Ghaffarietal2014.pdfChelonian Conservation and Biology, 2014, 13(2): 202–215 g 2014 Chelonian Research Foundation Home Range and Habitat Selection of the Endangered Euphrates Softshell Turtle Rafetus euphraticus in a Fragmented Habitat in Southwestern Iran *, FLORA IHLOW , MICHAEL V. PLUMMER , MAHMOOD KARAMI , EMATOLLAH KHORASANI , BARBOD SAFAEI-MAHROO , AND DENNIS RO 1Department of Environmental Science, Graduate School of the Environment and Energy, Science and Research Branch, Islamic Azad University, Tehran, Iran [firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; email@example.com]; 2Herpetological Department, Zoologisches Forschungsmuseum Alexander Koenig (ZFMK), Adenauerallee 160, 53113, Bonn, Germany 3Department of Biology, Harding University, Searcy, Arkansas 72149 USA [firstname.lastname@example.org]; 4The first two authors contributed equally to this article *Corresponding author ABSTRACT. – We present information on movement patterns and habitat selection of theendangered Euphrates softshell turtle Rafetus euphraticus (Daudin 1802) from KarkhehRegulating Dam Lake in southwestern Iran. Twelve adult turtles were trapped, fitted withradio-tracking transmitters, and relocated 21 to 51 times between May 2011 and July 2012. Themean linear range size was 2.54 ± 0.83 km, the mean river channel area was 55.35 ± 17.98 ha,the mean minimum convex polygon (MCP) size was 47.49 ± 23.36 ha, and the mean 95% kerneldensity estimator (KDE 95%) measured 21.75 ± 9.44 ha with a core area (KDE 50%) of5.74 ± 2.87 ha. Range overlap was generally high; on average, individual MCPs overlapped withthose of 7.5 other turtles, individual KDEs with those of 7.3 other turtles, and core areas withthose of 5.5 other turtles. Selection of habitat types was not proportional to availability. Studyanimals preferred shallow-water edge habitats covered with Phragmites australis over all otherhabitat types.
KEY WORDS. – habitat selection; fixed kernel density estimator; minimum convex polygon; linearhome range; radio-tracking; Khuzestan Province The Euphrates softshell turtle, Rafetus euphraticus the species' habitat requirements and movement ecology (Daudin 1802), is a highly aquatic and cryptic trionychid (Pittman and Dorcas 2009). So far the species has been turtle found in the Euphrates and Tigris rivers and their studied almost exclusively in Turkey (Gramentz 1991; tributaries in Turkey, Syria, Iraq, and Iran (Tas¸kavak and Tas¸kavak and Atatu¨r 1995; Biricik and Turg˘a 2011). The Atatu¨r 1995, 1998; Ghaffari et al. 2008; Biricik and Turg˘a present study reports the first data on movement patterns, 2011). In Iran, the species is restricted to the Karoon, home range sizes, habitat selection, and basking of the Karkheh, Dez, and Jarahi rivers and their tributaries as well endangered species from a fragmented habitat in south- as the Hawr-al-Azim marshlands in the southwestern part western Iran.
of the country (Ghaffari et al. 2008). Throughout its rangeR. euphraticus is severely threatened by ongoing habitat destruction and fragmentation caused by conflicts and warsin the past, by drainage to reclaim areas for agricultural Study Area. — The Karkheh Regulating Dam Lake purposes, and by an increasing number of dams (Tas¸kavak (KRDL) is situated in the northwestern part of Khuzestan and Atatu¨r 1995; Partow 2001; Ihlow et al. 2014). The Province in southwestern Iran (Fig. 1). It was part of the species is also affected by water pollution through Karkheh River until the construction of the Pay-e-Pol fertilizers and pesticides, oil, garbage, industrial chemicals, Regulating and Diversion Dam, which separated it from and incidental capture with fishing gear (Ghaffari et al.
the main river in 2009. The study area is bordered by the 2008). Populations have been reported to be declining in Karkheh Dam in the north and by the Pay-e-Pol Turkey and Iran (Gramentz 1991; Tas¸kavak and Atatu¨r Regulating and Diversion Dam in the south. The 1995; Ghaffari et al. 2008; Biricik and Turg˘a 2011). In meandering lake measures 266.42 ha, is 101 to 658 m 1996, R. euphraticus was consequently listed as endan- wide, and stretches10 km from north to south. The lake is gered on the International Union for Conservation of generally deep (10–15 m) but also has shallow edges and Nature (IUCN) Red List of Threatened Species (Biricik several small islands. Tributaries and channels range and Turg˘a 2011; IUCN 2013).
