Line Transect Method Research Articles

Abundance of humpback whales in the eastern Indian sector of the Southern Ocean in 2018/19 using opportunistic sighting survey data with a note on the occurrence of other cetaceans

Past commercial whaling depleted the humpback whale in the Southern Ocean; however, its population has recovered since hunting was terminated in 1966. Information on abundance is essential not only managing target animals but understanding the ecosystem because the species is one of the main consumers of Antarctic krill. Abundance of this species has not been reported in the eastern Indian sector (80–150°E) of the Southern Ocean since the mid-2000s. A multidisciplinary ecosystem survey focusing on Antarctic krill was conducted in the area by the Japanese research vessel Kaiyo-maru in 2018/19 austral summer. An opportunistic cetacean sighting survey (platform of opportunity (POP) survey) was conducted as part of the survey. Four baleen and five toothed whale species were sighted during the sighting survey. Humpback whales (113 schools/178 animals) were most frequently observed, followed by fin whales (15/36). Abundance of humpback whales was estimated as 22,395 individuals (CV = 0.270, 95 % confidence intervals: 13,310–37,663) based on the design-based line transect method. Krill consumption by humpback whales in this area was tentatively estimated as 1.336 million tons, corresponding to 30.9 % of krill biomass, although the amount varied greatly depending on the consumption rate’s assumption. The estimated abundance was comparable with previous estimates, however, there are some caveats in interpreting the results. As no approaching whale sightings were made during this POP survey, the proportion of sightings of unidentified large whales was high, possibly leading to an underestimation of the abundance. Dedicated sighting surveys are desirable to obtain more accurate and unbiased abundance estimates, especially for management purposes, although the results of this study could be used for ecological studies in combination with other data sets recoded by the multidisciplinary survey.

Community Diversity of Fungi Carried by Four Common Woodpeckers in Heilongjiang Province, China.

Woodpeckers exhibit selectivity when choosing tree cavities for nest development in forest ecosystems, and fungi play a significant and important role in this ecological process. Therefore, there is a complex and intricate relationship between the various behaviors of woodpeckers and the occurrence of fungal species. Research into the complex bond between fungi and woodpeckers was undertaken to provide more information about this remarkable ecological relationship. Through the process of line transect sampling, woodpecker traces were searched for, and mist nets were set up to capture them. A total of 21 woodpeckers belonging to four species were captured. High-throughput sequencing of the ITS region was performed on fungal-conserved samples to enable an in-depth analysis of the fungal communities linked to the woodpeckers' nests. Members of Ascomycota were the most abundant in the samples, accounting for 91.96% of the total, demonstrating the importance of this group in the forest ecosystem of this station. The statistical results indicate significant differences in the fungal diversity carried by woodpeckers among the different groups. Species of Cladosporium were found to be the most prevalent of all the detected fungal genera, accounting for 49.3%. The top 15 most abundant genera were Cladosporium, Trichoderma, Beauveria, Epicococcum, Hypoxylon, Penicillium, Nigrospora, Aspergillus, Oidiodendron, Cercospora, Talaromyces, Phialemo-nium, Petriella, Cordyceps, and Sistotrema. The standard Bray-Curtis statistical technique was used in a hierarchical clustering analysis to compute inter-sample distances, allowing for the identification of patterns and correlations within the dataset. We discovered that in the grouped samples from woodpeckers, there were differences in the diversity of fungal communities carried by four woodpecker species, but the less dominant fungal species were still similar. The findings highlight the need to consider these diverse ecological linkages in woodpecker research and conservation efforts.

Habitat Characteristics and Morphology of Chlorophyta (Order Bryopsidales) on the Intertidal of Pandanan Hamlet, West Sekotong

Bryopsidales order macroalgae can be found on various substrates in marine waters. The Bryopsidales order has a morphological form that is shaped like a filament or shaped like a leaf and has pigments like land plants. The study aims to determine the habitat characteristics and morphology of the Bryopsidales order on the coast of Pandanan Hamlet. Sampling was carried out using the line transect method and 1x1 meter quadrant. A total of 5 transect lines were stretched from the shoreline to the point where macroalgae were found. Each transect is placed in quadrants every 20 meters in a zigzag manner. The Bryopsidales order found consisted of 13 species, 3 families and 4 genera growing in habitats with substrates of loamy sand, loam, sand, and sandy loam, rock, dead coral, coral fragments, and live coral. There are 3 types of holdfast were found, namely bulbous, fibrous, and sprawling growers. There are also three blade shapes in this order, namely creeping blades in the Caulerpaceae family, segmented blades in the Halimedaceae family, and blades that are neither creeping nor segmented that resemble sponges in the Codiaceae family.

