 2015; Melo et al. 2020; Moudry et al. 2021). Island bird species in the tropics are threatened by several environmental challenges, including habitat change and destruction (Duncan & Blackburn 2007; Taylor & Kumar 2016; Radley et al. 2020; Dri et al. 2021). Habitat destruction causes changes in the structure and composition of vegetation in bird habitats, thus affecting the survival and reproduction of bird populations (Ruiz-Gutierrez et al. 2008; Matthews et al. 2015; Tulloch et al. 2016; Tchoumbou et al. 2020; Atikah et al. 2021).
One of the native and endemic bird species in the Maluku Islands is the Moluccan megapode (Eulipoa wallacei), which is only found in northern Maluku and central Maluku. Like other megapodes, the Moluccan megapode is super-precocial and classified as a terrestrial bird (Colar et al. 1994; Argeloo & Dekker 1996; Dekker et al. 2000; Heij & Rompas 2011). Moluccan megapodes inhabit coastal areas through tropical rain forests of more than 750 m asl (Dekker et al. 1995; Heij et al. 1997; Heij 2001; Heij & Rompas 2011; BirdLife International 2022). The occurrence of the birds in coastal areas is related to their nesting behavior, which involves digging holes in the sand substrate to lay their eggs (Dekker et al. 1995; Jones et al. 1995; Dekker et al. 2000; Heij et al. 1997; Heij & Rompas 2011). The population of Moluccan megapodes has been decreasing due to habitat destruction and egg harvesting (Colar et al. 1994; Argeloo & Dekker 1996; Dekker et al. 2000; Heij & Rompas 2011), so it has been designated as a vulnerable species by the IUCN since 1994 (BirdLife International 2016). Studies in 1997 by Heij et al. (1997) confirmed that habitat destruction caused the Moluccan megapode to become rare on several large islands, such as Seram Island and Bacan Island, and smaller islands, such as Ambon Island and Ternate Island. Likewise, several nesting sites have been abandoned and are no longer used by birds due to the destruction of their nesting habitat. The effect of habitat destruction on the decline of the Moluccan megapode indicates that habitat quality and composition play an essential role in the bird populations. Adult Moluccan megapodes use vegetation around their nesting site for perching before and after nesting activities. Meanwhile, newly hatched chicks require vegetation cover as shelter from predators (Heij et al. 1997; Heij & Rompas 2011).
In Central Maluku, one of the largest nesting sites of the Moluccan megapode is Tanjung Maleo in Haruku Island (Heij et al. 1997; Heij & Rompas 2011). Until recently, information about the habitat used by Moluccan megapodes on Haruku Island has been scarce and limited to habitats around bird nesting sites (Heij et al. 1997; Heij & Rompas 2011; Sjafani et al. 2015), while daily habitat use studies have never been reported. Better knowledge of the specific habitats used by Moluccan megapodes allows conservation managers to carry out appropriate engineering to protect bird habitats from expanding settlements near nesting habitats or opening new agricultural fields in their daily habitats. Habitat protection engineering can be carried out by delimiting habitat boundaries, maintaining the composition of vegetation strata, or providing corridors for the distribution of chicks and pathways for adult birds to and from their nesting habitat in Tanjung Maleo. This study investigated habitat use by Moluccan megapodes on Haruku Island. We also analyze the composition of the vegetation and the diversity of plant species in these habitats to understand the influence of habitat on birds’ daily activity patterns.
MATERIALS AND METHODS
Study area
The study was conducted on Haruku Island in Central Maluku District (3.5670S, 128.4830E) (Figure 1). Haruku Island has an area of 274 km2 and a topography of mountains and hills, with the highest point reaching 554 meters above sea level. The climate on Haruku Island is locally influenced by tropical marine climate and monsoon climate (Aldrian & Dwi Susanto 2003; Wirjohamidjojo & Swarinoto 2010) with relatively high rainfall of 224.58 mm per year in 2021 (BPS Propinsi Maluku 2022).
Identification of bird habitat
Bird habitat identification was conducted by using radio-tracking. During 40 days of observation from December 2020 until January 2021, 330 points of bird presence were recorded. Individual females and chicks were tracked from their nesting sites to collect data on the relationship between nesting habitats and daily foraging habitats. This study did not use adult males because only adult females carried out nesting activities at nest sites in Tanjung Maleo, while adult males remained in their daily habitat (Heij et al. 1997; Heij & Rompas 2011). Adult male birds were challenging to catch in their daily habitat because of their camouflage amidst the surrounding understory vegetation. Eight birds were utilized, including four newly hatched chicks and four adult females. Chicks and adult females were caught using a hand capture technique (De Beer et al. 2001; Bloom et al. 2007; Whitworth et al. 2007; Busse & Meissner 2015) during nesting and when the chicks emerged from their nesting holes. For tracking purposes, the Sirtrack V8009 transmitter was utilized for chicks, and the Sirtrack P04347 transmitter for the adult birds. Using Loctite cyanoacrylate (Bowman et al. 2002; Diemer et al. 2014), the transmitter was attached to the base of the wing. The movement and position of individual birds were tracked using Biotrack Sikka VSR 04, receiver, Yagi antennae, and GPS Garmin 64S. The birds were tracked every day on foot (ground tracking). The position of the Universal Transverse Mercator coordinate for each bird was plotted on a map of the study site to determine the area used by birds using ArcGIS 10.3 and ArcMap 10.3.