from 30 to 67 m in width. The KRDL is spring-fed by Impact assessments regarding habitat loss and drivers numerous natural springs. The water level is regulated by for population decline are currently lacking and are dam gates and is highly variable. During the summer and difficult to formulate without appropriate knowledge on autumn months, a few small temporary ditches exist in
GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Figure 1. Topographic map of Iran, displaying the study area in Khuzestan Province as a black dot. Map designed using ArcGis 9.3.
Elevation data: CGIAR SRTM (Jarvis et al. 2008).
close proximity to the northern edge of the lake that Radiotelemetry and Data Collection. — Fourteen R.
potentially serve as nurseries for R. euphraticus hatch- euphraticus were caught in a large submerged turtle trap.
lings. The rich submerged vegetation includes Potamo- The trap design was developed based on local fishermen's geton pectinatus and Ceratophyllum demersum. The lake experience and constructed of iron bars and chicken wire is partly encompassed by a dense stand of Phragmites (Fig. 4). It was baited with approximately 400 g of fresh australis, which reaches 3 m in height. The surrounding chicken intestines placed in bags made of chicken wire.
area is mainly covered by shrubs including Tamarix spp.
Empty water-bottle buoys marked trap locations and and Prosopis farcta and a few scattered trees, mainly facilitated retrieval. Although trapping in shallow water Populus euphratica and Ziziphus spina-christi (Figs. 2 was more successful in previous studies in Turkey and 3). Several stretches of shoreline without any (Gramentz 1991), the trap was placed in a depth of 10 m vegetation potentially serve as basking or nesting sites.
to prevent it from being taken by local fishermen. The Human population density is generally low, but the trap was checked every 8–12 hrs to prevent captured area is frequently used by local people for fishing, turtles from drowning (Kuchling 2003). Although R.
boating, hunting, and camping. Vertebrate species found euphraticus was reported to be mostly diurnal (Gramentz in the KRDL include Caspian pond turtles (Mauremys 1991; Tas¸kavak and Atatu¨r 1995), trapping was unsuc- caspica siebenrocki), various species of fish (including cessful during the daytime (between 1000 and 1700 hrs, several species of the genus Barbus, Cyprinus carpio, n 5 6 d). Thus, trapping was performed during the night Cyprinion macrostomum, Glyptothorax kurdistanicus, and between 2000 and 0800 hrs (n 5 13 nights). The trap was Glyptothorax silviae), and several species of amphibians placed in 13 different locations between 1 April and 31 (e.g., Pseudepidalea variabilis, Hyla savignyi, and May 2011 (Fig. 4). Fourteen R. euphraticus were caught, Pelophylax ridibundus). Numerous invertebrates, includ- including 2 juveniles with straight-line carapace lengths ing abundant insect larvae, aquatic insects, and snail (SCL) , 15 cm and 12 turtles with body sizes suitable for species, serve as potential prey for Rafetus.
radio tracking (SCL . 29 cm).
CHELONIAN CONSERVATION AND BIOLOGY, Volume 13, Number 2 – 2014 Figure 2. Map of the Karkheh Regulating Dam Lake highlighting the 4 major habitat types available at the study site.
Captured turtles were marked for individual identi- diameter) through 2 holes punched with a needle in the fication using a notching system modified for softshell posterior margin of the turtles' carapace (Fig. 5). The turtles (Plummer 2008). Morphometric characteristics of wire was passed through a plastic button on the ventral turtles were collected following Tas¸kavak and Atatu¨r plastral surface to prevent the transmitter from pulling (1998) using digital calipers (202010, Vogel Germany out. The mean weight of the transmitter assembly totaled GmbH & Co. KG, Kevelaer, Germany). Measurements 35 g and therefore was less than 1.1% of the smallest were taken to the nearest 0.01 mm. The 12 turtles turtle's body mass (BM; Table 1) and well below the 10% exceeding 29 cm SCL were taken to the Department of recommended maximum for reptiles (Anonymous 1987).
