boundary bay salt marsh restoration project standwatch ... › wp-content › uploads › ...aug 21,...

Suite 250 – 1380 Burrard Street

Vancouver, BC V6Z 2H3

T: 604.669.0424

F: 604.669.0430

hemmera.com

Boundary Bay Salt Marsh Restoration Project

Standwatch Bird Surveys – Winter 2013/14

Report Date July 25, 2014

Survey Dates & Times

The following is a summary of the survey dates and associated times:

• December 19, 2013 – 07:55 to 15:16

• January 6, 2014 – 09:05 to 16:37

• January 17 – 08:05 to 16:40

• January 31, 2014 – 08:15 to 17:05

• February 17, 2014 – 08:30 to 16:52

• February 28, 2014 – 08:40 to 17:13

• March 13, 2014 – 08:00 to 15:22

• March 28, 2014 – 09:00 to 17:24

Weather & Tidal Conditions

The following is a detailed summary of the weather conditions (general conditions and temperature) and tides on each of the survey dates, for the associated times:

• December 19, 2013 – overcast skies, average temperature: -2.3 degrees Celsius; low tide of 3.3 m at 13:16 and high tide of 3.7 m at 17:16

• January 6, 2014 – overcast skies, average temperature: -1.9 degrees Celsius; high tide of 4.7 m at 09:24 and low tide of 2.2 m at 16:07

• January 17, 2014 – overcast skies, average temperature: 4.6 degrees Celsius; high tide of 4.4 m at 07:06 and low tide of 3.1 at 12:46

• January 31, 2014 – clear skies, average temperature: 2.1 degrees Celsius; high tide of 4.6 m at 06:18 and low tide of 2.9 m at 11:52

• February 17, 2014 – partly cloudy, average temperature: 6.5 degrees Celsius; high tide of 4.2 m at 07:02 and low tide of 2.3 m at 13:15

• February 28, 2014 – clear skies; average temperature: 5.1 degrees Celsius; low tide of 2.6 m at 10:48 and high tide of 4.0 m at 16:09

• March 13, 2014 – partly cloudy, average temperature: 7.0 degrees Celsius; low tide of 2.7 m at 11:07 and high tide of 3.5 m at 16:10

• March 28, 2014 – overcast skies, average temperature: 7.5 degrees Celsius; low tide of 2.2 m at 10:47 and high tide of 3.8 m at 16:24

Weather data from Government of Canada hourly climate data for Delta Burns Bog: 32TUhttp://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=BC&StationID=49088&dlyRange=2011-01-25%7C2014-06-29&cmdB1=Go&Year=2014&Month=3&cmdB1=Go#U32T

Tide data from Government of Canada 7 days tidal predictions for Tsawwassen: 32TUhttp://www.waterlevels.gc.ca/eng/station?type=0&date=2014%2F03%2F28&sid=7590&tz=PDT&pres=1U32T

http://www.hemmera.com/http://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=BC&StationID=49088&dlyRange=2011-01-25%7C2014-06-29&cmdB1=Go&Year=2014&Month=3&cmdB1=Go%23http://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=BC&StationID=49088&dlyRange=2011-01-25%7C2014-06-29&cmdB1=Go&Year=2014&Month=3&cmdB1=Go%23http://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=BC&StationID=49088&dlyRange=2011-01-25%7C2014-06-29&cmdB1=Go&Year=2014&Month=3&cmdB1=Go%23http://www.waterlevels.gc.ca/eng/station?type=0&date=2014%2F03%2F28&sid=7590&tz=PDT&pres=1http://www.waterlevels.gc.ca/eng/station?type=0&date=2014%2F03%2F28&sid=7590&tz=PDT&pres=1

Boundary Bay Salt Marsh Restoration Project – Winter 2013/14 Standwatch Bird Surveys July 25, 2014

Survey Areas

Port Metro Vancouver’s (PMV’s) Habitat Enhancement Program – Boundary Bay Salt Marsh Restoration Project, Delta, BC.

Salt marsh restoration work involved the removal of dense accumulations of woody debris from three sites along Boundary Bay, referred to as sites 3.3, 3.4, and 3.5. For the purposes of conducting winter bird surveys, these sites were further divided into six restoration (or “treatment”) standwatch survey stations labelled 3.3.a, 3.3.b, 3.4, 3.5.a, 3.5.b and 3.5.c. Additional standwatch surveys were conducted at five non-treatment (“control”) stations labelled Ref.a, Ref.b, Ref.c, Ref.d and Ref.MB (Figure 1). Standwatch stations were 200 meters wide (east to west) and extended 300 meters southward into the marsh and 100 meters northward into the upland.