Avifaunal Diversity of Cantonment Area, Lucknow, Uttar Pradesh, India

Birds have always fascinated mankind with their naturally attractive plumage, harmonious songs and creative behavior. Avifaunal Diversity is one of the most important ecological indicators, displays the environmental quality of an area, its pollution level, safety and accessibility of food and habitat. Cantonment area is one of the distinctive locations represents a sub-urban area of Lucknow. Cantonment area is an abundant green area around 23.43 square kilometer, preferred by number of bird species at its different types of habitat like shaded trees, bushes, grasses, grounds some parks and buildings etc. They provide food and shelter for the urban terrestrial bird’s community. The study was performed in Cantonment area for six months from February, 2022 to July, 2022. Bird surveys were carried out using the Line transect method across four different transects at this area. As a result of six months observation, 55 bird species were recorded belonging to 15 orders and 29 families. Majority of species were observed in the order Passeriformes and family Muscicapidae. Data analysis showed that 29 avian species were Common, 12 were Fairly Common, 6 were Uncommon and 8 were Rare, whereas 52 avian species were residents and 3 avian species were migrants.

EDNA Metabarcoding Reveals the Species-Area Relationship of Amphibians on the Zhoushan Archipelago.

The species-area relationship is important for understanding species diversity patterns at spatial scales, but few studies have examined the relationship using environmental DNA (eDNA) techniques. We investigated amphibian diversity on 21 islands of the Zhoushan Archipelago and nearby mainland areas in China using the combination of eDNA metabarcoding and the traditional line transect method (TLTM) and identified the species-area relationship for amphibians on the islands. The mean detection probability of eDNA is 0.54, while the mean detection probability of TLTM is 0.24. The eDNA metabarcoding detected eight amphibian species on the islands and nine species in the mainland areas, compared with seven species on the islands and nine species in the mainland areas that were identified by TLTM. Amphibian richness on the islands increased with island area and habitat diversity. The species-area relationship for amphibians in the archipelago was formulated as the power function (S = 0.47A0.21) or exponential function (S = 2.59 + 2.41 (logA)). Our results suggested that eDNA metabarcoding is more sensitive for the detection of amphibian species. The combined use of eDNA metabarcoding and the traditional line transect method may optimize the survey results for amphibians.

Heterogeneric Diversity and Richness of Avifauna in a Degraded Landscape of Arial Beel in Bangladesh

Bird diversity and richness reflect the habitat quality of ecosystems. The species composition, diversity, and richness of birds were studied at Shologhar Union, a degraded landscape of Arial Beel, from March 2016 to February 2017, using line transect and point count methods. A total of 75 species of birds belonging to 14 orders and 35 families were recorded; most of them were residents (83%). Non-passerine birds were predominant (40 species, 53% of total species), with 18 families and 38 genera. Only one near-threatened species (Yellow Wattled Lapwing Vanellus malabaricus) was recorded. Among resident birds, Baya weaver (Ploceus philippinus) was dominant, and the Yellow Wagtail (Motacilla flava) was predominant among migratory birds. Most species were terrestrial (51 spp., 68% of total birds), contributing only 23% of the population. The individual rarefaction revealed the highest species richness in March and the lowest in May and June. The highest population was recorded in winter (38%), and insectivore species (40%) were the highest. No significant seasonal variation occurred in the richness of birds (Kruskal-Wallis test: K = 0.05 df = 2, p = 0.971) and in different feeding guilds (Kruskal-Wallis test: K = 0.86, df = 5, p = 0.65). Ardeidae and Sturnidae represented the highest diversified families (6 species in each, RDi = 8), and Baya Weaver contributed the highest (26%) population. The presence of different species of birds suggests that this site could provide a suitable habitat for wild birds, and restoration management of this part of Arial Beel should require conserving the habitat of avifauna. Jagannath University Journal of Life and Earth Sciences, 9(1): 19-44, 2023 (June)

