Diet composition based on stable isotopic analysis of fecal samples
revealed the preference of Black-faced Spoonbill (Platalea minor) for
natural and artificial wetlands
Abstract
Background: Black-faced spoonbill (BFS) is a global endangered species,
distributed only in the coastal zones of East Asia. Xinghua Bay is one
of the main wintering sites and migration stopovers of BFS in mainland
China. However, with the reduction and degradation of natural wetlands,
it is uncertain whether the constructed wetland can provide habitat for
the endangered BFS. Research on diet of BFS will help to understand
their preference between natural and artificial wetlands, and also
provide reference for their conservation and habitat restoration.
Methods: From December 2017 to February 2020, 45 potential food samples
and 199 fecal samples of BFS were collected during six sampling period,
of which Cyprinidae, Mugilidae, Portunidae, Gobiidae and Palaemonidae
were collected from natural wetlands and Crucian (Carassius auratus) and
Whiteshrimp (Litopenaeus Vannamei) were collected from artificial
wetland. Their stable isotope values (δ13C, δ15N) were measured to
obtain the food composition information of BFS. Results: In the early
winter, the proportion of Palaemonidae in BFS’s food was as high as
74.4%, while that of other food was only 3.0% to 6.0%. In the late
winter, the food contribution of BFS was as follow: Portunidae 39.3%
> Palaemonidae 26.1% > Cyprinidae 8.8%
> Mugilidae 8.5% > Gobiidae 7.3%
> Crucian 5.1% > Whiteshrimp 4.8%. The
proportion of Portunidae exceeded that of Palaemonidae, and together
with Palaemonidae, it has become the main food of BFS in late winter.
Conclusion: The diet composition of BFS between the early and late
winter was significantly different, which may be due to seasonal changes
in food resources. Natural wetlands are the main feeding grounds of BFS,
but artificial wetlands also provide them with supplementary feeding
grounds and resting places. Aquaculture ponds play an important
ecological function in maintaining the overwintering population of BFS
in Xinghua Bay.