AMJV Technical Committee Digest

Winter 2023
 

Fieldwork/Projects

New Jersey
 

Forestry Implementation, Bird Monitoring Results, and Habitat Evaluation on Sparta Mountain WMA: 2022
Sharon Petzinger, Senior Zoologist, NJ Fish and Wildlife’s Endangered and Nongame Species Program

Forestry Implementation: After incorporating feedback provided during the public comment periods in calendar year 2022 on Sparta Mountain WMA (SMWMA), a 10-acre shelterwood treatment was completed in March and a 10-acre modified seed tree treatment began in November. The shelterwood retained about 23 large trees (avg. 17” dbh) per acre as well as smaller (<6” dbh) oak and hickory trees with a residual basal area of approximately 40 ft2/acre (Fig. 1). The modified seed tree will retain about 21 trees per acre with a residual basal area of approximately 24 ft2/acre. Tree species targeted for retention in both treatments were the more vigorous oaks and hickories, which grow faster, use less water, and will be better suited to future climate conditions than the maple and black birch species growing in the understory before treatment. 

Figure 1. Proportion of trees retained (blue) vs cut (orange) by DBH size class on the 2022 shelterwood treatment in Stand 9 on SMWMA.

Bird Monitoring Results: In 2022, 55 species were observed in at least one of the ten managed sites on SMWMA. Of those, 24 are listed in the NJ State Wildlife Action Plan (2018) as Species of Greatest Conservation Need (SGCN), 29 have declined (five have lost > ½ their population) since 1966 per the 3 Billion Bird Decline (2019), three are on alert, and one is at its tipping point per the 2022 State of the Birds Report. This year’s results bring the total number of bird species observed across all years in these managed sites to 84 (32 SGCN).
 
Managing the forest to open the canopy on SMWMA more than doubles the average total number of bird species, including declining and rare species, detected during surveys compared to the average number of species detected before management (Fig. 2). Bird surveys at the shelterwood treatment implemented in 2022, for example, detected seven bird species before treatment (3 SGCN) and 19 bird species after treatment (8 SGCN). These increases occurred despite slight changes (avg. 1-2 species) in species richness across unmanaged control sites within the same region and period.

Figure 2. Average number of bird species (blue) and bird species of concern (orange) observed during breeding bird surveys on SMWMA from 2012-2022. Pre-treatment surveys were conducted on site prior to treatment or in 2008 near treatment sites.
 
Habitat Evaluation: The increase in number of bird species may be correlated with a reduced tree canopy cover as well as the amount of herbaceous and shrub cover within the site (Fig. 3). Bird species richness was lowest in closed-canopy forests before management, where there was also little herbaceous and shrub cover, then peaked between 2-4 years post-management alongside the growth of herbaceous vegetation, shrubs, and saplings until the average shrub and herb cover were both between 25 and 35%. On average, invasive plants within the managed sites were very low (<5% of total cover), with the majority found along existing access roads, powerline corridors, and trails resulting from the illegal use of dirt bikes.
 
In summary, forestry activities that open the forest canopy on SMWMA to allow for herbaceous and small woody vegetation (shrub and saplings) to grow increase the habitat suitability for many more bird species that use the area before the area is managed. This includes SGCN in NJ which constitute an average 41-50% of the bird species observed in these sites after forestry activities are conducted. These activities also increase the diversity,and resiliency and reduce the vulnerability of these forests to future climate conditions. 

Figure 3. Average number of bird species (blue line) observed during breeding bird surveys on SMWMA in managed areas before and after management. Columns represent different types of average vegetation cover: Trees include all woody vegetation >4m tall, shrubs include all woody vegetation <4m tall, and herbs are all non-woody vegetation (N=3-8). The red line represents the percentage of the area with invasive plants (tree, shrub, and herb).

NJ Forest Habitat Management Evaluations
Sharon Petzinger, Senior Zoologist, NJ Fish and Wildlife’s Endangered and Nongame Species Program

In 2022, 145 locations were surveyed for all bird species to evaluate the success of habitat management efforts to create young forest habitat, including Working Lands for Wildlife (WLFW). These locations were split into four different types of sites: 46 WLFW, 26 Management (MGMT), 68 Natural (NAT), and 5 pre-management (PRE). NAT sites represented naturally occurring “young forest” habitat within wetlands and were considered controls. WLFW sites were properties enrolled in the WLFW-Golden-winged Warbler (GWWA) program. MGMT sites represented other forest management prescriptions on private and public lands to promote young forest habitat but not enrolled in WLFW. PRE sites were intended to be managed for young forest habitat regardless of ownership or enrollment in WLFW. Most PRE sites were closed-canopy deciduous forest stands with an average age between 70 and 100 years.
 
