Transcript Synthesis of Noise Effects on Wildlife Populations

Synthesis of Noise Effects
on Wildlife Populations
Paul Kaseloo
Department of Biology
Virginia State University
Purpose
To create a review and literature database
that could be used to review the effects of
noise (particularly road noise) on wildlife
Covers animals (invertebrate and
vertebrate) – greatest amount of
information deals with birds and mammals
Background
It has been estimated (in part based on
the estimates of the effects on birds) that
20% of the land area of the United
States is ecologically affected by public
roads
(Forman, 2000; Cons. Biol. 14:31-35)
Questions
What is known about the response of birds
to road noise?
What are the implications of these
findings?
What future work could be considered to
answer outstanding questions?
Effect Distance
The distance from the road up to the point
where reduced density was recorded
Early work
Avoidance (i.e. reduced breeding density) by at
least two grassland species (lapwing and blacktailed godwit)
Rural road (Effect distance ~ 500-600 m) with
50 vehicles/day
Highway (Effect distance ~ 1600-1800 m) with
54,000 vehicles/day
(van der Zande et al., 1980; Biol. Cons. 18:299-321)
Woodland birds
A study of 43 bird species (in deciduous and
coniferous forests) found reduced breeding
densities of 26 species (60%) with effect
distances that increase with the amount of
traffic:
40–1500 m at 10,000 vehicles/day
70-2800 m at 60,000 vehicles/day
(Reijnen et al., 1995; J. Appl. Ecol. 32:187-202)
Woodland birds (cont…)
In a multi-year study 17 of 23 species
studied showed a decrease in breeding
density near the road in at least one year
(40-52,000 vehicles/day)
This effect was reduced (only 4 species) in
years with high population density
Woodland birds
High overall population levels will lead to
underestimation of the quality of the
habitat (i.e. would not see the effect in
years of high density)
(Reijnen and Foppen, 1995; J. Appl. Ecol. 32:481-491)
(Reijnen et al., 1997; Biodiv. Cons. 6:567-581)
Grassland Birds
Similar to the earlier study 7 of 12 species
studied showed a reduction in breeding
density adjacent to roads
The effect distances varied with species
and increased with traffic density
Grassland birds (cont…)
Effect distances ranged between:
20-1700 m at 5,000 vehicles/day
65-3530 m at 50,000 vehicles/day
(Reijnen et al., 1996; Biol. Cons. 75:255-260)
Grassland Birds (cont…)
Five years of data on birds (mainly based on two species
- bobolinks and meadowlarks) near Boston found:
Effect distances:
3,000-8,000 vehicles/day – none
8,000-15,000 vehicles/day – 400 m
(breeding only)
15,000-30,000 vehicles/day – 700 m
≥30,000 vehicles/day – 1200 m
(Forman et al., 2002; Environ. Manage. 29:782-800)
Previous Recommendations
Sound levels above about 50 dB(A)
Estimate effect distances of about
1000 m
(Reijnen et al., 1997; Biodiv. Cons. 6:567-581)
Other Possible Causes
Visual disturbance
Air pollution
Microclimatic effects
Road kill
Increased attraction of predators
Unlikely to have an effect at the distances
reported
(Forman et al., 2002; Environ. Manage. 29:782-800)
Other Considerations
Not all species appear sensitive
(e.g. Study in Spain estimated ~ 15% of breeding bird
species sensitive, although total density did not differ at
different levels of traffic)
(Peris and Pescador, 2004; Appl. Acoustics 65:357-366)
Some species become more common near roads
(ecotonal environment)
(Michael et al., 1976; Proc. 1st Nat. Symp. Environ. Conc.)
(Ferris, 1979; J. Wildl. Manage. 43:421-427)
(Adams and Geis, 1981; FHWA/RD-81/067)
Other Considerations
Some species breed well even in
noisy environments (e.g. California
gnatcatchers)
(Awbrey et al., 1995; Inter-noise 65:971-974)
Other Considerations
Rights-of-way have been shown to provide
breeding habitat for some species (e.g.
pheasants, ducks, passerines) –
particularly in areas of disturbance such as
agricultural areas
(Warner and Joselyn, 1986; J. Wildl. Manage. 50:525-532)
(Oetting and Cassel, 1971; J. Wildl. Manage. 35:774-781)
(Voorhees and Cassel, 1980; J. Wildl. Manage. 44:155-163)
(Laursen, 1981; Biol. Cons. 20:59-68)
(Warner, 1992; Biol. Cons. 59:1-7)
Mechanisms
It has been found that higher-pitched
frequencies in bird songs may make
species less susceptible to noise effects
from roads implying masking as a
causative mechanism
(Rheindt 2003; J. für Ornith. 144:295-306)
Mechanisms
Birds in noisier urban environments also
increased amplitude of songs when
background noise increased
(Brumm, 2004; J. Anim. Ecol. 73:434-440)
Important Questions
Is noise alone sufficient to cause the effect
seen?
– It has been established that it is not the
presence of a road, but the level of traffic that
influences the densities of birds, presumably
due to noise because of the distances
involved
– Will mitigation of noise alone be sufficient to
change the response?
(Reijnen et al., 1997; Biodiv. Cons. 6:567-581)
Future Research
Can noise (as opposed to noise with
associated traffic) cause the same effect?
(i.e. can mitigation of noise be expected to
reduce the effect zone)
Will reduction in noise lead to a return of
affected species? (How long until this
response is seen?)
Future Research
What are the proximate effects of noise on
birds?
– Masking of vocalization?
– Physiological changes?
– Locomotor activity?
– Behavioral patterns?
Future Research
Can we see areas where noise mitigation
(for other purposes) has altered species
composition compared to areas without
mitigation?
Acknowledgements
Undergraduate research assistant
Katherine Tyson
Paul Garrett @ FHWA for support and
advice
Funded through FHWA cooperative
agreement DTFH61-03-H-00123
Questions?