Survey Team Andrew Venning, Biologist (Hemmera); Sam Gidora, Biologist (Hemmera)

Scope of Work

As part of Port Metro Vancouver’s Habitat Enhancement Program, a salt marsh restoration project was undertaken in September of 2013 in Boundary Bay. Restoration works involved the removal of woody debris directly adjacent to the dike. Accumulations of woody debris can smother vegetation and compact soils, impeding the growth and production of salt marsh vegetation. Treated wood, such as creosote-treated poles and timbers, can also introduce toxic or harmful substances into the environment. In order to provide some enhanced wildlife habitat features, short snags were installed at all three restoration sites to function as raptor perches and “plucking posts”.

In order to better understand the use of these salt marsh habitats by raptors and other bird groups during the overwintering period, eight standwatch bird surveys were conducted on a biweekly basis from December 19, 2013 to March 28, 2014. Raptors were the focal species group for these standwatch surveys, however use by all bird species was also part of this survey work.

Survey Methods

One surveyor conducted 30 minute standwatches from the Boundary Bay dike at each of the eleven stations during each survey. Raptors and other birds were documented 300 meters in front of surveyor (southward) and 100 meters behind surveyor (Figure 1). Birds were grouped into one of four strata within each station:

1. Back stratum – behind surveyor and within the upland, up to 100 meters from dike

2. Woody debris stratum – within woody debris removal area (for treatment stations) or woody debris area (for control stations)

3. Buffer stratum – seaward of the woody debris removal/woody debris area, extending to a distance matching width of woody debris removal/woody debris area

4. Far stratum – seaward of buffer stratum, extending up to 300 meters from dike

The focus of surveys was to document birds within or near woody debris stratum and thus survey efforts were focused in front of observer. As a result, back stratum data collection was not as rigorous as the three front strata.

Binoculars and spotting scope were used to identify birds within survey areas. For each bird documented, the following information was recorded: species, number, time, stratum, distance from dike, behavior, and flyover direction.

Bird numbers presented may not reflect actual abundance of birds present, as some birds may have been counted more than once. In any situations where a bird was counted in one station and moved to another station coinciding with movement of the surveyor from one station to the next, the bird was counted in each of the two survey areas.


Results

Results from treatment and control stations are presented in Tables 1 and 2, respectively. A summary of all species observed is presented in Table 3. Total abundance of species groups is presented in Figure 2 and Figure 3. Figure 2 represents a broad data set and reflects the habitat mosaic both on the upland and seaward sides of the standwatch locations, while Figure 3 is focused strictly on the seaward side of the salt marsh habitats.

Average numbers of bird observations per station in all strata (excluding back stratum) are presented in Figure 4. Overall, more birds were observed in control stations, particularly in the far stratum. Average numbers of raptor and other bird observations per station in woody debris stratum are presented in Figure 5. In woody debris stratum, more birds were observed in control stations, however more raptors were observed in treatment stations.

The majority of birds observed in woody debris stratum consisted of songbirds/passerines (Figure 5). The higher abundance of songbirds/passerines observed in control stations, relative to treatment stations, is likely due to a higher concentration of upland vegetation at control stations. Upland vegetation at Ref.a and Ref.b, in particular, is comprised of dense deciduous trees and shrubs several meters high. Upland vegetation at the remaining stations is primarily agricultural land or golf course (i.e., mowed grass).

At Boundary Bay during these overwintering surveys, the majority of observations were comprised of dabbling waterbirds (n=1,156), songbirds (n=449) and other passerines (n=360) (Figure 2). 345 separate raptor observations and seven owl observations were recorded. The most common species observed at Boundary Bay were American Wigeon (n=714), European Starling (n=206), and Bald Eagle (n=180) (Table 3).

Nine raptor/owl species were observed during overwintering surveys: Bald Eagle (n=180); Northern Harrier (n=156); Short-eared Owl (n=7); American Kestrel (n=2); Peregrine Falcon (n=2); Cooper’s Hawk (n=1); Merlin (n=1); Red-tailed Hawk (n=1); Sharp-shinned Hawk (n=1); Unidentified raptor (n=1). Raptors were most commonly observed hunting (31% of raptor observations), flapping (29% of raptor observations) and perching (10% of raptor observations). Owls (exclusively Short-eared Owls) were most commonly observed flapping (43% of owl observations), hunting (29% of owl observations) and perching (29% of owl observations).