Relative Abundance, Diversity and Threats of Avian Fauna at Dhanmondi Lake in Dhaka, Bangladesh

A study was conducted on the relative abundance, diversity, and threats of avifauna in Dhanmondi Lake, Dhaka, Bangladesh from March to December 2021. Data was collected by following the line transect sampling method and direct field observations, where four days were spent every month in the study area. A total of 34 species of birds were observed, belonging to 9 orders and 20 families. Out of 34 species of birds, 94% were residents and 6% were migrants; of them, 55% were non-passerines and 45% were passerines. The relative abundance of avifauna was also estimated as 29% of species being very common, 15% being fairly common, 27% being common, and 29% being few. The highest number of individuals was observed in December (209 individuals), followed by 199 individuals in April, 189 individuals in March, 187 individuals in October, 178 in November, 177 in August, and 170 in June. The Shannon-Weiner index was estimated to be at its maximum (H′ = 2.98) in March-21, and its minimum value was obtained (H′ = 2.62) in June-21. Similarly, the value of Simpson’s index of diversity was obtained to be maximum (D = 0.09) in June-21 and minimum (D = 0.06) in December-21. Human activities such as large gatherings, random assemblies, festivals, dumping of waste, throwing of papers, polythene, and plastics here and there, and finally, noises from the different vehicles, were identified as major threats to avian species. Jagannath University Journal of Life and Earth Sciences, 9(1): 95–109, 2023 (June)

Assessing coarse woody debris by integrating full area sampling and line intersect sampling: Combining the best of both worlds

Effective and comprehensive monitoring of the quantity of deadwood has become an important aspect of forest inventories for studies on structural and demographic dynamics, biodiversity and carbon stocks. Assessing dead wood quantity, however, is challenging and time consuming due to the structural complexity of deadwood. To monitor coarse woody debris (CWD) in a 10-year remeasuring cycle, we propose to combine full area sampling, to assess and position large-diameter CWD, with line intersect sampling, to estimate the volume of small-diameter CWD. The aim was to simultaneously I) lower the work load in the field, II) ensure low variability in average CWD volume and III) enable remeasurement of a high share of individual CWD objects to study dead wood dynamics and related biodiversity. Using data from 1601 circular plots measured with full area sampling in 16 temperate forest reserves (Flanders, northern Belgium), we simulated line intersect transects and tested threshold diameters between 10 and 130 cm to subdivide CWD to be measured with full area or line intersect sampling. The work load of the combined sampling with a threshold diameter of 20 to 40 cm was about 50 to 90% of the full area sampling work load respectively. Yet, no significant increase in the coefficient of variation (CV) of the average CWD volume was registered for threshold diameters up to 30 cm (133 %) compared to the full area sampling (125 %). The probability to relocate a 30 cm diameter CWD object after 10 years was 50 % and the probability for remeasuring increased with diameter. Using full area sampling with 10 cm threshold results in only 32 % of the objects relocated and remeasured after 10 years; using the combined sampling, only positioning logs over 30 cm increases this figure to 67 %, thus avoiding idle work. We conclude that combining full area and line intersect sampling has the advantage of lowering the work load, increasing the share of relocated objects over time, while not significantly increasing the variability in average CWD volume. An optimal threshold diameter between both methods was comprised between 20 and 40 cm but might further depend on relative importance of work load, need for relocation, CV, the study setup (e.g. number and size of plots), stand characteristics (e.g. CWD volume, dominant tree species) and decay rate. We propose to use a 30 cm threshold diameter for measuring CWD in temperate forest reserves.

