Barn Owl Research Articles

Are Roadkills Density-Dependent? Case Study of the Barn Owl (Tyto alba)

Even though birds are some of the most common road-killed animals, it remains to be determined whether avian roadkills are related to breeding numbers and breeding success, mainly due to a lack of study areas that monitor breeding populations and roadkills. We studied whether barn owl breeding numbers and breeding success are related to roadkills. We monitored yearly barn owl breeding numbers (2174 breeding attempts and 1682 adults ringed) and breeding success (9380 nestlings ringed) and monitored 95 km of roads weekly for roadkills from 2009 to 2017 in the Beit Shean and Emek Yizreel Valleys, Israel. During the study period, we documented 1073 road-killed barn owls, of which 328 were ring recoveries. The highest mortality occurred between July to September, coinciding with the barn owl post-fledging period. The number of breeding pairs and the number of nestlings ringed were positively related to the total number of barn owl roadkill, the proportion of roadkill ring recoveries, and the proportion of ring recovered roadkills in the first year of their life. First-year owls represent the majority of ringed owls, accounting for 64.6%, while adult owls compose 35.4%. Notably, a substantial fraction of adult ring recoveries, encompassing 67.2%, may pertain to floaters since we did not observe these individuals as breeding adults. Even though more females were found as roadkill ring recoveries, the proportion of male/female ring recoveries from roadkills was similar to that of adults ringed at the nest boxes. This study is the first that shows that barn owl roadkills are density-dependent and demonstrate the importance of monitoring breeding and population numbers in roadkill studies.

Owl-Neck-Spine-Inspired, Additively Manufactured, Joint Assemblies with Shape Memory Alloy Wire Actuators.

Nature provides a considerable number of good examples for simple and very efficient joint assemblies. One example is the enormously flexible cervical spine of American barn owls, which consists of 14 cervical vertebrae. Each pair of vertebrae produces a comparatively small individual movement in order to provide a large overall movement of the entire cervical spine. The biomimetic replication of such joints is difficult due to the delicate and geometric unrestricted joint shapes as well as the muscles that have to be mimicked. Using X-ray as well as micro-computed tomography images and with the utilisation of additive manufacturing, it was possible to produce the owl neck vertebrae in scaled-up form, to analyse them and then to transfer them into technically usable joint assemblies. The muscle substitution of these joints was realised by smart materials actuators in the form of shape memory alloy wire actuators. This actuator technology is outstanding for its muscle-like movement and for its high-energy density. The disadvantage of this wire actuator technology is the low rate of contraction, which means that a large length of wire has to be installed to generate adequate movement. For this reason, the actuator wires were integrated into additively manufactured carrier components to mimic biological joints. This resulted in joint designs that compensate for the disadvantages of the small contraction of the actuators by intelligently installing large wire lengths on comparatively small installation spaces, while also providing a sufficient force output. With the help of a test rig, the developed technical joint variants are examined and evaluated. This demonstrated the technical applicability of this biomimetic joints.

Influence of prey availability on habitat selection during the non-breeding period in a resident bird of prey

BackgroundFor resident birds of prey in the temperate zone, the cold non-breeding period can have strong impacts on survival and reproduction with implications for population dynamics. Therefore, the non-breeding period should receive the same attention as other parts of the annual life cycle. Birds of prey in intensively managed agricultural areas are repeatedly confronted with unpredictable, rapid changes in their habitat due to agricultural practices such as mowing, harvesting, and ploughing. Such a dynamic landscape likely affects prey distribution and availability and may even result in changes in habitat selection of the predator throughout the annual cycle.MethodsIn the present study, we (1) quantified barn owl prey availability in different habitats across the annual cycle, (2) quantified the size and location of barn owl breeding and non-breeding home ranges using GPS-data, (3) assessed habitat selection in relation to prey availability during the non-breeding period, and (4) discussed differences in habitat selection during the non-breeding period to habitat selection during the breeding period.ResultsThe patchier prey distribution during the non-breeding period compared to the breeding period led to habitat selection towards grassland during the non-breeding period. The size of barn owl home ranges during breeding and non-breeding were similar, but there was a small shift in home range location which was more pronounced in females than males. The changes in prey availability led to a mainly grassland-oriented habitat selection during the non-breeding period. Further, our results showed the importance of biodiversity promotion areas and undisturbed field margins within the intensively managed agricultural landscape.ConclusionsWe showed that different prey availability in habitat categories can lead to changes in habitat preference between the breeding and the non-breeding period. Given these results we show how important it is to maintain and enhance structural diversity in intensive agricultural landscapes, to effectively protect birds of prey specialised on small mammals.