Three raptor species, one songbird species and one other passerine species were observed perching at various occasions on installed short snags in the treatment sites: Bald Eagle (1) (Photo 1), Northern Harrier (1) (Photo 2), Short-eared Owl (1) (Photo 3), European Starling (6), and Northwestern Crow (1) .

It is important to note that these standwatch surveys were conducted only 2.5 to 5 months after woody debris removal and prior to any notable recovery of salt marsh vegetation within the treatment sites. As a result, bird use observations from this past winter should be further augmented with additional surveys after vegetation has had a better opportunity to re-colonize the site (e.g., winter 2014/15).


Tables

Table 1 Species observed at Boundary Bay treatment sites during winter 2013/14 standwatch surveys; Delta, BC.

Station Species Group

Common Name Latin Name Behaviour Abundance of Species

Abundance of Species

Group

3.3.a

Gull and Terns

Unidentified Gull Larus sp. flapping 5 5

Other

European Starling Sturnus vulgaris

feeding, flapping, walking

53

56 Northwestern

Crow Corvus

caurinus flapping,

singing/calling 3

Raptors

Bald Eagle Haliaeetus

leucocephalus

flapping, perched in snag/dead tree, standing

7

22 Northern Harrier Circus cyaneus

flapping, gliding, hunting, perched

in snag/dead tree, harassing

another, loading/resting

13

Short-eared Owl Asio flammeus hunting,

harassing another

2

Songbirds

American Robin Turdus

migratorius flapping, perched

in live tree 2

16

Northern Flicker Colaptes auratus

flapping 3

Western Meadowlark

Sturnella neglecta

flapping, landing, singing/calling

8

White-crowned Sparrow

Zonotrichia leucophrys

perched in live tree

3

Waterfowl

American Wigeon Anas

americana walking, feeding 592

634

Eurasian Wigeon Anas penelope walking, feeding 1

Green-winged Teal

Anas crecca walking, feeding 2

Mallard Anas

platyrhynchos

flapping, landing, swimming,

loafing/resting, being harassed, walking, feeding

36

Northern Pintail Anas acuta flapping 3

3.3.b

Gull and Terns


Heron Great Blue Heron Ardea herodias landing,

singing/calling, standing, hunting

2 2





Group

Other


flapping, perched in live tree,

singing/calling 67

80

Northwestern Crow

Corvus caurinus


perched on guy wire,

singing/calling

13

Raptors

American Kestrel Falco

sparverius perched in live tree, taking off

1

29 Bald Eagle

Haliaeetus leucocephalus

flapping, harassing

another, perched in live tree, perched in

snag/dead tree

23

Northern Harrier Circus cyaneus

flapping, gliding, landing, hunting,

perched in snag/dead tree

5

Shorebirds Killdeer Charadrius vociferus

walking 1 1

Songbirds


migratorius

feeding, perched in live tree, flapping,

singing/calling

7

46

Black-capped Chickadee

Poecile atricapillus

singing/calling 2

Dark-eyed Junco Junco hyemalis perched in live tree, walking,

feeding 8

Golden-crowned Kinglet

Regulus satrapa

perched in live tree,

singing/calling 5

House Finch Haemorhous mexicanus

singing/calling 1


singing/calling, perched in live

tree 3

Song Sparrow Melospiza melodia

walking, feeding, singing/calling

8

Spotted Towhee Pipilo

maculatus singing/calling 3

Western Meadowlark

Sturnella neglecta

landing, singing/calling

9

Waterfowl Mallard Anas

platyrhynchos flapping 18 18





Group

3.4

Gull and Terns


Heron Great Blue Heron Ardea herodias walking, hunting 1 1

Other



singing/calling 1

8

Northwestern Crow

Corvus caurinus


singing/calling, taking off, perched in