Relationships between Anthropogenic Activities and Distribution of Medium to Large Mammal Species Assemblage in Madi Wildlife Corridor: Implication for Biodiversity Conservation in Uganda

Wildlife corridors between protected areas increase connectivity by integrating populations into single demographic units, thereby increasing gene flows within populations and thus probability of survival. This study assessed the relationship between anthropogenic activities and mammal species assemblage within and around Madi wildlife corridor. The study adopted recce walks along a zig-zag line transect and straight line transect methods of game tracking. Global Position System (GPS) was used to map locations of direct mammal sightings, vocalizations, tracks, dung/droppings, diggings, carcasses, and skeletal remains of mammal species. Similarly, anthropogenic activities such as hunting using bow and arrows, rifles, trapping, tree cutting, charcoal burning, bush burning, cultivation, and settlements that seemed to influence assemblage of the mammals in the area of study were mapped. The result showed that the Madi wildlife corridor still contained diverse mammal species including but not limited to; the African Elephants (Loxodonta Africana sp.), Buffaloes (Syncerus caffer) Leopards (Panthera pardus), Spotted Hyena (Crocuta Crocuta), Northern Giraffe (Giraffa Camelopardalis), Uganda kob (Kobus kob thomasi), Hartebeest (Alcelaphus buselaphus) and Reedbuck (Redunca arundinum), which were comparable to that of the adjacent Murchison Falls National Park (MFNP). The relationship between anthropogenic activities and species assemblage showed a negatively skewed distribution of some of the large mammal species specifically Elephants, Giraffes, and Hippopotamus. The study recommends gazettement of a wildlife corridor between MFNP and East Madi Wildlife Reserve to promote wildlife connectivity between two adjacent ecosystem-protected areas in northern Uganda. As a long-term strategy for wildlife conservation, it is crucial to undertake a systematic assessment and prioritization and demarcation of wildlife corridors and development of a comprehensive action plan for securing them. We further recommend development of a national Wildlife Corridor Regulations to provide a framework for the sustainable conservation of biodiversity

Macrozoobentos Diversity In The Mangrove Ecosystem In Bagan Asahan Village, North Sumatra Province

Macrozoobenthos are organisms that live by crawling, sticking, burrowing, and burrowing both at the bottom of the water and on the surface of the water bottom. Macrozoobenthos that live in mangrove areas mostly live on hard sediments to mud. The existence of macrozoobenthos can be influenced by various environmental factors such as the physical, chemical, and biological properties of water. This research aims to determine diversity, uniformity, and the macrozoobenthos dominance of the mangrove ecosystem in Bagan Asahan Village. The method used in this research is to combine two methods, namely the square method and the line transect method. The quadratic method is used to see the macrozoobenthos found in the quadratic method in a biological system, while the line transect method is used as a point to determine the description of the macrozoobenthos. The results of the research show that there are 8 species of macrozoobenthos consisting of 3 classes with a total of 179 individuals. The diversity of macrozoobenthos in the mangrove ecosystem area in Bagan Asahan Village is classified as moderate with a diversity index H'' ranging from 1.54-2.01, the uniformity index is classified as stable ranging between E= 0.76-0.99 and the dominance index is low, ranging between C= 0.14-0.31. Keywords: Tanjung Balai, Macrozoobenthos, Mangrove, Diversity

Avian species and diversity on the campus of Universitas Sumatera Utara, Medan City

Universitas Sumatera Utara (USU) is strategically situated for conducting investigations into the biodiversity of flora and fauna, serving as a source of genetic resources for educational purposes. USU, as a green campus, plays a multifunctional role in determining, protecting, and disseminating information regarding biodiversity, including avian diversity, to support environmentally sustainable development. The USU campus area essentially serves as an urban zone with a focus on species diversity and conservation, making it a key aspect of management. This study aims to identify bird species and diversity on the campus and analyze the diversity index and evenness of bird species on the campus. The methods employed involve direct observations using the line transect method combined with the point count method. We documented a total of 36 bird species, encompassing 22 families. The Avian Diversity Index value on the campus was calculated as 3.117, and the Avian Evenness Index was 0.870. The most prevalent families were Columbidae and Cisticolidae, constituting 3.8% of the total.

Population of The Javan Surili Langur (Presbytis Comata) in The Taman Safari Indonesia Bogor Forest Area

Taman Safari Indonesia Bogor is a buffer zone for the Taman Nasional Gunung Gede Pangrango conservation forest area and is one of the habitats for the Javan surili langurs, but there is no research data on wild Javan surili langur populations. The object of research is to find out how many populations of Javan surili langurs are in the TSI Bogor forest area. The research method used the line transect method by collecting data on the number of individuals, the number of groups, the sex ratio, and the age structure. The research was conducted in four observation areas with varying lengths, observations were made at (06.00 - 17.00 WIB), and four repetitions were carried out on each observation path, the results showed that there were 16 Javan surili langurs individuals divided into one group, and the estimated population density was 0.06 individual/ha. The sex diversity of male and female surili langurs in the TSI Bogor forest area is 1:6 where the female Javan surili langurs are more than the male Javan surili langurs and for the age structure the largest Javan surili langurs are in the adult age class with a percentage of 43.75%, juvenile 31.25%, and the percentage of infant is 25%.

