DOI: 10.5061/dryad.h9w0vt4gp
title: Habitat Selection by a Threatened Desert Amphibian

description: Aim. Habitat degradation and fragmentation are major drivers of amphibian
 declines. The loss of environmental features that allow for movement
 between water sources may be particularly detrimental for amphibians in
 arid environments.  Climate changes will increase the importance
 of microhabitats to amphibians. Enhancing areas to facilitate movement may
 be a necessary conservation strategy for many animal species that depend
 on wetlands, including federally-threatened Chiricahua leopard frogs
 (Lithobates chiricahuensis).  Habitat preferences of
 this frog species are not well understood.  We sought to
 better understand fine-scale habitat selection, to inform conservation of
 Chiricahua leopard frogs. Location. We conducted our study on the Ladder
 Ranch, a privately-owned working bison ranch in New Mexico, USA that
 supports a large proportion of the remaining Chiricahua leopard frogs in
 the state. Methods. We attached radio transmitters to 44 frogs during
 summer 2014.  We located each frog daily for up to 8
 weeks (median = 30 days). We assessed fine-scale habitat selection by
 comparing characteristics at each frog location and a random location 5
 meters away using conditional logistic regression.  Results.
 Frogs preferred features that likely reduce desiccation, even after
 accounting for the presence of water.  Frogs selected
 areas with more low-lying cover, especially aquatic vegetation and woody
 debris, a tree overstory, and a mud substrate.  Main Conclusions.
 We recommend managing potential movement corridors for Chiricahua leopard
 frogs by ensuring the presence of muddy creek bottoms, woody debris,
 riparian overstory, low-lying ground cover, and
 pools.  Microclimates created by these features seem
 especially valuable given warming temperatures and modified precipitation
 regimes, resulting in decreased surface water, soil moisture, and
 vegetation cover.  Retaining or creating preferred
 habitat features and microclimates in areas between water sources may
 increase connectivity among isolated populations of Chiricahua leopard
 frogs and could improve persistence and recovery of other water-obligate
 species in arid landscapes.
description: We captured Chiricahua leopard frogs and fitted them with radio
 transmitters during summer 2014 on the Ladder Ranch, New Mexico, USA. We
 relocated frogs with radio telemetry and quantified habitat variables at
 the frog's location, within a 1m-diameter circle centered on the
 frog. We used a random number generator to determine a random compass
 bearing (1-360), and walked 5m on that bearing and performed a second
 habitat quantification at that random location. 
description: The dataset is formatted as pairs of locations. The first
 spreadsheet line of a DATE/TIME/FROGID unique combination is the frog
 location. The second line of that unique DATE/TIME/FROGID combination is
 the random location 5m away from the frog. UTME and UTMN, cartesian
 coordinates for exact frog locations, have been removed from the dataset
 because of the sensitive nature of endangered animal locations. Please
 contact the authors if exact locations are needed.
 <em><strong>Variable
 definitions:</strong></em> DATE: Date in
 DD-MMM-YY format TIME: Time of relocation in 24 hr
 format FROGID: unique identifier for each frog. FROGIDs
 with multiple numbers (e.g., 503/017) were a single frog fitted with
 multiple transmitters.  USE: A binary indicator for the
 locations used by a frog (1) or the random location 5m away (0).
 UTME/UTMN: location of frog and random location. Removed for
 protection of endangered species. WATER: binary
 indicator for presence of standing or flowing liquid water at the location
 (y=yes/n=no) DIST: if location was not in water,
 distance to the nearest source of liquid water.
 SUBSTRATE: dominant substrate class at the location (within the
 1m-diameter circle) See article text for condensation of variable
 categories. FCOVERPCT: the percentage of low-lying
 cover (originally called "frog cover") at each location,
 quantified by visual estimation. FCOVERTYP: the type of
 low-lying cover (originally called "frog cover") at each
 location. See article text for condensation of variable
 categories. OCOVERTYP: the type of overstory cover at
 each location. See article text for condensation of variable
 categories. OCOVERPCT: the percentage of overstory
 cover at each location, quantified by visual estimation.
 PHOTO: binary indicator for if a photo was taken of the location
 (### = photo number/n=n) NOTES: any notes on the
 location from the observer.