小燕鷗(Sternula albifrons)在台灣的繁殖族群之遷徙路徑研究

Abstract

None.

The Little tern is a migratory sea bird with a wide range, and populations found on every continent except for Antarctica and the continental Americas. Recently these populations have been experiencing a decline due to habitat degradation and human disturbance. To implement more comprehensive approaches to retain stable populations, dynamic conservation tactics must be employed. The prerequisite for this is detailed knowledge of a bird’s annual cycle, to ensure protection at all stages. The movement of the Taiwanese population of the Little tern has previously been estimated solely based on banding data. For this reason, this project aimed to obtain a more detailed understanding of the movement of the Taiwanese breeding population of the Little tern over its yearly cycle. This was executed by utilizing geolocator tracking data from 5 individuals from 2 breeding grounds in the northeastern breeding site in Yilan County, Taiwan during the 2013 and 2016 breeding periods. This allowed for the elucidation of their southbound and northbound migration routes, as well as the identification of stopover locations used. Results obtained were then confirmed with banded bird sightings from the projected regions and were then compared with routes of the previously tracked population in Chiba, Tokyo and Okinawa, Japan. All tracked birds used the East-Asian Australasian Flyaway from the breeding grounds in Taiwan to arrive to non-breeding grounds in Western and South-Eastern Australia. Along the route, The Philippines and Eastern Indonesia were utilized as stopover sites, with the southbound movement lasting longer than the northbound movement. This is the first geolocator study to describe the routes for Taiwanese Little terns. The routes employed by the terns are used by a wide range of sea birds, and therefore the findings from this study can be used to identify conservation gaps in regions along the flyway.