FIRE EFFECTS AND USE
WILDLIFE SPECIES: Buteo swainsoni | Swainson's Hawk 



DIRECT FIRE EFFECTS ON ANIMALS : 
Fire directly reduces Swainson's hawk reproductive success if the fire
crowns in occupied nest trees [25].  Fires that kill or otherwise alter
unoccupied nest trees may disrupt reproduction if acceptable nest trees
are scarce.  The Swainson's hawk arrives on breeding grounds
comparatively late and so must establish or reestablish a nest site
among earlier migrant and resident raptors [31].  Low-severity fires
probably have little direct effect on Swainson's hawks.  Landers [25]
commented that light winter burning probably does no substantial harm to
raptors.


HABITAT RELATED FIRE EFFECTS : 
The Swainson's hawk occurs in the following four major fire-dependent
plant associations in the western United States:  grassland, semidesert
grass-shrub, sagebrush grass, and pinyon-juniper [26].

Although fire may reduce potential nest trees, it may enhance the
foraging habitat of Swainson's hawks.  Fires that reduce vegetation
height and create open areas probably increase hunting efficiency by
Swainson's hawks.  Open-habitat raptors such as the Swainson's hawk use
scattered patches of woody vegetation near open foraging areas for
nesting and perching.  However, where extensive invasion of woody
species has occurred, Swainson's hawk foraging habitat may be reduced.
The Swainson's hawk is favored by fires that reduce pinyon-juniper
woodlands [26].  Raptors associated with pinyon-juniper woodlands depend
upon edges of openings created by fire and scattered islands of unburned
woodlands [13].  Fire suppression in pinyon-juniper habitats of the
Great Basin of California may have reduced suitable Swainson's hawk
habitat in this area [26].

Regular burning helps to maintain habitat for many prey species of
Swainson's hawk [13,25].  Several studies indicate that many prey
populations increase rapidly subsequent to burning in response to
increased food availability [13].  Fire suppression in grasslands was
detrimental to small bird and mammal populations due to organic matter
accumulation and reduced plant vigor [36].  The Swainson's hawk has been
observed hunting on recently burned areas in Colorado county, Texas [2].
On the Bridger Teton National Forest, Swainson's hawks were more
commonly observed using a high-severity fall burn than a low-severity
spring burn in the same area [27].


FIRE USE : 
Prescribed fire can be benefical to Swainson's hawk populations by
enhancing habitat and increasing the prey base [13,25].  Burning in
grasslands where scattered trees are retained benefits Swainson's hawk
populations, particularly in areas where nesting sites are limited.
Prescribed burning plans should strive for creation of maximum
interspersion of openings and edge, with high vegetative diversity.
Habitats should be maintained in a random mosaic.  In most cases,
burning plans must be integrated with proper range management.
Reseeding of perennial grasses as well as rest from livestock grazing
may be necessary to achieve desired goals.  Burning should be deferred
until nesting is completed in areas where impact to breeding Swainson's
hawk may occur [13].


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Buteo swainsoni | Swainson's Hawk