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Managing habitat for the Oregon Forestsnail Allogona townsendiana

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<strong>Managing</strong> <strong>habitat</strong> <strong>for</strong> <strong>the</strong> <strong>Oregon</strong> <strong>for</strong>est snail<br />

<strong>Allogona</strong> <strong>townsendiana</strong><br />

Species at Risk Stewardship Practices on <strong>the</strong> South Coast<br />

Karen Steensma, Trinity Western University<br />

November 2, 2011, Seabird Island First Nation, Agassiz, British Columbia


Presentation overview<br />

• Background on <strong>the</strong><br />

species<br />

• Research program<br />

• Life history/<strong>habitat</strong><br />

• Management<br />

implications<br />

© P. Lilley


<strong>Allogona</strong> <strong>townsendiana</strong><br />

• Large terrestrial gastropod<br />

• Range: BC to central <strong>Oregon</strong><br />

• Forest decomposition role<br />

• COSEWIC listing in 2002<br />

TWU<br />

site<br />

CWS,2004


TWU research program began in 2000


• 1990’s bioinventory work initially revealed<br />

snails<br />

• Harmonic radar used <strong>for</strong> tracking 18 individual<br />

adults <strong>for</strong> up to 5 years<br />

• Home range up to 300 m 2<br />

• Insights on seasonal <strong>habitat</strong> use


3.5<br />

Number of snails per sq. m<br />

3<br />

2.5<br />

2<br />

1.5<br />

1<br />

0.5<br />

0<br />

Site 1 Site 2 Site 3 Site 4<br />

Densities <strong>for</strong> 4 subpopulations of A. <strong>townsendiana</strong>


• Mating occurred in proximity to woody debris<br />

and stinging nettle, peaking March-April


16<br />

14<br />

12<br />

10<br />

8<br />

6<br />

4<br />

2<br />

0<br />

Forest Edge Field/meadow<br />

Habitat type<br />

• Nesting peaked in April-May<br />

• Primarily <strong>for</strong>est and edge <strong>habitat</strong>s


• Clutch size averaged 34 eggs<br />

• Micro<strong>habitat</strong>: leaf litter/soil<br />

14<br />

12<br />

10<br />

8<br />

6<br />

4<br />

2<br />

0<br />

Leaf litter/soil<br />

Soil<br />

Leaf litter<br />

Gravel<br />

Vegetation<br />

Soil/gravel<br />

Moss<br />

Substrate


• Hatching: 63 days after oviposition<br />

• Dispersal: ~1 month<br />

300<br />

Total number of juveniles<br />

250<br />

200<br />

150<br />

100<br />

50<br />

0<br />

2008-07-11<br />

2008-07-13<br />

2008-07-15<br />

2008-07-17<br />

2008-07-19<br />

2008-07-21<br />

2008-07-23<br />

2008-07-25<br />

2008-07-27<br />

Sampling date<br />

2008-07-29<br />

2008-07-31<br />

2008-08-02<br />

2008-08-04<br />

2008-08-06<br />

2008-08-08<br />

2008-08-10


Tracking, size data suggested lifespan > 5 years


Management actions<br />

• Bioinventory mixed<br />

deciduous <strong>for</strong>est<br />

patches<br />

• Educate landowners,<br />

residents, users<br />

• Convince decisionmakers


Management actions (continued)<br />

• Minimize trails and roads to avoid fur<strong>the</strong>r<br />

<strong>habitat</strong> fragmentation<br />

• Retain stinging nettle, bigleaf maple<br />

• Allow fallen trees/limbs to decompose<br />

• Remediate with above elements if necessary


Recommended plant<br />

species <strong>for</strong> <strong>Allogona</strong><br />

restoration<br />

• Bigleaf maple<br />

• Black cottonwood<br />

• Western red cedar<br />

• Red elderberry<br />

• Indian plum<br />

• Salmonberry<br />

• Stinging nettle<br />

• Sword fern


Acknowledgments<br />

• Students: Sooze Waldock, Hea<strong>the</strong>r Zandberg,<br />

Martyna Kus, Martin Rekers, Deanna Leigh,<br />

Amanda Edworthy, Marie Den Haan, Jordan<br />

Thiessen<br />

• Faculty & staff: David Clements, Dennis Venema,<br />

Christopher Hall, Stephanie Leusink, Melissa<br />

Oakes, Cathy White, Liz Robertson<br />

• Funding: TWU Biology and Environmental Studies<br />

Programs, Endangered Species Recovery Fund<br />

(Environment Canada/WWF)<br />

• A Rocha Canada: Patrick Lilley, Glen Carlson,<br />

Markku Kostamo<br />

• Kristiina Ovaska<br />

• Christian Englestoft<br />

• Jennifer Heron<br />

• BC Ministry of Environment

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