Nest Boxes Research Articles

Alleviating competition increases raptor breeding success: A case study of Jackdaws and Lesser Kestrels

Anthropogenic changes in the natural environment have led to the need to find alternative resources to ensure the persistence of biodiversity. In birds, nest sites can be a limiting resource in stenotopic populations. A method of active protection is the building of nest boxes. However, attractive nest sites attract target species and their competitors. From the species conservation point of view, our target species was the Lesser Kestrel (Falco naumanni), whose populations have recovered owing to the establishment of nest box colonies across Europe. However, they have been out-competed by Jackdaws (Corvus monedula) in recent years. Because corvids are intelligent and aggressive, we had to artificially control the competition from Jackdaws to allow Lesser Kestrels to nest. We aimed to discourage Jackdaws from taking over the studied colony and to ensure the continued breeding of Lesser Kestrels by manipulating access to the nest boxes. Data were collected during three breeding seasons in a Lesser Kestrel nest box colony using two manipulations in which we prevented Jackdaw occupation by closing some of the nest boxes and then gradually opening them. We found a significantly lower probability of Lesser Kestrels nesting and lower breeding performance in the control year than in the years in which access to the boxes was manipulated. The field experiment shows the high efficiency of manipulating the accessibility of nest boxes by closing and opening them at the right time in the context of their occupation by the target species and thus influencing their breeding performance.

Crossing Worlds in Buildings

Holes in the houses of Brussels, as in other buildings across Europe, have long been the preferred nesting sites of the common swift (Apus apus), a bird famous for its fast flight and for spending most of its life on the wing. For several decades, however, urban construction and renovation has led to the destruction of swifts’ breeding sites, contributing significantly to their disappearance, and have prompted amateur naturalists to spatial interventions in ways that they hope the birds will accept. This essay explores this form of care that is forging a new path through the more-than-human city. It starts with an account of how swifts “story” the cavities they inhabit, and then describes the engagement of a devoted swift caretaker with the birds’ astute knowledge of buildings and their meaningful worlds. Moving across sites in Brussels, the essay articulates how an attentiveness takes shape between swifts, their storied-places, and the human caretakers who learn about them, as well as the tensions and contradictions that arise. Such a care practice involves noticing and experiential learning, it requires conveying importance to unfamiliar interlocutors, and leads both to the reactivation of architectural heritages and pleasure at aesthetic encounters with the birds. In some cases, the employment of nest boxes and other technologies may also risk greenwashing ecologically harmful operations. Caring for swifts, the essay concludes, involves a reciprocal co-becoming at specific architectural interfaces, through attentive and imaginative practices. These modes of attention and of imagination enable material interventions in buildings with a fuller appreciation of swifts’ storied worlds.

Queering Sight: Visualising the Transversal Other in Josh Malerman’s Bird Box

The gaze has hitherto occupied a contentious position within theoretical discourse. While feminist and postcolonial approaches have succeeded in productively interrogating the unequal power dynamics produced by the gaze, purely naming and uncovering how these visual oppressions function do little to conceptualise possibilities of moving beyond sight’s vilification in identity formations. Unlike other physical senses such as touch and smell that have already been theorised as bases of ethical intersubjective relationality, sight has yet to be reclaimed as part of an affirmative politics to disrupt the exclusionary processes that undergird identity politics. This article is, therefore, concerned with queer interventions to rethink sight as a possible mode of transgression from restrictive binarisms within identity formation. It argues that sight instead possesses the potential to liberate bodies and constrained subjectivities from the coercive frameworks of visual objectification. By queering sight, the article positions itself as a rejection of dualistic paradigms by subversively envisioning identities as transversal processes of liberation and becoming. To this end, I will engage with Josh Malerman’s Bird Box (2014) where mediated acts of looking represent queer(ed) sources of danger and liberation. In its peculiar and particular denial of direct visual access, the novel’s aesthetics allow for productive possibilities of visualising the transversal Other.