Environment in Dezful and fitted with radio-tracking All turtles tagged were released at their capture locations transmitters (164 MHz; Al-2F, Holohil Systems Ltd., within 2 d of capture.
Caro Ontario, Canada) by professional veterinarians.
Fieldwork was carried out for 1 wk per month After testing, transmitters were mounted on aluminum between May and October 2011, 2 d in January and plates and attached with stainless steel wire (0.9-mm March 2012, and for 1 wk per month between April and
GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Figure 3. Habitat of R. euphraticus at the Karkheh Regulating Dam Lake in Khuzestan Province, Iran. Left: shallow-water shorelinescovered with Phragmites australis. Right: calm open water. Photographs by Hanyeh Ghaffari.
July 2012. During fieldwork, turtles were tracked daily Blouin-Demers 2006; Ryan et al. 2006). Furthermore, between 0800 and 1800 hrs by boat using a hand-held MCPs often include unused or unavailable habitats such receiver (TRX-1000S W, 164 MHZ, Wildlife Materials as terrestrial habitats for highly aquatic species. To International Inc., Illinois, USA) and a 3 element fold- address this issue the terrestrial portion of each MCP ing Yagi antenna (Yagi 3 Element Folding Antenna, was excluded based on satellite pictures (Indian Remote 164 MHZ, Wildlife Materials, Inc., Murphysboro, IL).
Sensing satellite map, resolution 24 m). An MCP is usually Locations were recorded using a hand-held global dependent on the number of fixes (Jenrich and Turner positioning system unit (GPS map 78s, Garmin Interna- 1969). Due to several field constraints, equal numbers tional Inc., Olathe, KS). At the end of the tracking study of fixes could not be gathered for turtles. Despite the all radio-tracking transmitters were carefully removed disadvantages of the MCP method, it is the most frequently from the turtles' shells.
used approach to analyze animal movement (Powell 2000; Habitat Selection. — Based on remote sensing data Nilson et al. 2008) and therefore can facilitate comparisons (Indian Remote Sensing satellite image, 2007), we of results with previous studies (Nilson et al. 2008). MCPs constructed a habitat map that subdivided the study area were calculated using ArcGis 9.3 and the Hawth's Analysis into 4 major habitat types to which turtle locations were Tool extension (Beyer 2004).
assigned (Fig. 2): 1) shallow-water shorelines covered by The KDE provides a probability range around each Phragmites australis (20.22 ha, 17%); 2) shallow-water location, giving areas used more frequently a higher shorelines without any vegetation (7.3 ha, 6%); 3) value; it therefore provides information on habitat floating vegetation and shallow vegetated areas inside selection patterns by quantifying the intensity of use the KRDL (2.89 ha, 2%); and 4) open, deep water within an area (Row and Blouin-Demers 2006). Estimates (85.59 ha, 74%).
of total home range (95% KDEs) and core areas (50% Data Analysis. — ArcGis 9.3 (ESRI, Redlands, CA) KDEs) were performed using ESRI ArcGis 9.3 and the was used to measure linear range (LR) size as the straight- Hawth's Analysis Tool extension. The smoothing param- line distance between the most distant locations of each eter h was determined by least-square cross validation turtle (Sexton 1959; Pluto and Bellis 1988; Lue and Chen using Animal Space Use 1.3 (Horne and Garton 2009). To 1999). Because the species is highly aquatic, LRs crossing ensure comparability of KDEs, the mean smoothing terrestrial areas were modified to represent the shortest parameter (h 5 50.22) was used as recommended by distance in water (Carrie re 2007).
Kenward (2001). Due to the turtles' highly aquatic Turtles' movements were analyzed using a river lifestyle, the terrestrial portion was excluded from the channel area (RCA) estimator, a minimum convex polygon resulting KDEs based on satellite pictures. In addition, estimator (100% MCP; Mohr 1947), and 95% and 50% interindividual overlap areas of MCPs, KDEs, and core fixed kernel density estimators (KDE). The RCA was areas were compared. One individual was excluded from determined by multiplying the aquatic LR length of each the analysis due to an insufficient number of fixes (n 5 6; turtle by average river width (Plummer et al. 1997; Doody minimum number of fixes required 5 20).
et al. 2002; Kay 2004; Souza et al. 2008).
