Summary of Landbird Monitoring 2006
HFQLG Monitoring Program
Three habitats were monitored during the 2006 season; riparian, conifer/oak, and conifer.
The riparian habitat was monitored as part of a series of aspen enhancement projects and
the conifer/oak habitats were monitored under an on-going oak enhancement project,
which is part of the overall DFPZ strategy outlined in the HFQLG FEIS. The conifer
habitats have been monitored as part of a large DFPZ project (Creeks Forest Health
Project) which has yet to be implemented.
Aspen enhancement has occurred primarily on the Eagle Lake Ranger District, Lassen
National Forest for several years now. The findings to date emphasize that riparian
habitats, including aspen, remain one of the most important habitats for birds. The
monitoring has confirmed several key elements of riparian management:
¾ Manage for multiple age and cover classes to maintain avian richness.
¾ Manage for a dense and diverse understory, and
¾ Post treatment it may be necessary to protect treated areas from grazing and
overbrowsing to maximize aspen regeneration.
The monitoring data showed that several woodpecker species (hairy woodpecker and redbreasted sapsucker) had significantly higher populations in treated aspen stands than in
untreated aspen stands and non-aspen stands. In addition to increases in woodpeckers,
mountain bluebird and chipping sparrow populations increased over baseline populations
and when compared to untreated stands.
The cooperative monitoring effort between PRBO Conservation Science and Lassen
National Forest has provided data for a recent “white paper” (Managing Aspen Habitat
for Birds in the Sierra Nevada) summarizing the findings and providing management
recommendations.
The Brown’s Ravine Oak Enhancement/DFPZ Project is the first DFPZ project
associated with the HFQLG monitoring plan to have post-treatment monitoring data on
landbirds. To date, monitoring has shown that the project area had lower than expected
bird diversity and richness. It is believed that bird diversity and richness will increase as
oak canopies become denser and due to the more open nature of the canopy. Posttreatment data was not available for this report as 2006 was the first year of posttreatment data collection and the data has not been assembled.
Managing Aspen Habitat for Birds
in the Sierra Nevada
Aspen are often out-competed by conifers in the Sierra Nevada, due to extensive livestock grazing and
the absence of regular fire. As a result, the health of aspen has deteriorated and estimates suggest its
extent in western North America has been reduced by as much as 96%. Aspen habitat, especially when
associated with riparian vegetation, is the single most species-rich avian habitat in the Sierra Nevada.
Several bird species of management interest are associated with aspen including Northern Goshawk,
Red-breasted Sapsucker, Warbling Vireo, and Mountain Bluebird. With its disproportionate importance
to birds and other wildlife, limited extent on the landscape, and significant loss and degradation, aspen
restoration should be among the highest priorities of land managers in the Sierra Nevada.
Key Aspen Bird Species
Northern Goshawk
Red-breasted Sapsucker
Warbling Vireo
Western Wood-Pewee
Dusky Flycatcher
Tree Swallow
Mountain Bluebird
Swainson’s Thrush
Chipping Sparrow
Sandy Scoggin
EricPreston.com
With the extensive loss and degradation of aspen throughout the
Sierra, large-scale restoration efforts are called for to avoid further
losses and increase the ecological value of this vital habitat. The
following are a list of the most important considerations for managing
aspen for breeding birds:
1. Promote aspen regeneration and expansion. This is the
single most important management consideration to avoid further
losses and degradation of this important habitat.
2. Manage for multiple age and cover classes. Smallest size
classes of aspen are important predictors of avian richness.
3. Restore riparian aspen communities. When healthy, this is
the single most species-rich habitat in the Sierra, supporting
numerous birds species of management concern.
4. Manage for dense and diverse understory. Understory aspen and riparian shrubs are important for numerous avian species.
5. Limit grazing and over-browsing. Grazing and over-browsing
can significantly reduce aspen regeneration, understory foliage
volume, and the structural diversity important for numerous bird
species. Grazing may also increase cowbird abundance which can
negatively impact breeding birds.
