RhWR and members provided funds for wages, benefits, and housing for three Research Technicians during the four month field season in 2025 and funds for an additional 6 months of data analysis for one Research Technician. Funds were also provided for the purchase of 25 transmitters to be place on nestling and adult Red-headed Woodpeckers.
RhWR volunteers installed 11 portholes into active Red-headed Woodpecker nests for access to nestlings to place transmitters and color bands onto selected nestlings.
RhWR volunteers concluded 6 full years of installing, removing, maintaining, changing batteries and memory cards, downloading and reviewing all videos from our nest cameras. This year’s added videos combined with previous year’s pictures and videos for a total of over 500,000 pictures and videos and nearly 250,000 hours of surveillance.
RhWR volunteers conducted the eighth year of an acorn production survey on the same 200 oak trees inside Red-headed Woodpecker (RHWO) nesting areas. This survey has shown a significant correlation between Pin Oak acorn production and
RHWOs deciding to remain on site or migrate away for the winter.
RhWR volunteers once again conducted intensive nest surveys and located a record 73 active nests within an approximately 500 acre area.
RhWR volunteers (23) conducted 42 breeding bird surveys over 14 one kilometer transect routes documenting 102 species of birds present.
A RhWR volunteer conducted 5 public bird hikes showing participants RHWO nests and adult birdsalong with numerous other bird species.
RhWR conducted numerous tabling sessions and gave several presentations around the region in 2025.
This historical information highlights a few of the activities that RhWR has been engaged in each year.2024The Red-headed Woodpecker Recovery (RhWR) became a non-profit corporation in May 2024. It was given the IRS Tax Exempt Status under Sec. 501(c)(3) on July 3, 2024. The RhWR can now accept tax exempt gifts and donations.
Note: In 2024 the RhWR provided funds to cover wages, benefits, and housing for three research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for transmitters. What follows are comments on activities during the field season.
The RhWR volunteers continue to search for nesting activity at Cedar Creek Ecosystems Science Reserve (CCESR). After our volunteers locate an active nest, the field technicians verify eggs or young are present in the nest by taking photos using the nest hole camera.
The Roost Biology Study is continuing at CCESR. Again, partly funded by the RhWR. Nest port holes are being made by RhWR volunteers to be able to capture nestlings so they can be color banded and fitted with a radio transmitter for this study. Some adults are also being caught, color banded and fitted with a radio transmitter for the study.
The RhWR nest cameras are still in place taking candid videos of everything that moves in front of them. These cameras are maintained and the videos downloaded and previewed by RhWR volunteers. The videos are prepared for viewing on the Zooniverse website by our volunteers to assist researchers in paring down the very large number of videos for more intense scrutiny. The nest cameras provide new information about RHWOs and the other animals that interact with the woodpeckers and their nest cavities.
The breeding bird surveys conducted by RhWR volunteers has completed its second year documenting birds and some other animals at CCESR.
The acorn production survey by RhWR volunteers completed its seventh year at Cedar Creek with the highest number of Pin Oak acorns per tree counted to date which coincided with the highest number of RHWOs ever recorded overwintering at Cedar Creek.
Note: In 2023 the RhWR provided funds to cover wages and benefits for two research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment, transmitters, and other costs.
Dr. Elena West is beginning a Red-headed Woodpecker (RHWO) Roost Biology Study primarily funded by the RhWR. Field research technicians are placing radio transmitters on both adults and nestlings so that they can determine where they roost for the night. RhWR volunteers assist this program by helping to identify nest sites and regularly monitor the nests throughout the summer. This helps identify potential nest trees that nest portals can safely be put into nest trees by RhWR volunteers and allows the field technicians to remove the nestling before it fledges so that it can be color banded and fitted with radio transmitter.
The RHWO Bioacoustics study is in its second year with RhWR funded field technicians placing acoustic recording units (ARUs) at randomly selected public locations around Minnesota to make recordings of sounds that a computer analysis can determine if there are RHWOs calling in the area, thereby being able to get a count of birds in an area and using statistical technique to be able to get an accurate estimate of the RHWO population in Minnesota.An acorn survey has been conducted at CCESR for the last six years by RhWR volunteers with this year’s crop being the largest to date. This indicated to us that the RHWOs would not leave for the winter and they did not. Read the article in the Fall 2023 The REDHEAD.