Assessing concrete nest boxes for cavity-nesting bees

AbstractArtificial nest boxes for solitary bees and other cavity-nesting Hymenoptera are increasingly used for a variety of purposes, including ecological research, crop pollination support and public outreach. Their attractivity and colonization success by cavity-nesting solitary bees depend on their design and placement, including hole dimensions, orientation and the neighboring habitats and available resources. While most bee nest boxes are made of wooden materials, we assessed here the suitability of perennial, concrete nest boxes for cavity-nesting bees. We carried out a three-year nesting survey of 52 custom-made nest boxes located in 11 different sites throughout France and totaling 2912 available holes of 6, 8, 10 or 12 mm in diameter. Concrete nest boxes successfully attracted reproductive females of solitary bee species and supported successful larval development until the emergence of new individuals. Preferred cavities were the smallest ones (6-8 mm), located at the lowest tested positions above ground (31-47 cm) and oriented southward. Local bee populations established in nest boxes steadily increased throughout the three successive seasons in nearly all study sites. The cavity-nesting bee communities were mostly composed of rather common and generalist species, but also comprised a foraging specialist. Additionally, two cleptoparasitic bee species were detected. All species belonged to the Megachilidae. We further discuss the effects of neighboring urban and natural habitats as potential source or sink of nesting bees, as well as opportunities of concrete nest boxes as tools for urban agriculture and more generally for the new biomimetic urban designs to restore local ecosystem services in cities.

Pine marten predation of common goldeneye nests: Effects of cavity age and habitat override any effect of microtine rodent abundance.

According to the alternative prey hypothesis (APH), the temporal synchrony in population fluctuations of microtine rodents and other small herbivores in boreal areas is caused by generalist predators with numerical and functional response to microtines, leading to an increased predation of prey alternative to microtines in the low phase of the microtine population fluctuations. The tree-climbing pine marten (Martes martes) is a food generalist that includes bird eggs among its alternative prey, also eggs of the cavity-nesting common goldeneye (Bucephala clangula). We used long-term data to test whether pine marten predation of goldeneye eggs in nest boxes varied as predicted by the APH. As a measure of microtine abundance at the time of nesting, we applied two measures. First, for goldeneye nests located <40 km from our microtine trapping site, we applied the trapping index of microtine rodents. Second, to also use data from nests located >40 km from our microtine trapping site, and from nests in years when trapping was not conducted, we used two proxies for the microtine abundance: whether boreal owls (Aegolius funereus) nested in any of our boxes <40 km from each goldeneye nest and the average clutch size of these boreal owls. The probability of predation of a goldeneye nest was independent of the microtine trapping index and independent of the proxies for microtine abundance. However, it increased with cavity age, taken as the number of nesting seasons elapsed since the actual nest box was installed, and declined with distance from habitat with forest canopy. The effect of cavity age confirms that the long-term spatial memory of pine marten is an important factor in the pattern of its predation on nests in tree cavities.

Untangling behaviours: independent expressions of female–female aggression and snake-like hissing in the blue tit (Cyanistes caeruleus)

Aggression plays a crucial role in deterring predators and securing resources to promote fitness. Nevertheless, studies focussing on female aggression remain scarce. In songbirds, aggression is prevalent during the breeding season, when same-sex individuals compete for limited resources. Additionally, females of some bird species exhibit snake-like hissing behaviour during incubation presumably to lower predation rates and improve fitness. Such behaviours may co-vary, forming a behavioural syndrome that could constrain trait expression. Here, we investigated a resident population of blue tits (Cyanistes caeruleus), to examine the repeatability and covariation of female–female aggression and hissing behaviour, aiming to determine if these constitute a behavioural syndrome. We quantified female–female aggression during simulated territorial intrusions and measured number of hissing calls in response to a simulated predator intrusion into the nest box. We found that both female–female aggression and hissing behaviour were repeatable traits, and that older females approached the intruder less. However, we found no evidence of covariation between female–female aggression and hissing behaviour. Thus, our findings suggest that female–female aggression and hissing behaviour, although both displayed in a nest defence context, are evolutionarily independent traits in the blue tit.