Peter LaTourrette
Peter LaTourrette
Mountain Bluebird
Strategies for Enhancing Aspen Bird Habitat
Key Habitat Features
Structural diversity
Dense herbaceous layer
Decay in Live stems
Cavities
Multiple size classes
Riparian shrub understory
Tree Swallow exiting aspen nest cavity
Adaptive Management
Response to Treatment
EricPreston.com
A vital part of effective aspen management is developing a monitoring and adaptive
feedback framework. As aspen restoration treatments are a new practice in the Sierra
Nevada, monitoring the treatment effects on the ecosystem and feeding information
back into future management actions will result in the greatest benefit to wildlife and
achieving other restoration objectives. Bird monitoring is an ideal tool for providing
cost-effective feedback on a whole community of organisms.
In the Eagle Lake Ranger District (ELRD) of the Lassen National Forest (LNF), within Red-breasted Sapsucker
five years treated stands had higher species richness and abundance of most key aspen species, including
woodpeckers, Mountain Bluebird, and Chipping Sparrow. Treated sites were flush with new aspen growth
and a lush understory vegetation community. We expect restored sites to support even greater avian
diversity and abundance as more structural complexity and foliage volume develops at treated sites.
Cavity Nesting Birds
0.8
Mean Detections per Point
Numerous studies have shown aspen is an important
habitat for cavity nesting birds. In the ELRD woodpeckers were 2 to 3 times more abundant at restored aspen
sites than either untreated aspen or non-aspen conifer
sites (see figure). Woodpeckers play a vital role by
creating cavities for use by a vast array of birds and
other wildlife species. Key management actions to
benefit cavity nesting birds:
♦ Significantly reduce conifer cover
♦ Retain dead and dying aspen stems
♦ Retain large conifer snags & some large logs
Treated A spen
0.7
Untreated A spen
0.6
No n-A spen
0.5
0.4
0.3
0.2
0.1
0
Hairy
Wo o dpecker
Red-breasted
Sapsucker
A ll
Wo o dpeckers
8
6
4
2
Avian Species Richness
10
Structural Diversity
The great structural diversity associated with healthy
aspen stands is likely a primary reasons this habitat
supports such a diverse assemblage of avian species. In
the ELRD, the best predictor of avian richness was
understory aspen stems. This feature has been lost in
many stands due to overgrazing and browsing, and
conifer encroachment.
Ensuring that this habitat
component is represented on the landscape in
perpetuity is critical to providing high quality aspen bird
habitat. Structural diversity can be achieved by:
♦ Aspen release through conifer removal
♦ Limiting grazing and over-browsing of stands
♦ Removing excessive conifer duff and slash
0
50
100
150
200
# of Understory Aspen Stems
Aspen Resources
♦
♦
♦
♦
♦
♦
Aspen Delineation Project
www.aspensite.org/
Lassen National Forest Aspen Restoration Team
trickman@fs.fed.us
Riparian Bird Conservation Plan
www.prbo.org/calpif/htmldocs/riparian.html
US Forest Service RMRS Aspen Restoration Site
www.fs.fed.us/rm/aspen/
PRBO Conservation Science Sierra Nevada Program
rburnett@prbo.org
US Forest Service PSW Sierra Nevada Research Center
www.fs.fed.us/psw/programs/snrc/
Funding Provided by: The National Fire Plan and USDA Forest Service: Region 5, Lassen National Forest, & HFQLG Monitoring Funds.
Managing Mixed Conifer-Hardwood Habitat
for Birds in the Sierra Nevada
Mixed-conifer hardwood (MCH) is among the most avian species-rich forest habitats in the Sierra
Nevada, and supports the greatest number of neotropical migrants. Several bird species are strongly
associated with hardwoods - especially black oak. The high structural complexity and floristic diversity
typical of healthy MCH habitat is thought to be a primary driver of avian diversity. Additionally, the
acorns produced by oaks provide a unique and important resource for an array of wildlife species. In the
absence of fire, these habitats have become less complex and diverse, with pines and hardwoods being
replaced by dense stands of fir and cedar. In the absence of natural disturbance regimes, management
intervention appears necessary; if taken in the form of strategically designed thinning and prescribed fire
it can mimic natural processes and restore the important habitat components and ecological processes
that support the full range of MCH associated bird species.