Muscle architecture of the hindlimb of Tyto furcata (Aves Strigiformes): Highlights in owl morphology.

The American barn owl is a nocturnal bird of prey in which hind limb movements are a key factor in obtaining food; however, the architectural properties of its hind limb muscles have not been studied. This study sought to identify functional trends in the Tyto furcata hindlimb muscles by studying muscular architecture. The architectural parameters of the selected hip, knee, ankle, and digit muscles were studied in three specimens of the Tyto furcata and joint muscular proportions with an additional dataset were calculated. Previously published information on Asio otus was used for comparison. The flexor muscles of the digits had the highest muscle mass. Regarding architectural parameters, the main flexor of the digits (flexor digitorum longus) and the muscles that extend the knee and ankle joints (femorotibialis and gastrocnemius) showed a high physiological cross-sectional area (PCSA) and short fibers, allowing powerful digit flexion and knee and ankle extension. These mentioned features are in accordance with hunting behavior, in which prey capture is not only closely linked to the flexion of the digits but also to the movements of the ankle. During hunting, the distal hind limb is flexed and then fully extended at the moment of contact with the prey, whereas the digits are close to grasping the prey. The hip muscles showed a predominance of extensors over flexors, which were more massive, with parallel fibers and without tendons or short fibers. These features lead to a higher capacity to generate velocity to the detriment of forces, as indicated by the high values of the architectural index, their relatively low PCSA, and short or intermediate fiber length, which enhance the control of the joint positions and muscle length. Compared to Asio otus, Tyto furcata showed longer fibers; however, the relationship between fiber length and PCSA was similar for both species.

Efficacy of cholecalciferol rodenticide to control wood rat, Rattus tiomanicus and its secondary poisoning impact towards barn owl, Tyto javanica javanica

Studies were conducted on the potential use of cholecalciferol as an alternative to anticoagulant rodenticides to control common rat pest in oil palm plantations, i.e., wood rats, Rattus tiomanicus, and the secondary poisoning impact of cholecalciferol on barn owls, Tyto javanica javanica. The laboratory efficacy of cholecalciferol (0.075% a.i.) was compared with commonly used first-generation anticoagulant rodenticides (FGARs): chlorophacinone (0.005% a.i) and warfarin (0.05% a.i). The 6-day wild wood rat laboratory feeding trial showed cholecalciferol baits had the highest mortality rate at 71.39%. Similarly, the FGAR chlorophacinone recorded a mortality rate of 74.20%, while warfarin baits recorded the lowest mortality rate at 46.07%. The days-to-death of rat samples was in range of 6–8 days. The highest daily consumption of bait by rat samples was recorded for warfarin at 5.85 ± 1.34 g per day while the lowest was recorded in rat samples fed cholecalciferol, i.e., 3.03 ± 0.17 g per day. Chlorophacinone-treated and control rat samples recorded consumption of about 5 g per day. A secondary poisoning assessment on barn owls in captivity fed with cholecalciferol-poisoned rats showed after 7 days of alternate feeding, the barn owls appeared to remain healthy. All the barn owls fed with cholecalciferol-poisoned rats survived the 7-day alternate feeding test and throughout the study, up to 6 months after exposure. All the barn owls did not show any abnormal behavior or physical change. The barn owls were observed to be as healthy as the barn owls from the control group throughout the study.

Diet Composition of a Pair of Tyto furcata pratincola (American Barn Owl) in an Urban Park and Natural Area Fragment in South Florida

Tyto furcata pratincola (American Barn Owl) is a widespread bird of prey with great adaptability that can be found in partially urbanized areas. We examined the prey composition of a pair of American Barn Owls through dissection and analysis of a subset of cast pellets found at a roost site in an urban park in South Florida by comparing hair, bone, and teeth to online identification guides and museum specimens. The main identified prey species were rodents, with Sigmodon hispidus (Hispid Cotton Rat) accounting for 63.0% of all prey identified. Within the home range of these owls were 9 known colonies of endangered and common species of bats, but no evidence of depredation was found in the pellet analysis. Other small mammals, reptiles, and invertebrates made up the remainder of the diet, which is consistent with other similar studies in more natural settings.