In 2022 the RhWR provided funds to cover wages and benefits for two research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment, transmitters and other needs.
Dr. West described her upcoming research in the Fall 2021 The REDHEAD.
This will be the first year of the Bioacoustics Study that will be funded by a grant from the Legislative and Citizen Commission on Minnesota Resources (LCCMR). The RhWR provided the Community Partner portion of funding to assist this study. This year will involve recording Red-headed Woodpecker (RHWO) calls and using them to prepare algorithms to be used to identify RHWO calls amongst the sounds recorded by the acoustic recording units (ARUs). The Summer 2022 The REDHEAD features an article describing the calls and their spectrograms.
Red-headed Woodpecker Recovery (RhWR) volunteers (18) have completed three Breeding Bird Surveys at Cedar Creek Ecosystem Science Reserve (CCESR) on 13 one-kilometer long transects with 5 count points on each transect. The transects were developed and mapped out by a RhWR volunteer. This was the first year of the survey and they are expected to continue each coming year. The CCESR administration requested that the RhWR conduct these surveys to document the many different bird species found at CCESR.
Eight nest cams will again be taking short videos of activity at the nest holes. These cameras are maintained and videos downloaded and previewed by RhWR volunteers. If we add the hours of observation time that these nest cameras have added since last fall, the cameras will have logged over 125,000 hours at RHWO nests since they were started in late 2019. The data collected so far has documented behaviors and activities at these nest cavities that are new and exciting and in extensive detail.
Note: In 2021 the RhWR provided a grant to cover wages and benefits for two research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment and other needs. What follows are comments made by volunteer team member Siah St.Clair on activities during the field season.
Trail cameras at Cedar Creek reveal new animals and behaviors
RhWR nest cameras are continuing to yield exciting new behaviors not seen before and some surprising life and death encounters. Most RHWO nests are in dead or dying trees, including a few that one can hardly believe are still standing. During a strong windstorm in the early morning hours of June 24th, an active nest tree was blown down and broken apart. Miraculously, the two nestlings inside were not injured, the cavity was not damaged and landed with the hole facing up. Surprisingly, the nest camera was also not damaged and continued to collect images. By sunrise, the parents were at the nest cavity, now on the ground, looking into the nest hole, making concerned calls.
By 6:15 am the trail camera recorded them bringing food to the nestlings (see picture of adult at the cavity on the ground) who maintained their loud calls for food after the fall. At 12:27 pm, two members of the research team (including a RhWR volunteer) discovered the nest on the ground and with quick thinking, dug a hole in the ground nearby and “re-planted” the section of the tree that had the nest cavity in it. The adult woodpeckers were recorded at the cavity feeding the nestlings within minutes of the researchers leaving. What’s particularly interesting about this event is that the trail camera captured how the parents at this nest continued to attend to their nestlings, despite it being on the ground.
Unfortunately, the journey of this nest did not end well, as a large Bull Snake made its way up the tree on July 2 and ate the two nestlings inside.
This nest had also previously survived a predation attempt by a Fisher (see below for details), but unlike this large mammal, the snake was able to get inside the cavity. The replanted tree was only 5-6 feet high and may have been low enough for the snake to smell the nestlings and access them. Bull snakes are one of the very few successful nest predators of RHWOs that have been documented so far.
Before this nest blew down and met its end by the Bull snake, it also had an encounter with a Fisher, which was the first time our research team has captured one on video. Fishers are uncommon in the Twin Cities metropolitan area but are seen more regularly in the north metro and the area around Cedar Creek Ecosystem Science Reserve (Cedar Creek).
There were three nestlings in the nest on June 16th when a Fisher was captured by the trail camera at the cavity entrance trying to get at the nestlings. The Fisher put its nose into the cavity and could likely smell the nestlings inside. The shape of the nest cavity excavated by the parents —narrow at the top and deep — foiled the Fisher and it went away empty handed, or with empty paws.