The term ‘‘home range'' was applied as defined by The MCP connects the outermost relocation points, Kenward (2001) as ‘‘an area repeatedly traversed by which yields a convex polygon that provides a maximum the study animal.'' An incremental area analysis was home range estimate but does not provide information on performed on MCP estimates of home range to assess habitat use and selection (Kenward 2001; Row and whether home range size estimates reached asymptotes,
CHELONIAN CONSERVATION AND BIOLOGY, Volume 13, Number 2 – 2014 1998). A total of 100 RWMs were generated for eachturtle's kernel density estimate home range and core areaand compared with real observed movement. Animalsare deemed to be exhibiting site fidelity when observeddistributions of real individuals are significantly smallerthan computer-simulated RWMs (Munger 1984; Spenceret al. 1990).
Range overlap for each turtle was determined as the percentage of its total home range that overlapped rangesof other turtles (Geffen and Mendelssohn 1988). Theanalysis was performed using the ‘‘adehabitat'' packagefor Cran R (Calenge 2006).
Data were checked for normality using a Kolmogorov- Smirnov test and log10-transformed prior to statisticalanalysis with SPSS 14.0 (SPSS Inc., Chicago, IL).
Significance was determined at a 5 0.05. The relationshipof range size and body size was determined using aSpearman's rank correlation test. Potential habitat selectionwas determined using a x2 goodness-of-fit test (Neu et al.
1974; Manly et al. 2002; Ryan et al. 2006). Confidenceintervals were determined using a Bonferroni z-test (Neuet al. 1974; Ryan et al. 2006). Range estimates tend toincrease with number of fixes, which may lead to a bias ifsample sizes obtained are variable among study animals(White and Garrott 1990). As sample size in this study washighly variable, a linear regression analysis of MCP sizeson number of fixes was performed to analyze the data setfor a potential bias due to sample size (Dreslik et al. 2003).
Means are reported as ± 1 standard deviation (SD).
Turtle Trapping. — Trapping was successful in 5 of 13 trapping locations (38.5%), all along the western shore(Fig. 4). The highest numbers of R. euphraticus werecaught in locations 6 and 9 (n 5 3 each). Successfultrapping locations were less than 20 m from denselyvegetated water edges (habitat type 1). Two successfultrapping locations (4 and 6) were situated at the entrance Figure 4. Industrial drawing of turtle trap construction as wellas a map of the Karkheh Regulating Dam Lake indicating of side channels. Sixty percent of the study animals were trapping locations.
caught within their subsequently defined 95% KDErange, 20% were caught in close proximity (5–20 m) to using a randomized resampling approach with 10 their subsequently defined 95% KDE range, and only iterations in the packages ‘‘adehabitat'' (Calenge 2006), 20% were caught at greater distances. Thirty percent of ‘‘maptools'' (Bivand and Lewin-Koh 2013), and ‘‘fields'' the study animals were caught within their core areas, (Furrer et al. 2013) for Cran R (R Development Core 20% were caught in close proximity (5–20 m), and 50% Team 2012) as described by Harris et al. (1990) and were caught more than 20 m from their core areas.
Kernohan et al. (2001). In order to investigate whether Home Range Size. — Due to transmitter failure in 4 turtles performed nomadic movements or exhibited site cases, movement was analyzed for a total of 8 turtles.
fidelity, the radio-tracking data sets were compared with Except for occasional basking, movement was exclusively computer-simulated distribution models (Munger 1984; aquatic (96%; n 5 254 total number of fixes).
Spencer et al. 1990; Turchin 1998; Schwarzkopf and Incremental area analysis curves for turtles' MCPs Alford 2002). ‘‘Random walk models'' (RWMs) were revealed that 22 fixes were required to capture 90% of the performed for each turtle using ‘‘turning angles'' and study animals' home range size, suggesting the study ‘‘distances between successive fixes'' from real radio- period was sufficient to obtain home range size estimates tracking data using a bootstrapping approach with 100 (Fig. 6). Comparison of observed movements and results iterations using the above packages for Cran R (Turchin gained by the simulated RWMs revealed turtles' observed
GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Figure 5. Rafetus euphraticus with a very-high-frequency radio-tracking transmitter attached to its posterior carapace. Photograph byHanyeh Ghaffari.
movement patterns to be significantly smaller than The number of fixes was highly variable among random walk estimates, suggesting that turtles exhibited individuals (range 20–51) and a linear regression analysis site fidelity (Table 2).
