Chick rearing is one of the most energy-expensive phases of the breeding cycle for adult birds. It has been suggested that the daily energy expenditure (DEE) that birds may sustain over extended time periods may be set at approximately 4×basal metabolic rate (BMR). Parent birds can be expected to face the upper limit of DEE during the chick-rearing period. To determine whether parents rearing chicks exceed the sustainable limits of DEE in the temperate regions, in this study we measured parental DEE of Rhinoceros Auklet Cerorhinca monocerata using the doubly-labeled water method in 2018 and 2019 on Teuri Island, Japan. We found that, with only on exception, all individuals had DEE below 4×BMR. Our findings suggest that Rhinoceros Auklets basically have DEEs within “the maximum sustained working level”.

Suitable climatic conditions for the species are known to improve the breeding success of birds, and the ways in which climatic conditions affect bird breeding have been well studied in temperate and subarctic zones. However, hypotheses made from limited regional information may not be adaptable to other regions, and studies in other areas are needed. It is important to determine the impact of weather conditions on birds on isolated islands, because it is difficult for them to adjust their habitats in response to climate conditions. This study elucidated the effects of weather conditions on the breeding of Ryukyu Scops Owls Otus elegans on the subtropical Minami-daito Island, Japan. The study used data from 806 chicks over a six-year period from 2016 to 2021. We found that heavy rain caused increased chick mortality. Chicks weighed less and had shorter tarsi and wings when precipitation was higher. Structural equation analysis showed that high precipitation reduced chick weight and indirectly increased mortality. Heavy rains were thought to have restricted the foraging behaviour of the parents, resulting in a decrease in chick weight.

Although the Oriental Magpie Pica serica does not occur naturally in Japan, a small population has been established in the urban and suburban areas of Tomakomai City, southern Hokkaido since the 1990s. Here, we estimated the proportion of pet food in the magpie diet by using stable isotope analysis to evaluate its contribution to the successful establishment of the population. For tissue analysis, we collected magpie eggshell membranes and feathers, which can indicate the magpie diet during the egg-laying period (spring) and the moulting season (summer to early autumn), respectively. We collected ground-dwelling invertebrates from the field and several commercial pet food varieties as putative food sources. Pet food was isotopically distinct from invertebrates in both δ¹³C (–19.7 ‰ vs. –27.3 ‰, respectively) and δ¹⁵N (4.0 ‰ and 2.6 ‰, respectively). Our stable isotope analysis with a Bayesian mixed model framework, MixSIAR, showed that the proportion of pet food in the magpie diet was approximately 44.6% and 21.8% based on the eggshell membrane and feather samples, respectively. These estimates imply that the Oriental Magpie has succeeded in establishing a population in Tomakomai by exploiting pet food.

The Luzon Hornbill Penelopides manillae manillae, one of the smallest hornbills in the Philippines, is endemic to the lowland forests of Greater Luzon. Due to the intensifying threats of deforestation and wildlife poaching, this species has been uplisted to Vulnerable in the Philippine Red List. However, despite this concerning situation, ecological data on the species remains limited. In this paper, we present information on tree and cavity characteristics, nesting diet, some aspects of breeding biology, and the first description of the nesting behavior of the Luzon Hornbill. We examined seven nests in the Subic Watershed Forest Reserve by using single rope climbing techniques. One nest was monitored for 75 hours from March to June 2022 to acquire data on nesting diet and behavior. Luzon Hornbill nests in natural cavities in live, large-girthed trees particularly White Lauan Shorea contorta (Dipterocarpaceae). Cavity opening dimensions (W×L) ranged from 6.5–16 cm×8.5–34 cm with vertical depths (floor to ceiling) of 34–300 cm and a mean depth of 3.86±4.91 cm, suggesting a preference for shallow cavities with high ceilings and small entrances. The male hornbill delivered food (mainly the fruits of 32 species of plants) through the cavity slit 11–27 times a day. Investigation of the nests post-fledging revealed elytra of jewel beetles (Buprestidae) and intact shells of land snails. The female hornbill was estimated to have remained within the cavity for approximately 90 days. Cooperative breeding, as has previously been reported for the genus Penelopides, was not observed in this study. Our findings provide vital information that may guide the development of conservation tools and forest management policies that aim to increase foraging and nesting opportunities for breeding hornbills.

Adverse meteorological events are, to some extent, frequent and recurrent phenomena in the lives of avian species. Nevertheless, climate change in recent decades has led to a significant increase in the frequency and intensity of changes in temperature, excessive or absent rainfall, strong wind currents, and storms. The consequences of these events have also been extended, including floods, droughts, wildfires, heatwaves, and cold waves. Such events can directly and indirectly impact the daily lives of individual birds and negatively affect the demography and survival of entire populations. In this review, I summarize and synthesize the effects of abrupt meteorological events and adverse weather on birds, addressing their physiological effects as well as their negative impacts on the behaviour and breeding of bird species. Furthermore, I address the significant implications of these events on distribution and vagrancy, habitat destruction, and resource depletion. To mitigate the impact of these events on avian species, actions must be taken before, during, and after catastrophic meteorological occurrences, including the creation of action plans, the monitoring of selected species, populations, and habitats more prone to suffering from these events, and management actions to protect individuals and nests at risk. In addition, efforts should focus on rapid habitat recovery post-event. Despite weather events being of natural occurrence, it is undeniable that human actions have intensified meteorological disasters. Therefore, it is essential to implement conservation and management actions not only to predict, but also to mitigate the effects of these events on the future of bird populations.

Anting (using ants for grooming) is a rare behaviour pattern observed in birds. It is more common in Passeriformes than in other avian orders. Anting behaviour has been reported in only a few non-passerine species, or only doubtful observations have been reported, such as in the Strigiformes. Using a trail camera, we recorded a potential example of passive anting behaviour of a nocturnal raptor (Little Owl Athene noctua) in eastern Spain. This circumstantial record of apparent anting behaviour could be of significance, as it appears that Little Owl sometimes exhibits anting behaviour, which has not been previously documented. We think that some avian spreadeagled postures might have previously been misclassified as sunbathing because this behaviour has been poorly studied, whereas they may have actually involved anting behaviour.

The identification of predatory animals is essential to reducing fisheries damage. In this study, we investigated the presence of fish genes in the excrement of Great Cormorant Phalacrocorax carbo at a reservoir in Gifu Prefecture, Japan. DNA metabarcoding analysis revealed that most fish species eaten by Great Cormorants were Japanese Barbel Hemibarbus barbus (number of birds detected/tested, 10/16), Japanese Dace Pseudaspius hakonensis (9/16), and Japanese Smelt Hypomesus nipponensis (9/16), whereas the genes of released fish were detected in only a few samples. Our findings suggest that cormorants living at the reservoir rarely consumed released fish.