Effects of Forest Management on Songbirds in the Missouri Ozarks

Andrew Forbes, Resource Scientist Missouri Dept. of Conservation

Objective: MOFEP Songbird Project

To determine the effects of evenage, unevenage, and no harvest management on forest songbirds by comparing abundance and reproductive success of birds on sites

managed using these practices

Focal Species- Forest• Ovenbird • Wood Thrush• Acadian Flycatcher• Worm-eating Warbler• Kentucky Warbler

Focal Species- Early Successional• Indigo Bunting• Prairie Warbler• Yellow-breasted Chat• White-eyed Vireo• Hooded Warbler

Key questions

• How do different bird species respond to habitat treatments?– Forest species leave?– Early successional species arrive?– How do predation/parasitism rates differ?

Data collection

• Bird densities measured using spot-mapping and point counts– Each site divided into 7 subplots

Data collection, cont’d.

• Bird densities measured using spot-mapping and point counts– Each site divided into 7 subplots

• Nest searching/monitoring– Nests checked every 3-5 days

• Birds were also monitored using mist-netting/banding

Bird Response to 1st round of treatments- Forest Bird Densities

• Following treatments, all five focal forest species declined on all study sites, including NH– Ovenbirds declined more on treatment sites,

especially EAM sites– Clearcuts had significant negative effect on ACFL,

OVEN, and WEWA densities

Forest Bird response, cont’d.• Following treatments, all five focal forest species

declined on all study sites, including NH– Ovenbirds declined more on treatment sites,

especially EAM sites– Clearcuts had significant negative effect on ACFL,

OVEN, and WEWA densities– However, densities of WOTH and KEWA

increased within 100m of clearcuts– Interior regions >100m from clearcuts showed no

change in bird densities (except a slight increase in WOTH)

Bird response to 1st round of treatments- ES Bird Densities

• INBU and YBCH densities were significantly higher in both EAM and UAM sites

• HOWA, which were largely absent prior to treatment, have moved into cuts produced by both EAM and UAM

• PRAW densities were significantly higher in EAM sites

• From 2001-2003, most ES densities peaked, and have been declining since then

Nest Success

• Daily survival rates were high overall across sites, and BHCO parasitism rates were low.

• No changes were evident pre- and post- treatment

Banding data

• Capture rates low overall, and remained low post – treatment

• Numbers of forest birds captured around perimeter of clearcuts equaled or even exceeded the number of early successional species

Moving forward

• As trees regrow within clearcuts, forest species will return and ES species will drop out- but when?

• How will birds respond to second round of treatments?

• What will cumulative effects look like across sites?

• How long do forest birds really use clearcuts?

Questions?