Yakama Nation Fisheries
TFW-Wildlife
TFW-Wildlife
In 2003 we began conducting research on
cavity nesting birds in managed ponderosa pine (Pinus
ponderosa) forests along the eastern slope of the Cascade Range in
Washington. Our three
primary
study areas are west of
the City of Yakima and located in the Nile Creek Basin on the
Okanogan-Wenatchee National Forest,
the
Wenas Wildlife Area,
and
Ahtanum State Forest.
The focal species of our research is the White-headed Woodpecker
(Picoides albolarvatus) which
is restricted to ponderosa pine dominated forests in Washington State.
The White-headed Woodpecker is a primary excavator, meaning that it excavates its own cavity within a snag (or rarely a live tree). This species is classified as a weak excavator, and thus needs snags that are in moderate to advanced stages of decay in order to excavate a nest cavity (for other interesting facts about White-headed Woodpeckers, click here). The cavities that are created by woodpeckers are used by a wide variety of secondary cavity-nesting species, or species that nest in cavities but cannot (or rarely) excavate their own cavities for nesting. Thus, woodpeckers are considered keystone species in many forested ecosystems.
Photos by George Vlahakis
The White-headed Woodpecker is considered to be one of the least studied woodpeckers in North America; this being one reason why we focused our research on this species. The other reason for studying this species is its narrow range in Washington due to its dependence on ponderosa pine. Ponderosa pine forests in the Pacific Northwest have had a long history of timber harvest and timber management due to its low elevation occurrence and being readily and easily accessible, even in winter. Thus, the forests this woodpecker occupies today are radically different from what the species historically adapted too.
Historic ponderosa pine forests
consisted of average densities of 50 trees/ha, average diameters at
breast height (dbh) of 60-70 cm, and fire return intervals of 5 to 15
years (Agee 1996; Gaines et al. 2007).
As a result of selective logging prior to 1930 (Hessburg and Agee
2003), continued harvesting, and increased frequency of stand
replacement fires, many ponderosa pine forests are now stocked at 3-10
times the historic density, dominated by smaller trees that average
20-30 cm dbh (Harrod et al. 1999), and are prone to in-growth of
understory shade tolerant trees (e.g., Douglas-fir [Pseudotsuga
menziesii] and
Grand Fir [Abies grandis];
Fulé et al. 1997; Hessburg and Agee 2003; Keeling et al. 2006).
In 2002, while reviewing proposed timber
sales in ponderosa pine stands, we would occasionally see White-headed
Woodpeckers. Knowing that
previous research conducted in California and Oregon has repeatedly
linked the occurrence of White-headed Woodpeckers in pine dominated
habitats to old-growth components, we began thinking that if
White-headed Woodpeckers are in these managed stands with relatively
small diameter trees, how well are they reproducing?
Thus, a research project was born.
When we began our initial field work in
2003, our goal was to find nests of any cavity-nesting bird, monitor
them to determine if they fledged young (were successful) and then
collect vegetation data associated with each nest site.
By the end of the 2004 field season, we had monitored 13
White-headed Woodpecker nests and 121 nests of 13 other cavity-nesting
birds. Up to this point, we
were unable to look inside cavities and it was difficult to determine
success or failure of nests.
In addition, we had no way to determine clutch sizes, number of
young fledging, and other important demographic data that was lacking
for many of the species we were monitoring.
Thus, we began looking for equipment that would enable us to look
into the cavities.
We found a device called the TreeTop Peeper IV (Sandpiper Technologies, Manteca, CA) that would allow our to look into tree cavities. By the end of 2005, we had found 9 White-headed Woodpecker nests and 104 nests of 15 other cavity-nesting bird species. At this point, we were getting overwhelmed by the number of nests we were finding, monitoring and conducting vegetation sampling around. We needed to reduce our work load so we decided to focus on three species in addition to the White-headed Woodpecker. These were the Northern Flicker (Colaptes auratus), Hairy Woodpecker (Picoides villosus), and Western Bluebird (Sialia mexicana). These were the most numerous species we were encountering and we were able to look in their cavities with the TreeTop Peeper (cavities of nuthatches and chickadees had too small a diameter to fit the probe in from the Peeper).
Pictures by George Vlahakis
The flicker is a large and common
woodpecker in ponderosa pine forests; however, little research has been
done on flicker reproductive ecology in dry forests of Washington.
The Hairy Woodpecker is common in all conifer forest types
(generalist) of Washington, but there is a lack of detailed demographic
information available for this species.
The Hairy Woodpecker is also a good species to compare to the
White-headed Woodpecker, which is a habitat specialist in Washington.
Because both these species are nearly identical in size, it will
be interesting to see what differences exist in their breeding ecology
that may prevent these species from competing with each other.
The Western Bluebird is a secondary cavity nester that relies on
these three woodpeckers for creating cavities.
Although research has been conducted on its nesting ecology, most
of that work has been done using nest boxes, with little research
focused on this species nesting in tree cavities.
For current research projects click here.
Literature
Cited:
AGEE, J. K., 1996. Achieving conservation biology objectives with fire in the Pacific Northwest. Weed Technology 10:417-421.
Gaines, W. L., M. Haggard, J. F. Lehmkuhl, A. L. Lyons, and R. J. Harrod. 2007. Short-term response of land birds to Ponderosa Pine restoration. Restoration Ecology 15:670-678.
Harrod, R. J., B. H. McRae, and W. E. Hartl. 1999. Historical stand reconstruction in Ponderosa Pine forests to guide silvicultural prescriptions. Forest Ecology and Management 114:433-446.
Hessburg, P. F., and J. K. Agee. 2003. An environmental narrative of inland northwest United States forests, 1800-2000. Forest Ecology and Management 178:23-59.
Fulé, P. Z., and W. W. Covington, and M. M. Moore. 1997. Determining reference conditions for ecosystem management of southwestern Ponderosa Pine forests. Ecological Applications 7:895-908.
Keeling, E. G., A. Sala, and T. H. DeLuca. 2006. Effects of fire exclusion on forest structure and composition in unlogged Ponderosa Pine/Douglas-fir forests. Forest Ecology and Management 237:418-428.
Research
Papers Published:
Kozma, J.
Kozma, J. M. 2010. Characteristics of trees used by White-headed Woodpeckers for sap feeding in Washington. Northwestern Naturalist 91:1 81-86. .pdf
Kozma, J. M. and
Kozma, J. M. 2011. Composition of forest stands used by White-headed Woodpeckers for nesting in Washington. Western North American Naturalist 71:1-9. .pdf
Kozma, J. M. 2011. Black bear (Ursus americanus) predation on nest contents of cavity-nesting birds along the east slope Cascades. Washington Birds 11:1-7. .pdf
Kozma, J. M. 2011. White-headed Woodpeckers successfully fledge young after snag containing the nest cavity was felled for firewood. Washington Birds 11:18-21. .pdf
Kozma, J. M. and A. J.
Kroll. 2012. Woodpecker nest survival in burned and unburned
managed ponderosa pine forests of the northwestern USA. Condor
114:173-184.
General Reports:
Lorenz, T,
Contact:
Jeff Kozma
(509) 865-5121 ext: 6343
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