snag/dead tree

7

Raptors


leucocephalus


landing, perched in snag/dead

tree, singing/calling,

soaring

19

31


flapping, gliding, hunting,

standing, taking off

11

Sharp-shinned Hawk

Accipiter striatus


1

Songbirds




tree 1

11

Dark-eyed Junco Junco hyemalis feeding, taking

off 3



singing/calling 3



singing/calling, perched in

shrub/hedge, walking

4

Waterfowl


americana

feeding, flapping, loafing/resting,

walking 50

185 Gadwall Anas strepera

feeding, loafing/resting,

swimming 20

Green-winged Teal

Anas crecca swimming,

feeding 22





Group

Mallard Anas

platyrhynchos

feeding, landing, loafing/resting,

preening, swimming,

walking

46

Northern Pintail Anas acuta loafing/resting 4

Northern Shoveler

Anas clypeata feeding,

swimming 43

3.5.a

Gull and Terns


Heron Great Blue Heron Ardea herodias flapping 1 1

Other


flapping, perched in shrub/hedge, singing/calling,


23

26

Northwestern Crow

Corvus caurinus

flapping, perched on pole

3

Raptors


leucocephalus

flapping, gliding, perched in

snag/dead tree, perched on pole

8

40 Northern Harrier Circus cyaneus

flapping, gliding, hunting, landing, flapping, perched

in snag/dead tree,

singing/calling

28

Short-eared Owl Asio flammeus

flapping, perched on fence/post,

landing, perched in live tree

4

Songbirds




tree 4

30



2

Red-winged Blackbird

Agelaius phoeniceus

singing/calling 3


feeding, standing,

perched in live tree, perched in snag/dead tree, singing/calling,

perched on pole

11





Group


maculatus

feeding, perched in live tree, perched in

shrub/hedge

4



feeding, perched in shrub/hedge,

walking 6

Waterfowl American Wigeon Anas

americana walking, feeding 45 45

3.5.b

Gull and Terns


Heron Great Blue Heron Ardea herodias

flapping, standing,

loafing/resting, walking, hunting

6 6

Other


perched in snag/dead tree,

standing 61

62

Northwestern Crow

Corvus caurinus

flapping, harassing another

1

Raptors

American Kestrel Falco

sparverius flapping, feeding 1

43


leucocephalus flapping, soaring 20


being harrassed, harassing

another, flapping, gliding, hunting,

perched in shrub/hedge,

perched in snag/dead tree, singing/calling

21

Red-tailed Hawk Buteo

jamaicensis flapping, being

harassed 1

Songbirds


singing/calling 1

39


Agelaius phoeniceus

singing/calling 4

Savannah Sparrow

Passerculus sandwichensis

perched in snag/dead tree, singing/calling,

perched on fence/post

3





Group


feeding, perched in shrub/hedge, perched in live tree, perched in snag/dead tree, singing/calling,

walking

9

Unidentified Sparrow

- perched in

shrub/hedge 2




20

3.5.c

Gull and Terns Unidentified Gull

Larus sp. flapping 15 15

Heron Great Blue Heron Ardea herodias flapping,

singing/calling, standing

2 2

Other Northwestern

Crow Corvus

caurinus

landing, walking, perched in live tree, perched in snag/dead tree

4 4

Raptors


leucocephalus

flapping, gliding, perched in

snag/dead tree, soaring

13

29


flapping, harassing

another, hunting, perched in

snag/dead tree, gliding

16

Shorebirds Killdeer Charadrius vociferus

walking, singing/calling

39 39

Songbirds


migratorius standing 1

4 Song Sparrow Melospiza melodia

singing/calling 2

Tree Swallow Tachycineta

bicolor flapping,

singing/calling 1

Waterfowl

Gadwall Anas strepera walking, feeding 2

4 Mallard

Anas platyrhynchos

walking, feeding 2


Table 2 Species observed at Boundary Bay control sites during winter 2014 standwatch surveys; Delta, BC.




