Avian Populations on the Niagara Escarpment and Credit Valley Watershed

Robert Milne Wilfrid Laurier UniversityKata Bavrlic Credit Valley ConservationLorne Bennett University of GuelphKamal Paudel Credit Valley Conservation

Presentation Outline•

Overview of Credit Valley Avian monitoring program

•

Spatial patterns of avian species response to stressors at various scales▫

Regional

▫

Landscape▫

Site

•

Recommendations for site and landscape management

Monitoring Program•

Credit Valley Conservation Integrated Monitoring Program

•

Integration of habitat and wildlife▫

Forest interior and avian populations

▫

Wetland and amphibian populations•

Scales▫

Region –

physiography and land use

across various landscapes▫

Landscape –

complexity of land units

▫

Site –

land unit

Regional Level•

Lower Watershed -

Peel Plain

▫

Mississauga –

Georgetown▫

urbanizing landscape –

rapid growth

•

Mid-Watershed –

Niagara Escarpment▫

Protected areas –

Niagara Escarpment Plan –

aggregate development•

Upper watershed –

Moraines

▫

combined agriculture, aggregate, rural residential

Physiographic Regions

Forest Cover

Peel Plain -

Rattray Marsh

Escarpment –

Silver Creek

Upper Watershed -

Alton

Landscape Level •

Ecological Land Classification

•

Complexity of land units

•

2 km circle –

measure percentage of natural area

AggegateAgriculureAquaticCulturalForestMarshPlantationSettlementSwamp

ELC Subwatershed 11

Site LevelBird Populations Trail Parameters

•

30+ sites representing sub-

watersheds•

80+ stations (1-5 per site)•

Partnered with forest plots –

EMAN ▫

6 one hectare▫

22 20x20 metres•

Point counts -

two visits –

breeding season –

late May to early July

•

unlimited count with focus on first 100m

•

Site hardening

•

Development of trail system

•

Evidence of level of use▫

Bike and ATV tracks

▫

Hiking

▫

Structures

•

Access

Bird Guilds•

Habitat Associations▫

Generalists

▫

Forest interior

▫

Edge / Early Successional

•

Migratory Behaviour▫

Resident

▫

Short-distance

▫

Long-distance

•

Nesting and Foraging▫

Ground nesting

▫

Shrub nesting

▫

Canopy/Sub-canopy nesting

▫

Cavity nesting

▫

Aerial foragers

Richness

•

Overall richness and abundance increasing across watershed

•

Highest on Escarpment•

Upper is similar to middle

•

Lowest in Lower watershed

Forest Specialists

•

High in Upper and Escarpment•

Characteristic species in forest interior

•

High in upper and Escarpment

•

Threatened by urban encroachment

Ground-nesting Species

Forest Species

Short-distance Migrants

•

Higher in lower watershed

•

Escarpment and upper –

relatively low

Long-distance Migrants•

Higher in upper and Escarpment

•

Lowest in lower watershed

•

Importance of forest interior

Migrants

Edge / Early Successional

Edge –

Early Successional

•

Highest in lower watershed

•

Characteristic species in upper watershed

•

Area of change, fragmentation

Escarpment –

Forest

Lower -

Urban

Upper –

Successional

Landscape Level –

Core Buffer•

Least buffered sites in lower watershed –

increasing

urbanization•

Greatest buffer on Escarpment

Upper watershed•

Fragmentation –

increasing demand for aggregate and rural growth

Site Level -

Trail Stressors•

Greatest impact in lower watershed

•

Least impact in upper watershed

Escarpment•

Passive recreation

•

Some heavy use•

Introduction of exotics

ManagementLower Watershed•

Lowest level of forest interior

•

Greatest impact from landscape and site level stress•

Manage/educate users in remaining natural sites

Upper Watershed•

Similar values for forest interior and related guilds

•

Moderate levels of landscape and land use stressor•

Manage for increase in rural development –

increase in

both landscape and site level stressors

ManagementEscarpment Forests •

Largest forests and low landscape stress

•

Moderate level of recreation stress•

Future monitoring of passive recreation use in protected areas (with an eye to trends and associated impacts)

Watershed •

Better understanding of role of Escarpment forests in greater watershed

•

Continued monitoring –

track urban encroachment and human activity