Falcons and vineyards research a win-win
Falcons and vineyards research a win-win for winemakers and predator conservation
October 31, 2012
A University of Canterbury (UC) researcher has found benefits in encouraging New Zealand falcons into Marlborough vineyards for pest control.
UC biology researcher Sara Kross, from Blenheim, said the country’s only remaining endemic bird of prey, the falcon, is a perfect match for vineyards.
Falcons have been dwindling in numbers and range in the last 150 years. Her PhD at UC has provided research to prove that such win-win ecology can exist between predator conservation and vineyard agriculture.
``Encouraging wildlife onto farms by providing food sources or shelter can increase the abundance of beneficial species that provide ecosystem services, such as pest control, for farmers.
``I studied a project that re-introduced the threatened New Zealand falcon from the hills of Marlborough into vineyards, to determine if predators could survive within an agricultural landscape while simultaneously providing that landscape with biological control services.
``Falcons in Marlborough have been pushed into the high-country hill habitat surrounding the fertile river valleys of the region. But my study looked at whether re-establishing falcon populations in the valleys would benefit the falcons because of the abundance of food sources (the pest birds that feed on grapes), while at the same time providing grape growers with a natural form of pest control,’’ Kross said.
To assess the potential of falcons for pest control, Kross used pest-bird abundance counts and grape-damage surveys. Vineyards with resident falcons had significantly fewer introduced pest-birds such as starlings, blackbirds and song thrushes.
The research showed that the presence of a falcon in a vineyard could reduce the damage caused by introduced species of birds by 95 percent and could reduce the damage caused by the native silvereye by 55 percent.
This resulted in an average savings for growers of $285 per hectare for sauvignon blanc grapes and a savings of $398 for pinot noir. Kross’s research has been published in leading international journal Conservation Biology.
Her research is the first to show a significant benefit to farmers associated with conservation of a predator.
``I also assessed the quality of vineyards for the falcons themselves. I did this by comparing the nesting and diet habits of falcons in the hills from which they had been translocated with the nesting and diet habits of falcons in the vineyards.
``I had to wear a thick leather hat because falcons will attack any nest intruders relentlessly. To avoid disturbing the nesting pairs more than necessary, I had cameras controlled from a recording station 25m from the nest.
``To determine the impact of reintroductions on falcon behaviour, I collected a total of over 5398 hours of video footage at six falcon nests in the hills and at four falcon nests in the vineyards.
``I found that falcons breeding in the vineyards had higher nest attendance, higher brooding rates and higher feeding rates than their counterparts breeding in the hills. Additionally, parents in vineyard nests fed their chicks a greater amount of total prey and larger prey items compared to parents in hill nests.’’
Kross is programme manager for the Marlborough Falcon Conservation Trust, a charitable trust she co-founded during the first year of her thesis.