Environ Monit Assess (2009) 156:1–16
DOI 10.1007/s10661-008-0459-3
A comparison of techniques to sample salamander
assemblages along highland streams of Maryland
G. F. Strain · R. L. Raesly · R. H. Hilderbrand
Received: 4 December 2007 / Accepted: 26 June 2008 / Published online: 18 July 2008
© Springer Science + Business Media B.V. 2008
Abstract Amphibians may be useful indicators
of biological condition in small streams so de-
termining which sampling technique maximizes
encounters at the least cost and at the optimal
time of year is important. Area constrained sur-
veys (ACS), used by the Maryland Biological
Stream Survey, were tested against cover board
surveys, drift fences with pitfall and funnel traps,
quadrat leaf litter searches, and leaf litter bags.
Sixteen, 100 m-long sites were established in head-
water streams in the Savage River State For-
est in Garrett County, Maryland. Each technique
was randomly assigned to a 25 m stream section
within each overall sampling site, and sites were
sampled once each month from May to October
(2005) with additional sampling in March and
April (2006). Area constrained surveys yielded
means of 2.7 taxa and 14.9 total individuals per
sampling visit, which was significantly higher than
the yield of all other methods in all months except
October and March, when yields were low for all
G. F. Strain (B ) · R. L. Raesly
Department of Biology, Frostburg State University,
Frostburg, MD 21532, USA
e-mail: gstrain54@yahoo.com
R. H. Hilderbrand
Appalachian Laboratory, University of Maryland
Center for Environmental Science, Frostburg,
MD 21532, USA
techniques. Area constrained surveys were also
significantly more cost-effective per taxon and per
individual compared to all other methods. Sep-
tember produced the most taxa and individuals,
October and March produced the least, and yields
for April through August were similar to Sep-
tember. We employed removal sampling at four
sites in April 2006, but abundance could not be
estimated because a significant linear decrease in
the accumulated catch versus catch per unit effort
did not occur for three of the sites.
Keywords Amphibians · Area constrained
survey · Biological monitoring · Cover board
survey · Drift fence survey · Highland streams ·
Leaf litter bags · Maryland · Quadrat leaf litter
search · Salamanders
Introduction
The Maryland Biological Stream Survey (MBSS),
a probability-based survey of Maryland’s non-
tidal streams (Klauda et al. 1998), uses metrics for
fishes and benthic invertebrates to assess stream
condition. Indices of biotic integrity (IBIs) using
fishes, however, are not useful for streams drain-
ing catchments of less than 300 acres because
fish species richness and abundance are too low
(Klauda et al. 1998; Southerland et al. 2000, 2004).
Multiple geological and hydrological barriers