Data from: Habitat attributes associated with short-term settlement of Ozark hellbender (Cryptobranchus alleganiensis bishopi) salamanders following translocation to the wild

1. Organisms associated with lotic systems rank among the most threatened
because of global change. Although translocation is being increasingly
applied as a conservation strategy, most studies have focused on survival
and recruitment of individuals, and few have attempted to identify how
habitat attributes influence short-term settlement of animals during the
critical post-release period. 2. We demonstrate the application of
resource selection modelling in an information theoretic framework to
identify release-site characteristics that will increase the likelihood of
settlement for a fully aquatic benthic stream salamander, the Ozark
hellbender (Cryptobranchus alleganiensis bishopi). We fit discrete choice
models using data from 29 radio-tagged hellbenders that were translocated
to two sites in the North Fork of the White River (NFWR), Missouri
(U.S.A.). We defined resource availability at two spatial scales (stream
reach and home range) and quantified abiotic habitat attributes at 3181
salamander locations and 6329 random available locations collected between
May 2008 and August 2009. 3. At both sites and spatial scales, a single
model received substantially greater support (0.96–1.00 of total model
weight) than all other models, and top-ranked models were similar in form
and predictive ability. At both spatial scales, selection was positively
influenced by the presence of cobble-boulder substratum relative to
bedrock and finer substrata. We also noted a negative interactive effect
between distance to the nearest substratum particle large enough to
provide cover (i.e. at least one axis ≥15 cm in length) and an increase in
either a direct or relative (i.e. pool, run, and riffle) measure of water
velocity. 4. Collectively, salamanders released in our study selected
resources indicative of long-term benthic microhabitat stability. However,
despite strong selection of cobble-boulder substratum, 8% (282 of 3181) of
captive-reared hellbender locations occurred in bank crevices and root
masses. Although several studies have reported the importance of near bed
hydraulics in determining occurrence of stream macroinvertebrates, our
findings are the first to indicate that spacing among cobble-boulder
substrata may be important for hellbenders. 5. To increase the likelihood
of short-term settlement of captive-reared hellbenders in the wild, we
recommend prioritising release sites where the average distance between
cobble-boulder particles within habitat patches is minimised. In general,
average spacing among cobble and boulder substrata should be <1 m
in habitat patches where mean benthic water velocity exceeds 0.1 m s−1,
and <0.5 m where water velocity approaches 0.30 m s−1. Based on
home range sizes of captive-reared Ozark hellbenders, the collective
extent of suitable cobble-boulder habitat patches within release sites
should approximate at least 10 m2 per salamander released.