@article {41709, title = {High densities of water-birds at two New Zealand fresh-water urban lakes}, journal = {Notornis}, volume = {65}, year = {2018}, pages = {84{\textendash}91}, abstract = {

Abstract We compared summer counts of water-birds (November\–January, 2012\–2016; mainly Anatidae, Phalacrocoracidae,
Rallidae, Laridae) at 2 small, shallow, urban lakes set in parkland surroundings: Western Springs Lake (Auckland)
and Henley Lake (Masterton), New Zealand. We recorded 25 species of water-birds; 17 at Western Springs Lake and 22
at Henley Lake, with 14 species in common. The average total densities (and biomasses) were 61 birds/ha (113 kg/ha) at
Western Springs Lake, significantly higher than the 40 birds/ha (95 kg/ha) at Henley Lake. Ducks (Tadorninae, Anatinae)
made the biggest single contribution to numbers at both lakes (40\–60\% of total water-bird density). Swans and geese (Anserinae)
were less common than ducks but because they were heavier birds they accounted for 60\–70\% of total biomass,
and were therefore the main consumers of food and producers of droppings. Introduced water-birds made up 60\–70\% of
the density at both lakes, and 80\–90\% of the biomass, with no significant differences between lakes. The presence of some
native species (in significantly greater total density and biomass at Western Springs Lake), and breeding of the endemic
New Zealand scaup at both sites, illustrate the potential conservation value of New Zealand\’s small urban lakes.

}, keywords = {aquatic birds, Biomass, Density, Henley Lake, Waterfowl, Western Springs Lake}, issn = {0029-4470}, author = {Gill, BJ and West, RC} } @article {Wood2012, title = {The impact of waterfowl herbivory on plant standing crop: a meta-analysis}, journal = {Hydrobiologia}, volume = {686}, number = {1}, year = {2012}, pages = {157{\textendash}167}, abstract = {

Waterfowl can cause substantial reductions in plant standing crop, which may have ecological and economic consequences. However, what determines the magnitude of these reductions is not well understood. Using data from published studies, we derived the relationship between waterfowl density and reduction in plant standing crop. When waterfowl density was estimated as individuals ha\−1 no significant relationship with reduction in plant standing crop was detected. However, when waterfowl density was estimated as kg ha\−1 a significant, positive, linear relationship with reduction in plant standing crop was found. Whilst many previous studies have considered waterfowl species as homologous, despite large differences in body mass, our results suggest that species body mass is a key determinant of waterfowl impact on plant standing crop. To examine relative impacts of waterfowl groups based on species body mass, a measure of plant biomass reduction (R s) per bird per hectare was calculated for each group. Comparison of R s values indicated some differences in impact between different waterfowl groups, with swans having a greater per capita impact than smaller-bodied waterfowl groups. We present evidence that this difference is linked to disparities in individual body size and associated differences in intake rates, diet composition and energy requirements. Future research priorities are proposed, particularly the need for experiments that quantify the importance of factors that determine the magnitude of waterfowl impacts on plant standing crop.

}, keywords = {Allometry, Aquatic ecology, Biomass, Density, Diet, Ducks, Geese, herbivory, Limnology Ornitholimnology, Macrophyte, Plant standing crop, Primary consumer, Sheldgeese, Swans, Vegetation, Waterfowl, Wildfowl}, issn = {0018-8158}, url = {http://link.springer.com/10.1007/s10750-012-1007-2}, author = {Wood, Kevin A. and Stillman, Richard A. and Clarke, Ralph T. and Daunt, Francis and O{\textquoteright}Hare, Matthew T.} } @article {Wood2012a, title = {The impact of waterfowl herbivory on plant standing crop: a meta-analysis}, journal = {Hydrobiologia}, volume = {686}, number = {1}, year = {2012}, month = {feb}, pages = {157{\textendash}167}, keywords = {Allometry, Aquatic ecology, Biomass, Density, Diet, Ducks, Geese, herbivory, Limnology Ornitholimnology, Macrophyte, Plant standing crop, Primary consumer, Sheldgeese, Swans, Vegetation, Waterfowl, Wildfowl}, issn = {0018-8158}, url = {http://link.springer.com/10.1007/s10750-012-1007-2}, author = {Wood, Kevin A. and Stillman, Richard A. and Clarke, Ralph T. and Daunt, Francis and O{\textquoteright}Hare, Matthew T.} }