between range size estimates and the number of fixes Mean LR size was 2.54 ± 0.83 km SD and ranged obtained revealed a statistically significant bias (r2 5 from 0.80 to 3.41 km with a coefficient of variation (CV) 0.564, p 5 0.032, n 5 8). The turtles' mean total KDE of 33% (Fig. 7). Mean RCA was 55.35 ± 17.98 ha SD size was 21.75 ± 11.23 ha SD while individual 95% and ranged from 17.38 to 71.24 ha (CV 5 32%). There KDEs ranged from 9.04 to 39.51 ha (Fig. 8). While there was no statistically significant relationship of LR/RCA was no relationship between SCL and 95% KDE size size with either SCL or BM (LR/RCA with SCL: 0.595, p 5 0.12, n 5 8), 95% KDE size was 0.517, p 5 0.15, n 5 9; LR/RCA with BM: significantly related to BM (rs 0.886, p 5 0.019, 0.143, p 5 0.76, n 5 7). Sizes of MCPs varied n 5 8). Mean core area was 5.74 ± 2.87 ha SD (range 2.59–9.91 ha; Fig. 8) and was significantly negatively CV 5 49%) with a mean size of 47.49 ± 23.36 ha SD related to both SCL and BM (50% KDE and SCL: (Fig. 7). There was no significant relationship of MCP 0.714, p 5 0.047, n 5 8; 50% KDE and BM: size with body size (MCP and SCL: r 5 2 0.943, p 5 0.005, n 5 6).
Home Range Overlap. — The MCP of each turtle p 5 0.33, n 5 6).
overlapped with MCPs of 6–8 other turtles (mean 5 Table 1. Summary of turtles' body size and home range by minimum convex polygon (MCP), 95% and 50% kernel density estimator (KDE) core areas, linear range (LR), and river channel area (RCA).
a SCL, straight-line carapace length.
CHELONIAN CONSERVATION AND BIOLOGY, Volume 13, Number 2 – 2014 Figure 6. The incremental area analysis plot illustrates that 22 fixes were needed to capture 90% of a study animal's minimum convex polygon (MCP) home range size (horizontal bar). Vertical bars represent ranges of mean MCP area.
7.5 ± 0.71 SD, n 5 8; Table 3). The mean area of and 4 (open, deep water) were below expected propor- tions of use (Table 4). Analysis of habitat selection of 10.99 ± 3.92 ha SD (range 2.74–13.46 ha, n 5 6) and individual turtles was not possible due to insufficient 32.47 ± 16.66 ha SD (range 5.08–61.05 ha, n 5 8).
numbers of observations (, 5 observations) in several Total KDEs overlapped with 5–7 other turtles habitat type categories.
(mean 5 6.31 ± 0.78 ha SD, n 5 8) with mean overlap Basking and Nesting Habits. — Rafetus euphraticus areas ranging from 4.75 ± 2.52 ha SD to 10.04 ± 4.25 ha was observed basking along vegetated shorelines (35%), SD among individuals (Table 3). Core areas overlapped atop halms of Phragmites australis (30%), and on with 4–7 core areas of other study animals (mean 5 floating trunks of fallen trees within dense foliage 5.50 ± 1.22 SD; n 5 8).
(20%). In addition, turtles were observed to bask Habitat Selection. — Due to low sample sizes in partially submerged on gravel along the shoreline some habitats, habitat data from individual turtles were (14%) and fully exposed on the muddy shoreline pooled for analysis. Selection of habitat types was not approximately 1 m from the water's edge (1%). During proportional to availability (x2 5 2623, p , 0.0001).
basking, an individual's head and limbs were often Bonferroni confidence intervals (95%) showed proportion extended, as described by Gramentz (1991). One female of use for habitat type 1 (vegetated shorelines) was greater was observed nesting on the east shore by a local than the expected proportion of use, whereas the fisherman in 2011 but we could not find nests despite proportions of use for habitat types 3 (floating vegetation) Table 2. Range size estimates performed using kernel density estimators (KDEs, including the terrestrial portion) in comparison withrange sizes obtained from simulated random walk models. Results indicate Rafetus euphraticus possess home ranges, rather thanexhibiting a nomadic movement pattern.
95% KDE obs. (ha) 50% KDE obs. (ha) a CI 95%595% confidence interval.
b Significant alteration of observed range size used and random walk model results. 2 5 site fidelity; 0 5 random movement; + 5 observed movementexceeds random walk predictions.
GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Figure 7. Map of the study area showing the turtles' linear range (LR) and minimum convex polygon (MCP) home range. Mapdesigned using ArcGis 9.3.
this study with those of previous studies. The MCPestimator is heavily influenced by outlying locations and LR Size. — The only previously reported LR therefore may incorporate areas that have never been used estimates for trionychid turtles include the American by the animal and as a consequence, often overestimates species Apalone mutica (0.7 km in a small river; Plummer range size (Powell 2000; Kenward 2001). According to and Shirer 1975) and Apalone spinifera (1.5 km in a small Borger et al. (2006), MCPs are subject to unpredictable stream, Plummer et al. 1997; 11.1 km in a large river, bias. Nilson et al. (2008) also questioned the ecological Galois et al. 2002). Differences in sample sizes, study value of the MCP. Nevertheless, the MCP is commonly period, species, and habitat type hamper a direct used to perform home range estimates and to facilitate comparison among studies.
inter- and intraspecific comparison of different studies.
Home Range Sizes. — The use of different analytical The KDE is currently the most widely used approach methods complicates comparison of results obtained in for home range estimates and habitat selection analysis
CHELONIAN CONSERVATION AND BIOLOGY, Volume 13, Number 2 – 2014 Figure 8. Map of the study area showing the turtles' 95% and 50% KDE home ranges. Individual no. 8 was excluded from the analysis due to an insufficient number of fixes (n 5 6; minimum number of fixes required 5 20). Map designed using ArcGis 9.3.
(Worton 1995; Seaman and Powell 1996; Seaman et al.
significant relationships of home range sizes with BM 1999). However, the kernel technique may not accu- and SCL, whereas these relationships could not be rately estimate home range sizes for reptiles as the demonstrated using the MCP method. Whereas range size frequent multiple use of locations by an ectotherm leads may depend on habitat quality and resource availability, to autocorrelation (Row and Blouin-Demers 2006).
range shape and location may reflect resource distribution Home range size is generally known to depend on the and abundance (Bury 1979; Harestad and Bunnell 1979; study animal's body size (Harestad and Bunnell 1979), Savitz et al. 1983; Ims 1987; Macartney et al. 1988; Brown which previous studies confirmed for several reptile et al. 1994; Kenward 2001; Kjellander et al. 2004).
species, including aquatic chelonians (Schubauer et al.
Compared with studies conducted in relatively undisturbed 1990; Plummer et al. 1997; Perry and Garland 2002; areas, Galois et al. (2002) suggested that range size might Carrie re 2007). Despite the low sample size for R.
increase with increasing habitat fragmentation and modi- euphraticus, the KDE method revealed statistically fication, as in this study.
GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Plummer and Shirer (1975) and Galois et al. (2002) Table 3. Overlap of movement areas of 8 Rafetus euphraticus, reported females' ranges to be significantly larger than given as percentage of the total range of the individuals listed inthe left column (see Table 1 for definition of abbreviations).
those of males or subadults in A. mutica and A. spinifera.
As we were unable to determine sex or reproductive condition of turtles, their possible effects on range size in R. euphraticus is unknown.
The data collection intervals in our study were highly 45.66 15.44 26.74 64.31 25.44 23.12 variable with several fixes obtained in a single day and gaps of several weeks between subsequent field trips.
44.88 17.66 34.76 Since we required at least 20 fixes to calculate a home range, we included all fixes in the analysis. Because this 0.00 100.00 100.00 100.00 inclusion likely resulted in an autocorrelated data set and 88.59 33.72 100.00 biased home range estimates (White and Garrott 1990), results should be treated with caution.
Home Range Overlap. — As with R. euphraticus, home ranges are known to overlap among individuals of 38.48 42.86 25.81 24.16 100.00 53.49 43.71 18.54 A. mutica and A. spinifera (Plummer and Shirer 1975; Plummer et al. 1997). As a possible indicator of 50.77 26.83 20.08 25.51 intraspecific aggression in R. euphraticus, bite marks 44.33 30.66 30.66 along the posterior carapace edges have been reported by 0.00 70.70 85.54 65.70 Gramentz (1991) and along the lateral and caudal 33.21 100.00 43.96 17.61 carapace edges by Tas¸kavak and Atatu¨r (1995). Bite marks were present in both sexes and different size andage classes (Gramentz 1991; Tas¸kavak and Atatu¨r 1995).