Field estimation of fallen deadwood volume under different management approaches in two European protected forested areas

Abstract Fallen deadwood is essential for biodiversity and nutrient cycling in forest ecosystems. In modern forest management, there is growing interest in developing accurate and efficient methods for field estimation of deadwood volume due to its many benefits (e.g. carbon storage, habitat creation, erosion control). The most common methods for deadwood inventories are fixed-area sampling (FAS) and line-intersect sampling (LIS) methods. While the estimations of deadwood volume by LIS generally show results comparable to FAS estimations, active management (e.g. production forestry clearcutting, logging, and thinning activities) can impair LIS accuracy by changing local deadwood patterns. Yet, the comparison of LIS and FAS methods has typically focused on production forests where deadwood is limited and deadwood volumes are comparably low. In this study, we assessed fallen deadwood volume in two large national parks—one being a more actively managed landscape (including, e.g., selective thinning for maintaining cultural–historical values and enhancing recreational opportunities) with overall lower levels of fallen deadwood, and the other having a strict non-intervention approach with higher levels of deadwood. No significant differences between average FAS and LIS estimations of deadwood volumes were detected. Additional experimentations using simulated data under varied stand conditions confirmed these results. Although line-intersect sampling showed a slight overestimation and some variability at the individual plot level, it remains an efficient, time-saving field sampling method providing comparable results to the more laborious fixed-area sampling. Line-intersect sampling may be especially suitable for rapid field inventories where relative changes in deadwood volume rather than absolute deadwood volumes are of large interest. Due to its practicality, flexibility, and relative accuracy, line-intersect sampling may gain wider use in natural resource management to inform national park managers, foresters, and ecologists.

Insights into key threats and conservation status of the river lapwing, Vanellus duvaucelii (Lesson, 1826) in Northern India

Abstract The river lapwings are inhabitant of river banks with sand or gravel bars and river islands. In this study, we investigated vital threats (natural and anthropogenic) and the conservation status of river lapwing in the riverine ecosystem of Northern India. In this regard, we frequently visited selected study sites along the banks of the river Ganges in the district of Raebareli (Uttar Pradesh), India, from January 2016 to December 2019. To estimate perceived threats for river lapwing, we developed a questionnaire and collected threat scores. The line transect method was used to estimate the density of river lapwing. Predation and farming activities were the most potent threats influencing the survival and abundance of river lapwing. River lapwings were primarily observed at open unvegetated river banks and open unvegetated islands. They were seen in significant density near the water in the breeding season. We concluded that the population of river lapwing is relatively stable in the Gangetic plains of Northern India. However, it is declining in other parts of the world, for example, in Southern Laos. Though it is a relatively common species, robust scientific information about its population and habitat relation is mainly absent. Therefore, accurate counts from other parts of the world are needed to place the estimate for river lapwing into a comprehensible, inclusive perspective. Furthermore, detailed information on habitat relationships is also necessary to develop conservation strategies.

Avifaunal Diversity in Managed Urban Ecosystem: A Case Study of Banaras Hindu University, Varanasi

University campuses are becoming important places for conducting a large number of studies on plant and animal taxa including avian diversity. However, a systematic study on the avian diversity in the Banaras Hindu University (BHU) campus (Asia’s largest residential university campus) of Varanasi is still lacking. The present study deals with the species abundance, diversity and species richness of avian communities in the BHU campus. We conducted a bird survey in the BHU campus between 2019 and 2020. Employing line-transect method, a total of 141 bird species under 62 families were recorded from the study area. A rich diversity of species recorded indicates the importance of the university campuses in urbanized region to serve as a critical habitat for birds. To conserve this rich bird diversity of the campus, we suggest sustainable management of habitats through restoration of degraded habitats, reduction in habitat destruction, conservation awareness programmes and increased research on assessment of diversity.