In addition to recording the daily happenings at active nests, some of the nest cameras are also continuing to record videos of what goes on at nests that are no longer thought to be in use by RHWO. After reviewing some of the videos captured this year, a camera left at a previously used cavity (2020) had captured the same pair using it again this year as a “secondary” cavity. The pair had returned to Cedar Creek this spring and nested in a different hole about 120 feet from their 2020 tree.
The camera recorded them at the old cavity only a few times in 2021 until they started showing up fairly regularly in late June. On July 7th, one of the pair’s very new fledglings was recorded inside the cavity at about 8:45 pm with both parents present. Over the next six days both adults and 2-3 fledglings are recorded on over 200 different occasions. It appears to be quite a family affair as sometimes up to four members of the family are present in videos at one time. There are many videos of parents feeding the fledglings, of sibling fights and attempts at dominance. One fledgling can be seen inside the cavity (possibly roosting there at night). This is new and exciting behavior to document and demonstrates the importance of previously used trees for RHWO across multiple years.
Siah St. Clair
Potential RHWO Nest Cavity Use by Other Bird Species in Spring 2021
On April 22, 2021, three RHWO nest cameras that had been left out through the winter at Cedar Creek ESR had their memory cards replaced, and batteries checked to prepare for the returning RHWOs this spring. When a RhWR volunteer was looking at the memory cards that were removed it became obvious that a few bird pairs were considering or definitely preparing to use an old RHWO nest cavity for their own nests this spring. Returning RHWO pairs may dispute cavity ownership and may or may not win back their cavity if they choose to fight for it.
Nesting pair interests documented by the RHWO nest cameras this spring include:
1. A Pileated Woodpecker pair took an interest in the cavity at nest tree 84. The camera captured them 12 separate times at the nest since November 3, and as a pair present together at least 3 times. On March 22 they “talked” softly together while checking out the nest. Unfortunately, a windstorm blew the huge dead nest tree 84 down on March 24. So ended the exciting possibility of recording a Pileated Woodpecker pair nesting from beginning to completion in a former RHWO nest cavity.
2. On March 18th, a pair of Bluebirds were captured by the camera at nest 223. Both the male and female were going in and out of the cavity calling to each other. The camera recorded 61 events with this pair of Bluebirds removing old nest material from inside the cavity, talking and calling to each other, both going in and out of the cavity. Unfortunately, a pair of European Starlings also discovered the nest, and the Bluebirds finally stopped showing up on April 3.
3. On March 18th a pair of European Starlings also discovered the nest cavity at nest 223. The camera captured 83 events with Starlings at the cavity between March 18 and April 20. The camera captured a fight with an intruding 3rd Starling, Starlings removing mouthfuls of nest debris 29 times, and many interactions between the pair. There appears to be a good chance that this pair may nest at this site unless driven away by an aggressive pair of returning RHWOs.
As ecosystem engineers, Red Headed Woodpeckers create cavities that other species use or adapt for nests, roosts, and other purposes. RHWOs are important for the survival and reproductive success of other species within their ecosystem.
by Siah St. Clair
Note: In 2020 the RhWR provided a grant to cover wages and benefits for two research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment and other needs. What follows are comments made by the volunteer team member Dr.Jim Howitz and by Dr. Elena West on activities during the field season.
Tracking Data Reveals Red-headed Woodpecker Migration Route
By Dr. Elena West, University of Minnesota, Lead RHWO Researcher
Red-headed Woodpeckers are facultative migrants, meaning that they leave their breeding grounds during some winters but not during others. In general, facultative migration occurs in populations that experience seasonally fluctuating, but year-round, food at breeding sites, but it can occur due to other factors such as weather events. In contrast to facultative migrants, obligate migrants tend to leave breeding sites at the same time, in the same direction, and to the same wintering areas each year. The seasonal movements of facultative migrants are not well understood due to their irregular and often unpredictable occurrence.