Morphological examination and scanning electron microscopy of the barn owl's (Tyto alba) tongue.

The beak structure changes according to the feeding patterns of birds. Further, the morphological and histological structures of their tongues vary. Therefore, the current study aimed to perform macroanatomical and histological examinations and scanning electron microscopy of the barn owl's (Tylo alba) tongue. Two dead barn owls were brought to the anatomy laboratory and were used as study material. The tongue of the barn owl was long, triangular-shaped with a bifurcated tip. There were no papillae in the anterior 1/3 of the tongue, and the lingual papillae were shaped toward the back. The radix linguae were surrounded by a single row of conical papillae. Irregular thread-like papillae were found on both sides of the tongue. The salivary gland ducts were on the lateral margin of the corpus linguae and the dorsal surface of the radix linguae. The lingual glands were in the lamina propria near the stratified squamous epithelium layer of the tongue. The dorsal surface of the tongue comprised non-keratinized stratified squamous epithelium, and the ventral surface and caudal part of the tongue had keratinized stratified squamous epithelium. Hyaline cartilages were detected in the connective tissue immediately below the non-keratinized stratified squamous epithelium on the dorsal surface of the root of the tongue. The study results can contribute to the current knowledge on the anatomical structure of birds. Further, they can be useful in managing the barn owl when used as companion animals and in research activity.

Anatomical distribution of celiac artery with histochemical investigation to the proventriculus of barn owl (Tyto alba)

The present investigation was performed to transpire the celiac artery distribution, histological, and histochemical characteristics of the proventriculus in eight adult barn owls (Tyto alba) of both sexes. Six birds were subjected to anatomical investigation of the celiac artery distribution and two owls were used for routine histomorphological techniques. The proventricular length, width, and lumen diameter were measured at 14.18 ± 0.08, 6.46 ± 0.17 and 1.46 ± 0.14 mm, respectively. The celiac artery in barn owl gave off six collateral arteries before its division into right and left branches. The arteria hepatica dextra does not originate from the right celiac division. Unlike other birds, there were left dorsal and left ventral gastric arteries. Histologically, the proventricular wall consisted of main four tunics. The lining epithelium is simple columnar with plicae and sulci. The muscularis mucosa is absent. The submucosal gastric glands were in two rows in the cranial proventricular portion while were arranged in one parallel row in the middle and caudal portions with pear-shaped, oval to round tubuloalveolar lobules. The mucosal folds, tubular mucosal glands, tubuloalveolar lobules, and their mucus secretion in the collecting ducts were positively reacted to PAS and alcian blue stains. The interlobular collagen fibers, elastic fibers, and reticular network were intensely reacted to Masson’s trichrome, Orcein, and Gomori's reticulin stains, respectively. These anatomical and histomorphological features of the barn owl proventriculus were aimed to provide recent data comparable with most species of birds and the presence of diversity that might be attributed to their feeding demeanor.

Movement predictability of individual barn owls facilitates estimation of home range size and survival

BackgroundThere is growing attention to individuality in movement, its causes and consequences. Similarly to other well-established personality traits (e.g., boldness or sociability), conspecifics also differ repeatedly in their spatial behaviors, forming behavioral types (“spatial-BTs”). These spatial-BTs are typically described as the difference in the mean-level among individuals, and the intra-individual variation (IIV, i.e., predictability) is only rarely considered. Furthermore, the factors determining predictability or its ecological consequences for broader space-use patterns are largely unknown, in part because predictability was mostly tested in captivity (e.g., with repeated boldness assays). Here we test if (i) individuals differ in their movement and specifically in their predictability. We then investigate (ii) the consequences of this variation for home-range size and survival estimates, and (iii) the factors that affect individual predictability.MethodsWe tracked 92 barn owls (Tyto alba) with an ATLAS system and monitored their survival. From these high-resolution (every few seconds) and extensive trajectories (115.2 ± 112.1 nights; X̅ ± SD) we calculated movement and space-use indices (e.g., max-displacement and home-range size, respectively). We then used double-hierarchical and generalized linear mix-models to assess spatial-BTs, individual predictability in nightly max-displacement, and its consistency across time. Finally, we explored if predictability levels were associated with home-range size and survival, as well as the seasonal, geographical, and demographic factors affecting it (e.g., age, sex, and owls’ density).ResultsOur dataset (with 74 individuals after filtering) revealed clear patterns of individualism in owls’ movement. Individuals differed consistently both in their mean movement (e.g., max-displacement) and their IIV around it (i.e., predictability). More predictable individuals had smaller home-ranges and lower survival rates, on top and beyond the expected effects of their spatial-BT (max-displacement), sex, age and ecological environments. Juveniles were less predictable than adults, but the sexes did not differ in their predictability.ConclusionThese results demonstrate that individual predictability may act as an overlooked axis of spatial-BT with potential implications for relevant ecological processes at the population level and individual fitness. Considering how individuals differ in their IIV of movement beyond the mean-effect can facilitate understanding the intraspecific diversity, predicting their responses to changing ecological conditions and their population management.