Bite marks commonly occur on the posterior edge of the 40.45 14.88 17.70 carapace of male A. mutica and A. spinifera and are related to courtship aggression by females (Plummer 1977b; M.V. Plummer, pers. obs.). We found few bite marks along the lateral carapace edge of adult R.
26.10 58.40 35.24 euphraticus in our study, suggesting either lower levels of aggression or lower population density. Trappingsuccess in the present study was low in comparison withstudies of R. euphraticus in Turkey (Tas¸kavak et al., inpress), also suggesting either low population density or a The only areal ranges reported for a trionychid turtle reluctance to enter traps.
are those for A. spinifera in a small stream (11.6 ha; Habitat Selection. — In Turkey and Iran, R.
Plummer et al. 1997) and a large river (2424 ha; Galois euphraticus generally inhabits calm and shallow rivers, et al. 2002). The mean river channel area (55.35 ha) as preferring tributaries and the shallow backwaters of main well as the slightly smaller mean MCP 100% home range river channels and seasonal ponds and wetlands. Habitat (47.49 ha) for R. euphraticus in a much wider lake is preferences may differ between adults and juveniles comparable to the 95% MCP reported by Galois et al.
(Gramentz 1991; Tas¸kavak and Atatu¨r 1995, 1998; (2002). Correlation of habitat size and range size in Ghaffari et al. 2008; Tas¸kavak et al., in press). Adults freshwater turtles has previously been reported (Plummer preferred tributaries with access to deeper water (up to et al. 1997).
2 m), whereas juveniles preferred puddles (10–15 cm Table 4. Habitat selection of Rafetus euphraticus.
True proportion of observations (pi) a 95% confidence interval of area under an expected selection hypothesis.
b Significant preference for habitat type: + 5 significantly higher than expected; 2 5 significantly below expected; ns 5 not significant.
CHELONIAN CONSERVATION AND BIOLOGY, Volume 13, Number 2 – 2014 deep) with higher water temperatures and abundant strongly affect freshwater turtle populations (Dodd potential prey (Gramentz 1991; Tas¸kavak and Atatu¨r 1990; Gramentz 1993; Tas¸kavak and Atatu¨r 1995, 1995). Our results show that R. euphraticus favored 1998). Severe population decline as a response to dam vegetated shorelines over open deep water in concor- constructions on the Euphrates River was reported by dance with the previous studies in Turkey. While Gramentz (1993) and Tas¸kavak and Atatu¨r (1998).
vegetated shorelines are essential for nesting (Ghaffari Channelization and dam construction were also found to et al. 2013), vegetated edges may serve as refuge in heavily fragment remnant populations of R. euphraticus disturbed habitats such as reservoir lakes. Therefore the (Ihlow et al. 2014). Currently R. euphraticus is threatened presence of such vegetated shorelines is considered by the construction of several additional dams across its an important feature, providing retreats for the endan- range, which will cause further habitat fragmentation and gered species, especially in disturbed habitats. The loss and may even increase the probability of local preference for shoreline habitat may be related to the extinction (Gramentz 1991). In addition, the species is higher water temperatures at the edges or activity levels.
affected by water pollution through pesticides, fertilizers, For example, foraging individuals might select areas of oil, garbage, and industrial chemicals (Ghaffari et al. 2008).
higher food abundance (plant material, insect larvae, Turtles are frequently caught accidentally on baited hooks crustaceans, mollusks, amphibians, and fish) within the or entangle themselves in fishing nets (Ghaffari et al.
dense Phragmites australis stands along the lakes edges 2008). Despite fishing being prohibited in April and May in compared to deep open water, whereas inactive individ- Khuzestan Province, people were observed fishing uals might select areas based on suitability of retreat sites throughout the year, sometimes even using illegal electro- (Siebenrock 1913; Tas¸kavak and Atatu¨r 1998). We had fishing (H. Ghaffari, pers. obs.). Because turtles are difficulties determining the activity level of animals in wrongly believed to be detrimental to fish populations, dense vegetation as they were easily disturbed when they are often killed by fishermen (Ghaffari et al. 2008).
approached. Additional research needs to be done to As the endangered species' survival may soon clarify this issue.
