great-crested grebe nest

altricial australis beds bird birding birds closeup colymbus common cristatus dabchick diver egg environment eutrophied feather fowl greatcrested grebe guide hippuris hollow hunting lake locule loculus mace mares moorfowl nature nest nesting nestle nidicolous nidification nidology ornithology phragmites podiceps reed reproduction skein stinkpot study tail tour varmint vulgaris waders water waterbirds waterfowl wild wildlife