Presentation on theme: "Watershrew’s and wetland habitat quality Dawn Scott & Fran Southgate."— Presentation transcript:
Watershrew’s and wetland habitat quality Dawn Scott & Fran Southgate
Project background Partnership – SROP & UOB MPhil – Fran Southgate 27 study sites over 3 catchments Cuckmere, Ouse and Pevensey Levels Monitoring: Summer and Winter for 3 years
Map Data Copyright Collins Bartholomew 2003Collins Bartholomew
What is a water shrew? Noemys fodiens Largest UK shrew: 13g Dark, usually silver pale underside Fringed tail and feet Ecology: Breeding peak May & June (2 or < litters/season) Life span months Aquatic/Riparian (but can be found away from water) Insectivore: Diet 50: 50 terrestrial/aquatic invertebrates
Why focus on this species? Limited data on habitat requirements and distribution Conservation status? W&C act 1987 Predominantly feeds on aquatic prey Intolerant to poor water quality ??? Potential bio-indicator of water quality ??
Project aims Assess presence & abundance of water shrews across the 3 catchments and monitor these seasonally Assess habitat characteristics and habitat quality Assess presence and abundance of invertebrate prey base Record indicators of water quality
Methods Shrew scat tubes: P/A and relative abundance Wetland features: Bank slope, water body Plant diversity: Bank and in-stream Water quality: Temp,DO, pH, NH 4, P, N Habitat assessment: Composition and structure Invertebrates: Diversity, BMWP, ASPT
Habitat VariableWs relative abundance rsP Herb forb % cover Grass % cover Sedge % cover Reed % cover Litter % cover Bare ground % cover Shrub % cover Rush % cover Grass height (m) Litter height (m) Us/ds % tree cover Us/ds % shrub cover Us/ds tree density Us/ds shrub density
Water parameters PH, temp. & DO showed no significant effect on water shrew presence over all sample seasons Only DO in summer ’03 showed a significant effect on water shrew presence where higher DO = higher abundance Higher water temperature was associated with lower water shrew presence in Summer 03 and Winter 04 Data for phosphate, nitrates and ammonia showed no statistically significant relationships with water shrew abundance
Invertebrates Positive correlations between invertebrate diversity and richness scores and seasonal water shrew relative abundance in Summer 03, Winter 03 and Summer 04 However, statistical analysis confirmed that neither water shrew presence nor relative abundance were associated with any of the derived BMWP and ASPT scores.