Chemical and population genetic analysis show no evidence of ecotype formation in a European population of the parasitoid wasp Nasonia vitripennis

Ecotypes, subpopulations or strains of a single species locally adapted to divergent ecological conditions within the same habitat are often considered to be the first steps in sympatric speciation. It has been suggested that two ecotypes are distinguishable in Nasonia vitripennis, a prominent model organism for parasitic Hymenoptera, with one ecotype parasitizing fly pupae in bird nests, and the other one parasitizing fly pupae on carrion. This differentiation into two ecotypes has been hypothesized to indicate incipient sympatric speciation in populations of this globally distributed species. In the present study, we investigated the differentiation into these two distinct ecotypes focusing on chemical profiles and the population genetic divergence in a wild N. vitripennis population from the Netherlands. Isofemale lines were obtained from bird nest boxes and from deer carrion, respectively, representing both microhabitats. To test for phenotypic differentiation, we determined the surface cuticular hydrocarbon (CHC) profiles from wasps of both host patches. Using a panel of 14 microsatellites, we concordantly determined the population genetic structure and tested for genetic differentiation between foundresses obtained from both microhabitats. Both the phenotypic as well as the genetic datasets show no evidence for any kind of separation based on the postulated two ecotypes, but rather suggest free interbreeding with no gene flow interruption between the two distinct host patches. Our findings challenge previous assumptions on clearly distinguishable ecotypes in N. vitripennis, and demonstrate how a chemical ecological assessment coupled with population genetics can be instrumental in re-evaluating the potential of ecological differentiation and incipient speciation mechanisms in parasitoid wasps.

Nest Box Bacterial Loads Are Affected by Cavity Use by Secondary Hole Nesters.

Among the environmental factors that affect bird nesting in nest boxes, the influence of microbial communities is relatively poorly understood. In this study, nest boxes used for breeding by secondary cavity nesters were sampled before the start of the breeding season to assess the bacterial loads of the nest box in relation to their previous year status. Different parts of the wooden nest box offer variable conditions for the development of bacteria. During the breeding season, the nest box entrance hole is wiped out by birds, delivering bacteria to their bodies, but during winter, it is exposed to unfavourable external conditions. The interior of the nest box, in turn, is also wiped by birds, but the conditions during winter are more stable there. Therefore, samples from the entrance hole and the interior of the nest box were taken at two different study sites: an urban parkland and a natural forest. We predicted that both the occupancy of the nest boxes during the previous breeding season by birds and the nesting sites would influence the bacterial load of the nest box. To verify this prediction, two categories of nest boxes were sampled at both study sites: nest boxes occupied by any of the two tit species (Great Tit or Blue Tit) in the previous season for breeding and nest boxes that had remained empty that year. The interior bacterial load of the nest box was higher in the nest boxes occupied in the previous breeding season, but only in the forest area. Furthermore, the bacterial load of both the entrance hole of the nest box and the interior was significantly higher in the forest study area in both occupied and unoccupied nest boxes. Our results show that the bacterial load of the nest box is positively related to the presence of nests in the previous breeding season and can vary between different sites.

Use of nest boxes, reproductive success, and sex ratio in two screech-owls in the Peloncillo Mountains of southeastern Arizona

Use of nest boxes, reproductive success, and sex ratio in two screech-owls in the Peloncillo Mountains of southeastern Arizona

American Kestrels Compete with European Starlings over Nest Boxes in Eastern Pennsylvania

