Ibis numbers have decreased
IBIS numbers in Rockhampton’s Botanic Gardens are down 69% since the introduction of a management program last year, a new report reveals.
But Ecosure, the company responsible for the dramatic reduction in the pesky birds at the city’s best-loved park, warns the population could soar again if the program is not maintained.
Ecosure says the reduction would have been even more effective had workers been able to get at nests around the Murray Lagoon and in trees that are too tall for their equipment to be effective.
The management program was approved last October in the fallout from an unofficial cull of baby ibises in the gardens that led to fines for the council and veteran parks boss Tom Wyatt accepting a redundancy package.
Wildlife authorities finally accepted that the plague of ibises posed a health hazard for visitors and there was a risk to aeroplanes taking off and landing at Rockhampton Airport.
In a report to Rockhampton Regional Council’s Sport and Recreation Committee, Ecosure says last September there were 1047 ibises roosting in the gardens. A year on, the number had fallen to 325 thanks to regular visits from a team which removed eggs and destroyed nests.
The report says prolific outbreaks of water lettuce on the lagoon hampered efforts to reach breeding sites around the water’s edge and there had also been difficulties caused by egrets nesting in bamboo and the density of dead palm fronds in the tree tops.
Ecosure’s staff can reach nests up to 18 metres up, but there are trees in the gardens that are much taller.
The company is recommending efforts to remove water lettuce from the lagoon, trimming bamboo, removing dead palm fronds, removing coconuts to provide a safer environment for workers and visitors, and that a maintenance program continue to address those issues.
It warns that during periods of drought, ibises can be expected to forage in greater numbers at the city’s dump because the ground elsewhere is too hard for them to dig for insects.