background black and white concrete floor gray grey rough square texture tile build building cloud clouds construction crane cranes high lift lifting real estate sky tower alphabet black black-and-white computer control delete device enter input keyboard laptop line metal notebook numeric parallel pattern rectangle shift technology type typing white aggressive Australian birds chroicocephalus novaehollandiae common gray and white grey and white gulls Larus novaehollandiae Noisy prolific resting river river's edge riverside sand scavengers screeching seagulls sepia silver gull standing wading waiting watching anas-superciliosa aquatic-birds bank black-eye-stripe brown-duck chroicocephalus-novaehollandiae color colour differences diversity ducks edge fauna fowl grass grassy gray-and-white grey-and-white grey-duck harmonious harmony lake lakeside Larus-novaehollandiae non-threatening not-threatened Pacific-black-duck quiet relaxed relaxing seabirds shadows silver-gull slope sunlight sunshine together water waterbirds waterfowl widespread wild-ducks wild-life adaptable alert aloof appearance appearances carnivorous cat collar comfortable companionable domestic domesticated eyes felid feline felis-catus house-cat independent mammal pet popular positions posture postures reclining social stretched tag various-expressions warm whiskers felis catus house cat various expressions cascading city colors colours cool cooling edges edging flow flowing fountain levels light multi-level reflecting ripples rippling splashing