Vegetation sampling
Intensive floristic inventory and plot-based vegetation survey (Krebs 1998; Colwell 2009) was conducted at forest sites on Haruku Island that were used by individual Moluccan megapodes, specifically in Tanjung Maleo, Marunimei, and Lalean. Vegetation sampling was carried out at the same time as bird habitat identification. Twelve transect lines measuring 500 and 1000 meters were utilized, and the distance between transects was 250 meters. The distance between plots was 100 meters. The plot sizes were 1 m x 1 m (seedlings), 5 m x 5 m (saplings), 10 m x 10 m (poles), and 20 m x 20 m (trees) (Barbour et al. 1987; Woodward et al. 2009; Rahman et al. 2016; Kusmana 2017; Peng et al. 2018). The observed variables for each stage were as follows: (i) seedling stage: germinated seeds to < 1.5 m in height, (ii) sapling stage: height >1.5 m to a diameter at breast height (dbh) < 10 cm, (iii) pole stage: 10 cm < dbh < 20 cm (Barbour et al. 1987; Woodward et al. 2009; Kusmana 2017). There were 84 plots in Tanjung Maleo, 168 in Marunimei, and plots in Lalean. Vegetation parameters included species name, number of species, number of individual species, and diameter at breast height (dbh). Plant species were identified using a collection of identification guides (Whitmore 1978; Soerianegara & Lemmens 1994; Lemmens et al. 1995; Llamas 2003; Gunawan et al. 2019).
Data analysis
All coordinate positions of bird presence points were plotted onto the Haruku Island land cover map to obtain the Moluccan megapode habitat land cover type. The land cover map of the bird habitat area was determined using a 2021 Haruku Island land cover map combined with 2021 Google Earth imagery data, a 1:50,000 scale map of Haruku Island in 2021, and a 2020 Landsat 5 TM image (composite color band 4 - band 3 – band 2) with a spatial resolution of 30 meters. Land cover types on bird habitats were created using ArcMap 10.3. The land cover classification was based on the Indonesian National Land Cover Standards Agency (National Standardization Agency of Indonesia 2010). Vegetation structure and floristic composition were determined based on the analysis of the importance value index (IVI) (Bendre & Kumar 2010), species diversity (Shannon – Wiener index) (Shannon & Weaver 1963; Odum 1983), species evenness (Pielou index) (Odum 1983), and species similarity (Sorensen index) (Sorensen 1948). The importance value index (IVI) is the sum of relative frequency, density, and dominance values.
The species diversity was calculated by using the Shannon-Wiener index:where:
pi = proportion of individuals of the i-th species to individuals of all species found.
The species evenness index was calculated by using the Pielou index:
where:
H’ = Shannon-Wiener diversity indeks;
S = total number of species in the sample;
E = 1 if all species are represented equally in the sample, and E is close to zero if one species predominates strongly.
The species similarity index (SI) between sites was calculated using the Sorensen index:
where:
C = standard number of species at the two sites;
A = number of species at site A;
B = the total number of species at site B.
The F test was conducted using one-way ANOVA to compare the composition of vegetation growth strata between bird habitat forests.
RESULT AND DISCUSSION
Habitat of Moluccan megapode
The radio-tracking record of individual chicks and adult females of Moluccan megapodes on Haruku Island indicated that bird activity occurred in forest areas near their nesting sites. Birds were active in their nesting site at Tanjung Maleo, Marunimei, and Lalean forests. Marunimei Forest is ± 1.60 km northeast of Tanjung Maleo, and Lalean Forest is ± 2.50 km southeast of Tanjung Maleo. The Moluccan megapodes habitat was classified as moor-farm-field and dryland forest based on the land cover type. The type of land cover around the bird’s nesting site in Tanjung Maleo was classified as a development area because it was adjacent to a residential area. However, around the bird nesting site in Tanjung Maleo, there were still various types of vegetation specially guarded by the community as part of the bird’s nesting habitat. Meanwhile, the Marunimei forest, as the bird’s daily habitat, was classified as a moor-farm field, while the Lalean forest was classified as a dry land forest (Figure 2).