Spatial coding in the hippocampus and hyperpallium of flying owls

The elucidation of spatial coding in the hippocampus requires exploring diverse animal species. While robust place-cells are found in the mammalian hippocampus, much less is known about spatial coding in the hippocampus of birds. Here we used a wireless-electrophysiology system to record single neurons in the hippocampus and other two dorsal pallial structures from freely flying barn owls (Tyto alba), a central-place nocturnal predator species with excellent navigational abilities. The owl's 3D position was monitored while it flew between perches. We found place cells-neurons that fired when the owl flew through a spatially restricted region in at least one direction-as well as neurons that encoded the direction of flight, and neurons that represented the owl's perching position between flights. Many neurons encoded combinations of position, direction, and perching. Spatial coding was maintained stable and invariant to lighting conditions. Place cells were observed in owls performing two different types of flying tasks, highlighting the generality of the result. Place coding was found in the anterior hippocampus and in the posterior part of the hyperpallium apicale, and to a lesser extent in the visual Wulst. The finding of place-cells in flying owls suggests commonalities in spatial coding across mammals and birds.

A Four-Year Survey of Hemoparasites from Nocturnal Raptors (Strigiformes) Confirms a Relation between Leucocytozoon and Low Hematocrit and Body Condition Scores of Parasitized Birds.

Most hemoparasites hosted by wild birds appear to be harmless, but most of the blood parasite studies in avian wildlife are mainly focused on passerines or migratory species. This study aimed to assess the occurrence of blood parasites in nocturnal raptors (Strigiformes order) and their effect on hematological parameters. A total of 134 blood samples were collected during a four-year period for hematological analysis and hemoparasite detection and quantification by microscopical examination of the samples. Overall, the occurrence of hemoparasites was 35.1%, with Leucocytozoon being the most frequently detected (32.1%), followed by Haemoproteus (11.2%), Trypanosoma and Plasmodium (2.2% each). Among the different bird species, the Eurasian eagle-owl (Bubo bubo) showed the highest blood parasite positivity (94.7%). In barn owls, the positive birds displayed a lower hematocrit measurement and body condition score than the non-parasitized ones (p = 0.007 and p = 0.005, respectively), especially those parasitized by Leucocytozoon. Moreover, the analysis of the magnitude of this association revealed that the presence of hemoparasites is five times more frequent in barn owls with a 2/5 body condition score. Despite the host-parasite coevolution in Strigiformes, our results show a correlation between the presence of hemoparasites and some health parameters, including blood parameters.

Anatomicaland Histological study of the cerebellum in Tytoalba (barn owl) by using Giemsa stain method

تم إجراء الجوانب المورفولوجية والنسيجية على المخيخ من (بومة الحظيرة) من أجل معرفة حجم المخيخ والتصميم والتباين الورقي ووصف مكونات مناطق المخيخ على المستوى المجهري الضوئي باستخدام طريقة صبغة جيمسا. أظهرت نتائج المظاهر المورفولوجية أن المخيخ كان كبيرًا ومجرفًا في الشكل. وكشفت المقاطع السهمية الفصوص الثلاثة المطوية والترتيب والتسميات للأوراق الأولية العشر. أشارت نتائج الفحوصات الميكروسكوبية إلى أن الطبقات الثلاث المتميزة من القشرة ظهرت بشكل أكثر وضوحًا باستخدام طريقة صبغة جيمسا ، حيث احتلت الطبقة الجزيئية للضوء الخارجي السميك في الغالب بواسطة المحاور والتشعبات. تم العثور على الخلايا النجمية على شكل نجمة وخلايا السلة مبعثرة بينهما. تحتوي طبقة خلايا بوركينجي المفردة الوسطى على خلايا كبيرة على شكل قارورة ، وكانت الكثافة الخطية العالية في الفص الخلفي للمخيخ. تحتوي الطبقة الحبيبية الداخلية السميكة على العديد من الخلايا العصبية المختلفة ، وكانت المادة البيضاء التي شكلت النخاع هي منطقة الألياف المايلينية والنواة المخيخية العميقة