Step-point sampling for broadleaved species’ ground cover estimation in pastures – an evaluation of Cockayne’s point on a boot toecap method

ABSTRACT Step-point sampling, conceived by plant ecologist Dr Leonard Cockayne in ca. 1925 as a method for measuring the ground cover of species in New Zealand’s modified tussock grasslands utilises a point marked on the observer’s boot toecap. It is resource-efficient compared to other vegetation sampling methods and here we report on a unique evaluation of its accuracy and precision. The estimated cover of Taraxacum officinale in a grassy field (11%) was not significantly different from that obtained using line-point sampling (13%), but higher than that from line-intercept sampling (5.7%). It was unaffected across an order-of-magnitude range of sampling intensity (1600 to 160 observations/ha) and was acceptably precise with ≥ 400 observations/ha, although increased linearly with observation point size. These empirical results were supported by computer simulations enabling both accuracy and precision to be evaluated along with plant architecture. The simulations indicated that step-point sampling with ca. 400 observations per ha and an observation point diameter ≤ 1.1 cm (1.0 cm2), can provide ground cover estimates for a wide range of broadleaved species in pastures that are sufficiently accurate and precise for common pasture management applications. The method is deployed in the phone application, ‘Grassland Cover Estimator’ available at https://www.agresearch.co.nz/search?q = Grassland + cover + estimator.

Short Communication: Avifauna survey in Bama coastal area of Baluran National Park, East Java, Indonesia

Abstract. Siddiq AM, Sulistiyowati H, Setiawan R, Wimbaningrum R, Wahono ND. 2024. Short Communication: Avifauna survey in Bama coastal area of Baluran National Park, East Java, Indonesia. Intl J Trop Drylands 8: 14-20. Baluran National Park is an essential habitat for avifauna in the East Java region, Indonesia. We surveyed the avifauna in the Bama coastal area using the line transect method at three stations, including Kalitopo, Bekol-Bama, and Manting. During a three-day survey, we recorded 53 bird species belonging to 47 genera and 32 families. According to the IUCN Red List, there are three conservation statuses (least concern: 49 species, near threatened: one species, endangered: three species); then, based on the CITES status, there are two categories (non-appendix: 47 species, Appendix II: six species), and finally, based on national status, there are two categories (non-protected categories: 41 species, protected categories: 12 species). Based on the frequencies, 32 common and 21 rare bird species are reported in the Bama coastal area. Three of the common species are Sunda Pied Fantail (Rhipidura javanica), Cave Swiftlet (Collocalia linchi), and Oriental Pied Hornbill (Anthracoceros albirostris), which was found in all observation tracks. Furthermore, these surveys provide recommendations for further research related to ecological topics for several threatened bird species, such as Padda oryzivora, Pavo muticus, Acridotheres melanopterus, Gracula religiosa, A. albirostris, and Nisaetus cirrhatus.

Collecting behavioral evidence from a highly mobile and seasonal population: A protocol for a survey on quad bike injuries.

Quad bikes are popular recreational, four-wheeled bikes in the Middle East. Injury prevention programs targeting quad bike crashes in the United Arab Emirates (UAE) need evidence about the risk factors and behaviours associated with these crashes in the target population. This is a protocol for a study aiming to investigate quad bike rider behaviours and to assess the risk factors associated with related injuries in the UAE. This is a cross-sectional observational study aiming to describe a seasonal sport in a desert environment. With an estimated sample size of 451, the survey will follow a three-stage, location-based sampling strategy using the line-transect method. A sampling frame of desert locations with high injury incidences was developed, using Dubai ambulance injury records. Further expansion of the sampling frame was participatory, involving police, enthusiasts, emergency responders and gas station employees. The data collection will be limited to the winter months in fifteen high-injury desert locations across three major Emirates in the UAE. Trained researchers will observe the riders directly in the desert to note their riding habits, followed by a researcher-administered interview on riding and injury history. The interviews will be administered in Arabic and English using Qualtrics software on handheld tablets with offline and online entry mode. In addition, paper-based entry with the same format will be used as a contingency in busy quad bike locations. The objective of this study protocol is to develop a comprehensive survey that will furnish substantial evidence for the formulation of effective injury prevention strategies. To enhance the credibility of the recorded riding behaviors, field observations will be employed. The uniqueness of this study lies in its innovative sampling strategy, custom-tailored to accommodate the highly mobile and transient population of desert bikers in the UAE.