These results confirm previous research indicating that Moluccan megapodes could survive and thrive in various habitat types ranging from secondary forests to open beaches, lowland forests, and tropical rain forests (Dekker et al. 1995; Heij et al. 1997; Heij 2001; Heij & Rompas 2011). In contrast to their diverse daily habitats, bird nesting habitats were always found in coastal areas, specifically open beach areas surrounded by forest areas (Dekker et al. 1995; Jones et al. 1995; Dekker et al. 2000; Heij et al. 1997; Heij & Rompas 2011). Megapode species in island areas are known to be more active in tropical forests and use coastal areas for breeding. Therefore, both habitat types are essential for survival (Goth & Vogel 1995; Jones et al. 1995; Dekker et al. 2000; Pangau-Adam & Brodie 2019; Paguntalan et al. 2021). The daily activities of the Moluccan megapode within a radius of ± 2.50 km from their egg-laying locations in Tanjung Maleo indicated that most of their daily activities are not far from their egg-laying locations. Several studies of other bird species also show that most of the birds' daily activities occur in areas not far from their nesting sites (Ryan & Jamieson 1998; Yaremych et al. 2004; Bosch et al. 2010; Rechetelo et al. 2016).
Adult female Moluccan megapode used the forest in Tanjung Maleo for perching before starting nesting activities or as a perch after nesting, before flying away from the nest site (Heij et al. 1997; Heij & Rompas 2011). For chicks, the forest around their nesting site in Tanjung Maleo was used as a shelter from the moment they hatch (Heij et al. 1997; Heij & Rompas 2011) because of their super-precocial nature (Colar et al. 1994; Argeloo & Dekker 1996; Starck & Ricklefs 1998; Dekker et al. 2000). Consequently, vegetation around the nesting site was crucial to the chick’s survival. It has been reported that Moluccan megapode chicks immediately moved to nearby vegetation after hatching (Heij et al. 1997; Heij & Rompas 2011). The use of vegetation around the hatchery as a shelter for chicks has also been reported among the Australian brush-turkey chicks (Alectura lathami) (Goth & Jones 2001; Goth & Vogel 2002; Goth & Vogel 2003; Goth & Evans 2005).
Vegetation structure and floristic composition
Of the three forest locations used by the Moluccan megapodes, the Marunimei forest has the highest number of plant species (48 species). In contrast, the Tanjung Maleo forest has the most diminutive plant species (14) (Table 1). The number of plant species in the Tanjung Maleo forest is currently fewer than the study results in 1997. In 1997, approximately 20 species were found in the Tanjung Maleo forest (Heij et al. 1997; Heij & Rompas 2011). These results indicated that in the twenty-four years since 1997, the number of plant species in the Tanjung Maleo forest has decreased. Because Tanjung Maleo's forest was close to the villages, it was believed that the expansion of the residential area was responsible for the decline in species. The number of plant species in the Maluku megapod habitat on Haruku Island from this study was higher than the results of a survey conducted by Ahmad (2014) around bird nesting sites on Halmahera Island, which only found as many as 13 to 17 plant species.
This study also found that the highest number of plant families was found in the Marunimei forest area (30 families), and the lowest was in the Tanjung Maleo forest area (14 families) (Table 1, Figure 3). No dominant plant species families were found in the Tanjung Maleo forest; each family only consisted of one species. In contrast, in Marunimei and Lalean forests, members of the Fabaceae family dominated the vegetation. The current number of plant families in the Tanjung Maleo forest is the same as the 1997 study by Heij et al. (1997) and Heij & Rompas (2011), but in 1997 the Fabaceae family had more than one species.
The strata of vegetation growth in the three Moluccan megapodes habitat forest areas included trees, poles, saplings, and seedlings (Table 2). The tree strata dominated the forest area in Tanjung Maleo (63.39%) and Marunimei (43.18%), while the seedling strata dominated the Lalean forest area (44.35%). The F test showed that the vegetation's composition significantly differs between habitat forests (Fcount = 8.82 > Ftable = 4.26).
This study showed that the forest regions surrounding bird nesting sites were classified as having complex vegetation because they contain four growth strata: trees, poles, saplings, and seedlings. The Moluccan megapode habitat on Halmahera Island also consists of four growth strata (Ahmad 2014). Studies of several megapode species show that their habitat tends to be dominated by tree strata compared to other growth strata (Goth & Vogel 1995; Khairuddin & Yamin 2019; Pangau-Adam & Brodie 2019; Paguntalan et al. 2021; Dhafir et al. 2022 ). However, several species of megapodes, such as the Australian brush turkey (Alectura lathami) (Goth & Vogel 2003), the wattle brush turkey (Aepypodius arfakianus) (Pangau-Adam & Brodie 2019), and the orange-footed scrubfowl (Megapodius reindwartii) (Khairuddin & Yamin 2019) are also found in a sapling or seedling strata. Complex vegetation contributes to the survival of wild species populations by providing a suitable microclimate, shelter, and a place to rest and reproduce (Baldeck et al. 2012; Bu et al. 2014; Bergner et al. 2015). In Tanjung Maleo, the percentage of tree strata is currently higher than in 1997. In this study, the tree strata in the Tanjung Maleo forest reached 70 percent, whereas the 1997 study found only 67 percent (Heij et al. 1997; Heij & Rompas 2011). Likewise, tree strata dominated the Marunimei forest. On the other hand, the seedling layer dominated the Lalean forest. Tree strata in the Tanjung Maleo forest function as perching for birds when they come to the nest or leave their nesting sites, while the strata of seedlings and saplings serve as protection for the chicks after hatching (Heij et al. 1997; Heij & Rompas 2011). Observations in the study area show that the Moluccan megapodes also use trees in their habitat as perching to move between habitats or escape from predators. Individual birds used the tree layers in their habitat as perches, resting spots, and shelters. Moluccan megapodes' activity primarily occurs on the forest floor (Mackinnon & Wind 1980; del Hoyo et al. 1994; Strange 2012) and causes variations in vegetation strata to be essential for the survival of individual birds (Bucklin et al. 2015; Walther & Pirsig 2017; Velasques-Trujillo et al. 2021).
