The influence of forestry and

disturbance on White-tailed

eagle breeding success

Tibor Mikuska Croatian Society of Bird and Nature

Protection Szekszard, 17-18 Oct 2011

Acknowledgment

Data also supplied by: Andreja Radović, Valerija Hima (Lonjsko polje) Vlatko Rožac, Boris Bolšec, Sandor Horvat, Hrvoje Domazetović, Stjepan Tkalčec (Kopački rit) Predrag Livak, Tomislav Crnjac, Virna Krpan (Pozesko-slavonska county) Nenad i Mirko Šetina, Vesna Antić, Mario Pavičić (Slavonsko-brodska county) Pavle Dragičević, Stipa Matijašević (Vukovarsko-srijemska county)

Joint HU-HR group (Attila Morocz, Tamas Deme, Lorand Lukacsi et al.)

Threats by country

threats

DE AT SK HU HR RS BG RO

Forestry L ** C M H M H C

Land exploitation L M H L L L H L

River regulation / drainage N L M L H L M H

Disturbance L ** H M M M H C

Reduction of prey base N N U L L C L M

Shooting and trapping N U C L L L M H

Nest robbing N N L L L U L L

Poisoning L H C H U L U H

Lead poisoning * * U M H U U M

Pesticides and pollutants N U U M U M U L

Collision and electrocution L M H M L L U U

Data set & results

Year

Success

Failure

Total

% sucess

% failure

2006 18 7 25 72 28

2007 18 8 26 69 31

2008 12 11 23 52 48

2009 16 10 26 62 38

2010 34 35 69 49 51

2011 36 26 62 58 42

Total 134 97 231 58 42

successful58%

notsuccessful

42%

n = 231

Nesting failures

natural9%

human induced46%

unknown45%

N = 97

Human induced nesting failures

clear cut20%

forestry works62%

hunting9%

disturbance9%

n = 44

Position of the nest

Seven classess In the forest Edge of the

marsh River island Forest w/ road Marsh w/ road Edge of the

clear cut In the clear cut

Probability of nesting failure

Successful Not successful Significance

In the forest (n=53)

29 (55%) 24 (45%) X2 = 21,175 P = 0,0001**

Edge of the marsh (n=69)

48 (70%) 21 (30%) X2 = 4,696 P = 0,0302*

River island (n=7)

5 (71%) 2 (29%) X2 = 0,321 P = 0,5708 NS

Marsh w/ road (n=27)

15 (56%) 12 (44%) X2 = 10,083 P = 0,0015**

Forest w/ road (n=23)

11 (48%)

12 (52%)

X2 = 14,880 P = 0,0001**

Edge of the clear cut (n=20)

10 (50%) 10 (50%) X2 = 11,250 P = 0,0008**

In the clear cut (n=19)

8 (42%) 11 (58%) X2 = 17,053 P = 0,0001**

Protection status

Not protected (n = 68)

successful44%

not successful56%

Nature park (n = 112)

successful58%

not successful42%

Special reserve (n = 51)

successful76%

not successful24%

Definition of intensive forestry

Single species stands

Unified age of the stand

Management recommendations

How many trees / radius should be left?

X

Management recommendations

15-20 trees

X

Management recommendations

100 x 100 m

How many trees / radius should be left? – least number approach – wrong approach

Change from intensive to extensive forestry (PROSILVA forest management)

Strict obedience of nest protection zone during breeding season (300-500 m)

Creation of special reserves – appropriate for eastern European countries

Management recommendations