This is a project being done by PhD student Sara Kross

The New Zealand falcon (Falco novaeseelandiae) is New Zealand’s only remaining endemic diurnal raptor and is considered a chronically threatened species. Like all New Zealand birds, falcons evolved without the presence of land-dwelling mammalian predators, and therefore lack the morphological and behavioural adaptations necessary to deal with them. Falcons often nest in ‘scrapes’ on the ground, and are prone to high rates of nest mortality from raids by introduced mammalian predators. 

Introduced species of passerine birds are a particularly destructive force in the arable farming and vineyard landscapes of New Zealand, and have caused significant economic losses for both growers and associated industries. Vineyards are particularly vulnerable to the destructive patterns of passerine feeding, as grapes represent an abundant and easily targeted food source in summer and autumn. The species that cause the majority of losses to New Zealand vineyards are Blackbirds, Song Thrushes, Starlings and Silvereyes. The total cost of bird damage to the entire New Zealand wine industry may be in excess of $70 million annually, with effects in Marlborough, New Zealand’s largest wine growing region, costing growers millions in combined loss of crop and cost of bird control. As one of only two diurnal raptors in New Zealand, and a specialized avian hunter, the New Zealand falcon is potentially the most effective native predator for controlling pest bird populations. 

Falcons For Grapes (FFG), is a nonprofit organisation that has relocated falcons from the surrounding hills into the Wairau valley as a means of both providing conservation benefits for falcons, in the form of additional habitat and plentiful prey, and as means of biological control of pest birds. The innovation of FFG is that by relocating falcon chicks to vineyards it aims to create self-sustaining conservation; whereby an increase in falcon numbers, as new habitat and an abundance of prey are made available to them, concomitantly creates a form of integrated pest management that reduces the detrimental effect of passerines in vineyards. Consequently, the FFG initiative has the potential to be strongly beneficial to both falcons and vineyard operators.  

Although the success of FFG relies on detailed knowledge of the effect falcon reintroduction is having on the numbers, behaviour and ecology both of falcons and on the passerine species within the vineyards, no rigorous studies have taken place to determine this. Sara’s project will address how successful FFG is as a method for controlling grape damage caused by passerine birds, as well as its impact on falcon conservation. 

This project is being funded by the Brian-Mason Technical Trust.