Species composition and diversity
Based on the importance value index (IVI), the dominant species in each forest area were different (Table 3). The dominant species in the Tanjung Maleo forest were air plants (Kalanchoe pinnata) (IVI = 67.96) and sword ferns (Nephrolepsis exalta) (IVI = 61.47). Marunimei forest was dominated by cogongrass (Imperata cylindrica) (IVI = 36.80) and coco-grass (Cyperus rotundus) (IVI = 32.59), and the Lalean forest was dominated by Indian camphorweed (Pluchea indica) (IVI = 24.23) and lanzones (Lansium domesticum) (IVI = 18.30). The dominant plant species in the Tanjung Maleo forest differed from the dominant species around the Moluccan megapodes nesting site on Halmahera Island in North Maluku. The vegetation around the nesting site at Galela on Halmahera Island was dominated by more varied species, namely bay hops (Ipomoea pescrapae), clover (Marsilea creanata), mangrove (Rhizophora sp), and tropical almond (Terminalia catapa) (Sjafani et al. 2015). These results indicated that plant species around bird nesting sites did not significantly affect bird arrivals for nesting. Dominant plant species in both forest areas adjacent to nesting sites (Marunimei and Lalean forests) act as shelters and support the daily activities of Moluccan megapodes on Haruku Island.
The highest diversity of plant species in the three forest areas around the Moluccan megapodes site was in the Marunimei forest (H’ = 3.87), while the lowest was in the Tanjung Maleo forest (H’ = 2.27) (Table 4a). In terms of diversity, the plant species diversity in the three forest regions was categorized as moderate. In addition to its diversity, species abundance distribution in the three forest areas, as measured by an evenness index, was close to one. The Lalean forest had the most notable species distribution equality (E = 0.92) (Table 4a). The evenness index indicates that the distribution of plant species abundance in the three locations tends to be relatively even and does not indicate the dominance of one or more species. Nevertheless, according to the importance value index, each type of bird habitat contains several dominant plant species. Tanjung Maleo forest has a greater variety and more even distribution of plant species than Halmahera Island’s forest (Sjafani et al. 2015). The diversity and evenness of plant species in the Moluccan megapode habitat were higher than the orange-footed scrubfowl habitat on Moyo Island, West Nusa Tenggara (H’ = 2.42 dan E = 0.86) (Khairuddin & Yamin 2019).
This study found that from the three forest areas, the similarity of plant species between Tanjung Maleo forest, a bird nesting site, with the other two forests was low (IS = 25.81% and IS = 28.57%). On the other hand, the similarity of plant species between Marunimei and Lalean forests was high (IS = 60.53%) (Table 4b). Therefore, the dissimilarity of plant species between the bird’s nesting site in Tanjung Maleo and the other two forest areas indicates the difference in vegetation between the bird’s nesting and daily habitats. The difference in species diversity between the forests surrounding bird nesting sites on Haruku Island and Halmahera Island indicates that the habitat types of Moluccan megapodes were diverse and not influenced by specific plant species. The low average similarity between the three forests (SImean = 38.30 percent) reflects the diversity of vegetation in the forest surrounding the Haruku Island bird nesting site. However, the similarity index between the three bird habitats revealed vegetation type differences between nesting habitats and the habitat of the Moluccan megapodes on Haruku Island.
CONCLUSION
This study enhances our understanding of the habitat conditions of Moluccan megapodes on Indonesia’s Haruku Island. It was determined that the Moluccan megapodes on Haruku Island were active in the forest area approximately 2.50 kilometers from their nesting sites. Based on the distance from the nesting site, the forest area in Tanjung Maleo serves as a bird nesting habitat. In contrast, the other two forests (Marunimei and Lalean) are a bird’s daily habitat. Haruku Island’s bird habitat consists of four layers of vegetation that support the activities of chicks and adult birds during nesting, foraging, and perching. Variations in plant species diversity among the three habitats indicate Moluccan megapodes’ ability to occupy diverse habitat types. Regarding plant species diversity, nesting habitats and daily habitats of birds differ by more than 70% of plant species, indicating differences in vegetation between nesting habitats and daily habitats of birds. An important finding from this study was that conservation efforts for the Moluccan megapodes on Haruku Island should prioritize nesting and daily habitats in the forest area around the bird's nest sites.