Key MCH Bird Species
Flammulated Owl
Band-tailed Pigeon
Acorn Woodpecker
White-headed Woodpecker
Cassin’s Vireo
Warbling Vireo
Nashville Warbler
Black-throated Gray Warbler
MacGillivray’s Warbler
Western Tanager
Managing MCH Habitat for Birds
Nashville Warbler
With the apparent degradation of hardwoods and other open-forest
habitat features within mixed conifer forests in the Sierra, restoration
treatments are necessary. Improving the health and viability of
hardwoods while improving the habitat value to the MCH bird community is possible. In order to maximize the benefit to breeding birds
managers should consider the following:
1. Reduce conifer cover to enhance hardwoods. This is the
most important consideration necessary to avoid further reduction
in hardwoods and overall degradation of this important bird habitat.
2. Manage for cavities. Both snags and decay in living hardwoods
are critical sources of cavities. 30% of the breeding landbirds in
MCH habitat in the Northern Sierra nest in cavities.
3. Manage for structural diversity. Under and middle-story foliage volume are positively correlated with avian richness in MCH
habitat in the Sierra Nevada.
4. Manage for dense and diverse understory. Many avian species
forage or conceal their nests in the understory and on the ground
in MCH habitat (e.g., Nashville Warbler, Fox Sparrow).
5. Manage with Fire. Fire was a critical part of the natural cycle
that maintained hardwoods, snags, and understory plants in MCH.
Peter LaTourrette
Key Habitat Features
Structural diversity
Understory foliage volume
Oak regeneration
Mast production
Tree species diversity
Doug Backlund
Western Tanager
Adaptive Management
A vital part of effective land management is developing a program of monitoring and
adaptive feedback. As hardwood restoration treatments are a new practice in the Sierra
Nevada, monitoring the response of the ecosystem and feeding information back into
future treatments will result in the greatest benefit to wildlife. Bird monitoring is an
ideal tool for providing cost-effective feedback on a whole community of organisms.
Mimicking the Role of Fire
10
5
0
MCH Avian Focal Species Abundance
15
Fire suppression, even aged management, and likely climate change have resulted in
expansion of densely stocked white fir dominated forests in the mixed conifer zone. Band-tailed Pigeon
Due to their limited maximum height and shade intolerance, hardwoods and shrubs are dependent on
disturbance to create suitable conditions for growth and
regeneration. Throughout the mixed conifer zone in the
Northern Sierra, conifer encroachment is prevalent.
Often “skeletons” are all that remain of shrubs and
hardwoods in dense mid-successional fir dominated
stands. MCH avian focal species abundance is negatively
associated with White Fir cover in the Lassen National
Forest (see figure). Thinning in association with
prescribed burns may mimic the conditions created by
natural fires invigorating hardwood, shrub, and
herbaceous vegetation components of MCH habitat.
0
20
40
60
Forest Structure and Birds
White Fir
Foliage volume and structural diversity are key predictors of avian species richness in MCH forest. A
mosaic of canopy covers dominated by pine and hardwoods - likely typical under a natural fire regime can support vegetation structure from the forest floor to the canopy. Treatments to enhance this forest
type should focus on applying an uneven-aged mosaic design with dense patches of pine-dominated conifers, semi-open hardwood areas, and open patches with vigorous shrub and herbaceous vegetation.
