Urban crow nests built on electric utility poles sometimes cause power failure. In order to prevent such problems, utility companies conduct patrols and remove the nests. Using data provided from Hokkaido Electric Power Co., Inc. (HEPCO) on the number of nests removed, we conducted two analyses. First, we calculated the time spent by HEPCO removing crow nests — an estimated 19,656 hours per year. Second, we analyzed environmental factors affecting the number of crow nests on utility poles and found that the number of the nests increased in areas with larger human populations, higher temperatures and longer coastlines. Clarifying the mechanisms by which these factors cause increased crow nesting will contribute to the placement of anti-crow devices and the optimization of patrol routes.

Grey-headed Lapwings Vanellus cinereus nest in rice fields during the farming season, and hence must avoid human disturbance in order to rear their offspring. In this study, we examined the influence of human disturbance on the breeding success of this species. The survey was conducted from 2008 to 2015 in Ogura-ike Polder Reclaimed Land in Kyoto Prefecture. We found a total of 176 nests over eight years. Egg-laying occurred from March to July, but peaked in March and April. Before June, the main breeding habitat was rice fields, after which the birds moved to levees. Hatching success was highest in March and declined thereafter. Although egg-laying on levees increased in June, few nests succeeded in hatching. Hatching failure was caused by human disturbances (plowing and flooding) in rice fields. In the study area, full-scale plowing is during late April and early May. The incubation period of the Grey-headed Lapwing is known to be about a month, hence by laying eggs in March, they have a greater chance of avoiding serious human disturbance than if they nest later. In fact, nearly half of all surviving chicks were from eggs laid in March, thus early eggs contribute significantly to the next-generation. It is suggested that Grey-headed Lapwing are able to breed successfully by avoiding the human disturbances associated with rice farming.

The Daurian Redstart Phoenicurus auroreus, previously considered only a winter visitor in Japan, was found breeding for the first time in Fujimi-machi Nagano Prefecture, in June 2010. In the ten years since, we have confirmed a total of 137 breeding attempts by Daurian Redstart around Yatsugatake. The species was first found singing in Takayama City, Gifu prefecture, in 2014 since when we have surveyed the area for six years and recorded 174 breeding attempts. Breeding has continued annually and the species is now considered established in both regions. Various aspects of breeding status in each region were compared, these included the surrounding environment, the distance from the forest edge, the frequency or purpose of human use of the buildings where nests were found, nest location, nest height, and elevation. We found that villas and resorts around Yatsugatake and residential areas in Takayama City were used as the main nesting sites. The redstarts selected nesting locations close to forests in both regions. All nests were built on artificial structures including ventilation fan hoods. Nests were often built in box-shaped places or recesses providing shelter from predators. Because the Daurian Redstarts is considered to be adaptable to moderate urbanization, it is expected to expand its distribution in the future into areas close to humans, such as residential areas near forests and urban areas with plenty of greenery.

Crows sometimes nest on utility poles and their nests can cause electrical failures. In order to prevent such problems, electric power companies conduct patrols and remove nests. In this paper, using data provided by the Hakodate branch of Hokkaido Electric Power Co., Inc. (HHEPCO) for the number and distribution of crow nests removed from utility poles, we analyzed the relationship between crow nests on such poles and urban green areas. Crows were found to nest on utility poles far from urban green areas, indicating that allowing crows to nest in urban green areas may reduce the cost of removing crow nests from utility poles for electric power companies.

In Japan, the wild population of the Oriental White Storks Ciconia boyciana is increasing owing to reintroduction projects. In order to support the continuous population increase, we collected behavioural data on a breeding pair that had not received supplementary food for 20 months, focusing on their territory and home range sizes. We analyzed these areas by kernel density estimation for each sex, and determined the most plausible range of each territory by recording the locations where aggressive interactions occurred with other storks. Our results indicated that the territory of the study pair, within their home range, was a 40% kernel density of the overlap area (65.82 hectares) between pair members. Territorial defense consisted of direct fights (pecking and driving away) predominantly carried out by the male, and indirect fights (bill-clattering) performed equally by both sexes. The pair's home range sizes changed synchronously between the non-breeding period during 2017–2018 and the nest-building and copulation phase in 2019 preceding egg-laying. Different patterns of change for the male and female were found during the incubation period in 2019 and the early chick-rearing stage in 2019; in particular, the male stayed within the territory whereas the female frequently occurred outside the territory. These results suggest that the necessary conservation and management areas differ for male and female breeding Oriental White Storks.

Magnets are used for commercial bird deterrents. Even though birds can detect the global magnetic field, they may not avoid the disorder of magnetic field caused by a magnet. We tested the repellency of magnets against Carrion (Corvus corone) and Large-billed Crows (C. macrorhynchos) and Eurasian Tree Sparrows (Passer montanus). There were no differences between feeders fitted with or without magnets in terms of the number of visits, the consumption of food, and the average time spent on the feeders. Our results suggest that magnets ≤120 mT have no repellency for these species.

Mapping the flight altitude and position of raptors is useful for understanding their selection of migration routes with respect to geographic features and also to assess the impact of wind farms. We have previously studied the flight altitude of Grey-faced Buzzards Butastur indicus, based on their apparent wingspans in photographs, given their wingspan of 105 cm. However, this measurement is not representative of wingspan during flight, leaving some uncertainty in the results. In this study, we used a novel device to record an image and distance to the object at the same time allowing us to measure the actual wingspan of the Grey-faced Buzzard during flight. The average wingspan during flight was found to be 98.9 ± 3.6 cm (SD). This result will help improve the accuracy of measurements of the flight altitude of migrating Grey-faced Buzzards.