ACKNOWLEDGMENTS
Special thanks to D. Usemahu and Kailolo Village for their assistance and cooperation during fieldwork, R. Huda, and International Animal Rescue Indonesia Foundation for providing a tracking receiver and a Yagi antenna and School of Life Science and Technology, Institut Teknologi Bandung for supporting facilities during the study. This research was funded by the Directorate General of Higher Education, Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia as a scholarship and doctoral research grant to the first author.
REFERENCES
- Ahmad Z. 2014. Selection strategy for laying eggs by mamoa bird (Eulipoa wallacei Gray, 1980) in Galela. Biogenesis 2:79–88 [in Indonesia].
- Aldrian E, Dwi Susantio R. 2003. Identification of three dominant rainfall regions within Indonesia and their relationship to sea surface temperature. Internasional. Journal of Climatology 23:1435–1452.
- Argeloo M, Dekker RWRJ. 1996. Exploitation of megapode eggs in Indonesia: the role of traditional methods in the conservation of megapodes. Oryx 30(1):59–64.
- Atikah SN, Yahya MS, Norhisham AR, Kamarudin N, Sanusi R, Azhar B. 2021. Effects of vegetation structure on avian biodiversity in a selectively logged hill dipterocarp forest. Gobal Ecology and Conservation 28:e01660. DOI: 10.1016/j.gecco.2021.e01660.
- Badan Pusat Statistik Propinsi Maluku. 2022. Maluku Province in Figures 2022. Ambon (IN): Badan Pusat Statistik (BPS) Propinsi Maluku.
- Baldeck CA, Harms KE, Yavitt JB, John R, Turner BL, Valencia R, Navarrete H, Davies SJ, Chuyong GB, Kenfack D, Thomas DW, Madawala S, Gunatilleke N, Gunatilleke S, Bunyavejchewin S, Kiratiprayoon S, Yaacob A, Supardi MNN, Dalling JW. 2012. Soil resources and topography shape local tree community structure in tropical forests. Proceedings of the Royal Society B. Biological Sciences 280:2012 – 2532.
- Barbour MG, Burk JH, Pitts WD. 1987. Terrestrial Plant Ecology. New York (US): Benyamin Cummings Publishing Company.
- Bendre AM, Kumar A. 2010. A Textbook of Practical Botany II: Taxonomy, Economic Botany, Embryology, Anatomy, Ecology, Physiology, Biostatistics, Cytology, and Genetics. New Delhi (IN): Rastogi Publications.
- Bergner A, Mustafa A, Hasan E, Nicklas J, Mats N, Westerberg L, Milberg P. 2015. Influences of forest type and habitat structure on bird assemblagesof oak (Quercus spp.) and pine (Pinus spp.) stands in southwestern Turkey. Forest Ecology and Management 336:137–147. DOI: 10.1016/j.foreco.2014.10.025.
- BirdLife International. 2016. Eulipoa wallacei. The IUCN Red List of Threatened Species 2016: e.T22678632A92782396. http://dx.doi.org/10.2305/IUCN. UK. 2016-3.RLTS.T22678632-A92782396.en
- BirdLife International. 2022. Species factsheet: Eulipoa wallacei. Downloaded from http://www.birdlife.org on 06 Juli 2022.
- Bloom PH, Clark WS, Kidd JW. 2007. Capture techniques. In: Bird DM, Bildstein KL, Barber DR, Zimmerman A, editors. Raptor Research and Management Techniques. Blaine (US): Hankock House Publishers. p. 193–219
- Bosch R, Real J, Tinto A, Zozaya EL, Castell C. 2010. Home-range and patterns of spatial use in territorial Bonelli’s eagles Aquila fasciata. Ibis 152:105–117.
- Bowman J, Wallace MC, Ballard WB, Brunjes IV JH, Miller MS, Marquette-Hellman J. 2002. Evaluation of two techniques for attaching radio transmitters to turkey poults. J Field Ornithol 73(3):276–280.
- Bu W, Zang R, Ding Y. 2014. Functional diversity increases with species diversity along successional gradient in a secondary tropical lowland rainforest. Tropical Ecology 55:393–401.
- Bucklin DN, Basille M, Benscoter AM, Brandt LA, Mazzotti FJ, Romanach SS, Speroterra C, Watling JI. 2015. Comparing species distribution models constructed with different subsets of evironmental predictors. Diversity and Distributions 21:23–35.