Our understanding of the migratory movements of Red-headed Woodpeckers is limited to mostly anecdotal accounts and has focused on variation in food resources (i.e., annual mast production) as the primary factor hypothesized to drive whether individuals or populations leave their breeding sites in autumn. Determining the timing and distance of migratory movements, and sites used by Red-headed Woodpeckers outside of the breeding season are important for understanding their population dynamics, informing annual cycle conservation plans, and identifying the cues that may drive their migration patterns.
Over the last three breeding seasons at Cedar Creek Ecosystem Science Reserve (Cedar Creek), we have marked 50 adult Red-headed Woodpeckers with miniature GPS tags to track autumn and winter movements and to better understand the frequency, timing, routes, and overwintering locations of birds that migrate from Cedar Creek. Prior to marking birds with these GPS tags, we programmed GPS tags to record location estimates, once per week during the summer and winter months (May-August, December-February) and once every three days during the months in which we expected migration might occur (September-November, March-April). Each spring we attempt to recapture birds wearing these devices so that we can remove them (which are attached using harnesses made with strong ribbon) and download the stored data that shows where birds spent the non-breeding season.
Until recently, all of the data showed that the birds we recovered devices from spent their winters in and around Cedar Creek. However, in June 2019 we recaptured a female Red-headed Woodpecker that had been marked with a GPS tag in 2018, migrated to southeast Iowa in the fall, and returned to Cedar Creek sometime in 2019. The data from this bird’s device indicates that she left Cedar Creek between September 1 – 4, 2018 and arrived in southeast Iowa sometime between September 7 – 10, where she appears to have spent the fall and early winter. During this bird’s journey south, the device recorded a location on September 4, a few miles west of Wyalusing State Park, along the Mississippi River. On September 7, the device recorded a location a few miles outside of Dubuque, IA. Both of these locations appear to be in small, dense forest patches within landscapes dominated by agricultural fields.
Location data from the device indicate that this bird spent the next three months in the southeast corner of Iowa, near the borders of Illinois and Missouri, in a patch of dense forest a few miles from the Mississippi River. Battery life on this device was shorter than expected and it stopped collecting data after December 27, 2018. Presumably this bird spent the remainder of the winter in this area, then returned to Cedar Creek in the spring. While the map shows known locations taken during the bird’s fall migration, the lines connecting these points are not representative of the bird’s path—birds do not fly entirely straight during migration after all! Based on the proximity of the points to the Mississippi River, it seems likely that the bird traveled along the Mississippi River flyway from Minnesota to southern Iowa. Our hope is that over the next two years we are able to recover more GPS tags from Red-headed Woodpeckers that migrate from Cedar Creek so that we can learn more about the species’ migration patterns and inform conservation planning throughout its range.
2020 Research Team in addition to RhWR volunteers
The 2020 Red-headed Woodpecker Research team that is in addition to the RhWR volunteers includes Dr. Elena West, April Strzelczyk, and Kirsti Carr.
Dr. Jim Howitz, RhWR Research Team and Dr. Elena West, University of Minnesota, RHWO Researcher
The 2020 Red-headed Woodpecker (RHWO) field season at the Cedar Creek Ecosystem Science Reserve (Cedar Creek) ended in September and despite a number of constraints due to the Coronavirus pandemic, it was a very productive season. A large number of RHWO that overwintered at Cedar Creek this past winter also nested on site, so we (the research team) were able to hit the ground running in early May to begin nest monitoring, recapturing birds that were marked with GPS devices in 2019 and marking a new sample of birds with tracking devices. We were lucky to have two extraordinary field technicians, April Strzelczyk (joining us for a second year) and Kirsti Carr. Some highlights of our field work include:
- 57 RHWO nest trees monitored and a total of 68 nest attempts (first and second attempts combined)
- 45 of the nests we monitored successfully fledged at least one bird.
- Most first nests had fledglings by the end of June while fledging stretched into August and early September for second nest attempts.
