Browsing by Author "Melville DS"

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    Avian Influenza Virus Surveillance Across New Zealand and Its Subantarctic Islands Detects H1N9 in Migratory Shorebirds, but Not 2.3.4.4b HPAI H5N1
    (John Wiley and Sons Ltd, 2025-04) Waller SJ; Wierenga JR; Heremia L; Darnley JA; de Vries I; Dubrulle J; Robinson Z; Miller AK; Niebuhr CN; Melville DS; Schuckard R; Battley PF; Wille M; Alai B; Cole R; Cooper J; Ellenberg U; Elliott G; Faulkner J; Fischer JH; Fyfe J; Hay L; Houston D; Keys BC; Long J; Long R; Mattern T; McGovern H; McNutt L; Moore P; Neil O; Osborne J; Pagé A-S; Parker KA; Perry M; Philp B; Reid J; Rexer-Huber K; Russell JC; Sagar R; Ruru TT; Thompson T; Thomson L; Tinnemans J; Uddstrom L; Waipoua TA; Walker K; Whitehead E; Wickes C; Young MJ; McInnes K; Winter D; Geoghegan JL
    Highly pathogenic avian influenza (HPAI) virus subtype H5N1 has never been detected in New Zealand. The potential impact of this virus on New Zealand's wild birds would be catastrophic. To expand our knowledge of avian influenza viruses across New Zealand, we sampled wild aquatic birds from New Zealand, its outer islands and its subantarctic territories. Metatranscriptomic analysis of 700 individuals spanning 33 species revealed no detection of H5N1 during the annual 2023–2024 migration. A single detection of H1N9 in red knots (Calidris canutus) was noted. This study provides a baseline for expanding avian influenza virus monitoring in New Zealand.
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    Interacting Roles of Breeding Geography and Early-Life Settlement in Godwit Migration Timing
    (Frontiers Media SA, 17/03/2020) Battley PF; Conklin JR; Parody-Merino ÁM; Langlands PA; Southey I; Burns T; Melville DS; Schuckard R; Riegen AC; Potter MA
    While avian migration timing is clearly influenced by both breeding and non-breeding geography, it is challenging to identify the relative and interdependent roles of endogenous programs, early-life experience, and carry-over effects in the development of adult annual schedules. Bar-tailed godwits Limosa lapponica baueri migrate northward from New Zealand toward Asian stopover sites during the boreal spring, with differences in timing between individuals known to relate to their eventual breeding-ground geography in Alaska. Here, we studied the timing of northward migration of individual godwits at three sites spanning 1,100 km of New Zealand’s 1,400-km length. A lack of morphological or genetic structure among sites indicates that the Alaskan breeding population mixes freely across all sites, and larger birds (southern breeders) tended to migrate earlier than smaller birds (northern breeders) at all sites. However, we unexpectedly found that migration timing varied between the sites, with birds from southern New Zealand departing on average 9.4–11 days earlier than birds from more northerly sites, a difference consistent across 4 years of monitoring. There is no obvious adaptive reason for migration timing differences of this magnitude, and it is likely that geographic variation in timing within New Zealand represents a direct response to latitudinal variation in photoperiod. Using resightings of marked birds, we show that immature godwits explore widely around New Zealand before embarking on their first northward migration at age 2–4 years. Thus, the process by which individual migration dates are established appears to involve: (1) settlement by sub-adult godwits at non-breeding sites, to which they are highly faithful as adults; (2) a consequent response to environmental cues (i.e., photoperiod) that sets the local population’s migration window; and (3) endogenous mechanisms, driven by breeding geography, that establish and maintain the well-documented consistent differences between individuals. This implies that behavioral decisions by young godwits have long-lasting impacts on adult annual-cycle schedules, but the factors guiding non-breeding settlement are currently unknown.