Based on a two-tailed paired T-test, WLFW+MGMT sites post-management continued to have significantly greater species richness compared to the NAT sites (P=0.026), particularly when comparing just the rare and declining species of greatest conservation need (SGCN) as listed in the 2018 NJ Wildlife Action Plan (P<0.001; Fig. 4).

Figure 4. Average number of bird species (columns) observed during breeding bird surveys on managed lands (WLFW & public lands treated to create or enhance habitat for GWWAs) before and after management. The dashed lines represent the average number of bird species observed in passively managed wetlands as control sites (N=23-68).

The increase in number of bird species may be correlated with a reduced tree canopy cover as well as the amount of herbaceous and shrub cover within the site (Fig. 5). Bird species richness was lowest in closed-canopy forests before management, where there was also little herbaceous and shrub cover, then peaked 2-4 years post-management when average shrub cover was between 25 and 40%. 

Figure 5. Average number of bird species (blue line) observed during breeding bird surveys on managed lands (WLFW & MGMT) before and after management (N=21-62). Columns represent different types of average vegetation cover: Trees include all woody vegetation >4m tall, shrubs include all woody vegetation <4m tall, and herbs are all non-woody vegetation (N=20-47). The red line represents the percentage of the area with invasive plants (tree, shrub, and herb).
 
Opening the forest canopy to allow for herbaceous and small woody vegetation (shrub and saplings) to grow increases the habitat suitability of many different bird species, nearly doubling the number of bird species detected. This includes the SGCN in NJ which constitute 36-45% of the bird species observed in these sites. Furthermore, Golden-winged Warblers occupy a greater proportion of suitable managed forest sites than shrubby wetlands and powerlines combined.
 
Not only will managing forests targeting breeding Golden-winged Warbler habitat help prevent extirpation of this endangered species, but it will benefit many other rare and declining wildlife species that also need this habitat type.

A Sliver of Hope for Golden-winged Warblers in New Jersey
Sharon Petzinger, Senior Zoologist, NJ Fish and Wildlife’s Endangered and Nongame Species Program

Thirteen Golden-winged Warblers (GWWA) were detected in 11 out of 156 suitable NJ locations surveyed in 2022, which is an increase of about a third of breeding GWWA pairs detected in 2021. However, two of the 13 GWWA showed phenotypic signs of introgression.
 
All 11 locations with GWWA were in areas with >70% forest cover within a 1.5-mile radius of the location; ten out of 11 locations were in areas with >75% forest cover within the same radius. Naïve occupancy of GWWA observations was greatest in actively managed upland forest sites, followed by utility rights-of-way, then passively managed wetland sites (Table 1).

Table 1. Naïve occupancy of GWWA observed during the breeding season in suitable habitat types with 70% and 75% forest cover

Based on annually repeated Vermivora breeding surveys in suitable GWWA habitat with >70% forest cover within a 1.5-mile radius, the GWWA population decline has reduced slightly since 2012, from a 6.4% annual decline to a 5.9% annual decline, while the population of Blue-winged Warblers and hybrids have remained relatively stable (Fig. 6).

Figure 6. Change in Golden-winged, Blue-winged, and hybrid Vermivora warbler populations observed in 37-50 NJ locations surveyed at least 8 of the last 11 years in suitable habitat with 70% forest cover within a 1.5-miles radius. 

In addition to preferring areas with >75% mature forest cover (P=0.009), most GWWA breeding in NJ seem to prefer areas with >70% forest and shrub cover (P=0.005) and <1% agricultural cover (P=0.001) within a 1.5-mile radius of breeding territories. Blue-winged warblers showed no preference compared to the locations surveyed, while hybrids appeared to exhibit preferences similar to GWWA (Fig. 7). Managing upland forests to create shrubby areas within large tracts of forest away from agriculture may be an important component to increasing recruitment of breeding golden-winged warblers in NJ.

A

B

C

Figure 7 (A, B, and C). Distribution of locations with Vermivora species observed during the breeding season by the % of mature forest (A), forest and shrub (B), and agriculture (C) cover per NJ Land-Use/Land Cover GIS layer within a 1.5-mile radius of that location. The black line is the distribution of all locations surveyed for Vermivora from 2008 through 2022.