Hardwoods in a Conifer Sea
In the Sierra Nevada hardwoods represent a small
percent of the total forested habitat and are limited in
their extent. However, hardwoods are an important
wildlife resource in this “conifer sea.” Many bird species
reach their greatest abundance in conifer-hardwood
habitat, several of which are exclusively tied to
hardwoods, including Nashville Warbler, Band-tailed
Pigeon, and Acorn Woodpecker. Many insect-gleaning
birds choose to forage or nest in hardwoods over
conifers, including Warbling and Cassin’s Vireos and
Black-throated Gray and Nashville Warblers.
Resources
♦
♦
♦
♦
♦
Coniferous Forest and Sierra Nevada Bird Conservation Plans
www.prbo.org/calpif/
Lassen National Forest Biologists
mrwilliams@fs.fed.us crobbins@fs.fed.us
Pacific Southwest Research Station US Forest Service
www.fs.fed.us/psw/programs/snrc/
PRBO Conservation Science Sierra Nevada Program
rburnett@prbo.org
Birds and Burn Network
www.rmrs.nau.edu/lab/4251/birdsnburns/
Funding Provided by: The National Fire Plan and USDA Forest Service: Region 5, Lassen National Forest, & HFQLG Monitoring Funds
Managing Meadow Habitat for Birds
in the Sierra Nevada
Meadow and other riparian areas are the single most important habitat for birds in the west. Water
diversion and damming, mining, development, encroachment of conifers, and most importantly grazing
have caused a significant loss and degradation of meadow bird habitat in the Sierra. As a result, four
meadow bird species have been conferred special status in California (Sandhill Crane, Great-Gray Owl,
Willow Flycatcher, and Yellow Warbler). With most of the largest meadows in the Northern Sierra
privately owned, efforts to protect and manage these valuable resources will require a collaborative
effort between multiple partners. Recent restoration efforts - primarily in the form of removing grazing
- have resulted in increases in numerous meadow species, including Sandhill Crane and Willow
Flycatcher. With their limited extent on the landscape, wildlife value, and degraded state, meadow
restoration and management should be among the highest priorities for managers in the Sierra Nevada.
Key Meadow Bird Species
Sandhill Crane
Wilson’s Snipe
Calliope Hummingbird
Red-breasted Sapsucker
Warbling Vireo
Willow Flycatcher
Swainson’s Thrush
Yellow Warbler
Wilson’s Warbler
MacGillivray’s Warbler
Lincoln’s Sparrow
Sandy Scoggin
Ryan Burnett
Strategies for Managing Meadows for Birds
Ryan Burnett
Yellow Warbler
Key Meadow Features
Dense patches of willow/alder
Lush tall herbaceous layer
Large area to perimeter ratio
High elevation meadows
Soil moisture/standing water
Peter LaTourette
Lincoln’s Sparrow
With the extreme loss and degradation of meadow habitat throughout the Sierra, changes in meadow management are necessary. The
following are a list of the most important considerations for managing
meadows for breeding birds:
1. Get to know your meadows. Inventory and rank the habitat
value of meadows using key species listed above as indicators.
2. Make wildlife management the primary objective in the
meadows most important for birds. With their unmatched
ecological value and loss and degradation, the few remaining high
quality meadows should be managed exclusively for wildlife.
3. Restore degraded meadows. Several meadows in the N. Sierra have responded well to minimal restoration activities, including raising water tables with check dams and removing all grazing.
4. Manage for dense patches of willow/alder. Dense stringers
or patches of these shrubs are the single most important habitat
feature for meadow-dependent birds.
5. Manage for tall lush herbaceous vegetation. A vigorous
understory is important for concealing nests and supporting
invertebrates that birds prey upon. The Willow Flycatcher is
strongly correlated with this habitat feature in the Sierra.
Adaptive Management
A vital part of effective land management is developing a program of monitoring and
adaptive feedback. As meadow restoration treatments are necessary to enhance
this vital habitat, monitoring the effects of these actions and feeding information
back into future management decisions will result in the greatest benefit to birds and
other wildlife. Bird monitoring is an ideal tool for providing cost-effective feedback
on a whole community of organisms.
