Bird populations in Montana linear riparian habitats over 40 years.

Graduate Student Research: unintended consequences & opportunities

Original study in 1967 and 1968 on the North Fork of Elk Creek A second study in 1980 added Elk Creek for comparison In 2008, Stinkwater Creek added

Habitat Selection & Territory Establishment Habitat selection: follows a hierarchical decision-making process (Hutto 1985) involving innate and learned behaviorial decisions made by an animal about where it should be at different scales of the environment. Habitat preference: is restricted to the consequence of the habitat selection process, resulting in the disproportionate use of some resources over others. Territory: a defended area

Habitat Selection & Territory Establishment This study involved: 1. determining the chronological pattern of territory establishment of 5 species of Neotropical migrants along 3 riparian areas 2. Delineating territory boundaries 3. Testing whether the earliest arrivals selected different habitat than later arrivals

Hammond’s Flycatcher (Fig 1) MacGillivray’s Warbler Swainson’s Thrush American Redstart Warbling Vireo 5 species of Neotropical migrants

Elk Creek: typical of lower third of study area

Elk Creek: typical structure of upper portion

Stinkwater Creek, 2008; enters lower Elk Creek near Beginning of survey route.

North Fork: lower portion near confluence with Elk Creek

North Fork: upper portion of study area

:North Fork :wolf scat

“Chunka” 1967, 1968 “Raven” 2008 “Bearpaw” 1980

Oh to be 25 again!

In the beginning…, there was snow

Important Historical Information North Fork harvested in Major stand replacement fire in 1930 Removal of cattle grazing in 1982.

What has changed in 40 years? Decline and re-birth of mountain alder - Mortality in Feb., 1989 –Loss of canopy height and density –Increase in small diameter saplings Encroachment of conifers Cattle grazing pressure partly replaced by elk and deer browzing

JanuaryFebruary 1989 Leaf bud emergence Leaf buds killed

North Fork study area

Table. Characteristics of the live and dead mountain alder component of three riparian habitats in western Montana. North ForkElk CreekStinkwater Cr. MeanSEMeanSEMeanSE Live 1-5 cm cm cm cm Dead 1-5 cm cm cm cm

The cattle are gone, but….

Table. Frequency of occurrence of characteristic plants of three riparian areas. Species North Fork Elk Creek Stinkwater Cr.Overall mean Mountain alder, Alnus tenuifolia Red-osier dogwood, Cornus stolonifera Common Snowberry, Symphoricarpus albus Douglas maple, Acer glabrum Prickly rose, Rosa aciculars Northern black currant, Ribes hudsonianum Douglas-fir, Pseudotsuga menziesii Engelmann spruce, Picea engelmannii Highbush cranberry, Viburnum,edule

Field Methods for Birds Surveyed birds by mapping territories of singing males Number of surveys: Elk Creek- 1980: 14; 2008:31 North Fork: 1968:17; 1980:14; 2008:33 Stinkwater Creek: 2008:13

Species Winter Wren Song Sparrow Hammond’s Flycatcher Warbling Vireo MacGillivray’s Warbler American Redstart Lincoln’s Sparrow Total Table. Number of territories between among selected bird species along the North Fork of Elk Creek.

Species Winter Wren Song Sparrow Hammond’s Flycatcher Warbling Vireo MacGillivray’s Warbler American Redstart Veery Total Table. Number of territories between among selected bird species along Elk Creek.

I had visitors

Approximate territory boundaries for MacGillivray’s Warbler on a portion of the North Fork, Red indicates date of singing male observation.

Habitat Selection & Territory Establishment Habitat selection: follows a hierarchical decision-making process (Hutto 1985) involving innate and learned behaviorial decisions made by an animal about where it should be at different scales of the environment. Habitat preference: is restricted to the consequence of the habitat selection process, resulting in the disproportionate use of some resources over others. Territory: a defended area

Territory Establishment for MacGillivray’s Warbler along the North Fork of Elk Creek, 1968,1980 and 2008

Did early arriving MacGillivray’s Warblers select territories that were different with respect to certain veg characteristics along the North Fork? Veg parameters measured & tested: Riparian width Canopy cover of alder Canopy cover of dogwood Canopy cover of conifers Canopy cover of Ribes Canopy cover of snowberry Height of alder Height of dogwood ANSWER: NO

Did early arriving MacGillivray’s Warblers select territories that were different with respect to certain veg characteristics along Elk Creek? ANSWER: yes Riparian width (t = 6.12, P <0.0001) Alder height (t = 2.11, P = 0.04) Snowberry can. cover (t = 1.65, P = 0.10)

Territory Establishment for the MacGillivray’s Warbler in three riparian areas, western Montana, 2008

Territory Establishment for Hammond’s Flycatcher along Elk Creek, 1980 and 2008

Territory Establishment for the Hammond’s Flycatcher in three riparian areas, western Montana, 2008

Territory Establishment for Warbling Vireo along the North Fork of Elk Creek, 1968,1980 and 2008

June Snow: mortality of Neotropical migrants

Swainson’s Thrush

Chipping Sparrow

Summary Mountain alder mortality in 1989 impacted some birds since then Several species increased over time, some decreased, and some changed little the Veery, Red-eyed Vireo, and American Redstart either disappeared or were greatly reduced in 2008 Early arriving males did, in some cases, select habitat different in some attributes than later arriving males.