ABSTRACT The American Kestrel (Falco sparverius) has been steadily declining throughout most of its eastern North American range, and the cause of this decline is still relatively unknown. As a cavity nesting species, the American Kestrel often competes with other cavity nesters such as the invasive and abundant European Starling (Sturnus vulgaris) over nest boxes. The relationship between European Starling presence at nesting sites and American Kestrel occupancy and nesting success is understudied. We analyzed data from nest boxes monitored in eastern Pennsylvania, USA, from 1992 to 2021 to identify changes in occupancy of American Kestrels and competitors, and to examine the relationship between competition at nest boxes and American Kestrel nesting parameters. We found that American Kestrel occupancy decreased while European Starling occupancy increased over the study period. All other species occupying nest boxes (small mammals, passerines, owls, and snakes) showed no significant occupancy trends. On average 21% of nest boxes remained unoccupied annually, and 7% of occupied nest boxes were used by both American Kestrels and competitors in the same breeding season. The presence of these competitors had negative associations with American Kestrel occupancy, clutch size, number of fledglings produced, and overall nesting success. Specifically, the rate of nesting success decreased by 26% when European Starlings used the same nest box within the same breeding season. In recent years, nesting productivity of American Kestrels has decreased, with the average number of nestlings, fledglings, and nesting success rate all declining, while the average clutch size remained constant. Our results suggest that American Kestrel nesting parameters in eastern Pennsylvania are negatively associated with competition for nest boxes during the breeding season. The opposing trends in occupancy for the European Starling and the American Kestrel in this study area coupled with the declining productivity of American Kestrel nests raise concerns over the future of this raptor species in eastern Pennsylvania.

The Use of Nest Boxes in Malaysia: Design and the Potential for Research and In-situ Conservation of Birds

Nest boxes have been used as artificial cavities for decades to attract cavity-nesting birds that rely on such structures to roost and breed. Nest boxes aid research efforts to understand the biology and behaviour of birds and may increase breeding success, thereby contributing to the conservation of a species. The type and dimension of nest boxes and the survey design used in the tropics vary, depending on the targeted species. This paper reviewed 30 published in-situ works using nest boxes and their survey design in Malaysia. Most studies were done on Barn Owls (Tyto alba javanica) (25), followed by hornbills (5), where they were conducted in oil palm plantations (50%), rice fields (20%), forest habitats (16.7%), urban landscapes (10%), and different habitat matrices (3.3%). Attempts to enhance/manage the local populations were the main research purpose. Unlike studies from other tropical countries, studies involving nest boxes in Malaysia are still in their infancy. This review suggests future research focus on forest species, especially those requiring immediate conservation attention, and delineate parameters highlighted in published works to counter literature inconsistency. Such research involving nest boxes may also be further expanded to the study and/or conserve other interconnected fauna species.

Cavity‐nesting birds are limited by nesting habitat in Neotropical agricultural landscapes

AbstractMost studies comparing biodiversity between natural and human‐modified landscapes focus on patterns in species occurrence or abundance, but do not consider how different habitat types meet species' breeding requirements. Organisms that use or nest in tree cavities may be especially threatened by habitat conversion due to the loss of their nesting sites. Although cavity‐nesting bird diversity is highest in the tropics, little is known about how tropical birds use cavities, how agriculture affects their reproductive biology, and how effective nest boxes could be as a conservation strategy in tropical agriculture. Here, we explored how habitat conversion from tropical forests to pasture affects the abundance, nesting habitat availability, and nest success of cavity‐nesting birds in Northwest Ecuador. We conducted bird surveys and measured natural cavity availability and use in forest and agriculture. We also added artificial nest boxes to forest and agriculture to see whether cavity limitation in agriculture would elicit higher use of artificial nest boxes. We found evidence of cavity limitation in agriculture—there were many more natural cavities in forest than in agriculture, as well as more avian use of nest boxes placed in agriculture as compared to forest. Our results suggest that it is important to retain remnant trees in tropical agriculture to provide critical nesting habitat for birds. In addition, adding nest boxes to tropical agricultural systems could be a good conservation strategy for certain species, including insectivores that could provide pest‐control services to farmers.Abstract in Spanish is available with online material.