New York
 

Forest Program Updates from Audubon New York
Suzanne Treyger, Senior Forest Program Manager
 
Allegheny Highlands: Audubon and the Western Finger Lakes Chapter of the New York Forest Owners Association held a workshop at the Canadaway Creek Wildlife Management Area. There were 42 attendees at the workshop with backgrounds ranging from landowners, loggers, soil conservationists, and recreational birders. The workshop focused on the benefits of creating young forests for American Woodcock (AMWO) and Golden-winged Warblers (GWWA) through regeneration harvests. Attendees visited an overstocked mature stand, a stand marked to be cut, and a clearcut after 20 years of growth. This workshop yielded five scheduled site visits with landowners.

Harvests for Habitat (Upper Delaware Watershed): Staff presented information about Audubon’s Harvests for Habitat financial assistance program to more than 50 attendees at the annual Tree Farm Landowner Workshop in Delhi, NY. Since the summer of 2022, four landowners participating in Harvests for Habitat completed habitat management projects on a total of 207 acres. These harvests brought a total of 180 acres under improved management for Cerulean Warbler and 27 acres under improved management for Wood Thrush.


Patch cut to improve habitat for Wood Thrush, Upper DE Watershed. Photo by Zack Boerman, Audubon NY


Recent harvest to improve habitat for Cerulean Warblers, Upper DE Watershed. Photo by Zack Boerman, Audubon NY

North Carolina
 

Updates from the North Carolina Wildlife Resources Commission
Chris Kelly, Wildlife Diversity Biologist, North Carolina Wildlife Resources Commission
 
Upcoming fieldwork: In March 2023, North Carolina Wildlife Resources Commission (NCWRC) will begin phase two of a pilot bioacoustics study of Northern Saw-whet Owls with Dr. DJ McNeil of the University of Kentucky. Phase 1 surveys in March 2022 produced several detections, but more are needed for the call classifier and proof of concept. This spring we will deploy Autonomous Recording Units (ARUs) in an array around confirmed occupied sites to see if we can increase detections and to determine when and where the owls call within the habitat.
 
In April 2023, NCWRC will use ARUs for songbird surveys in regenerating logging units on the Nantahala National Forest that burned in the fall 2016 wildfires. The fires set succession back such that some units may still be suitable for species of early seral habitats such as Golden-winged Warbler, Prairie Warbler, and Indigo Bunting. Also in late April, the NCWRC bird crew will attempt to relocate Golden-winged Warblers that were color banded and/or nanotagged in 2022 in the Cheoah Mountains for the rangewide survival study led by the University of Maine.
 
Recent meetings: The Southern Appalachian Spruce Restoration Initiative held its annual meeting at the Grandfather Mountain Stewardship Foundation in October 2022. Out-going co-chair Matt Drury of the Appalachian Trail Conservancy welcomed Jason Rodrigue of the U.S. Forest Service as a new co-chair. Jason joins Gary Peeples of the U.S. Fish and Wildlife Service. With the majority of southern Appalachian red spruce forest occurring on national forest land in North Carolina, SASRI welcomes the continued leadership efforts from the U.S. Forest Service.
 
NCWRC’s First Motus Station in Western North Carolina Installed: NCWRC installed its first mountain-region Motus receiver station in November 2022, leaving time for troubleshooting our first station before spring migration. This is the first “post” in NCWRC’s planned “Motus Fence” of receiver stations in western North Carolina, which will be funded in part by a multi-state Competitive State Wildlife Grant and Pittman Robertson funds. The station was installed on Little Scaly Mountain in Macon County in November. Highlands Cashiers Land Trust connected NCWRC to The Mountain Retreat and Learning Center. Director Steph Anderson offered the use of the Center’s 40-foot Parry Family Tower - a perfect base for our Motus station! This new station is a “dual mode” Motus station, meaning its four antennas are listening for signals from both 166.380 and 434 MHz frequency radio tags. The receiver on Little Scaly complements an existing Motus receiver at the Pisgah Astronomical Research Institute in Balsam Grove. Biologists are planning the next posts in the Motus Fence at key points to the west of Little Scaly. We can hardly wait for spring migration to see what tagged birds, some traveling from as far away as South America, ping our new Motus station upon returning to North Carolina!  


