Vertebrate fauna recolonization of restored bauxite mines - key findings from almost 30 years of monitoring and research

Restore former mining or energy production sites

A replicated, site comparison study in 1978–2005 of former mines (total number not given) in jarrah forests in Western Australia, Australia (Nichols & Grant 2007, same experimental set-up as Nichols & Bamford 1985) found that restored areas were recolonized by a range of reptile species. Of 24 reptile species commonly found in upland jarrah forest, 21 were recorded in restored forest sites. The following results were not statistically tested. Two generalist reptile species (skink Tiliqua rugosa and Dugite snake Pseudonaja affinis) were recorded in restored sites after 2–3 years. Authors report that more specialist species (e.g. Phyllodactylus marmoratus and Ramphotyphlops australis) have only been observed in restored sites >12 years old (personal observations of other sites). The authors reported that older-style restored areas (established using trees only) were unsuitable for most reptile species, whereas more advanced restoration approaches (including direct topsoil return) supported more species and greater abundance of reptiles. Some reptile abundances were lower in restored forest compared to unmined areas (see original paper for details). In 1976, two sites were restored by seeding (1 site) or top soil addition (1 site). In 1990, further sites (number not given) were restored using various techniques, including topsoil return, deep ripping, understorey seeding of many local species and establishment of local eucalypt species. Wildlife corridors and specific microhabitats (e.g. hollow logs, stumps) were created. Reptiles in restored areas (of varying ages and restoration techniques) and undisturbed forest were monitored in 1981, 1987, 1993, and 1999.

(Summarised by: Katie Sainsbury)

Restore former mining sites

A replicated, site comparison study in 1978–2005 of former mines in jarrah forests in Western Australia, Australia (Nichols & Grant 2007) found that restored mined areas were recolonized by a range of mammal species within 10 years. Western grey kangaroo Macropus fuliginosus, mardo Antechinus flavipes and chuditch Dasyurus geoffroii were all first reported in restored mines 0–2 years after restoration, whereas common brushtail possum Trichosurus vulpecula was first reported after eight years and brush-tailed phascogale Phascogale tapoatafa after ten years. Mardo capture rates increased at restored sites (caught in 1% of traps 10 years after restoration) but remained lower than in adjacent undisturbed forest (2–11% of traps). Mined areas were revegetated using various techniques including topsoil return, deep ripping, understorey seeding of many local species and establishment of local eucalypt species. Wildlife corridors and specific microhabitats (e.g. hollow logs, stumps) were created. In 1993–1994, mammal nest boxes were placed in a range of sites (number not stated). Non-native red fox Vulpes vulpes control was carried out for several years from 1994. Mammals in restored areas (of varying ages and restoration techniques) and undisturbed forest were monitored using wire cage traps, large and medium aluminium box traps and pit traps.

(Summarised by: Nick Littlewood)

Restore or create forests

A controlled, replicated study at the same sites as studied in Nichols & Watkins (1984), from Feburary-March and July-August in 1992, 1995 and 1998 in jarrah forests in southwestern Australia (Nichols & Nichols (2003) found that bird species richness and diversity was comparable between four mined and restored, and four intact sites, eight years after rehabilitation. Of 70 bird species inhabiting intact jarrah forest, 95% were recorded in the rehabilitated sites at some point in the succession. Community dissimilarity (between mined and intact sites) decreased over time. Bird recolonisation was significantly correlated with vegetation growth. The four rehabilitated sites were established in June-July 1990 by re-contouring the mining pit to natural conditions, ripping the pit floor to reduce compaction, and replacing the topsoil. Local trees and understory species were directly seeded and covered with fertiliser.

Restore or create forests

A 2007 study (Nichols & Grant 2007) reports on longer-term studies of the jarrah areas described in Nichols & Watkins (1984). In some restored plots, avian communities were becoming very similar to that of native (undisturbed) forest sites (with 95% of species recorded) within 10 years of restoration.

Remove/control non-native mammals

A before-and-after study in 1980–2005 across an area of former bauxite mines in jarrah forest of Western Australia, Australia (Nichols & Grant 2007) found that controlling non-native red foxes Vulpes vulpes on restored mine areas resulted in increased abundance of chuditch Dasyurus geoffroii, quenda Isoodon obesulus and brushtail possum Trichosurus vulpecula. Results were not tested for statistical significance. Chuditch were caught in 0.2% of traps immediately after fox removal compared to none before, and in 1.4% of traps six years later. Quenda were caught in 2.7% of traps immediately after fox removal compared to none before, but they were also absent six years after fox removal. Brushtail possum were caught in 2.3% of traps six years after fox removal, compared to up to 0.5% before. Control of foxes, using poisoned baits, was carried out from 1994 and fox sightings decreased from 15 that year to none in 1999 and 2000. Mined areas were revegetated using various techniques. Mammals were monitored using wire cage traps, large and medium aluminium box traps and pit traps in 1980, 1993, 1997 and 2005.

(Summarised by: Rebecca Smith)

Provide artificial dens or nest boxes on trees

A study in 1993–2005 of restored sites within bauxite mined areas in the jarrah Eucalyptus marginata forest of Western Australia, Australia (Nichols & Grant 2007) found that nest boxes within restoration areas were used by western pygmy possums Cercartetus concinnus, mardo Antechinus flavipes and brush-tailed phascogale Phascogale tapoatafa. Western pygmy possum used nest boxes placed in 8–10-year-old restoration sites. Mardo and brush-tailed phascogale also used nest boxes and possibly bred in them (no further details provided). Mined areas were revegetated using various techniques. In 1993–1994, mammal nest boxes were placed in a range of sites. Control of non-native red foxes Vulpes vulpes was also carried out for several years from 1994. Nest box designs and monitoring protocols are not described.

(Summarised by: Nick Littlewood)