- We marked 24 adult RHWO with GPS devices, nearly all of which appear to have left Cedar Creek for the winter, which may be due to the lower than usual acorn count. The fact that so many adults appear to have migrated this year is an exciting prospect for their return to Cedar Creek in the spring when we hope to recapture these birds to retrieve their movement data.
Another highlight of the 2020 field season is the installation of 9 nest cameras that have revealed some very interesting findings about how RHWO and other animals use cavities. These cameras will continue to take videos of nest cavities during the fall, winter, and spring. We are working to develop a project accessible to the public so that volunteers can help classify the behaviors captured in these videos. Our hope is that the cameras will record additional information on the presence and activities of other animal species that use RHWO nest cavities throughout the year. Stay tuned.
We also completed a project to measure RHWO nest tree density; the results of which will help us understand the role of wood hardness in nest site selection and in limiting nesting opportunities. Ultimately, this information will be used to guide land managers and private landowners working on Red-headed Woodpecker habitat restoration efforts around the state.
We hope to be able to continue field work in spring 2021 as we move onto the next phase of our research.
2019 Research Team in addition to RhWR volunteers
Note: In 2019 the RhWR provided a grant for Dr. Elena West and two research technicians, April Strzelczyk and Sarah Stewart, to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment, transmitters, and lab costs. Several RhWR volunteers were also on this team.
Note: In 2018 the RhWR contracted Dr. Elena West (half time full year) and two research technicians (work field season) to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment, transmitters, and lab costs. What follows are comments by Dr. West about the activities accomplished.
Dr. Elena West, University of Minnesota, Contract RHWO Researcher
The 2018 Red-headed Woodpecker field season came fast and furious with a record setting mid-April snowfall and an early start to courtship and nesting by many of the birds at Cedar Creek Ecosystem Science Reserve (Cedar Creek). Red-headed Woodpeckers paid no mind to the cold and snowy conditions and started their breeding season activities approximately 3 weeks before last year’s breeding season. One of our most enthusiastic and skilled volunteer photographers, Siah St. Clair, was able to capture a number of Red-headed Woodpeckers actively foraging for insects on tiny leaves that had just emerged amidst the snow-covered trees. We suspect that the early start to breeding was a result of so many woodpeckers overwintering at Cedar Creek, allowing them ample time for courtship and cavity excavation during the spring.
Much of our research is made possible with the assistance of our citizen science volunteers who conduct surveys throughout Cedar Creek’s oak savannas to identify potential red-headed woodpecker nest sites. Volunteers identify these sites by observing woodpecker behaviors, including courtship displays, movements in and out of cavities, defensive displays, and cavity excavation. From May until August, over 40 citizen scientists conducted nearly 75 surveys, totaling more than 160 hours. Many volunteers also spent additional time photographing Red-headed Woodpeckers and their interactions with other bird species. We have over 19,000(!) photos, which is an incredible repository of information for the project.
Much of our work early in the field season is made up of daily nest checks. Once volunteers on the project locate potentially active Red-headed Woodpecker nests, members of the research team confirm whether the nest is active by hoisting one of our telescoping measuring poles toward the nest cavity, inserting the attached camera, and taking a look. This year we were able to monitor 44 nest trees and we noted at least three additional trees where nesting took place, but we were unable to monitor them because we could not access the cavity due to its height or entrance hole diameter. A total of 24 nests fledged at least one juvenile during first nest attempts, while 11 first nesting attempts failed. Of these 11 nests that failed, we were able to confirm that four were due to predation and one was caused by a tree blow down. We were unable to determine the cause of failure for the remaining six nests.
GPS Pinpoint
Radio Transmitter
We were pleasantly surprised to find that a number of pairs nested a second time this summer. We observed a total of 20 second nesting attempts, 12 of which fledged at least one juvenile and eight of which were unsuccessful. While we were able to confirm that three of these eight failures were caused by predation events, we were unable to determine the cause of failure for the remaining five nests. The challenge in these cases is that nests are found empty, and without visible evidence of a predation event or carcass(s) present, it’s difficult to determine the cause of failure.