Figure 8. We are on the Motus map! Motus station at The Mountain Retreat and Learning Center on Little Scaly Mountain (circled blue). Image screenshot from Motus.org 1/15/2022
 

Directional antennas atop The Parry Family Tower at The Mountain Retreat and Learning Center. Photo by Chris Kelly, NCWRC


Kendrick Weeks, Western Wildlife Diversity Program Supervisor & AMJV Board Member, solders a connector to a coaxial cable. Photo by Chris Kelly, NCWRC
 

This is a “dual mode” Motus station. The large yagi antenna (right) is tuned to 166.380 MHz while the smaller yagi antenna (left) is tuned to 434 MHz. Photo by Chris Kelly, NCWRC

Ohio
 

Motus Tower Expansion Competitive State Wildlife Grant (C-SWG) Update
Laura Kearns, Wildlife Biologist, Ohio Division of Wildlife

Five of six Motus towers installed across central Ohio in May-July 2022 as part of the Midwestern state C-SWG have continued to detect migrating birds through the fall and early winter. Locations, going from west to east are 1) Englewood Metropark, 2) Carriage Hill Metropark, 3) London State Fish Hatchery, 4) Deer Creek Wildlife Area, 5) Pickerington Ponds Metropark, and 6) Hebron State Fish Hatchery (Figure 9).


Figure 9.  New Motus towers in central Ohio (yellow) in 2022.  Gray represent previously installed towers by others.  

Unfortunately, one (Pickerington Ponds Metropark) was hit by lightning soon after it was installed and is currently under repair. It has been determined that the electrical system in the host building (an old barn) needs to be upgraded. All towers use the CTT SensorStations are attached to permanent buildings and can detect 166 MHz nanotags and 434 MHz CTT LifeTags. Although these towers are positioned just outside the AMJV boundary, they fill important gaps in the Motus infrastructure across Ohio and may provide data on migrating AMJV focal species. 

Fall 2022 Detections: As of December 31, 2022, over 40 individuals representing 14 different species targeted by 11 different research projects were detected by the five working stations (Tables 2,3). Notable detections concerning the AMJV include the following:

• Thirteen Kirtland’s Warblers, originally tagged in the summer in Michigan, were detected by the central Ohio towers.  At least three individuals continued across the Appalachians as they headed toward the Atlantic Coast. Two were detected at central Ohio towers before heading across West Virginia, with final detections at the Hanging Rock tower near the border of Virginia.  The other warbler was detected at the Deer Creek Wildlife Area tower, southwest of Columbus, before heading across West Virginia to the North Carolina coast near Wilmington.
• One Prothonotary Warbler, which was tagged in Ohio, headed across the Appalachians to Georgia, and then to Ding Darling NWR in Florida.  
• One American Woodcock, which collided with a building in Cleveland, Ohio during spring migration, was rehabilitated and released in May. On December 9, it was detected at the Hebron State Fish Hatchery tower west of Columbus, before a final detection at Massengale Mountain in Tennessee on December 18.
• A Red-eyed Vireo from the Georgian Bay, Ontario songbird research project crossed the Appalachians through Kentucky and Tennessee before detection in Colombia.

Table 2.  Species and Individuals Detected at Central Ohio Motus Stations – July 1 - December 31, 2022


Table 3.  Research Projects with Tagged Birds Detected at Central Ohio Motus Stations – July 1 - December 31, 2022

Pennsylvania

Raptor Population Index Project (RPI)
Rebekah Smith, Science-Education Outreach Coordinator, Hawk Mountain Sanctuary

The latest scientific analysis by the internationally award-winning Raptor Population Index Project (RPI) uses decades' worth of raptor migration count data from across North America combined with Christmas Bird Counts to examine long-term trends in raptor populations. Information is now summarized in a contemporary, easy-to-navigate, and graphically vibrant new website at rpi-project.org.
 
RPI is a longstanding collaborative between four North American nonprofit bird conservation organizations: Hawk Mountain Sanctuary, HawkWatch International, Hawk Migration Association of North America (HMANA), and Birds Canada, with each partner contributing an important piece of the population assessment puzzle.  The effort now draws on raptor migration count data from 76 sites across the continent to produce ten- and 20-year trends for each species by region and continent-wide.
 
“Graphs and statistics can seem intimidating,” says Dr. Laurie Goodrich, Hawk Mountain Sanctuary’s Sarkis Acopian Director of Conservation Science, and Co-Chair of the RPI Steering Committee, “which is exactly why we need to share the information visually on a new online platform to make the data more accessible for scientists as well as the general public and land managers,” she adds.