- Busse P, Meissner W. 2015. Bird ringing station manual. Warsaw (PL): De Gruyter Open Ltd.
- Collar NJ, Crosby MJ, Stattersfield AJ. 1994. Birds to watch 2. The world list of threatened birds. BirdLife Conservation Series No. 4. Cambridge (UK): BirdLife International.
- Colwell RK. 2009. Biodiversity: concepts, patterns, and measurement. In: Levin SA, Carpenter SR, Godfray HCJ, Kinzig AP, Loreau M, Losos JB, Wilcove DS, editors. The Princeton Guide to Ecology. New Jersey (US): Princeton University Press. p. 257–263.
- De Beer SJ, Lockwood GM, Raijmakers JHFA, Raijmakers JMH, Scott WA, Oschadleus HD, Underhill LG. 2001. Safring Bird Ringing Manual. ADU Guide 5. The South African Bird Ringing Unit – Avian Demography Unit. Rondebosch (ZA): University of Cape Town.
- Dekker RWRJ, Fuller RA, Baker GC. 2020. Megapodes: status survey and conservation action plan 2000–2004. WPA/BirdLife/SSC Megapode Specialist Group. Gland (CH): IUCN and Reading: the World Pheasant Association.
- Dekker RWRJ, Argeloo M, Jepson P. 1995. Notes on the Moluccan megapode Eulipoa wallacei (G.R. Gray, 1860) following the rediscovery of two major nesting grounds. Zoologische Mededelingen 69(19):251–260.
- del Hoyo J, Elliott A, Sargatal J. 1994. Handbook of birds of the world, Volume 2, New World vultures to guineafowl. Barcelona (ES): Lynx Edicions.
- Devenish-Nelson ES, Weidemann D, Townsend J, Nelson HP. 2019. Pattern in island endemic forest-dependent bird research: the Caribbean as a case study. Biodiversity and Conservation 28:1885–1904. DOI: 10.1007/s10531-019-01768-x.
- Dhafir F, Bustamin, Isnainar, Trianto M. 2022. Maleo bird laying behavior (Macrocephalon maleo S. Muller) at Lore Lindu National Park, Saluki Blok. Media Eksakta 18(1):74–80. DOI: 10.22487/me.v18i1.1712.
- Diemer KM, Wheeler HE, Nocera JJ. 2014. Retention rates of glue-attached radio-transmitters on two small bird species with contrasting life histories. The Wilson Journal of Ornithology 126(1):39 – 46.
- Dri GF, Fontana CS, de Sales Dambros C. 2021. Estimating the impacts of habitat loss induced by urbanization on bird local extinctions. Biological Conservation 256:109064. Doi: 10.1016/j.biocon.2021.109064.
- Duncan RP, Blackburn TM. 2007. Causes of extinction in island birds. Animal Conservation 10:149–150.
- Feng G, Huang X, Mao L, Wang N, Yang X, Wang Y. 2020. More endemic birds occur in regions with stable climate, more plant species and high altitudinal range in China. Avian Research 11:7. DOI: 10.1186/s40657-020-00203-y.
- Gao T, Hedblom M, Emilsson T, Nielsen AB. 2014. The role of forest stand structure as a biodiversity indicator. Forest Ecology and Management, 330:82–93. DOI: 10.106/j.foresco. 2014.07.007
- Goth A, Evans CS. 2005. Life history and social learning: megapode chicks fail to acquire feeding preference from conspecifics. Journal of Comparative Psychology 119(4):281–386.
- Goth A, Jones DN. 2001. Transmitter attachment and its effects on Australian brush turkey hatchlings. Wildlife Research 28(1):73–78.
- Goth A, Vogel U. 1995. Status of the Polynesian Megapodius pritchardii on Niuafo’ou (Tonga). Bird Conservation International 5:117–128.
- Goth A, Vogel U. 2002. Social behaviour of two free-ranging chicks of Australian brush-turkey Alectura lathami. Corella 26(2):55–58.
- Goth A, Vogel U. 2003. Juvenile dispersal and habitat selectivity in the megapode Alectura lathami (Australian brush turkey). Wildlife Research 30(1):69–74.
- Gunawan H, Sugiarti, Wardani M, Mindawati N. 2019. 100 species pohon nusantara target konservasi ex-situ taman keanekaragaman hayati. Bogor: IPB Press.
- Heij CJ, Rompas CFE. 2011. Ecology of Moluccan megapode (Momoa bird: Eulipoa wallacei) on Haruku Island and other island in Maluku, Indonesia. 3rd Ed. Rotterdam (NL): Meidoornsingel.
- Heij CJ. 2001. On the earliest written descriptions of Moluccan megapode Eulipoa wallacei and its peculiar nesting behaviour. Deinsea 8:253–255.
- Heij CJ, Rompas CFE, Moeliker CW. 1997. The biology of the Moluccan megapode Eulipoa wallacei (Aves, Galliformes, Megapodiidae) on Haruku and other Moluccan islands Part 2: Final report. Deinsea 3:1–124.