Effects on hematology and blood biochemistry profile of intramuscular meloxicam injection in Brahminy kite and Barn owl.

Meloxicam is used widely for exotic animal analgesia, but its toxicity in common raptor species in Thailand is unclear. This study evaluated the single-dose effect of intramuscular meloxicam in common raptor species in Thailand for short-term and long-term periods. Twenty-two raptors were administered a single 1 mg/kg dose of meloxicam individually via intramuscular injection. The following were evaluated: clinical appearance, body weight, body condition score, body temperature, fecal appearance, complete blood cell count, and biochemistry panel before (day 0) and after the injection (1, 7, and 30 days). The collected samples were categorized into three groups: Brahminy kite (Haliastur indus) (n = 10), adult Barn owl (Tyto javanica) (n = 4), and juvenile Barn owl (n = 8). None of the raptors in the study groups showed any abnormalities. The hematological profiles were significantly different in the short-term period (day 1 and day 7). The creatinine, aspartate aminotransferase, and creatinine kinase increased in several groups. On the other hand, the packed cell volume decreased in the Brahminy kite and juvenile Barn owl groups. According to the findings, an intramuscular injection of 1 mg/kg meloxicam affected the blood biochemistry panel of the muscle, but the affected raptors recovered within one week. An intramuscular injection of meloxicam at a single 1 mg/kg dose in Brahminy kites and Barn owls was not associated with the morbidity, hepatotoxicity, gastrointestinal toxicity, and nephrotoxicity in the short- and long-term periods.

Exclusion of barn owls Tyto alba from a greater horseshoe bat Rhinolophus ferrumequinum roost in Devon, UK

The greater horseshoe bat Rhinolophus ferrumequinum is a rare species in the UK that relies heavily on undisturbed stone buildings in which to breed. Barn owls Tyto alba are also a protected species that roost and raise their broods in similar places. This overlap in roosting requirements can lead to barn owls moving into buildings containing well-established greater horseshoe bat maternity colonies. This in turn could result in disturbance and abandonment of the building by the bats. Such an event occurred at one of the largest greater horseshoe bat roosts in the UK in 2018 when the colony deserted the roost after barn owls moved in. We describe measures used to exclude the owls while retaining access for the bats, to encourage the colony to return. The suite of modifications consisted primarily of wooden baffles and smooth surfaces on the entrances and doorways. Monitoring showed that the interventions were effective in excluding barn owls whilst allowing bats to access the building. Exclusion of the owls resulted in the return of the greater horseshoe bat colony in similar numbers to 2017 when owls were absent (2022: 92% of the adults) and breeding resumed (2022: 93% of the juveniles in 2017). This paper is the first to evaluate the before and after effects of protecting a bat roost from disturbance or predation by other species.

Further dietary samples for Eastern Barn Owls Tyto javanica near Tamworth, New South Wales, revealed by habitat clearance

The diet of the Eastern Barn Owl Tyto javanica was investigated by examination of two samples of pellets (n = 11 and 39), pellet debris and prey remains from: (1) an occupied nest with fledgling in May 2009, and (2) an Owl’s winter roost in August 2009 near Tamworth in the grain belt of New South Wales. The breeding diet consisted, by number, of 91% mammals (90% rodents, including 87% House Mice Mus musculus) and 9% common farmland birds (n = 116 food items). The winter diet consisted of 99% House Mice and 1% bird (n = 188 food items). The fledgling Owl was killed when it failed to flush from its nest hollow as the tree was being felled, during approved clearing of the now Critically Endangered White Box–Yellow Box–Blakely’s Red Gum Grassy Woodland and Derived Native Grassland. Given the dependence of the Barn Owl on House Mice, and the ongoing clearing of hollow trees, we note the potential for (a) secondary poisoning of owls by rodenticides, especially during plagues of the invasive House Mouse in the grain belt, and (b) the Barn Owl’s long-term decline in abundance in New South Wales.

