Fire,
Drought, Beetles, and Birds
 
|
|
|
FeederWatchers
notice the impact of natural disasters on jays
and nutcrackers
As
wildfires raged through California last autumn,
the flames threatened the livelihoods of people,
as well as the birds and other wildlife that resided
on the dry, forested hillsides. The difficult
challenge for the birds dispersing from burning
forests was to find adequate habitat elsewhere
in which to live. Where did the birds go? How
have their populations been affected? As in past
natural disasters, citizen scientists can help
us answer these questions.
|
 |
After
widespread fires across much of the West during
the summer of 2002, for example, participants in
Project FeederWatch reported changes in the abundance
of birds including Pinyon Jays (left), Steller's
Jays, and Clark's Nutcrackers at their backyard
feeding stations. Extensive drought combined with
a bark beetle infestation may have further influenced
the movements of these birds. |
|
The
three species inhabit coniferous woodlands, where
their life cycles are interwoven with those of
the pines. A single Clark's Nutcracker caches
as many as 98,000 seeds to store for one winter.
A flock of 250 Pinyon Jays stores some 4.5 million
pine seeds in autumn, when seeds are plentiful.
Steller's Jays have a more varied diet but they
also cache and consume pine seeds. In return,
the birds help disperse seeds and regenerate forests
in burned areas. Forgotten caches grow into new
trees, often in clusters where the seeds had been
hidden together. When the forests mature, the
jays and nutcrackers harvest the seeds they need
to survive winter and feed their young. When crops
fail, jays and nutcrackers irrupt in large numbers
in search of food.
Searching
for food after fires
In
September 2002, fires brought Pinyon Jays to the
yard of FeederWatcher Helen Mixa for the first
time in 30 years of observations. The Mixas live
in Vernal, Utah, just south of Flaming Gorge Reservoir,
where fire burned 20,000 acres of pines. According
to Helen, "The fire reduced the pinyon pines
to ash. There weren't even skeletons of trees
left. Nothing." After the fires, the jays
began coming to the feeders every day—as
many as 160 at a time.
|
|
|
|
Fires
also took their toll on Pinyon Jay habitat in
Wyoming. Jim and Gloria Lawrence of Casper, Wyoming,
occasionally see jays in their yard, but they
report that in 2002 "the unusual thing was
that the Pinyon Jays came and stayed for about
three weeks, visiting the yard daily to feed for
up to five hours a day." The Lawrences live
south of Mount Bessemer, which burned in 1998,
and Mount Coal, which burned in 2001.
In
other regions as well, fires may have caused Steller's
Jays to move into new areas. Colorado, Arizona,
and Oregon recorded their largest fires in the
last 100 years, according to the National Interagency
Fire Center. Bill Howe, a biologist with the U.S.
Fish and Wildlife Service, reported, "last
winter marked one of the largest flights of Steller's
Jays into the lowlands. The jays were everywhere
from the plains of Colorado to the lowlands of
the Rio Grande. People were reporting them on
birding lists and seeing them fly over cities."
Because there were still Steller's Jays in the
mountains of New Mexico and because the species
is typically scarce in the lowlands in winter,
Howe suspects that the fires in Colorado, combined
with drought conditions throughout the Southwest,
drove jays into new habitats.
Ironically,
fire suppression practices in many areas may be
contributing to widespread problems for coniferous
birds. Natural fires, although they destroy trees,
also help regenerate healthy new forests by burning
mature stands and releasing seeds from cones to
germinate. In the northern Rocky Mountains, where
fires have been suppressed, nutcrackers have suffered
major losses of high-elevation habitat. Without
fire, whitebark pine communities have aged and
become susceptible to outbreaks of introduced
white pine blister rust and pine beetles, or yielded
to other tree species less favorable for nutcrackers.
Meanwhile, fire suppression policies in southwestern
ponderosa-pine forests have provided fuel for
huge, uncontrolled wildfires that consumed thousands
of hectares of Pinyon Jay habitat in the late
1990s.
Food
shortage: drought, bark beetles, and dying trees
|
| Recent
droughts may also explain why some FeederWatchers
are seeing more jays and nutcrackers at their feeders.
Dr. Russ Balda, a leading expert on Pinyon Jays,
studies populations near Northern Arizona University
in Flagstaff. Balda and his students band hundreds
of jays at feeders each year, taking numerous measurements
and assessing the health of the birds. |
 |
| According
to Balda, the drought-stricken pinyon pines near
Flagstaff have not produced a seed crop since 1999.
