Seasonal changes of foraging habitats and prey species in the Japanese Crested Ibis Nipponia nippon reintroduced on Sado Island, Japan

Abstract

SummarySeasonal foraging habitats, prey species and foraging frequency of Japanese Crested Ibis Nipponia nippon in farmland were studied one year after its reintroduction on Sado Island, Japan. Paddies were the main foraging habitat in spring, early summer, autumn and winter. In late summer, ibises often used levees around paddies, grasslands, uncropped paddies and abandoned paddies. Small invertebrates were important prey components in terms of frequency (70–90%) throughout the year. Ibises took Misgurnus loaches (less than 20% of prey captured) throughout the year; the capture rate of loaches in ditches was especially high in winter. Ibises depended on terrestrial invertebrates, including earthworms, particularly in late summer. No clear correlations between the rate of capture for each prey species and the proportion of habitat use in each season were detected. However, abandoned and uncropped paddies provided suitable habitats for the ibis because human disturbance was relatively low and the rate of capture for each prey type was relatively high throughout the year. Management of grass height in grasslands and on levees around the paddies will be effective in ensuring the availability of foraging habitats in late summer. Seasonal changes in the availability of foraging habitats in farmland ecosystems should be considered when designing effective management strategies for the establishment of Japanese Crested Ibis populations.

Drivers of land-use changes in societies with decreasing populations: A comparison of the factors affecting farmland abandonment in a food production area in Japan

“…However, there are several activities intended to restore abandoned farmlands to original natural ecosystems in areas with high potential and needs for rewilding. On Sado island, abandoned paddies function as foraging habitats of the reintroduced Crested Ibis, Nipponia nippon [ 89 ], and in the Lake Inbanuma watershed, abandoned paddies on small valley bottoms have potential for multipurpose usages such as flood control, water purification, and wetland biodiversity [ 90 ]. In Hokkaido, the abandoned farmlands could be used to harbor organisms of wetland ecosystems [ 84 – 87 ] and provide wetland green infrastructure [ 91 ].…”

Dynamic wetland mosaic environments and Asian openbill habitat creation in peri-urban Bangkok

“…However, these studies mainly described rice fields as seasonally limited surrogate wet habitats as a source of food for wetland birds. For example, Endo and Nagata (2013) reported that the reintroduced Japanese crested ibis (Nipponia nippon) on Sado Island, Japan adapted to rice fields as a core food source as well as obtaining food from surrounding habitats during the annual single-cropping rice cultivation calendar. Masero et al (2011) reported that, in the west coastal area of the Iberian Peninsula, as a substitute for natural large-scale wetlands, rice fields have become a major habitat for long-distance migratory shorebirds, particularly during winter pooling.…”

Earthworm species and density in semi-natural grasslands on rice paddy levees in Japanese satoyama

“…In satoyama , traditional agricultural landscapes of Japan, various types of animals [e.g. Japanese marten ( Tatara and Doi 1994 ), moles ( Yokohata 2005 ), birds ( Minamiya et al 2007 , Nagata 2010 , Endo and Nagata 2013 ), frogs ( Hirai and Matsui 2000 , Hirai and Matsui 2001 ) and carabid beetles ( Okuzaki et al 2010 )] feed on earthworms. Thus, earthworms contribute to the sustainability of food webs in satoyama .…”

“…Since re-introduction, the wild population of crested ibis has been steadily increasing; the recent population estimate is 368 wild individuals in 2018 ( Bansho 2019 ). According to a recent study, wild crested ibis feed on earthworms on the levees of rice paddy margins, especially in the summer ( Endo and Nagata 2013 ). However, the species composition and density of earthworms within levee grasslands on the island have not been examined.…”