Mammals along the Egnatia Highway in Northern Greece. Internship - - PowerPoint PPT Presentation

“Assessment of the use of crossing structures by bears and other Mammals along the Egnatia Highway in Northern Greece.”

Author: Dimitras Elisabeth Master 2 “Ecologie & Biodiversité” research project Speciality: BIODIV “Biodiversity conservation” Internship supervisors: Theodorou Kostas Legakis Anastasios 2011-2012

• 1. Introduction

One cause of habitat fragmentation: Transport infrastructure (Forman, 2000)  Variable ecological risks :

• Fragmentation & Isolation of populations

 Loss of genetic diversity

• Wildlife-Vehicle collisions

New field of study: Road ecology Achieving the maintenance of opportunities for animals to move across broad landscapes. Design and incorporation of wildlife mitigation crossing structures into road construction and improvement projects.

(Clevenger & Waltho, 2005).

For most species, limited knowledge regarding :

• Effective & affordable crossing structure

design (Spellerberg, 1998).

• The characteristics that promote or

discourage their use (Clevenger & Waltho, 2000). “Location of a crossing structure in relation to habitat quality” or “structure design” ?

(Cain et al., 2003, Clevenger & Waltho, 2000, 2005; Ng et al., 2004).

Evaluation of the effectiveness of crossing structures  monitoring their use from wildlife species :

• Camera surveillance
• Sand or marble dust track-pads.

In Northern Greece :

Egnatia Highway, 2009 – present : 16 bear- vehicle collisions, 13 of which were fatal. Reasons:

• Highway situated in heart of bear’s habitat

(estimated population size 33-51 individuals) (Scouras & Drosopoulou, 2005, Karamanlidis et al., 2011)

• Inadequate means of protection (regarding

fences)

5 Different types of mitigation crossing structures on the Egnatia Highway:

Box Culvert Local Road Viaduct Wildlife Underpass Oversized Streamed Culvert

Aim of this study:

Whether and how much the mitigation crossing structures are used by the surrounding wildlife.

Particular focus on the Brown Bear (Ursus Arctos):

• Study area: part of the distributional range of

the larger of 2 independent populations (150

individuals out of a national population of 190-260 individuals).

• Species considered Endangered in Greece.

(Greek Red Data Book)

• “Priority Species” according to the European

Legislation (EU Directive 92/43, Annex II).

• 2. Materials & Methods

Study area: NW Greece, Grevena, Pindos mountain range

• 9,14 km highway

section: 10 mitigation crossing structures of 5 ≠ types.

• Monitoring period:
• Sept. – Dec. 2011

• 4 photographic cameras
• 6 video cameras

Checked every 12-15 days

Data analysis

• Analysis carried out on Data from 8 out of 10 sample locations
• Focused on: 6 key crossing characteristics

Analysis of key crossing characteristics

1.

the dimensions of the structures (height, length, width),

2.

the Openness Index [(width*height)/ (length)],

3.

the mean slope of their entrances/exits,

4.

the surrounding vegetation and the % of forest cover at 100m. & 500m. as well as the distances from water sources (streams and rivers),

5.

the distances from villages, livestock pens, forests, paved and unpaved roads,

6.

the amount of human activity in the area.

 Pearson’s rank correlations coefficients  Stepwise multinomial logistic regression

Structu re’s charac teristic s Landsc ape’s charact eristics

• 3. Results

i) Use by animal species

Crossings Total records Verified and probable crossings (as % of total records) Species Verified Probable Total No use Bear 14 14 14 100 Wolf 18 7 25 3 28 89,2 Total large mammals 32 7 39 3 42 92,8 Wildcat 3 1 4 4 8 50 Fox 8 13 21 11 32 65,6 Mustelid 4 4 1 5 80 Badger 1 1 2 2 100 Hare 2 2 Total small mammals 16 15 31 18 49 63,2 Cat 5 2 7 3 10 70 Dog 56 20 76 8 84 90,4 Total domestic animals 61 22 83 11 94 88,2

Table 1: Nature and frequency of use of all types of mitigation structures.

Species Frequency Percent Bear 14 7,6 Wolf 28 15,1 Native large mammals 42 22,7 Cat 10 5,4 Dog 84 45,4 Domestic animals 94 50,8 Budger 2 1,1 Fox 32 17,3 Hare 2 1,1 Mustelid 5 2,7 Wildcat 8 4,3 Small mammals 49 26,5

Table 2: Detections and frequencies (by total number and %) of each species. .