Group

Ref.a

Gull and Terns


Heron Great Blue Heron Ardea

herodias

flapping, standing,

loafing/resting, taking off,

singing/calling, walking, feeding

9 9

Other Northwestern

Crow Corvus

caurinus

flapping, singing/calling,


4 4

Raptors


leucocephalus

flapping, perched in snag/dead tree,

soaring 12

26 Northern Harrier Circus

cyaneus

gliding, hunting, landing, perched

in snag/dead tree, singing/calling

12

Peregrine Falcon Falco

peregrinus flapping, perched in snag/dead tree

2

Shorebirds Greater

Yellowlegs Tringa

melanoleuca singing/calling 1 1

Songbirds


migratorius


tree 1

55

American Tree Sparrow

Spizella arborea

walking, feeding 3



perched in shrub/hedge, singing/calling

6


singing/calling 1


landing, perched in live tree,


snag/dead tree, feeding, perched in shrub/hedge,

walking

9







Group


- flapping, walking,

perched in shrub/hedge

3





shrub/hedge

30

Waterfowl


22 Mallard

Anas platyrhynchos

flapping, landing 11

Ref.b


herodias

flapping, landing, standing,

loafing/resting, walking

15 15

Other Northwestern

Crow Corvus

caurinus

flapping, singing/calling, perched on guy

wire

6 6

Raptors


leucocephalus


perched on pole 19

33 Cooper's Hawk Accipiter cooperii

perched on pole 1

Northern Harrier Circus

cyaneus

flapping, gliding, hunting, perched in snag/dead tree

13

Songbirds


migratorius


singing/calling, walking, feeding

9

57

Bewick's Wren Thryomanes

bewickii


tree 1



perched on fence/post,


tree

5

Golden-crowned Sparrow

Zonotrichia atricapilla

feeding, walking 15


singing/calling 2


feeding, walking, perched in

shrub/hedge, perched in

snag/dead tree, singing/calling

17





Group


maculatus


8

Waterfowl


107 Green-winged Teal

Anas crecca walking, feeding 105

Ref.c

Gull and Terns



herodias

flapping, standing, gliding,

perched in snag.dead tree, loading/resting,

walking

8 8

Other Northwestern

Crow Corvus

caurinus - 1 1

Raptors


leucocephalus

flapping, gliding, harassing

another, being harassed, perched in

snag/dead tree, perched on pole,

preening, perched on

telephone/light pole, soaring

32

53


cyaneus

flapping, gliding, hunting, perched

in snag/dead tree, harassing

another, being harassed,

landing, perched in snag/dead tree,

singing/calling, standing

21

Shorebirds Greater

Yellowlegs Tringa

melanoleuca singing/calling,

flapping 1 1

Songbirds


migratorius


singing/calling 4

92


singing/calling 2


Agelaius phoeniceus


60



4





Group




- flapping, perched

in live tree 20

Waterfowl Mallard Anas

platyrhynchos

loafing/resting 2

4 taking off, flapping

2

Ref.d

Other European Starling Sturnus vulgaris


1 1

Raptors


leucocephalus

feeding, walking, flapping, gliding,

harassing another, perched in snag/dead tree, perched on pole,

perched on telephone/light

pole

25

34


cyaneus

flapping, gliding, hunting,

singing/calling 9

Short-eared Owl Asio

flammeus flapping 1

Songbirds


migratorius

perched in live tree, perched in shrub/hedge, singing/calling

3

74




singing/calling 6



feeding, walking, perched in live tree, flapping

20

Marsh Wren Cistothorus

palustris singing/calling 1


perched in snag/dead tree,

preening 1


feeding, walking, flapping, perched

in live tree, singing/calling

13




- flapping, perched

in live tree 9





Group



feeding, walking, flapping, perched in snag/dead tree

19

Waterfowl


americana feeding, walking 27

41

Mallard Anas

platyrhynchos feeding, walking 4

Northern Shoveler

Anas clypeata feeding, walking 1

Trumpeter Swan Cygnus

buccinator standing,

loafing/resting 9

Ref.MB

Gull and Terns



herodias loafing/resting,

standing 2 2

Other Northwestern

Crow Corvus

caurinus

flapping, singing/calling,

walking, feeding 112 112

Raptors


leucocephalus flapping 2

10 Merlin Falco

columbarius flapping, gliding 1


cyaneus gliding, hunting 7

Songbirds



feeding 1

23

Dark-eyed Junco Junco

hyemalis perched in

shrub/hedge 2

Fox Sparrow Passerella

iliaca feeding, walking 4




tree 1


flapping 1


feeding, perched in live tree,

singing/calling, flapping, walking

12


maculatus perched in live

tree 2

Waterfowl Mallard

Anas platyrhynchos

loafing/resting, swimming,

walking, feeding 10

105

Northern Pintail Anas acuta loafing/resting 95


Table 3 Summary of species observed at Boundary Bay (treatment and control data pooled) during winter 2014 standwatch surveys, note that raptors are highlighted; Delta, BC.

