cats

Posted by Samantha Lincoln @slin247

Over the course of this year I have been undertaking intense field work across some of Auckland Councils public parks. Urban ecology is inherently strange; emerging sweat-soaked from a long day’s work, and carrying a small colony of beetles in your hair onto a main road whilst startling local dog walkers and being serenaded by Auckland Zoo’s primates. While not as idyllic as disappearing to the mountains for a week, urban ecology is incredibly important when most of our human population is urban. Connecting with nature is undeniably important for our wellbeing.

Auckland has hundreds of public parks of all sizes, both without and without maintained walking tracks as I have discovered. They are refuges for native species in the middle of our manicured city, but how well do we really look after these spaces? During my field work my volunteers and I have found a range of debris: backyard clippings spreading weeds, Victorian inkwells, a year’s supply of newspapers courtesy of a lazy paperboy, shelters built by those with nowhere else to turn (a growing issue in Auckland) and a pile of books featuring a bunny not often seen during pest control.

Live capture of a rat during a capture-recapture study

As Auckland city grows, more pressure is being placed on these biodiversity refuges and how we value and care for them becomes more important as was noted last month. Will we value and nurture these green spaces, or will they fail under the pressure? Will we continue to use them as personal rubbish dumps, or will we take interest in the other species that use these spaces? I will be a science advocate – we can all lend our voices. To me nothing beats the feeling of following a fantail nest from first cheeps to first awkward flight, as I make my daily visit to the rat trap at the tree’s base.

Sam Lincoln is an MSc student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She is trying to disentangle interactions between domestic cats and rats in urban environments. She is supervised by Margaret Stanley, John Innes and Al Glen.

Posted by Sam Lincoln

Biological systems are incredibly complex (see ecological networks blog). Introducing a spider to eat a fly may not help; New Zealand found that out the hard way with rabbits and ferrets. When one food source is running low, most predators prey-switch, and in New Zealand that often means moving onto our native birds. We regularly control rats both in our homes and local parks with little knowledge of the indirect impacts wrought upon biological systems. My Masters project aims to take a first look at how domestic cats respond to the removal of rats in local parks – are they eating more of our birds?

In Auckland Council’s local parks, a mix of native and introduced birds share their space with predators such as rats and domestic cats. There has been much recent debate about the impact of cats in New Zealand; while scientists agree that cats have negative impacts on our native species, the SPCA often has a far more cat-friendly view citing rodent control by domestic cats as potentially helping birds. Even politicians are involved in the cat debate, with Conservation Minister Maggie Barry in one corner fighting for kiwi versus Prime Minister John Key representing Moonbeam. My pilot study of 11 cameras set for two nights captured 14 individual cats in two local parks (as well as a few possums and an MSc student).

Photos from cat camera pilot study, clockwise from top left: two cats, MSc student Sam Lincoln and a possum. Cats were photographed visiting both parks during the day and night.

By assessing the changes to cat behaviour after removing rats from half of the sites, I will get a first look into what really goes on between cats, rats and birds – is rat control bad for birds due to increased predation by cats, or are rats the main culprits in an urban environment? What would happen if cats were to go? Should we instead be moving toward a predator free New Zealand where our birds can exist without either of these mammalian invaders?