Advances in Clinical Toxicology depend on Ecotechnology

The oldest enriched habitat of the Banka-Siphon-Dam (BSD) of Banka River (BR) attached to Eden Canal (EC) of Damodar River (DR), Kanchannagar, Burdwan, West Bengal India, covering a 3-5 sq km area with different flora- and faunal diversity with agricultural fields and dense vegetation forty-five years ago. But it was decreasing gradually up to December 2019 due to massive visitors or tourists, picnic parties with large sound systems, irregular fishing, killing wild animals, cutting the trees, disturbing and catching different animals including migratory birds, unethical human behaviors, and urbanization nearby badly affected on ‘Advances in Clinical Toxicology’. On the other hand, the Covid-lockdowns also impacted the ecosystem health during the pandemic coronavirus-disease (COVID-19), it has also faced social and economic challenges among the communities, and health systems-“the invisible patients”, due to hampering truism and education, and suspicious killing or catch or death of grey-coloured water monitor lizards, fishing cats, civet cats, and barn owls, and even migratory birds also. And has lost the ecological balance of water, land and vegetation (micro bio-climate) with an increased viper snake, rodent population, etc. And adversely affect the environment (Water, Sanitation and Ecology) and societal problems. To overcome, it is therefore, augments and confirms that propagation of the artificial nests, awareness, plantation of different fruits plants, and cultivations would be beneficial to do away with the rodent menace primarily, and inhibit the damage and economic losses, without putting any severe implications on the sustainability of pisciculture-fishery agro-ecosystems of the “Banka-Siphon Eden-Canal of Damodar May be Develop as ‘Biodiversity-Biomedicines-Hub for Advances in Clinical Toxicology Depend on Eco-technology’ Improving World Policy”. And the perfect ecological balance of water, land and vegetation may develop any ‘Future-Socioeconomically-Ecological-Tourist-Hub with Advances in Clinical Toxicology Eco-Technology Hub’

New records of small mammals in American barn owl, Tyto furcata pellets from southeastern Ecuador

El análisis de egagrópilas de búhos es una alternativa eficiente para evaluar la composición de la comunidad de pequeños mamíferos. En Ecuador, existen análisis previos de egagrópilas de la lechuza de campanario americana, Tyto furcata en las tierras bajas del Pacífico y en los valles interandinos, resaltando un alto consumo de roedores. Describimos por primera vez la dieta de T. furcata en la región amazónica, sureste del Ecuador, resaltando la abundancia y distribución de los mamíferos presa. Colectamos egagrópilas de un individuo de T. furcata en Paquisha, cuenca del río Nangaritza, ladera oeste de la Cordillera del Cóndor. Disgregamos las egagrópilas, separamos huesos y otros restos de presas. Usamos las estructuras únicas como los cráneos y pares de mandíbulas para identificar y estimar el número mínimo de individuos de presa. Identificamos las presas usando claves taxonómicas y por comparación con material de referencia museológico. Encontramos principalmente pequeños mamíferos como presas: 2 didelphidos y 5 cricétidos. El ratón colilargo delicado, Oligoryzomys delicatus, es el registro más austral de su distribución; la marmosa esbelta de Bishop, Marmosops bishopi, es el primer registro en la provincia de Zamora Chinchipe. El ratón campestre de las Yungas, Akodon aerosus y O. delicatus fueron las presas más abundantes, por lo que podemos sugerir como comunes en la localidad. El análisis de las egagrópilas de T. furcata fue eficiente para registrar la diversidad de pequeños mamíferos en esta área previamente poco estudiada. Los cráneos encontrados aumentaron el material museológico, antes poco representado para algunas especies y también en la provincia. Finalmente destacamos a T. furcata como depredador de estos pequeños mamíferos, un aspecto importante de la historia natural del ave y de las presas.

Distribution of Four Vole Species through the Barn Owl Tyto alba Diet Spectrum: Pattern Responses to Environmental Gradients in Intensive Agroecosystems of Central Greece.

