But for conservationists and zoo supervisor Shelley Russell, Tuesday was International Tiger Day and a time to raise awareness of the critical danger facing tiger species the world over.

Ms Russell said Canberra residents could help conservation efforts by being more careful about what they buy at the supermarket, particularly by avoiding palm oil sourced unsustainably.

''It's in a lot of what we buy but there are sustainable sources,'' Ms Russell said.

''What we encourage is to buy sustainable products rather than not buying them at all, because it's nearly impossible to do that.''

Ms Russell said irresponsible harvesting of palm oil had destroyed tiger habitats and was found in a startling number of everyday products, such as toothpaste, biscuits and detergents.

The National Zoo plans to open a ''zoopermarket'' at which visitors can scan common products and learn whether their palm oil content was sourced sustainably.

Ms Russell also asked consumers to purchase Forest Stewardship Council (FSC)-certified paper products and support wild tiger conservation programs.

Meanwhile the zoo is hoping that Rhani and Berani can be encouraged to breed within the next six months.

More information about the sustainability of palm oil in consumer products can be found at www.zoo.org.au/zoopermarket.