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Foundation for nature project development

dr. Rimgaudas Treinys

Lesser Spotted Eagle in Lithuania: ecology, threats and conservation insights 2013-10-31

ProjektÄ… finansuoja


Presentation content

I part –Lesser Spotted Eagle in Lithuania II part – theoretical ground for conservations III part – limitations and threats IV part – insights in conservation


LSE in Lithuania – numbers 1 - No syste ati resear hes efore

’s

- Local researches based on nest search since 1990

- Since 1994 progressively increase in population estimation/ guesstimation 1500

900 - 1200 1000

700 - 1000 500 - 750 500

300 - 500

Solitary pairs 0 1980

1994

1996

1998

2001


LSE in Lithuania – numbers 2 Period: 2000- 2008 Methods: counting / nest search

10 km

“tudy plot i

’s Area: 13 study plots Random borders (1,300 sq.km)

Results: Mean 4 pairs / 100 sq. km range 1 – 9 pairs

Estimated population size 2,400 pairs (range 1,900 – 2,900)


LSE in Lithuania – numbers 3 LIFE+ project: 2011-2013 Methods: counting / nest search

Within project area: another set of 13 study plots Density: range 3 – 16 pairs, mean 8.8 / 100 sq.km Population could be near / over 3,000 pairs


LSE in Lithuania – productivity - Mean productivity 0,58 juv / pair present (2001 – 2008) - Between years fluctuate; range 0.29 – 0.81 juv / pair present

- 2011 – 2012 – productivity higher than average

0.81 0.77

0.71

0.7 0.59

0.43 0.36 0.29

2001

2002

2003

2004

2005

2006

2007

2008


LSE in Lithuania – diet -Rodents, amphibians, other small mammals and birds

- Switch on alternative prey when rodents decrease

(if territory support different habitats providing alternative prey)


LSE in Lithuania – diet & productivity

Productivity positively correlate with share of rodents in diet

Share of rodents

Produktivity of LSE

1 0,8 0,6 0,4 0,2 0

2001

2002

2003

2004 Year

2005

2006


LSE in Lithuania – main feeding habitats

Crop fields, forest edges etc

Meadows, grasslands


LSE in Lithuania – breeding habitats

Forests: gradient from isolated patches to edges of continuous forests tracks

 Medynai su lizdais:  amžius 30 – 180 (vid. 85)  eglė (28%), beržas (20%), plačialapiai (17%), pušis (11%), juodalksnis (10%), drebulė (8%)  laikinai užmirkę, užmirkę, pelkiniai – 75%  81% našūs (1a – 2 boniteto)


LSE in Lithuania – nest-site -Avoid pine forests at landscape, nest-stand and nest-tree level - Decidouos, mixed with spruce forest stands, mean age 85 years

 Medynai su lizdais:  amžius 30 – 180 (vid. 85)  eglė (28%), beržas (20%), plačialapiai (17%), pušis (11%), juodalksnis (10%), drebulė (8%)  laikinai užmirkę, užmirkę, pelkiniai – 75%  81% našūs (1a – 2 boniteto)


LSE in Lithuania – nest-tree

Spruce 51%

Oak 16%

Birch 16%


Theoretical ground for conservations - Populations are simultaneously regulated by multiple mechanisms through birth and mortality rates

- Intercontinental factor -Key demopgraphic rates for LSE: reproduction (breeding ground)

mortality (ad) (breeding, migr., winter gr.) mortality (first year) (migr.,winter ground)


Limitations / threats for reproduction

- Low reproduction – biological trait

- Reproduction regulated by prey abundace mediated by climate

conditions (Väli 2012)

-Reproduction is spatialy synchronic

over large areas (e.g., Baltic countries; Ü. Väli, U. Bergmanis, R.Treinys, unpubl. results)


Limitation / threats for reproduction – agriculture 1 Large scale socio – economic changes in agriculture practice with opposite directions

Intensification of agriculture in fertile regions Consequences - land use change, decrease in quality, unsuitable crops


Limitation / threats for reproduction – agriculture 2 Abandonment of agriculture in unfertile regions Consequences - overgrowth, loss of open habitats, decrease quality


Limitation / threats for reproduction – forestry 1 Forestry act at different nesting habitat scales I level - forest landscape scale and suitable for nesting patches 10 km

Suitable for nesting patches

230 210

190 170

4 pairs150/ 100 sq.km 130 110 90 70 50 1

6

11

11 pairs / 100 sq.km Pairs / 100 sq.km

G.Mozgeris, R. Treinys, unpubl.results

16


Limitation / threats for reproduction – forestry 2 At forest landscape scale – dynamic of suitable for nesting patches Trend of turnover - decrease by 12% during 2013 – 2023

50 km G.Mozgeris, R. Treinys, unpubl.results


Limitation / threats for reproduction – forestry 3

Next 50 years - decrease of mature forests

Dynamic of mature forest

2013

2018

2023

2028

2033

G.Mozgeris, R. Treinys, unpubl.results

2038

2043

2048

2053

2058

2063


Limitation / threats for reproduction – forestry 4 II level - nest site scale Felling during breeding season in vicinity of nest sites Direct destruction during clear felling


Limitation / threats for reproduction – forestry 5 III level - nest-tree scale Dried, damaged or felt down nest-trees


Limitation / threats for reproduction – forestry 6 IV level - nest support scale Weak branches, lack of horizontality etc.


Limitation / threats for adult mortality 1 -Development of wind energy since 2004 - In 2012 wind energy covered 12% of produced in LT

- Wind energy production concentrated in W Lithuania - Potential for future development in W LT almost depleted


Limitation / threats for adult mortality 2

- Wind energy development started in N LT - Greatest density of LSE in LT: mean 10.9 pairs / 100 sq.km --Suitable patches for nesting distributed over target area


Limitation / threats for adult mortality 3

- Target area support three “PA’s for L“E

- De elop e t of i d far s e e i

i i ity of “PA’s


Insights in conservation

Increase reproduction Conservation strategy Minimize mortality

Conservation assumptions

Lobby at EU and national levels Large population coverage


Insights in conservation : agriculture sector - Not waist funds for reconstructing feeding habitats for several eagle pairs – this not increase reproduction at population level

- Work on socio-economic issues in agriculture sector to look on possibilities how to shape agro-environmental policy at EU and national level


Insights in conservation : forestry sector 1 Wise inventory: - large scale inventory instead fine scale scientific / research based

inventory - state ownership orientated inventory - privet ownership orientated inventory only in areas covered by

compensations for felling restrictions


Insights in conservation : forestry sector 2 Artificial nests

-Recommended as short term measure for improving nest site quality

- Occupation rate ~ 50%


Insights in conservation : forestry sector 3 Need to discuss - how to increase availability of potential nest-trees in younger stands

-LSE built nests in young trees with previously damaged crowns

-Damaging tree crowns in young stands in vicinity of nest sites could be the measure encouraging future nest sites


Insights in conservation : wind energy sector

- Recent threat, need to known sector development extent

- Environmental policy at EU and national level - Close expert level communication to share on knowledge on impact for mortality and solutions - Research and development on mitigation measures


Thanks for attention


Lesser Spotted Eagle in Lithuania: ecology, threats and conservation insights