Headwater riparian habitat prime real estate for birds
Download
1 / 23

Headwater Riparian Habitat: Prime Real Estate For Birds - PowerPoint PPT Presentation


  • 115 Views
  • Uploaded on
  • Presentation posted in: General

Headwater Riparian Habitat: Prime Real Estate For Birds. Joan Hagar, USGS-FRESC Judy Li and Janel Sobota , OSU Department of Fish & Wildlife. Riparian Reserves. Designed to protect AQUATIC resources Riparian habitat is also important for some TERRESTRIAL wildlife species

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Headwater Riparian Habitat: Prime Real Estate For Birds

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Headwater Riparian Habitat: Prime Real Estate For Birds

Joan Hagar, USGS-FRESC

Judy Li and JanelSobota, OSU Department of Fish & Wildlife


Riparian Reserves

Designed to protect AQUATIC resources

Riparian habitat is also important for some TERRESTRIAL wildlife species

Function of headwater riparian areas as habitat for terrestrial species?


Riparian-Upland Gradients: Birds and Insects

Higher abundance and diversity of birds reputed for riparian habitat

Emergent aquatic insects may provide a “subsidy” to terrestrial consumers

Higher capture rates of some bird species in Trask headwater riparian areas compared to uplands

Do aquatic subsidies explain riparian association?


Riparian-Upland Gradients: Vegetation

Deciduous vegetation supports more arthropod prey than conifers

Deciduous tends to flourish streamside, Conifers upslope

Pattern less pronounced on high-gradient headwater streams

Changes in distribution of arthropod prey in relation to stream size?


Research Goal

Relate the distribution of birds along inter-riparian gradients in headwater forests to availability of insect prey


Research Questions

  • What are riparian-associated birds eating?

    • Aquatic vs terrestrial arthropods

  • Does prey availability (Terrestrial and Aquatic) differ between Riparian and Upland habitats?


Trask River Study Sites

6 Sites:


Methods: What are riparian-associated birds eating?

Swainson’s Thrush, Pacific-slope Flycatcher, Wilson’s Warbler, and Pacific Wren

Diet samples collected from birds captured in nets

ID fragments in fecal samples to Order; Aquatic vs Terrestrial


Methods: Assessing Prey Availability for Birds

Streamside and Upland

Malaise: Adult Aquatic and Terrestrial Insects

(once per week)

Stream

Emergence: Adult Aquatic Insects

(2x per week)


RESULTS:

What are the birds eating?


Diets of Pacific Slope Flycatcher (n=18) and Wilson’s Warbler (n=15)


Diets of Swainson’s Thrush (n=73) and Pacific Wren (n=23)


Bird Diet Highlights

Beetles and Flies were popular fare

Aquatic emergents (EPT) rare

Fruit was important in Swainson’s thrush diet


RESULTS:

Gradients in arthropod prey availability


Malaise trap Results:Flying Insects >2 mm <25 mm

*Others:Neuroptera, Psocoptera


Biomass of Flying Insects (>2 mm)


  • Flying Insects (>2 mm <25 mm) in Summer

2008


  • Flying Insects (>2 mm <25 mm) in Summer

2008

Individuals/day

(Mean + S.E.)


Conclusions


No Evidence of Aquatic Subsidy

  • Little evidence of aquatic emergent insects in bird diets

  • Aquatic insects represented small proportion of available prey biomass

  • Terrestrial food resources most important to birds


Prey abundance varied from streamside to upland

More prey in riparian than upslope samples

Distinct riparian vegetation may influence prey abundance


Conclusions

Riparian vegetation contributes to aquatic and terrestrial food webs

Understory may be helpful in defining management zones


ad
  • Login