RPI has delivered results online for a decade, albeit in a highly technical manner. Thanks to the generosity of Hawk Mountain supporter and former board member Al Douglass, the partners have completed a nearly two-year-long overhaul of the RPI website to make results and information more accessible than ever. The new site, rpi-project.org, includes easy-to-download analyses for each species, interactive migration maps, photo galleries, and more.
 
New analyses are conducted every three years. The recent population analyses examine raptor migration counts from 2009 to 2019 for 22 raptor species from 76 sites spanning from Mexico to Canada. One important revelation from these new analyses is that one of the most commonly observed migrants, the Sharp-shinned Hawk, shows declining counts at 48% of sites while Christmas Bird Count has not shown an increase. Other concerning declines include Northern Harriers, Northern Goshawks, Osprey, and American Kestrels. Kestrel data is summarized in a paper included in the June issue of the Journal of Raptor Research.


The Sharp-shinned Hawk shows declining counts at 48% of sites while Christmas Bird Count has not shown an increase.

For the first time ever, the RPI team identified “Raptors at Risk,” highlighting species showing widespread declines, and “Raptors on the Rise,” species showing notable increases across the continent.  These new pages include a snapshot of population health for each conservation-concern species – diving deeper into population changes, state and federal listings, Breeding Bird Survey trends, and potential conservation threats. Rebekah Smith, Hawk Mountain Sanctuary Science & Education Outreach Coordinator, synthesized data to produce the species assessments and new “Raptors at Risk” and “Raptor on the Rise” sections.
 

Species assessments and new “Raptors at Risk” and “Raptors on the Rise” sections can be found on the RPI website.

“We want people to access, understand, and use this information. Our goal is to reach the public, decision-makers, birders, land managers, and conservation groups so they, in turn, can identify possible threats to raptors, conduct needed research, and advocate for change at both regional and continental scales. That’s what it’s going to take to keep or remove species from the “Raptors at Risk” list,” says Dr. Dave Oleyar, Co-Chair of RPI Steering Committee and Director of Long-term Monitoring and Community Science at HawkWatch International.

For more information visit www.rpi-project.org.
 

Tennessee

Updates from the Tennessee River Gorge Trust
Eliot Berz, Conservation and Access Director, Tennessee River Gorge Trust

Over the winter, the Tennessee River Gorge Trust (TRGT) prepared for the installation of a Motus Tower in the Tennessee River Gorge. TRGT has partnered with the Prentice Cooper State Forest to install the tower on the bluff of the state forest property overlooking the gorge. The groups will be taking advantage of educational opportunities presented by the tower’s location near a public pavilion by installing educational signage about Motus. This tower will help fill a void in the Motus network in southeast Tennessee. The nearest tower is located at the Reflection Riding Nature Center and managed by Dr. David Aborn with the University of Tennessee Chattanooga.


A late fall migrating Hooded Warbler banded at the TRGT Bird Observatory. Photo by Eliot Berz, TRGT

TRGT is also working with the US Fish and Wildlife Service and the Tennessee Division of Forestry to begin long-term prescribed burns on a property within the Tennessee River Gorge. The primary goal of the burns pertains to shortleaf pine (Pinus echinata) regeneration. A relatively high density of mature shortleaf exists on the property, however, very little regeneration is occurring due to fire suppression and competition from other species. These burn plots will also serve as an educational tool for groups visiting the property and attending public bird banding days.


A shortleaf pine restoration project will begin across the river in 2023. Photo by Kevin Livingood
.

West Virginia
 

Grazing for Wildlife for the Golden-winged Warbler
Jane Capozzelli,  Partner Bird Biologist, WV DNR/NRCS

This year in West Virginia, about 100 ac of active cattle pastures on private lands have been evaluated for prescribed grazing plans to promote the Golden-winged Warbler. Cattle are “Mother Nature’s mowers,” and when used correctly can maintain rare, shrubland habitat long-term. Best management practices include rotational grazing, adaptive cattle stocking, clearcuts, cutback borders, and invasive brush management. To our knowledge, these projects are the first applications of grazing for wildlife on private lands in West Virginia.

Figure 10: When cattle are in a prescribed grazing plan for wildlife, they can maintain shrubland habitat long-term for the Golden-winged Warbler. Above illustrates how grazing for wildlife can integrate with West Virginia’s Wild and Wonderful landscape. Illustration by Joni Aldinger.