Wilson’s Warbler
.2
.1
Mean Willow Flycatcher Abundance
0
While Willow Flycatcher management should be a priority,
focusing meadow management solely on the needs of one
or two species is not likely to ensure the needs of all
meadow dependent birds species are being met. In the
Lassen region, Willow Flycatcher occupied meadows rarely
contain individuals of four important meadow-dependent
bird species (Warbling Vireo, Wilson’s Warbler,
MacGillivray’s Warbler and Lincoln’s Sparrow; see figure).
Using a suite of avian species that represent the full range of
meadow ecosystem attributes to guide management (i.e.,
“focal species”) is a more ecologically sound, well informed
approach.
.3
Single vs. Focal Species Approach
0
2
4
6
8
Abundance of 4 Meadow Focal Species
Meadow Grazing and Birds
It is well established in the scientific literature that grazing can negatively affect a number of meadowdependent breeding birds. Livestock can reduce vegetative cover making habitat unsuitable for many
riparian bird species that are sensitive to changes in vegetation complexity and structure. Degraded
meadows throughout the Sierra and the special status afforded a number of the associated species are
evidence of the effects over a century of grazing abuse has had on this sensitive and vital wildlife habitat.
Response to Restoration
In the Northern Sierra, meadow birds have responded positively to the removal of grazing. Several meadows, once
heavily grazed, now support breeding populations of Willow
Flycatcher, Sandhill Crane, and Yellow Warbler all of which
were rare to absent prior to cessation of grazing. At several sites, active restoration was necessary to restore incised stream channels, water tables, and functional geomorphology and hydrology. Increased soil moisture at these
sites along with no grazing pressure have resulted in natural
regeneration of dense young stands of riparian shrubs,
sedges, and grasses. Meadows in the Lassen region now
support over 90 Willow Flycatcher breeding territories.
Ryan Burnett
Humbug Valley - Plumas County, CA
Resources
Riparian & Sierra Nevada Bird Conservation Plans
http://www.prbo.org/calpif/plans.html
Institute for Bird Populations Sierra Meadow Project
www.birdpop.org/Sierra/meadows.htm
US Forest Service PSW Sierra Nevada Research Center
www.fs.fed.us/psw/programs/snrc/
TNC’s Northern Sierra Project
www.nature.org/wherewework/northamerica/
states/californiapreserves/art6324.html
♦ PRBO Conservation Science Sierra Nevada Program
rburnett@prbo.org
♦
♦
♦
♦
Funding Provided by: The National Fire Plan and USDA Forest Service: Region 5, Lassen National Forest, & HFQLG Monitoring Funds.
Managing Shrub Habitats for Birds
in the Sierra Nevada
Shrub-dominated habitats are a vital component of Sierra forests for numerous bird species. Over 20%
of landbirds breeding in the Sierra Nevada nest in shrub habitat. These shrub communities appear at
risk for several reasons. First, the role of fire has been and continues to be reduced in shaping the
Sierra ecosystem. Second, forest management has moved away from practices that create early
successional habitat in favor of ones that emphasize late seral closed canopy forests. Finally, in many
areas shrubs have been targeted for elimination under fuels reduction projects - with mastication and
even herbicide treatments being implemented. The cumulative effects of all of these management
decisions, raise concern that open forest habitats that support a shrub understory and early successional
shrub fields will decrease in quantity and quality in the Sierra Nevada and with them shrub-dependent
birds and other wildlife.
Key Shrub Bird Species
Mountain Quail
Calliope Hummingbird
Dusky Flycatcher
Olive-sided Flycatcher
Yellow Warbler
MacGillivray’s Warbler
Green-tailed Towhee
Fox Sparrow
White-crowned Sparrow
Ryan Burnett
Peter LaTourette
Key Habitat Features
Shrub Diversity
>50% Shrub Cover
>5 acre patch size
Large Snags & remnant trees
Leaf Litter
Ryan Burnett
Dusky Flycatcher on nest
With current management direction focused on increasing canopy
cover and reducing fire hazards, shrub habitat is at risk. The needs of
shrub-dependent birds can be met by incorporating the following
recommendations into project planning and other management
activities:
1. Value Shrubs as important wildlife habitat. All management
activities that may impact shrub habitats should consider the
ecological value of this habitat to wildlife.
