Apply ecological compensation for developments
Overall effectiveness category Evidence not assessed
Number of studies: 2
Background information and definitions
Development projects destroy or disturb natural habitats, displacing animals living there. Ecological compensation for developments aims to create new habitat, or improve the condition of existing habitat, outside of the development area, to replace that which is lost (Kleintjes et al. 2003). This intervention tests whether these compensation areas are effective for butterflies and moths.
Kleintjes P.K., Sporrong J.M., Raebel C.A. & Thon S.F. (2003) Habitat type conservation and restoration for the Karner blue butterfly: a case study from Wisconsin. Ecological Restoration, 21, 107–115.
Supporting evidence from individual studies
A site comparison study in 1997–2001 in a shrubland in Wisconsin, USA (Kleintjes et al. 2003) reported that an area containing lupine Lupinus perennis transplanted from a development site was used by a similar number of Karner blue butterflies Lycaeides melissa samuelis as an area with no transplanted lupines. Results were not tested for statistical significance. One–four years after restoration, 4–8 Karner blue butterflies/year were recorded in an area with transplanted lupines, compared to 1–8 butterflies/year in an area without transplanted lupines. In June 1997, seventy-five plugs of lupine (0.76-m diameter, 1.2-m-deep) were removed from a construction area and planted in a 5 × 15 grid covering a 324-m2 area cleared of young pine trees. In November 1997, the surrounding 641 m2 was hand-seeded with a dry sand prairie seed mix (40% grasses, 50% non-woody broadleaved plants (forbs), 10% scarified lupine seed) at 22.6 lbs/ha. An adjacent 0.8-ha area, where the topsoil had been temporarily removed, was seeded with the same mix. In October 1999–2001, two 0.2-ha patches in each of the transplanted and seeded areas were cut to a height of 16 cm each year. From 1998–2001, Karner blue butterflies were surveyed 5–6 times/year (covering both flight periods) on a 103-m transect through the transplanted and seeded area, and a 570-m transect through the seeded non-transplanted area. The highest number of butterflies counted on a single date in each flight period at each site was used as the abundance for that year.Study and other actions tested
A study in 2004–2007 in one shrubland in New South Wales, Australia (Mjadwesch & Nally 2008) reported that, three years after translocation, along with habitat management and host plant translocation, a population of purple copper butterfly Paralucia spinifera caterpillars that had been moved from land designated for development to an adjacent area of managed compensatory habitat and retained habitat had increased in number. The site designated for development and adjacent area initially had an estimated purple copper population of 2,000 caterpillars. After the development and translocation of butterflies into the retained and compensatory habitat, which had received habitat management, the estimated caterpillar population size reduced to 1,600 in the following year but increased to an estimated 1,995 two years and 2,780 three years after translocation. Of the caterpillars found in the third year, 39% were in the compensatory habitat and 61% were in the area of retained original habitat. In 2004–2005, two thirds of an area of purple copper butterfly habitat was cleared for road-building and an area adjacent to the retained third was designated as compensatory habitat. Invasive plants were cleared from the retained and compensatory habitat and caterpillars and their host plant blackthorn Bursaria spinosa var. lasiophylla were moved from the land about to the cleared to the retained and compensatory habitat. Over 12 nights in December 2004–January 2005, a total of 1,260 caterpillars were moved. In 2005–2007 blackthorn plants in the retained and compensatory habitats were surveyed for caterpillars, signs of their feeding, and their mutualistic ants Anonychomyrma itinerans. Estimated caterpillar population sizes were calculated by multiplying the number of caterpillars found by five.Study and other actions tested