With a healthy dollop of facetiousness, I planned to cross Wallace’s Line, which separates the Oriental and Australian (latterly, Wallacean) faunal regions, to check out its validity by birding first Bali Island and then Flores, Komodo & Rinca Islands of the Lesser Sundas. Unfortunately, I had a ridiculously short time to do this, so my data would be statistically very inadequate.
Nevertheless, superficially, my records roundly confirmed Wallace’s Line. My trip list comprised 97 species. On Bali, west of Wallace’s Line, I ticked 43 species that I did not see on Flores, Komodo or Rinca, east of Wallace’s Line. Subsequently, on Flores, Komodo and Rinca, I ticked 47 species that I did not see on Bali. I ticked only 7 species (7/97 or 7%) on both sides of Wallace’s Line. No question!—Wallace’s Line demarcates the boundary of the two major biogeographical zones!
But there were extenuating circumstances. (1) I spent only 22.5 hours birding Bali and 22.0 hours birding Flores, Komodo and Rinca. (2) Although I spent time in native forest in both areas, more of my time was spent in suburban environments, along Bali mangrove mudflats, and on the inter-island seas of Komodo, Rinca and Flores, quite different habitats on each side of the Line; specifically—
Bali (Jan 11–14): Forest 10 hrs, suburban/park 8.5 hrs, mangrove mudflats 4 hrs. (Total 22.5 hrs)
Flores, Komodo & Rinca (Jan 15–18): Forest 9.5 hrs, suburban/park 5.5 hrs, sea 7 hrs. (Total 22.0 hrs)
In fact, according to official lists, many more of my species have been recorded on both sides of the Line. Of those I ticked in Bali alone, only 11 have not been recorded in the Lesser Sundas; of those I ticked in Flores, etc., alone, only 15 have not been recorded in Bali. Therefore a more informed estimate would be that almost 75% of the bird species I saw are common to both sides of Wallace’s Line, making it a much more permeable boundary than my own experience had suggested.
(Warning: If you are seeking a guide, do NOT utilize birdpacker.com, who repeatedly assured me that they had arranged a Lombok birding guide for me—without supplying any contact information—right up until the week of my departure, when they no longer answered my emails.)
BALI ONLY SIGHTINGS
1 Little Pied Cormorant
2 Striated Heron
3 Cattle Egret
4 Javan Pond Heron
5 Little Egret
6 Black Eagle
7 Common Greenshank
8 Gull-billed Tern
9 Little Cuckoo-dove
10 Grey-cheeked Green Pigeon
11 Zebra Dove
12 Oriental Cuckoo
13 Plaintive Cuckoo
14 Cave Swiftlet
15 Cerulean (Small Blue) Kingfisher
16 Collared Kingfisher
17 Orange-fronted Barbet
18 Freckle-breasted Woodpecker
19 Black-winged Flycatcher-shrike
20 Scarlet Minivet
21 Common Iora
22 Yellow-vented Bulbul
23 Ashy Drongo
24 Sunda Whistling-thrush
25 Mountain Leaf Warbler
26 Sunda Warbler
27 Olive-backed Tailorbird
28 Fulvous-chested Jungle-flycatcher
29 Little Pied Flycatcher
30 Asian Brown Flycatcher
31 Yellow-rumped Flycatcher
32 Grey-headed Canary-flycatcher
33 Pied Fantail
34 Mangrove Whistler
35 Javan Myna
36 Short-tailed Starling
37 Indonesian Honeyeater
38 Blood-breasted Flowerpecker
39 Orange-bellied Flowerpecker
40 Oriental White-eye
41 Javan Grey-throated White-eye
42 White-headed Munia
43 Scaly-breasted Munia
SIGHTINGS ON BOTH BALI & FLORES/KOMODO/RINCA
1 Common Sandpiper
2 Spotted Dove
3 Black-naped Oriole
4 Rusty-breasted/Tenggara Whistler
5 Olive-backed Sunbird
6 Javan Munia
7 Eurasian Tree Sparrow
FLORES/KOMODO/RINCA ONLY SIGHTINGS
1 Great Frigatebird
2 Lesser Frigatebird
3 Brown Booby
4 Nankeen (Rufous) Night Heron
5 Great-billed Heron
6 Pacific Reef Egret
7 Brahminy Kite
8 Bonelli’s Eagle
9 White-bellied Sea Eagle
10 Spotted Kestrel
11 Orange-footed Scrubfowl
12 Green Junglefowl
13 Whimbrel
14 Far Eastern Curlew
15 Greater Crested Tern
16 Lesser Crested Tern
17 Ruddy Cuckoo-dove
18 Barred Dove
19 Green Imperial Pigeon
20 Yellow-crested Cockatoo
21 Lesser Coucal
22 Pacific Koel
23 Wallace’s Scops Owl
24 Tenggara (Glossy) Swiftlet
25 Edible-nest Swiftlet
26 Glittering (White-rumped) Kingfisher
27 Blue-tailed Bee-eater
28 Sunda Pygmy Woodpecker
29 Striated Swallow
30 Richard’s Pipit
31 Little Minivet
32 Wallacean Drongo
33 Large-billed Crow
34 Flores Crow
35 Cinereous Tit
36 Chestnut-capped Thrush
37 Pied Chat
38 Arctic Warbler
39 Black-naped Monarch
40 Flores Monarch
41 Brown-capped Fantail
44 Helmeted Friarbird
45 Flame-breasted Sunbird
46 Brown-throated Sunbird
47 Black-fronted Flowerpecker
42 Yellow-ringed White-eye
43 Thick-billed Dark-eye/Heleia