High-resolution GPS Tracking of American Kestrels Reveals Breeding and Post-Breeding Ranging Behavior in Northern Virginia, USA

ABSTRACT Long-term monitoring data indicate a persistent decline in American Kestrel populations across North America. Loss or alteration of habitat have been listed as potential causal factors, but basic information on kestrel space use, including breeding home range size, is lacking. No study has provided robust estimates of the ranging behavior of breeding kestrels based on tracking data of any resolution. We fitted 19 adult female kestrels with solar-powered GPS transmitters during the incubation period in northern Virginia. High-resolution tracking began during the early nestling stage for 17 birds. We collected an average of 1710 locations per bird through the end of the breeding season (31 August), with 13 birds tracked through the fledging of their young. Autocorrelated kernel density home range estimation showed that female kestrels used breeding home ranges that were smaller (average: 0.32 km2) than most previously published range sizes. Home ranges did not vary significantly in size across breeding stages and demonstrated little overlap with the ranges of neighboring kestrels. Five females shifted their territories in the post-breeding stage (i.e., after disappearance or dispersal of fledglings) between 1.5 and 12.3 km from their nest box; they maintained these new ranges at least to the migration period. We also documented home range excursion forays (n = 128) by all 12 consistently tracked females. Mean (4.0 km) and maximum (127.7 km) foray distances were some of the largest reported among birds and mammals relative to home range size. Weekly foray rates were highest during the nestling stage, and for birds that ultimately shifted from their breeding home range. The existence of long-distance foray behavior and the use of multiple summer home ranges, both shown here for the first time for this species, has a direct impact on interpretation of kestrel nest-site and habitat selection data, and on the assessment of potential threats to this species in the breeding season.

Deixis Analysis Found In “Bird Box” Movie

Deixis is part of pragmatics that people make in communication. In this research, the researchers analyzed deixis in utterances and the movie “Bird Box” is data source. The movie is 2018 horror movie that has deixis in the movie. The researchers analyze all utterances in the movie. This descriptive qualitative research found out types deixis in utterances of characters. The researchers used observational method with the technique of non-participatory. The pragmatic identity method with competence- in equalizing were used by the researchers. Then, the researchers use the theory from Yule (2017) to analyze deixis types that characters make. The findings show that deixis were used in the communication of the movie. There were totally 34 deixis data in spatial deixis, temporal deixis, and person deixis. 16 were in spatial deixis, 12 data in person deixis, and 6 data in the temporal deixis. The dominant is spatial deixis used by the characters to point places to other hearers in Bird Box movie.

FROM POPULATIONAL OBSERVATIONS TO AN ASSESSMENT OF THEIR STATE: EXPERIENCE FROM A COMPREHENSIVE STUDY ON THE DEMOGRAPHIC PARAMETERS OF THE WESTERN SIBERIAN POPULATION OF THE EUROPEAN PIED FLYCATCHER, &lt;i&gt;FICEDULA HYPOLEUCA&lt;/i&gt; (MUSCICAPIDAE, PASSERIFORMES)

Key demographic parameters were calculated using the European pied flycatcher (Ficedula hypoleuca) as a model species for the study of bird population ecology. In the Tomsk Region, southeastern part of western Siberia, birds nesting in nest boxes situated in natural forests for 22 years were continuously studied. Where possible, life tables, probability models (CJS), and population matrix models were employed in the calculation of demographics. A comprehensive study of population characteristics made it possible to compare them with the results of other research and to demonstrate the degree of divergence in the estimation of demographic parameters obtained using different methods. On average, nestlings successfully left their nests in 87.6% of breeding attempts. The percentage of immigrants, residents, and autochthons in the static age distribution of females amounted to 41.7, 25.3, and 33.0%, respectively, vs 30.8, 25.3, and 43.9% in males, The maximum age for female autochthons was 7 years, compared to 8 years for male autochthons. Male residents lived to be x + 5 years old, while female residents lived to be x + 7 years old. Autochthonous males and females showed about the same local survival rates. These were the highest in yearlings (0.54) and gradually decreased with the age of individuals. The local survival rate of males of unknown origins is comparable to that of autochthonous males. Females of unknown origins had the lowest local survival rates. Birds could start nesting as young as one year old and as old as six years. Ringing revealed that 68.9% of males started breeding in their first year of life, compared to 59.9% of females that started in their first year. Only 39.2% of females and 46.3% of males among the birds that survived and returned to our control sites started breeding as yearlings, vs 66.9% of two-year-old females and 71.1% of males. The proportion of the birds that returned to their birth place amounted to 11.1%. Females produced 9.1 fledglings on average per lifetime, vs 9.6 fledglings for males. The minimum life expectancy for fledglings was 1.2–1.49 and 1.2–1.62 years, vs the maximum life expectancy for individuals that survived for one year, which was 1.94 and 1.96 years for males and females, respectively. For males and females, the generation time was 3.13–3.32 and 3.18–3.39 years, respectively. The sensitivity and elasticity analysis of the population growth rate based on the constructed projection matrix revealed that it was the survival rate of juvenile and sexually mature individuals between one and two years of age that primarily drove the population growth rate. Using the demographic data obtained for the species’ population in natural habitats in the Southeast of western Siberia and the population matrix model constructed on its basis, we believe it is possible to compare the state of populations inhabiting ecosystems, both unspoiled and disturbed (transformed), in various areas across the distribution range of the European pied flycatcher.