• 185 Detections of 255

Individuals (some of the records captured grouped individuals).

Table 3: Human presence in all mitigation structures

Type of human presence Frequency Pedestrians 46 Bicycles 5 Shepherds with Livestock 100 Motocross 71 Vehicles 247 Total 469

Figure 1: Histogram showing the number of detections by mitigation structure, clustered by Pass Through.

Figure 2: Line chart showing the use of mitigation structures by each species clustered by day and night. “At night many large predators species move along roads that have little vehicular or people traffic” Forman & Alexander, 1998

ii) Correlation with mitigation structures attributes and the surrounding landscape

Species Height Openness Index Length Width Distance from villages Distance from Livestock's pens Distance from water resource Vehicles passed through the mitigation structures Bears 0,794* 0,824* NS NS 0,737* NS

• 0,843**

0,741*

Table 4 : Pearson’s rank correlation coefficients for bear crossings (verified and probable crossings combined)

Statistically significant relationships are indicated with asterisks (*P.value<0.05, **P.value<0.01) NS=Non Statistical Significance

Species Distance from forests from the right entrances Mean slope at 500m. Wolf 0,882**

• 0,709*

Fox 0,901** NS Wildcat 0,834** NS Dog 0,847**

• 0,735*

Table 5: Pearson’s rank correlation coefficients for other species crossings (probable and verified crossings combined).

p < 0. 01 p < 0.05 NS = Non Statistical Significance

Predictor variables influencing the model Model fitting information Goodness Of Fit (GOF) Pseudo R-square Parameter Estimates Openness Index Sig.=0,001<0,05 Pearson 41,362 Deviance 39,766 Cox and Snell 0,152 Nagelkerke 0,160 McFadden 0,054 Sig.=0,003<0,05 (Bears) Distance from water sources Sig.=0,000<0,05 Pearson 44,438 Deviance 46,582 Cox and Snell 0,157 Nagelkerke 0,165 McFadden 0,056 Sig.=0,001<0,05 (Bears)

iii) Multinomial Logistic Regression Table 6: Information regarding the Multinomial Logistic Regression.

df = 35 df = 42

Concerning the structure’s characterist ics Concerning the landscape’s characterist ics

• 4. Discussion

Concerning the Brown Bear:

• The brown bear prefers large and open

structures (O.I = 1.68).

• In accordance with other studies : Cavallaro et al., 2005, Putnam, 1997,

Kusak et al., 2009, Clevenger & Waltho, 2000. ! In contrast with previous study : Tritsis, 2010: Bears also used structures

• f low openness (0.075 ≤ O.I ≤ 0.5).

Reasons which can explain this discrepancy

• Studies conducted in

different seasons (Summer vs. Autumn).

• Small sample size of bear

detections in both studies.

• Bears avoid mitigation crossing structures

near rivers and streams !!!

Result of human activity (Smith, T.S., 2001) / Turney & Roberts, 2004 : Opposite conclusion on Grizzly Bears

• Significant positive correlation:

Distance from villages ~ use of the crossings by Bears.

(ease of finding food within agricultural areas nearby?)

• Positive correlation:

Use of the crossings by Bears ~ presence of vehicles  Bears not disturbed by daily high use of crossings by vehicles  Local Roads efficient corridor for Bear movements  Mitigation crossing structures constructed near local roads maybe an overage…

Concerning species other than Bears:

• Negative correlation: Wolves’ & Dogs’ movements

~ mean slope at 500m from mitigation crossing structure’s entrance <=> Wolves are using for their movements areas with smoother terrain (Iliopoulos,

2010).

• Foxes, wolves, dogs and wildcats prefer to use

structures with cover nearby.

• Similar results for wildcats & foxes by Rodriguez et al. on 1997.
• For medium mammals, generally, in accordance with many previous studies : Ng

et al., 2004, Clevenger et al., 2001, Clevenger et al., 2003.

• In contrast (foxes) with Mata et al., 2005

• 5. Conclusion

In NW Greece :  Openness Index most important for Bears.  Structure’s location & Vegetation Cover more important for wolves, foxes & wildcats. Further work needed in order to reveal the influence of seasonality in Bear movements!

• 6. Overview

Field work : Elisabeth Dimitras &

• Y. Lazarou &

Y. Mertzanis (from Callisto team) GIS Database : Distances from villages, water sources, mean slopes etc. Alexios Giannakopoulos (from Callisto team) Statistical analysis : Elisabeth Dimitras with the guidance from an expert on SPSS

Thank you for your attention !!!!