FIRE EFFECTS AND USE
WILDLIFE SPECIES: Speotyto cunicularia | Burrowing Owl 



DIRECT FIRE EFFECTS ON ANIMALS : 
Fire-related mortality of burrowing owl has not been documented in the
literature.  Burrowing mammals that stay in their burrows during fire
are usually unharmed; burrowing owls in their burrows during fire
probably are probably unharmed as well.  Some burrowing mammals have
asphyxiate in their burrows during fire; this may also happen to
burrowing owls in their burrows during fire [14].  When caught outside
their burrows during fire, adult burrowing owls probably escape fire
easily; some young that cannot yet fly may be injured or killed.


HABITAT RELATED FIRE EFFECTS : 
Fire affects burrowing owl in two ways:  by altering vegetation and by
altering their prey base [3].

Fire effects on vegetation:  Wright and Bailey [66] indentified three
major fire-dependent plant associations (grassland, semidesert
grass-shrub, and sagebrush-grass) in which burrowing owl occur.
Frequent fire can maintain or improve burrowing owl habitats by reducing
plant height and cover around burrows and by controlling woody plant
invasion.  For example, 3 months following a May prescribed fire on the
Nebraska sandhills prairie, where burrowing owl occur, vegetative cover
on burned sites averaged 16 percent less than on adjacent unburned sites
[7].  One year after a May 1965 wildfire on Nebraska sandhills prairie,
vegetative growth was 53 to 91 percent greater on unburned than on
burned sites [65].

Fire in grasslands has been shown to reduce encroachment of woody shrubs
and trees [66].  Mixed-grass prairie of South Dakota, for example, has
become invaded by ponderosa pine (Pinus ponderosa) in the absence of
fire; it is estimated that in the Black Hills, 50 percent of
presettlement prairie has converted to ponderosa pine woodland [20].

Fire effects on prey:  Periodic fire in grasslands probably increases
prey diversity for raptors including burrowing owl, and may increase
overall prey density [3].  Rodent populations in grasslands usually show
an initial drop after fire; loss of cover makes rodents more vulnerable
to predators such as burrowing owl [12].  After a 1- to 3-year reduction
in prey, rodent numers usually match or exceed prefire levels [66].
Deer mouse (Peromyscus maniculatus) numbers have returned to prefire
levels in the first postfire growing season [12].  Ground squirrels, an
important burrowing owl prey, also increase in number after fire [5,21].

Since arthropods form the majority of the burrowing owl's diet, fire
effects on burrowing owl's arthropod prey are an important management
consideration.  Because beetles, grasshoppers, and crickets form the
majority of the burrowing owl's arthropod diet, they are discussed here.

Beetles are a diverse order, and the effects of fire on beetles are
variable.  Generally, however, beetle populations in grassland habitats
recover quickly from fire.  After a March wildfire on an Illinois
prairie, beetle numbers initially dropped 15 percent, but nearly
equalled beetle numbers on an adjacent unburned prairie within a month.
Rove beetle (Aleocharinae) numbers on burned sites, however, stayed
below those on adjacent unburned prairie throughout the month of the
study [52].  On Minnesota tallgrass prairie, Tester and Marshall [60]
recorded an increase in beetles following fire.  On the Konza Prairie
Research Natural Area of Kansas, scarab beetle (Scarabaeideae) grub
numbers were significantly (p<0.05) greater on annually burned prairie
than on unburned prairie [55].  (Data for other beetle families were not
collected.)

Most grasshopper species increase after spring fire due to increased
nutritional quality of new grasses [39,52,60].  On native tallgrass
prairie in Kansas, grasshopper numbers were highest after early spring
prescribed burning, followed by mid-spring burning; numbers were lowest
on late-spring burned sites [39].  In a review of fire effects on
insects, Warren and others [64] reported that grasshoppers and crickets
(Orthoptera) generally increase after fire in any season; however, "hot"
grass fires that occur before Orthoptera have developed wings may reduce
their numbers.  Jerusalem crickets are a key element in the diet of
burrowing owl in many areas.  Unlike most Orthoptera, they are wingless
even as adults.  They habitually burrow or hide under rocks, where they
are probably protected from fire.  After rangeland fire in northern
Utah, Jersalem crickets occurred exclusively on burned areas [25].

Florida burrowing owl:  Periodic fire is important in keeping the sandy
soils open for burrowing.  It also maintains the early successional
stages that burrowing owl and most of their herptile and mammal prey
require [42].


FIRE USE : 
NO-ENTRY


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Speotyto cunicularia | Burrowing Owl