Enhanced Natural Regeneration Potential of Sessile Oak in Northern Hungary: Role of Artificially Increased Density of Insectivorous Birds

Both artificial and natural regeneration of oaks strongly depend on the quantity and quality of the acorn crop, which show high year-to-year variation. The volume of the acorn crop is influenced by many factors including biotic and abiotic effects. The quality (i.e., germination ability, nutrient reserves) of acorns can be decreased by carpophagous insect and fungal pathogen damage or by inadequate weather conditions. Defoliating insects (caterpillars, sawfly larva, etc.) can significantly decrease the acorn crop as well. The most important predators of the defoliators are insectivorous birds during their nesting period. However, in the oak forests of the northern Hungarian mountains, there is a shortage of natural nesting holes. The main aim of our study was to artificially increase the number of the available nesting holes by nest boxes and to maximize the number of breeding insectivorous birds and register the direct (Lepidoptera densities) and indirect (acorn crop quantity and quality) effects of their presence. We found only slight effects on Lepidoptera densities, so we failed to demonstrate a direct effect in the relatively low time frame of our study. But, we could show the indirect positive effect of increased predation on the health state of the acorn crop, resulting in higher seedling densities, which may improve the natural regeneration potential of sessile oak. This result supports the outstanding importance of natural nesting holes in broadleaved forests.

Implementation of the QCDMSE Strategy in the Community Empowerment Program to Utilize the Sulawesi Masked Owls as a Natural Predator for Rodents

Rodent pest is known for its detrimental impact on agriculture where it is responsible for for more than 10% of crop loss across worldwide. Although a number of conventional rodent-control methods such as electric current, fumigation, trapping and rodenticide are applied, however there are growing concerns related to their effectiveness and safety concerns. Joint Operating Body Pertamina – Medco E&amp;P Tomori Sulawesi (JOB Tomori) initiated community development program to address this issue by utilizing Sulawesi Masked Owl as agricultural rodent control. Starting from 2017, at approximately 84 artificial nest boxes and 175 perch pillars were installed in paddy fields located in 3 subdistrict in Banggai, Central Sulawesi. Here we present a novel approach of using QCDSME strategy in the context of the community empowerement program. The advantages, limitations, lesson learned and further recommendation of the QCDSME approach are also discussed in this paper.

Bold–shy continuum does not account for egg rejection behaviour in the Japanese tit