Voles are the most common vertebrate pests in European agriculture. Identifying their distribution and abundance patterns provides valuable information for future management. Barn Owl diet analysis is one of the optimum methods used to record small mammal distribution patterns on large spatial scales. From 2003 to 2005, a total of 10,065 Barn Owl pellets were collected and analyzed from 31 breeding sites in the largest agroecosystem in Greece, the Thessaly plains. A total of 29,061 prey items were identified, offering deep insight into small mammal distribution, specifically voles. Four discrete vole species (Harting's vole Microtus hartingi, East European vole Microtus levis, Thomas's pine vole Microtus thomasi, and Grey dwarf hamster Cricetulus migratorius) comprised 40.5% (11,770 vole prey items) of the total Barn Owl prey intake. The presence and abundance of the voles varied according to underlying environmental gradients, with soil texture and type playing a major role. M. levis showed no significant attachments to gradients, other than a mild increase in Mollisol soils. It was syntopic in all sites with M. hartingi, which was the dominant and most abundant small mammal species, preferring non-arable cultivated land, natural grasslands, set-aside fields, and fallow land. M. thomasi was strictly present in western Thessaly and strongly associated with a sandy-clay soil texture and Alfisol soils. C. migratorius was the least represented vole (162 items), exclusively present in eastern Thessaly and demonstrating a stronger association with cereals, Mollisol soils, and an argillaceous-clay soil texture. This is the first study in Greece at such a large spatial scale, offering insights for pest rodents' distribution in intensive agroecosystems and their response to environmental gradients including soil parameters.

Monitoring of the mammal fauna by studying owl pellets: a case of small mammals in protected areas of Podillia

Using owl pellets analysis to monitor mammals in protected areas makes it possible to accumulate a unique material to study the distribution and relative abundance of both common and rare species. Due to the ease of collecting and accumulating of pellets, this method helps to quickly obtain a large amount of material to monitor the changes in natural areas and objects during certain time intervals without interfering with the course of natural processes. The proportions of small-mammal species in the diet of most owls are representative of the proportions of species in their groups. Therefore, the pellet method can be used to organise monitoring of mammal species of natural regions. We analysed nearly 2000 pellets of several species of owls collected in Podillia in the course of the study. Pellets are mostly collected within protected areas. Small mammals form the basis of the diet of the studied species of owls. The diet of the short-eared owl is the most diverse, and it includes 18 species of small mammals. The common vole occurs the most often. The diet of other owl species is also diverse, in particular of the little owl, tawny owl, and eagle owl. As in the case of the short-eared owl, the main prey of the barn owl and grey owl is a common species—the common vole. The diet of the eagle owl, unlike others, is dominated by larger small-mammal species—brown rat, white-breasted hedgehog, and European hamster. In addition to common species, the analysis of owl pellets allows us to identify not only the most common, but also rare species, such as the European hamster, bicoloured shrew, lesser white-toothed shrew, and various bats. Therefore, the pellet method of research is highly effective in analysing the composition of the fauna and the structure of communities, of both prey and predator species. Owl pellet analysis is a valuable asset during small-mammal monitoring studies, and is especially useful for sampling of indicator small-mammal species during environmental impact assessments in protected areas. The method has considerable advantages compared to standard survey methods of small mammals— it does not require the removal of animals from the natural environment, which makes it relevant for use in protected areas.

JENIS BURUNG PEMANGSA DI RESORT TEGALLEGA TAMAN NASIONAL GUNUNG GEDE PANGRANGO

The presence of birds of prey at the ecosystems in Gunung Gede Pangrango National Park (TNGGP) is very important as the top predator that helps stabilizing the pyramid or food chain. This study purpose to examine the diversity of raptors at Tegallega Resort in TNGGP. Fieldwork had been conducted from June 2021 to Maret 2022 and Oktober 2022 at this resort. Data collection used 1 km line transect where the point counts applied. Three line transects with 1 km in between distance were visited 11 times during the field data collection. The result shows that Tegallega Resort has five raptor species: crested serpent-eagle Spilornis cheela, changeable hawk-eagle Nisaetus limnaeetus, javan hawk-eagle N. bartelsi, Eurasian sparrowhawk Accipiter nisus, and barn owl Tyto alba. The eagles and hawk are protected by Indonesian regulations, while the owl is least concern species according to IUCN Redlist. When found the eagles flies in circles (soaring) with a sound when the weather is sunny and hot.