2. Manage group selects and post-fire for shrubs. Timber
harvest or fires that significantly reduce canopy in areas >5 acres
can provide high quality habitat for shrub-dependent birds.
Herbicide, mastication, and conifer release treatments that inhibit
natural shrub regeneration eliminate important bird habitat.
3. Prioritize mixed shrub habitats over monotypic stands
Mixed species shrub fields support greater diversity and densities
of shrub-nesting birds than manzanita-dominated sites.
4. Increase use of prescribed fire. Fire can help regenerate
senescing shrubs, reduce surface fuels that inhibit shrub
recruitment, and thin encroaching conifers.
Mountain Quail
Strategies for Managing Shrub Habitat for Birds
Adaptive Management
A vital part of effective land management is developing a program of monitoring and
adaptive feedback. Shrub habitats have been undervalued and little studied in the Sierra. Understanding the habitat features influencing shrub-dependent birds and their
response to treatments is critical to ensuring the long-term viability of many of these
birds. Bird monitoring is an ideal tool for providing inexpensive feedback on a whole
community of organisms.
Undesirable or Important Habitat?
Fox Sparrow
Over 20% of the songbirds breeding in the Sierra nest in shrubs (see figure). Several species, including
the Sierra Nevada subspecies of Fox Sparrow, are dependent on shrub habitat. Shrub fields are a source
of fruit, nectar, and seeds used by shrub nesting birds, as well as adjacent forest nesting species.
Clear Cuts and Stand Replacing Burns as Habitat
While much has been said about the negative effects
Percent of Breeding Bird Species in each
wildfires and clear cuts have on wildlife habitat, they
Nesting Guild in the Sierra Nevada
both can result in high quality early successional
forest and shrub communities. A study in the
35
30
Lassen National Forest showed that 40 acre clear
25
cuts provided high quality habitat for a number of
20
important bird species 10 to 20 years after being
15
10
cut. These sites supported breeding territories for
5
Olive-sided Flycatcher, Fox Sparrow, Yellow and
0
Gro und
Shrub
Understo ry Cano py Tree
Cavity
MacGillivray’s Warblers, and Dusky Flycatcher.
Tree
Shrub cover at these sites averaged over 50% and
nests of the 3 primary shrub bird species were
located in areas with significantly more shrub cover within 5 meters of the nest than random non-nest
sites (see figure below). Leaving small pockets of mature trees and maximizing snag retention in these
areas may significantly increase bird diversity and woodpecker abundance.
Shrubs in the Forest
Shrub Cover at Nest Sites in the
Lassen National Forest
100
80
% Cover
Historically, shrubs occurred in the understory of
open conifer forest. Due to fire suppression and
even-aged management, sites that once contained
open forest habitat with shrub understory are now
stocked with high densities of medium-sized trees
that have shaded out shrubs and other understory
plant species. Shrubs provide important understory
structure and food sources for many bird species.
Forest treatments should be designed to create
conditions suitable for shrub recruitment and
persistence within a forested matrix.
60
40
20
0
Dusky
Flycatcher
Fo x Sparro w
M acGillivray's
Warbler
Rando m No nnest Sites
Resources
♦
♦
♦
♦
Coniferous Forest Bird Conservation Plan
www.prbo.org/calpif/
PRBO Conservation Science Sierra Nevada Program
rburnett@prbo.org
Institute for Bird Populations
www.birdpop.org/Sierra/spimon.htm
US Forest Service PSW Sierra Nevada Research Center
www.fs.fed.us/psw/programs/
snrc/
Funding Provided by: The National Fire Plan and USDA Forest Service: Region 5, Lassen National Forest, & HFQLG Monitoring Funds.