Abstract In response to brood parasitism, which significantly reduces the reproductive success of avian hosts, hosts have evolved the ability to recognize and reject parasitic eggs. Many studies have revealed the factors influencing egg recognition and egg rejection. Recent work has demonstrated that host personality along the bold–shy continuum can influence egg rejection behaviour. In addition, the egg rejection behaviour of hosts differs among populations, suggesting that individuals with different personalities might evolve various adaptive behaviours under different parasitic pressures, but there have been few relevant experiments to test this. In the present study, two populations of the Japanese tit, Parus minor, distributed in China were used to examine whether there were differences in egg rejection behaviour of individuals with different personalities. The results showed that egg rejection rates of bold individuals (which remained in the nest box when encountering human invaders) and shy individuals (which immediately flew away from the nest box when encountering human invaders) were similar in both populations of the Japanese tit, and there were also no significant differences in egg rejection rates between individuals of the same personality in the two populations. This study suggests that host personality along the bold–shy continuum does not account for egg rejection behaviour in Japanese tits. This might be attributable either to other factors that affect egg rejection behaviour counteracting the effect of personality or to the presence of multiple personality traits that act together in the Japanese tits, counteracting the effect of a single personality trait.

Cavity-breeding birds create specific microhabitats for diverse arthropod communities in boreal forests

The nests of secondary cavity-nesters located in tree cavities may form specific microhabitats of conservation importance due to their limited accessibility and availability. Species-specific nesting materials in nests of different secondary cavity-nesters may furthermore provide very different microhabitats for arthropods. The potential differences in arthropod communities inhabiting nests of different bird species in excavated cavities or nest boxes have, however, rarely been studied despite their relevance for conservation. Here we investigated the diversity and composition of arthropod communities in these different cavity types and bird species’ nests in managed boreal forests. We identified morphologically and by DNA-metabarcoding arthropods in nest materials that were collected in and compared between (i) woodpecker-size cavities from seven different combinations of cavity type (nest box or excavated cavity), tree species (aspen or pine) and accumulation history of nest materials (single-season cleaned or uncleaned nest boxes that accumulated nests of passerines or an owl species); and (ii) nests of two different passerine species in small nest boxes. We identified 64 arthropod taxa in ten orders, from which Diptera, Coleoptera, Siphonaptera, and Lepidoptera were the most abundant. Shannon diversity index was similar among the cavity-nest-type combinations, but taxa richness was the highest in the owl nests. The arthropod communities (especially Histeridae beetles) deviated most from the other types of nests in owl and aspen cavity nests with more advanced decomposition of nest material (soil or wet environment related taxa). The differences in arthropod communities between the different nest types point out the importance of the ecological chain “tree cavities—bird nests—arthropod communities”.

The carrying capacity of Nusa Penida Island, Bali, Indonesia for Bali myna (Leucopsar rothschildi Stresemann, 1912)

Abstract. Hardini J, Wirayudha IGB, Rosyidi A, Rita NMA, Mawanti I, Kalih LATTWS, Joni M, Sudaryanto FX. 2023. The carrying capacity of Nusa Penida Island, Bali, Indonesia for Bali myna (Leucopsar rothschildi Stresemann, 1912). Biodiversitas 24: 3462-3470. This study is to analyze the carrying capacity of Nusa Penida Island on the existence of Bali myna (Leucopsar rothschildi Stresemann, 1912), because the population is increasing. Bali myna counting method: (i) Counting Bali myna on the tree where she sleeps. (ii) Counting Bali myna at the time of doing daily activities. Bali myna population in 2021, Ped Village 58 birds, and Toyapakeh Village 4 birds. In 2022, Bali myna in Ped Village had 102 birds, and in Toyapakeh Village 6 birds. On Nusa Penida Island, food sources of fruits and insects are abundant. There is enough nest box or tree hole to make a nest. Bali myna nest nuisance animals are bee honey (Trigona itama, Cockerel 1918 and ant (Ochetellus glaber (Mayr, 1862)), while predators are tokay gecko (Gekko gecko (Linnaeus 1758)), and water monitor (Varanus salvator Laurenti 1768). It is suspected that some Bali myna moved from Ped Village to Toyapakeh Village due to a large number of nesting disturbing animals in Ped Village. Until now, the people of Nusa Penida Island still carry out awig-awig (customary law) to protect Bali myna. From this research, it is known that the carrying capacity of Nusa Penida Island for Bali myna. The move of Bali myna from Ped Village to Toyapakeh Village is not due to a lack of carrying capacity but because of the presence of Bali myna nuisance animals.