- Jones D, Dekker R, Roselar C. 1995. The megapodes. New York (US): Oxford University Press Inc.
- Khairudin K, Yamin M. 2019. Megapodius reinwardt conservation based on ecological knowledge of local people to support sustainable ecotourism on Moyo Island. AIP Conference Proceedings 2199:050004. DOI: 10.1063/1.5141302
- Krebs CJ. 1998. Ecological methodology. 2nd Edition. New York (US): Benjamin Cummings.
- Kusmana C. 2017. Metode survey dan interpretasi data vegetasi. Bogor (ID): IPB Press.
- Llamas KA. 2003. Tropical flowering plants: a guide to identification and cultivation. Portland (US): Timber Press Inc.
- Lemmens RHMJ, Soerianegara I, Wong WC. 1995. Plant resources of South-East Asia, No. 5(2) Timber Trees: Minor Commercial Timbers. Bogor: Prosea Foundations
- MacKinnon J, Wind J. 1980. Birds of Indonesia. Rome (IT): Food and Agriculture of the United Nation.
- Matthews TJ, Cottee-Jones HEW, Whittaker RJ. 2015. Quantifying and interpreting nestedness in habitat islands: a synthesis analysis of multiple data- sets. Diversity and Distribution 21:392–404. DOI: 10.1111/ddi.12298.
- Melo MA, Da Silva MAG, Piratelli AJ. 2020. Improvement of vegetation structure enhances bird functional traits and habitat resilience in an area of ongoing restoration in the Atlantic Forest. An Acad. Bras. Cienc 92(Suppl 2):e20191241.
- Moudry V, Moudra L, Bartak V, Bejcek V, Gdulova K, Hendrychova M, Moravec D, Musil P, Rocchini D, Stastny K, Volf O, Salek M. 2021. The role of the vegetation structure, primary productivity, and senescence derived from airborne LiDAR and hyperspectral data for bird's diversity and rarity on a restored site. Landscape and Urban Planning 210:104064. DOI: 10.1016/j.landurbplan.2021.104064
- National Standardization Agency of Indonesia. 2010. Land Cover Classification. Indonesian National Standart (SNI). No. 7645. Jakarta
- Odum EP. 1983. Basic Ecology. Philadelphia (US): Saunders College.
- Paguntalan LJ, Oquendo MFJM, Bonares BA, Villegas GM. 2021. Ecology of Philippine scrubfowl Megapodius cumingii on Palwan with notes on other islands. Journal of Asian Ornithology 37:99–106.
- Pangau-Adam MZ, Brodie JF. 2019. Threats to the populations of two endemic brushturkey species in Indonesian New Guinea. Journal of Asia-Pasific Biodiversity 12:488–492. DOI: 10.1016/j/japb.2019.07.005
- Peng Y, Fan M, Song J, Cui T, Li R. 2018. Assessment of plant species diversity based on hyperspectral indices at fine scale. Scientific Report 8:4776. DOI: 10.1038/s41598-018-23136-5.
- Radley PM, van Etten EJB, Blake S, Davis R.A. 2020. Breeding and feeding habitat selection by an island endemic bird may increase its vulnerability to climate change. Biotropica 00:1–11. DOI: 10.1111/btp.12885
- Rahman AU, Khan SM, Khan S, Hussain A, Rahman IU, Iqbal Z, Ijaz F. 2016. Ecological assessment of plant communities and associated edaphic and topographic variables in the Peochar Valley of the Hindu Kush Mountains. Mountain Research and Development 36(3):332–341.
- Rechetelo J, Grice A, Reside AE, Hardesty BD, Moloney J. 2016. Movement patterns, home range and habitat selection of an endangered resource tracking species, the black throated finch (Poephila cincta cincta). PLoS ONE 11:20167254. DOI: org/10.1371/journal.pone.0167254.
- Rocha R, Virtanen T, Cabeza M. 2015. Bird assemblages in Malagasy forest-agriculture frontier: effects of habitat structure and forest cover. Tropical Conservation Science 8(3):681–710
- Ruiz-Gutierrez V, Gain TA, Dhondt A. 2008. Habitat fragmentation lowers survival of a tropical forest bird. Ecological Applications 18(4):838–846.
- Rutten G, Ensslin A, Hemp A, Fischer M. 2015. Vertical and horizontal vegetation structure across natural and modified habitat types at Mount Kilimanjaro. PLoS ONE 10(9):e0138822. Doi: 10.1371/journal.pone.0138822.
- Ryan CJ, Jamieson IG. 1998. Estimating the home range and carrying capacity for Takahe (Porphyrion mantelli) on predator-free offshore islands: implications for future management, New Zealand Journal of Ecology 22(1):17–24.
- Shannon CE, Weaver W. 1963. The mathematical theory of communication. Urbana. Illinois (US): University of Illinois Press.