become critical, knowledge of its ecology is desperately Although the results of statistical analysis generally needed to prepare a conservation management plan for the agreed with observations of habitat selection made, species. To successfully sustain viable populations, avoidance of habitat type 3 (floating vegetation) does hunting, fishing, and pollution need to be reduced to a not. The distribution and abundance of vegetation at the minimum while patrolling needs to be initiated. Consid- KRDL is known to be highly variable among seasons and ering our results on range sizes and habitat selection, years. The satellite images used were taken in 2007 and future conservation efforts should focus on large but vegetation cover likely has changed since dam construc- shallow interconnected wetlands and rivers with side tion. In addition, habitat selection analysis procedure channels and backwaters. Regarding the increasing requires that temporal spacing between observations is modification of natural rivers, artificial habitats consid- free from autocorrelation (Byers and Steinhorst 1984), ered suitable for R. euphraticus should provide unvege- which unfortunately was not the case in this study.
tated water edges as well as retreat sites covered with Gramentz (1991) suggested habitat use and selection vegetation. To prevent further fragmentation of popula- might vary seasonally in R. euphraticus. Unfortunately, tions through dams, future dam constructions should be data spanning all seasons in this study were few, equipped with passes for turtles and other aquatic species especially for the winter. Likewise, although sexual to facilitate emigration (Ihlow et al. 2014).
differences in habitat selection in softshell turtles are To establish successful conservation management, known (Plummer 1977a), no comparable data for R.
we consider capacity-building and education of the native euphraticus were collected.
populations to be highly important. A program to protect Basking Habits. — Basking of individuals or groups the Euphrates softshell turtle populations in Khuzestan of up to 10 R. euphraticus was observed by Griehl (1981).
Province was carried out by the Pars Herpetologists In concordance with Gramentz (1991), basking was Institute from 2009 to 2012 through a partnership program frequently observed close to the water's edge, mostly on with the Global Environment Facility funded by the Small the muddy shore but also on grass or stone. Turtles in this Grants Programme of the United Nations Development study tended to bask in more hidden places such as Programme. The project focused on education and raising vegetated shorelines, floating tree trunks, and floating awareness and highlighting the necessity of conservation vegetation, which may be related to frequent disturbance measures to protect and conserve the Euphrates softshell by fishermen.
turtle. This project already has proven successful and Conservation Status. — Recent regulations of rivers induced a significant behavioral change among the local for flood control and hydroelectric power have severely population, providing confidence for future projects. The altered environmental conditions (Partow 2001). Water establishment of the introduced softshell turtle species level fluctuation and decreasing temperatures have been Pelodiscus sinensis, abandoned from the pet trade, may reported to cause the depletion of food items and become another threat for the species in the near future.
induce changes in aquatic and riverine vegetation that Although R. euphraticus is not consumed by native GHAFFARI ET AL. — Home Range of Euphrates Softshell Turtle in Iran Iranians, Chinese employees of the National Iranian Oil BORGER, L., FRANCONI, N., DE MICHELLE, G., GANTZ, A., MESCHI, Company catch the species for human consumption, F., MANICA, A., LOVARI, S., AND COULSON, T. 2006. Effects of especially in the Hawr-al-Azim wetland and along the sampling regime on the mean variance of home range sizeestimates. Journal of Animal Ecology 75:1493–1405.
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moudi-Rad (head of the Department of Environment of BYERS, C.R. AND STEINHORST, R.K. 1984. Clarification of a Khuzestan Province) for kindly issuing the relevant technique for analysis of utilization-availability data. Journal permits. We are indebted to Behrooz Nejati (former head of Wildlife Management 48:1050–1053.
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Tender systems for outpatient pharmaceuticals in the European Union: Evidence from the Netherlands and Germany Panos Kanavos with the assistance of Alessandra Ferrario Elena Nicod and Dale Sandberg LSE Health London School of Economics FOR THE EUROPEAN COMMISSION - DG ENTERPRISE
COMMISSIONED PAPER (UK) This paper was commissioned by FECAVA for the Special issue of EJCAP, Genetic/Hereditary Disease and Breeding. Must not be copied without permission © 2014 Chiari–like malformation and syringomyelia Clare Rusbridge Introduction Syringomyelia is a condition characterised by fluid filed cavities (syrinxes or syringes) within the central spinal