کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4540411 1326667 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Seasonal variation and tidal influences on estuarine use by bottlenose dolphins (Tursiops aduncus)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Seasonal variation and tidal influences on estuarine use by bottlenose dolphins (Tursiops aduncus)
چکیده انگلیسی

In order to show that dolphins use estuary habitats differently depending on the season and tidal state, possibly in response to prey distribution, temperature, risk of stranding and accessibility, Indo-Pacific bottlenose dolphins (Tursiops aduncus) were observed year-round during a 3-year study in the Clarence River estuary (CR) and Richmond River estuary (RR) in northern New South Wales, Australia. Peak dolphin sightings occurred during the spring season and one or 2 h prior to high tide. The spatial distribution of the dolphins in each estuary was analysed using the distance in kilometres that the dolphins travelled upstream with seasons and tidal phase as determinants. A General Linear Model showed that in the CR the dolphin spatial distribution in the estuary was not determined by season (F = 0.434, df = 3, P = 0.729) but was by tidal phase (F = 9.943, df = 3, P < 0.001) and the interaction between season and tidal phase (F = 3.398, df = 9, P < 0.002). However, in the RR the spatial distribution of the dolphin use of the estuary was not determined by either season (F = 1.647, df = 3, P = 0.194) or tidal phase (F = 0.302, df = 3, P = 0.824). In the CR, the spatial distribution of the dolphins was largest on high and flood tides. This pattern of spatial distribution may occur because the CR is a relatively shallow estuary and this increased spatial distribution may reflect a lower stranding risk and an increase in accessibility of shallow areas during periods of higher tide. These areas could also provide access to their preferred prey items of sea mullet (Mugil cephalus) and sand whiting (Sillago ciliata).


► Dolphin spatial use in estuaries was examined using distance they travelled upstream.
► Tidal phase and interaction between season and tidal phase was significant.
► Largest spatial distribution occurred on high and flood tides in spring.
► Reasons include prey distribution, temperature, stranding risk and accessibility.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Estuarine, Coastal and Shelf Science - Volume 93, Issue 4, 20 July 2011, Pages 389–395
نویسندگان
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