Breeding birds during 50 years of post-fire succession in the Sierra Nevada

Martin G. Raphael, Daniel A. Airola, Gary A. Falxa, Roger D. Harris, and Peter A. Stine

1960 - The Donner Fire burned ~18,000 ha on the eastern Sierra

Nevada

1965 – two 8.5-ha permanentplots established

Burned Plot

Unburned Plot

Objectives

Examine and contrast changes in vegetation over ~50-yr time series

Estimate bird abundance and diversity and compare results on burned and unburned plots over 50-yr

Relate changes in bird community to changes in vegetation

Monitoring timeline

Donner

fire

1966-68

1975-79

1981-85

2010-14

1960 1970 1980 1990 2000 2010

Burned plot has changed dramatically over time

(no management or harvest)

1965 2012

Field equipment (and people) have changed too

1965 2012

Density of Snags(number > 38 cm/ha)

1968 1975 1983 20120

5

10

15

20

25

30

35

BurnedUnburned

Percent Cover, Shrubs(n = 1170 points)

1975 1983 20110

10

20

30

40

50

60

70

80

BurnedUnburned

Herbs & Grasses(% cover, n = 1170 points)

1975 1983 20110

10

20

30

40

50

60

70

BurnedUnburned

Basal Area of Conifers(m2/ha)

1975 1983 20110

10

20

30

40

50

60

1975 1983 20110

10

20

30

40

50

60

Other

White fir

Yellow pine

Burned Unburned

Conifer Canopy Cover(%, n = 1170)

Burned Unburned0

10

20

30

40

50

60

70

80

90

19752011

Total Bird Territories

1960 1970 1980 1990 2000 2010 20200

10

20

30

40

50UnburnedBurned

Species Richness

1960 1970 1980 1990 2000 2010 20200

5

10

15

20

25

30

Un-burned

Foraging guilds

Wood excavating (woodpeckers) Bark gleaning (nuthatches, brown

creeper) Flycatching (nighthawk, flycatchers) Canopy foliage searching (jays,

chickadees, kinglets, vireos, warblers) Ground/brush searching (quail,

dove, hummingbirds, bluebird, solitaire, thrush, robin, towhee, juncos, finches, sparrows)

Wood Excavating

Bark gleaning

Flycatching

Canopy Foliage Searching

Ground/brush Searching

Percent Similarity(Ruzicka’s Index)

1966-68

1975-79

1981-85

2010-14

0

10

20

30

40

50

60

Burned vs Unburned

Burned Unburned0

10

20

30

40

50

60

1966-68 vs 2010-14

Major Changes in Species Abundance

IncreasedSpecies 1960s 2010s

Hermit warbler

Absent Common

Pileated woodpecker

Common raven

Osprey

Northern goshawk

Absent Rare

Clark’s nutcracker

Black-throated gray warbler

Green-tailed towhee

DecreasedSpecies 1960s 2010s

Mountain bluebird

Common Absent

Brewer’s sparrow

Cooper’s hawk

Sooty grouse Moderate Absent

House wren

Pygmy nuthatch

American kestrel

Lazuli bunting

Rare Absent

Lewis’ woodpecker

Temperature has increased over time

Summary

Vegetation is still changing, 50 years after fire on the burned plot, but also on the unburned plot

Bird community structure (guilds and species represented) has changed dramatically on the burned plot in response to vegetation change

The bird community on the unburned plot has also changed, to a smaller degree

Overall species richness has been comparable on plots over time

Bird abundance (# territories) has increased by roughly 50% on both plots

Some bird population changes could be due to climate change

Thanks to

Sagehen Creek Field Station for accommodation and logistics

Station managers Jeff Brown and Faerthen Felix for help and advice

Carl and Jane Bock for initiating this work and suggesting our recent follow-up surveys

Meryl Sundove and Joe Batres for field assistance

Truckee Ranger District for protecting plots Pacific Northwest and Pacific Southwest

Research Stations for funding