By Ben Hope

Possums and rats eat pine seeds which birds ignore

Scion is a Crown research institute that specialises in research, science and technology development for forestry, wood product and wood-derived materials enterprises.

The findings that possums are eating pine seeds came as a surprise to scientists as the seeds are small, about 2mm-4 mm on average, so it was supposed possums would have difficulty in finding them.

Not so surprising relative to the small size of seeds and animal body weight was that rats and mice were the biggest eaters. However, possums ate a greater quantity of seeds per animal.

In dense forests, home to large populations of mammals, about 90 percent of seeds was eaten whereas in tussock habitat, only half of the seed quantity was consumed. That highlights how vulnerable those areas were to invasion by pines, Scion’s Dr Tom Carlin says.

Another surprise was that birds, whether native or introduced, had no interest in making a meal of the seeds especially since some “experts” considered birds would be taking seeds.

Helping to slow the spread of wilding pine

The results of the research strongly point to programmes of introduced mammal control or attempted extermination, will probably result in “increasing invasive conifer populations by reducing seed predation pressure”.

However, finding that mammals are an asset in the fight against wilding pine spread gives hope. Since it is almost certain that the country will not be able to exterminate possums and rats, wilding pine spread will be lessened.

Scientist confirm that the seeds do not survive through the gut of possum or rats.