- Sjafani N, Hakim L, Nurgiartiningsih VMA, Suyadi R. 2015. The habitat and estimation population of mamoa bird (Eulipoa wallacei) in Galela-Halmahera. Journal of Biodiversity and Environmental Science 7(2):1–9.
- Sodhi NS, Sekercioglu CH, Barlow J, Robinson SK. 2011. The state of tropical bird biodiversity. In: Sodhi NS, Sekercioglu CH, Barlow J, Robinson SK, editors. Conservation of Tropical Birds. First Edition. Lichester (UK): Willey-Blackwell Publishing Ltd. p. 1–26.
- Soerianegara I, Lemmens RHMJ. 1994. Plant resources of South-East Asia, No. 5(1) Timber Trees: Major Commercial Timbers. Bogor: Prosea Foundations
- Sorensen T. 1948. A method of establishing roups of equal amplitude in plant sociology based on similarity of species and its application to analyses of the vegetation on Danish commons. Kongelige Danske Videnskabernes Selskab 5(4):1–34.
- Strange M. 2012. A photographic guide to the birds of Indonesia. 2nd Edition. Singapore (SG): Tuttle Publishing.
- Starck JM, Ricklefs RE. 1998. Pattern of development: the altricial- precocial spectrum. In: Starck JM, Ricklefs RE, editors. Avian Growth and Development: Evolution Within the Altricial Precocial Spectrum. New York (US): Oxford University Press. p. 3–30.
- Tassicker AL, Kutt AS, Vanderduys E, Mangru S. 2006. The effects of vegetation structure on the birds in a tropical savanna woodland in north-eastern Australia. The Rangeland Journal 28:139–152.
- Taylor S, Kumar L. 2016. Global climate change impacts on Pacific Islands terrestrial biodiversity: a review. Tropical Conservation Science 9:203–223.
- Tchoumnbou MA, Malange EFN, Tiku CT, Tibab B, Fru-Cho J, Tchuinkam T, Awah-Ndukum J, Nota DA, Sehgal RNM. 2020. Response of understory bird feeding groups to deforestation gradient in a tropical rainforest of Cameroon. Tropical Conservation Science. 13:1–12. DOI: 10.1177/1940082920906970.
- Tews J, Brose U, Grimm V, Tielborger K, Wichmann MC, Schwager M, Jeltsch F. 2004. Animal species diversity is driven by habitat heterogeneity/diversity: the importance of keystone structures. Journal of Biogeography 31(1):79–92. DOI: 10.1046/j.0305-0270.2003.00994.x.
- Tulloch AIT, Barnes MD, Ringma J, Fuller AR, Waston JEM. 2016. Understanding the importance of small patches of habitat for conservation. J Appl Ecol 53:418–429.
- Velásquez-Trujillo V, Betancurt-Grisales JF, Vargas-Daza AM, Lara CE, Rivera-Páez FA, Fonturbel FE, Castaño-Villa GJ. 2021. Bird Functional Diversity in Agroecosystems and Secondary Forests of the Tropical Andes. Diversity 13:493. DOI: 10.3390/d13100493.
- Walther BA, Pirsig LH. 2017. Determining conservation priority areas for palearctic passerine migrant birds in sub-Saharan Africa. Avian Conservation and Ecology 12(1):2. DOI:10.5751/ACE-00934-120102.
- Whitmore T. C. 1978. Tree flora of Malaya: a manual for foresters. Volume 3. Malaysia: Longman Malaysia SDN.
- Whitworth D, Newman S, Mundkur T, Harris P. 2007. Bird handling and ringing techniques. In: Whitworth D, Newman SH, Mundkur T, Harris P, editors. Wild Birds and Avian Influenza: An Introduction to Applied Field Research and Disease Sampling Techniques. Rome (IT): Food and Agricultural Organization of the United Nation. p. 51–72.
- Wirjohamidjojo S, Swarinoto Y. 2010. Indonesian Climate (Dynamics and Synoptic), Indonesian Meteorology. Jakarta (ID): Climatology and Geophysical Agency.
- Woodward A, Hutten KM, Boetsch JR, Acker SA, Rochefort RM, Bivin MM, Kuth LL. 2009. Forest Vegetation Monitoring Protocol for National Parks in The North Coast and Cascades Network: U.S. Geological Survey Techniques and Methods 2-A8, U.S. Geological Survey, Reston.
- Yaremych SA, Novak RJ, Raim AJ, Mankin PC, Warner RE. 2004. Home range and habitat use by American crows in relation to transmission of West Nile virus. Wilson Bulletin 116(3):232–239.
- Yuni LPEK, Yuda IP. 2020. The Island Biogeography of Wallacea and Krakatoa Island. In: Goldstein MI, DellaSala DA, editors. Encyclopedia of the World’s Biomes. Volume 1. London (UK): Elsevier. p. 217–229.