The Untidy Garden
Messy yards benefit New Zealand lizards
Who cares what the neighbors think. That scraggly flower garden may be better for city-living lizards, concludes a new study from New Zealand.
“The responses of lizard populations to urbanization are probably the least understood of all vertebrates,” Yolanda van Heezik and Karin Ludwig of the University of Otago in New Zealand write in Landscape and Urban Planning. At the same time, “private gardens cumulatively comprise a large proportion of the total area in many cities”– 20% of more of the land area. And “the greater the degree of urbanization, the more important gardens become” for urban wildlife.
To better understand the link between urban gardens and wildlife, the pair studied the distribution of the common skink (Oligosoma nigriplantare polychrome) in suburban private gardens in the small city of Dunedin. To survey the skinks, they invited homeowners to place artificial sunning spots in their gardens, or report seeing the lizards among their flowers. Then, they looked for factors – ranging from the presence of nearby grasslands to the amount of development – that might explain the presence or absence of garden lizards.
Overall, “skink occurrence was influenced mainly by landscape-level features,” such as distance to the city’s edge, and things like the presence of cats, native vegetation and south-facing sites.
Another factor, however, was garden “messiness.” Skinks were “more likely to occur in gardens that contain areas of overgrown vegetation,” the authors report. “Skinks and probably many other small species benefit from messy habitat, however cultural norms play a strong role in reinforcing traditional values of neatness among home owners, with the result that an apparent lack of care or disorderliness in gardens can be perceived as undesirable and socially unacceptable.” And “pesticide and herbicide use may be more prevalent in tidy gardens as well as higher levels of human disturbance, both of which are likely to have detrimental impacts on skinks and their prey.”
“The majority of householders in this study were enthusiastic about having skinks in their garden,” they note, suggesting that “skinks could be promoted as a flagship species in urban areas.” But “it is unlikely that they will thrive in urban areas,” they warn, “unless gardening practices change to increase resource availability and provide refuges from predators.” Translated: Get rid of the cat – and put away the shears and mower. – David Malakoff | November 8, 2011
Source: van Heezik, Y., & Ludwig, K. Proximity to source populations and untidy gardens predict occurrence of a small lizard in an urban area. Landscape Urban Plan. (2011), doi:10.1016/j.landurbplan.2011.10.016
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