Wide-ranging Movement and Foraging Strategy of the Critically Endangered Red-headed Wood Pigeon (Columba janthina nitens): Findings from a Remote Uninhabited Island

Genetic and ecological conservation issues for oceanic island birds, revealed by a combination of the latest molecular techniques and conventional field work

“…In the case of the nominal subspecies of Japanese wood pigeon C. j. janthina , inter‐island movement and seasonal population fluctuation among islands has been observed in the Izu Islands (Ando, Mori, & Sato, ; Wild Bird Society of Japan, ). In the Ogasawara Islands, movements of banded individuals of the C. j. nitens among islands were directly observed (Ando et al, ; Suzuki et al, ), and one of the individuals made a round trip between the Bonin and Volcano Islands within 2 months (Ando, Sasaki, et al, ). These findings may indicate that individual movements between the two island groups are not occasional events but can occur over a short period of time within a year.…”

“…These findings may indicate that individual movements between the two island groups are not occasional events but can occur over a short period of time within a year. Indeed, pigeons' diets and the composition of fruiting trees was different among three island habitats: Chichijima and Hahajima in the Bonin Islands and Kita‐Iwoto Island in the Volcano Islands, and fruit abundance fluctuated seasonally and annually (Ando et al, ; Ando, Sasaki, et al, ). These findings may indicate that pigeons use available food resources in each island flexibly by moving widely among island habitat.…”

“…Various types of food resources that are difficult to identify through other traditional methods have been detected due to the method's high resolution (Ando et al, ; Soininen et al, ). Using this method, Ando et al (, ) and Ando, Sasaki, et al () conducted dietary analyses of the C. j. nitens by sequencing a part of the chloroplast trn L region (Taberlet et al, ; Valentini, Miquel, et al, ). As a result, clear seasonal and inter‐island variations in the pigeon diet and their frequent consumption of introduced plants in specific seasons were determined (Figure ).…”

“…As a result, clear seasonal and inter‐island variations in the pigeon diet and their frequent consumption of introduced plants in specific seasons were determined (Figure ). The combination of the data on food resource availability and nutrient composition of fruits indicated the pigeons' food selection pattern, selecting lipid‐rich fruits but flexibly using various food resources available in each island habitat (Ando et al, ; Ando, Sasaki, et al, ). Although the lipid ratios of introduced fruits were lower than those of the pigeons' preferred native fruits, some introduced plants that provide large amount of fruits were thought to be preferred resources for the C. j. nitens when other native fruits are rare (Ando et al, ).…”

Evaluation of plant contamination in metabarcoding diet analysis of a herbivore

“…Most metabarcoding diet studies of herbivores have been conducted with mammals 4 , 8 , 11 , 12 , 24 , 25 and birds 5 , 10 , 26 , 27 . However, contamination of herbivore feces with plant DNA sequences is difficult to discern because there are various sources of plant contamination around samples in the field, most of which can be consumed by the target animals.…”