Abundance assessment of Sulawesi Banded Swallowtail, Papilio gigon gigon and availability of resource plants in Bantimurung Bulusaraung National Park, South Sulawesi, Indonesia

Abstract. Ismail T, Maulany RI, Ngakan PO. 2024. Abundance assessment of Sulawesi Banded Swallowtail Papilio gigon gigon and availability of resource plants in Bantimurung Bulusaraung National Park, South Sulawesi, Indonesia. Biodiversitas 25: 673-682. The Sulawesi Banded Swallowtail (Papilio gigon gigon Felder & Felder, 1864) is an endemic butterfly species of Sulawesi, Indonesia currently under threat from hunting and trade activities and habitat degradation. This study aims to examine the abundance of P. gigon gigon and resource plants' availability and to analyze the relationship between resource host and nectar plant density with the abundance of the butterfly species in Bantimurung Bulusaraung National Park, South Sulawesi, Indonesia. Data were collected using the line transect method in two habitat types: settlement and forest located in three observation sites (Bantimurung, Leang-leang, and Pattunuang). The data were analyzed with Spearman's correlation test. The results showed a significant positive correlation in Bantimurung between the host plant densities (r = 0.258; p = 0.010) and nectar plants (r = 0.211; p = 0.036) with the abundance of P. gigon gigon. In Pattunuang, the host plants had indicated an insignificant correlation (r = 0.061; p = 0.548) with the abundance of P. gigon gigon, and in contrast, the nectar plants showed a significant positive correlation (r = 0.487; p = 0.000). Only in Leang-leang the correlation between the abundance of P. gigon gigon showed no significant correlation with both host (r = 0.152; p = 0.132) and nectar plants (r = 0.041; p = 0.686). Differences between the observation areas were suspected to be influenced by human activities such as tourism and hunting. Therefore, management interventions by the national park are required to support the conservation of P. gigon gigon in the area.

The ACCOBAMS survey initiative: the first synoptic assessment of cetacean abundance in the Mediterranean Sea through aerial surveys

The “ACCOBAMS Survey Initiative” (ASI) is a pilot programme aimed at establishing an integrated and coordinated monitoring system for cetaceans across the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic (hereafter “ACCOBAMS”) area. Conducted in coordination with Mediterranean coastal countries, it supports the implementation of European and regional policies, in particular the EU Marine Strategy Framework Directive and the Ecosystem Approach process. In summer 2018, a synoptic survey was conducted across the Mediterranean Sea and contiguous Atlantic area, combining visual monitoring from aircrafts with visual and passive acoustic monitoring from vessels. Species density and abundance were estimated through design-based approach in a line-transect sampling framework. Based on data arising from the aerial survey only, uncorrected design-based abundance was obtained for striped (N=426,744, CV=0.13), common (N=65,359, CV=0.4), bottlenose (N=63,333, CV=0.17), and Risso´s dolphins (N=26,006, CV=0.3), Cuvier’s beaked whales (N=2,929, CV=0.4) and long-finned pilot whales (N=5,540 CV=0.4). A merged category of either striped or common dolphins resulted in 212,828 individuals (CV=0.26). Fin whales abundance of 1,749 animals (CV=0.3) was corrected for both availability and perception biases and resulted in 3,282 (CV=0.31). The ASI survey offers an overall picture of the distribution and abundance of cetaceans throughout the Mediterranean basin, providing robust estimates to be considered as a baseline for future regional systematic monitoring programmes. The ASI survey is the first step towards establishing a long-term monitoring program across the entire ACCOBAMS area, and, as such, it sets the basis for further future basin-wide monitoring efforts using systematic, shared, coordinated and comparable methods. The information gathered will further enhance knowledge on cetacean status, facilitating the development of informed conservation and mitigation measures, as well as supporting the implementation of international obligations. Furthermore, the outcomes of this survey will support both place- and threat-based conservation efforts in the ACCOBAMS area, through the identification of Important Marine Mammal Areas and Cetacean Critical Habitats. Here the results of the ASI survey are presented and discussed alongside proposed management and conservation actions aimed at ensuring the persistence of cetacean populations in the region.