Offshore islands that act as gathering points or stop-over points during migration for the flycatchers, cuckoo, reed-warbler or wagtails should be considered separately from mainland Australia. These islands are unlikely to support biologically significant populations, even if multiple birds pass through on passage, because migration appears to be on a broad front. This will be reviewed as further information is gathered given that islands are nevertheless likely to support, over the course of a migration season, more individuals than equivalent areas of mainland. Table 4 Areas of important habitat for each species likely to result in a significant impact if affected. Species Area thresholds (ha unless otherwise stated ) 1% 0.1% Osprey 840 km coastline 84 km coastline * * White-throated Needletail * * Fork-tailed Swift 250,000 25,000 Oriental Cuckoo 2,600 260 Black-faced Monarch 865 87 Monarch Satin Flycatcher 4,400 440 Spectacled Monarch 2,100 210 Southern Spectacled Monarch 1,300 130 Wet Tropics Spectacled Monarch 1,100 110 Cape York Spectacled Monarch 1,300 130 Rufous Fantail 7,500 750 Southern Rufous Fantail 2,600 260 North-eastern Rufous Fantail 3,400 340 Arafura Rufous Fantail 4,500 450 Oriental Reed-warbler * * * * Barn Swallow * * Red-rumped Swallow Grey Wagtail * * Yellow Wagtail * * * No threshold area can be determined at this time or has identified given lack of knowledge or rarity. Research on White-throated Needletail may reveal site thresholds in tall forest used by roosting birds. Table 5 The proportions of each migratory species population likely to result in a significant impact if affected. Species Thresholds ( no of individuals) 1% 0.1% Osprey 240 24 10 White-throated Needletail 100 100 Fork-tailed Swift 1,000
Offshore islands that act as gathering points or stop-over points during migration for the flycatchers, cuckoo, reed-warbler or wagtails should be considered separately from mainland Australia. These islands are unlikely to support biologically significant populations, even if multiple birds pass through on passage, because migration appears to be on a broad front. This will be reviewed as further information is gathered given that islands are nevertheless likely to support, over the course of a migration season, more individuals than equivalent areas of mainland. Table 4 Areas of important habitat for each species likely to result in a significant impact if affected. Species Area thresholds (ha unless otherwise stated ) 1% 0.1% Osprey 840 km coastline 84 km coastline White-throated Needletail * * Fork-tailed Swift * * Oriental Cuckoo 250,000 25,000 Black-faced Monarch 2,600 260 Monarch 865 87 Satin Flycatcher 4,400 440 Spectacled Monarch 2,100 210 Southern Spectacled Monarch 1,300 130 Wet Tropics Spectacled Monarch 1,100 110 Cape York Spectacled Monarch 1,300 130 Rufous Fantail 7,500 750 Southern Rufous Fantail 2,600 260 North-eastern Rufous Fantail 3,400 340 Arafura Rufous Fantail 4,500 450 Oriental Reed-warbler * * Barn Swallow * * Red-rumped Swallow * * Grey Wagtail * * Yellow Wagtail * * * No threshold area can be determined at this time or has identified given lack of knowledge or rarity. Research on White-throated Needletail may reveal site thresholds in tall forest used by roosting birds. Table 5 The proportions of each migratory species population likely to result in a significant impact if affected. Species Thresholds ( no of individuals) 1% 0.1% Osprey 240 24 White-throated Needletail 100 10 Fork-tailed Swift 1,000 100
migratory-birds-draft-referral-guideline.docx