Assisting Birds to Cross the Hume Highway, NSW

Comparing the Effectiveness of Two Bird Crossing Designs in an Open Rural Landscape.

Stephen J. AmbroseAmbrose Ecological Services Pty Ltd

Types and Locations of Bird Crossings

Mountain Creek (east of bridge)

Mountain Creek (west of bridge)

Mt McKenzie Bird Underpass (western side)

Mt McKenzie Bird Underpass (eastern side)

Methods: May 2012 – May 2014

For both Mountain Creek Bridge & Mt McKenzie Bird Underpass: 5 survey periods: autumn (May) & spring (Oct) survey periods. 6 survey sessions (3 mornings, 3 afternoons) per survey period. In each survey session: 15-minute stationary obs. @ 12

transects:

(a) Three transects each side of bridge/underpass (3 north, 3 south, 100 m apart).

(b) Three 15-minute surveys on each side (west and east) of bridge or underpass (over/under/through bridge or underpass).

All transects: 20 m wide, perpendicular to highway. Order of transect surveys randomised.

Highway Bird Crossings: Total No. Sightings

Sides of bridge

Over Bridge

Under Bridge

0

300

600

900

1200

1500

1800

2100

1464

1726

1260

Mountain Creek Bridge (∑ = 4450)

0

250

500

750

1000

1250

1500 1427

551

154

Mt McKenzie Bird Underpass (∑ = 2132)

Highway Bird Crossings: Total No. Species

Sides of bridge

Over Bridge

Under Bridge

0

10

20

30

40

50

3740

22

Mountain Creek Bridge (49 spp.)

Mt McKenzie Bird Underpass (47 spp.)

0

10

20

30

40

5042

33

7

Mt McKenzie Bird Underpass (47 spp.)

Mountain Creek Bridge

Sides of bridge

Over Bridge Under Bridge

0

2

4

6

8

10

12

8.49.6

7.6

Mean (± SE) Bird Sight-ings/15 min survey period Under v Sides of Bridge:

NS (t = 0.58, df = 312).

Under v Over Bridge:NS (t = 1.29, df = 312).

Over v Sides of Bridge:

NS (t = 0.71, df = 312).

Total Highway Crossings: Mountain Creek

Welco

me Swall

ow

Common Starl

ing

Australi

an Rav

en

Australi

an M

agpie

Crimso

n Rosella

Little Rav

en

Willi

e Wag

tail

Easte

rn Rose

lla

Black-f

aced Cucko

o-shrik

e

Australa

sian Pipit

Black-s

houldered Kite

Little Pied Corm

orant

Red Watt

lebird

Fairy

Marti

n

Whist

ling K

ite

Laugh

ing Kooka

burra

Australi

an Kestr

el

Euro

pean Blac

kbird

Yellow-fa

ced Honeye

ater

Jacky

Winte

r

Striat

ed Thorn

bill

Grey S

hrike-th

rush

Yellow-tu

fted Honeyeate

r

Little Cucko

o-shrik

e

Rufous Whist

ler0

200

400

600

800

1000

1200

1400

Bird Movements Under Mountain Creek Bridge

0

100

200

300

400

500

600

700

800

900

1000

Mt McKenzie Bird Underpass

Through v Sides of Underpass:P < 0.001 (t = 8.28, df = 358).

Through v Over Underpass:P < 0.001 (t = 5.56, df = 358).

Over v Sides of Underpass:P < 0.001 (t = 6.66, df = 358).

0123456789 7.8

2.4

1.0

Mean (± SE) Birding Sightings/15 min survey

period

Total Highway Crossings: Mt McKenzie

Red-rumped Parr

ot

Australi

an Rav

en

Sulphur-c

reste

d Cockato

o

Little Rav

en

Magpie-la

rk

Superb

Fairy

-wre

n

Fusco

us Honeye

ater

Black-s

houldered Kite

Yellow-ru

mped Thorn

bill

Fairy

Marti

n

Australi

an W

ood Duck

Australa

sian Pipit

Rufous Songla

rk

Little Lo

rikeet

Laugh

ing Kooka

burra

White

-bellied Cucko

o-shrik

e

Crimso

n Rosella

Australi

an Kestr

el

Yellow-tu

fted Honeyeate

r

Flame Robin

White

-face

d Heron

Little Cucko

o-shrik

e

Little Pied Corm

orant

Little Blac

k Corm

orant

0

50

100

150

200

250

300

350

Bird Movements Through Mt McKenzie Bird Underpass

0

10

20

30

40

50

60

70

80

90

Proportion of Recorded Woodland Bird Species in Locality (85 spp) Observed Moving Across Highway

Type of Crossing Mountain Creek Bridge

Mt McKenzie Underpass

Over highway (north/south of bridge or underpass)

43.5% 49.4%

Over bridge or underpass 47.0% 38.8%

Under bridge/through underpass 25.9% 8.2%

Total 57.6% 55.2%

Acknowledgments

RMSPeter Hurst, Michial Sutherland, Amy Evans, Kevin Roberts & Josie Stokes.

SMECTom Newsome, Kirsten Velthuis, Jennifer Anson, David Sharpe, Simone d’Unienville & Catherine Gallery.