Common Name Latin Name Number Species Group

American Wigeon Anas americana 714 Dabbling waterbirds

European Starling Sturnus vulgaris 206 Other Passerines

Bald Eagle Haliaeetus leucocephalus 180 Raptors

Northern Harrier Circus cyaneus 156 Raptors

Northwestern Crow Corvus caurinus 154 Other Passerines

Mallard Anas platyrhynchos 131 Dabbling waterbirds

Green-winged Teal Anas crecca 129 Dabbling waterbirds

Northern Pintail Anas acuta 102 Dabbling waterbirds

Song Sparrow Melospiza melodia 89 Songbirds

White-crowned Sparrow Zonotrichia leucophrys 78 Songbirds

Unidentified Gull Larus sp. 75 Gull and Terns

Red-winged Blackbird Agelaius phoeniceus 67 Songbirds

Great Blue Heron Ardea herodias 46 Herons

Northern Shoveler Anas clypeata 44 Dabbling waterbirds

Golden-crowned Sparrow Zonotrichia atricapilla 36 Songbirds

Gadwall Anas strepera 35 Dabbling waterbirds

Unidentified Sparrow - 34 Songbirds

American Robin Turdus migratorius 27 Songbirds

Black-capped Chickadee Poecile atricapillus 25 Songbirds

Spotted Towhee Pipilo maculatus 23 Songbirds

Northern Flicker Colaptes auratus 19 Songbirds

Western Meadowlark Sturnella neglecta 17 Songbirds

Unidentified Bird - 14 -

Dark-eyed Junco Junco hyemalis 13 Songbirds

Trumpeter Swan Cygnus buccinator 9 Swans

Short-eared Owl Asio flammeus 7 Owls

Golden-crowned Kinglet Regulus satrapa 5 Songbirds

Fox Sparrow Passerella iliaca 4 Songbirds

Unidentified Swan Cygnus sp. 3 Swans

Savannah Sparrow Passerculus sandwichensis 3 Songbirds

American Tree Sparrow Spizella arborea 3 Songbirds

Eurasian Collared-Dove Streptopelia decaocto 2 Songbirds

American Kestrel Falco sparverius 2 Raptors

Killdeer Charadrius vociferus 2 Shorebirds

Peregrine Falcon Falco peregrinus 2 Raptors


Common Name Latin Name Number Species Group

Greater Yellowlegs Tringa melanoleuca 2 Shorebirds

Cooper's Hawk Accipiter cooperii 1 Raptors

Bewick's Wren Thryomanes bewickii 1 Songbirds

Eurasian Wigeon Anas penelope 1 Dabbling waterbirds

House Finch Haemorhous mexicanus 1 Songbirds

Merlin Falco columbarius 1 Raptors

Northern Shrike Lanius excubitor 1 Songbirds

Red-tailed Hawk Buteo jamaicensis 1 Raptors

Sharp-shinned Hawk Accipiter striatus 1 Raptors

Tree Swallow Tachycineta bicolor 1 Swallows

Unidentified Raptor - 1 Raptors

Marsh Wren Cistothorus palustris 1 Songbirds


Figures

Figure 1. Boundary Bay standwatch survey study areas; Delta, BC.


Figure 2. Abundance of species groups observed at Boundary Bay (including back stratum) during winter 2013/14 standwatch surveys; Delta, BC.

Figure 3 Abundance of species groups observed at Boundary Bay (excluding back stratum) during winter 2013/14 standwatch surveys; Delta, BC.

0

200

400

600

800

1000

1200

1400

Nu

mb

er

of

Bir

ds

Ob

serv

ed

0

50

100

150

200

250

300

350

400

Nu

mb

er

of

Bir

ds

Ob

serv

ed


Figure 4 Average number of birds observed per station at Boundary Bay during winter 2013/14 standwatch surveys (back stratum data removed). ‘Unknown’ data reflects data from first survey, before strata were decided; Delta, BC.

Figure 5 Average number of birds observed per station in woody debris stratum at Boundary Bay during winter 2013/14 standwatch surveys; Delta, BC.

0

20

40

60

80

100

120

140

160

Treatment Control

Av

era

ge

Nu

mb

er

of

Bir

ds

pe

r S

tati

on

Unknown

Far

Buffer

Woody Debris

0

5

10

15

20

25

30

35

40

45

50

Treatment Control

Av

era

ge

Nu

mb

er

of

Bir

ds

pe

r S

tati

on

Swans

Swallows

Herons

Shorebirds

Dabbling waterbirds

Songbirds/Passerines

Raptors


Photos

Photo 1 Immature Bald Eagle perched on installed short snag at Boundary Bay; Delta, BC.

Photo 2 Northern Harrier perched on installed short snag at Boundary Bay; Delta, BC.


Photo 3 Short-eared Owl perched on installed short snag at Boundary Bay; Delta, BC.

boundary bay salt marsh restoration project standwatch ... › wp-content › uploads › ...aug 21,...

Documents