The researchers have found that each year since
1999 juvenile Pinyon Jays are weighing less, indicating
that food resources are limited. The research shows
that birds are moving across vast regions in search
of food, showing up in places where they have not
been recorded before, such as Santa Rosa, California,
and even Mexico. Pinyon Jays were seen at more FeederWatch
locations in 2002–2003 than during the previous
season, indicating that birds were leaving their
native habitat and seeking supplemental food at
feeding stations (Figure 1). |
| Drought
sent Pinyon Jays into the yard of Claire Bassett
in Pueblo West, Colorado. In the five years she
has lived in Pueblo West, she had never seen Pinyon
Jays in her yard. During the winter of 2002–2003,
up to five jays visited almost every day. She said
that the trees died in the foothills to her west
where Pinyon Jays are commonly found and the nearby
reservoir was at its lowest level in 15 years. |
| According
to the Sunday Journal in Albuquerque, New
Mexico, a bark beetle infestation damaged thousands
of pinyon pines in New Mexico, pushing Pinyon Jays
into new habitats. The infestation of these native
beetles is associated with widespread drought. |
 |
|
When
a beetle bores into bark, a healthy tree responds
by producing pitch that drowns or evicts the beetle.
During infestations in times of drought, however,
trees may not produce enough sap pressure to control
the hundreds of beetles that may attack. The insects
carve pathways under the bark, eventually killing
the afflicted trees. The outbreak in New Mexico
is the worst since at least 1950, according to
Debra Allen-Reid of the USDA Forest Service, and
it is so widespread that control methods are not
feasible.
The
effects of drought and insects were not lost on
Barbara Smith of Silver City, New Mexico. In her
yard the evergreen oak trees lost their leaves
in autumn, something that normally only happens
in the spring as new leaves replace the old. According
to Smith, Steller's Jays usually stay in the pine
forests on top of the hills several miles from
her home, but the drought last summer caused the
jays to move down into the foothills. "In
Santa Fe I saw whole hillsides of dead junipers
and pinyon pines killed by the bark beetle,"
said Smith.
|
| In
a normal FeederWatch season she would see only one
or two Steller's Jays (right) during the entire
winter, but during the winter of 2002–2003,
she always had six or seven jays, and one day she
had twelve. |
 |
|
The
combined data from FeederWatchers counting birds
across the region also revealed interesting shifts
in sightings of nutcrackers. In 2001–2002,
FeederWatchers reported Clark's Nutcrackers on
the eastern front range of the Colorado Rockies,
but last year reports of this species also came
from the valleys on the western side of the mountains,
presumably because of failures in seed crops.
According to The Birds of North America,
"Poor condition of many irrupting birds indicates
that some may not survive; some settle in new
areas with cone crops and may not return home."
Unfortunately,
Clark's Nutcrackers and Pinyon Jays may have fewer
choices now about where to go than in the past.
According to The Birds of North America,
approximately 1.2 million hectares of pinyon/juniper
woodland were converted to grazing land between
1950 and 1964. Along with the effects of fire,
fire suppression, drought, and bark beetle infestation,
prime habitats for these species are becoming
more difficult to find.
FeederWatchers
needed
What
impact will the fires of 2003 have on bird populations
in California? FeederWatchers can contribute essential
information by submitting reports of the birds
seen at their feeders. More than 400 FeederWatchers
submitted data from California last winter, setting
up an important baseline of information prior
to the fires. By continuing to participate in
2004, these FeederWatchers will help us learn
where the birds moved following the wildfires
of 2003.
Meanwhile,
Project FeederWatch invites new and continuing
participants everywhere to help document shifts
in the distribution of birds during winter—insights
needed to better understand how complex ecological
factors and human activities are influencing the
movements of birds. Join
Project FeederWatch to help.
Reference:
Tomback, D. F.; Balda, R. P. The Birds of North
America, Nos. 331 and 605. The Birds of North
America, Inc., Philadelphia, PA.
Originally published in BirdScope, Winter 2004,
Volume 18, No. 1
Pinyon
Jay photos taken by Linda Rawson, Santa Fe, New
Mexico.
Steller Jay photo taken by Vernon Dayhoff, Colorado
Springs, Colorado.
|
|
|
2001–2002
2002–2003 
2001–2002
& 2002–2003