In addition to nest monitoring, one of our major tasks this summer was to recapture as many of the adult woodpeckers we marked with pinpoint GPS units during the 2017 breeding season. We were able to retrieve five GPS units (out of 20) and we’re hopeful that we will be able to recover additional units over the next few breeding seasons, including the 12 that we attached to birds this summer. Data from the GPS devices will provide information on whether birds migrated or overwintered at Cedar Creek. Attached to each GPS device is a geolocator, which measures light-level data, which will provide information on cavity use and incubation.
Much of the fieldwork this summer was also spent tracking individual adults and juveniles that had been marked with radio-transmitters. We tracked 16 adults to collect habitat use and home range data, including territory size and overlap. We marked 18 nestlings with radio-transmitters prior to fledging in order to track their daily movements, habitat use, and post-fledging survival. We also collected tissue samples from each captured bird, which we will compare to prey samples using stable isotope analysis as part of our study to determine woodpecker diets. Stable isotopes are a useful tool for reconstructing consumer diets as the isotopic ratios of nitrogen (15N/14N, noted δ15N) and carbon (13C/12C, noted δ13C) in consumer tissues predictably reflect those in their diets.
By the end of September, we were unable to locate most of the birds we had marked with radio-transmitters. Many adults appear to have migrated (adults) or made first-year dispersal movements (juveniles). As the field season ended, the most dramatic moments seemed a distant memory. A huge highlight from the season include was our determination that two “trios” of birds were exhibiting polyandry, which is the first time this behavior has been described in this species (more to come on this story this fall and winter!).
Data analysis is in full swing and will be ongoing throughout the duration of our multi-year study. We look forward to sharing preliminary results in the coming months and planning for another action-packed field season. A huge thank you to all of our fantastic volunteers for their interest, support, and dedication to Red-headed Woodpecker research and recovery!
Note: In 2017 the RhWR contracted Dr. Elena West (half time full year) and two research technicians to conduct research on Red-headed Woodpeckers at Cedar Creek ESR with additional funds for equipment, transmitters, and lab costs. What follows are comments made by the two research technicians who worked during the field season.
By Jesse Beck and Candace Stenzel, RhWR Research Technicians
The Red-headed Woodpecker Recovery project 2017 breeding season is soon coming to an end. Our project goals for this season have been to 1) find and monitor active Red-headed Woodpecker nests, 2) build port holes to extract nestlings from nest cavities, 3) capture adults and nestlings for banding, body measurements, blood sampling, and attachment of geolocator backpacks, 4) track backpacked fledgling movement using radio telemetry, and 5) recapture backpacked adults to retrieve movement data from geolocator chips.
While the first 3 goals were more heavily focused throughout the first half of the season, our efforts shifted more on the last 2 goals during August and September.
To quickly recap the numbers for this season, we have so far captured 66 individual birds, with 50 being adults and 16 being hatch-years. We attached geolocator backpacks on the first 20 adults, and radio-transmitter backpacks on 15 of the 16 hatch-years. After attaching the radio-transmitter units, we have been going out at least 3 to 4 times a week to track hatch-year movements and habitat use post-fledge. We are currently tracking only 4 of these 15 birds. For the 11 other birds, 3 were confirmed as being predated (we found piles of feathers surrounding the transmitter units), 2 of the backpacks fell off post-fledge, which no longer allowed us to track, and 6 birds mysteriously went missing (we haven’t been able to pick up any signals on the receivers we use for tracking).
Goal 5, recapturing the geolocator backpacked adults, has proven to be a larger challenge than we originally expected. Earlier in the summer, we were effectively using Potter traps baited with peanuts for trapping birds. We assumed that this method would be just as effective when recaptures started in August. However, once we began the recapture attempts, the birds seemed to have lost all interest in the peanuts and no longer fly into the traps. Thus, we switched to using mist nets for recapture efforts, which has been working out better, but we still have only captured 8 of the 20 backpacked adults. We think that some of the birds may have already begun migration, or shifted to a different area, for we haven’t been able to find them for quite some time. However, we still have another 2 weeks left of the research season and hope to capture at least 2-4 more. For the 8 birds that we have recaptured, we have been hooking their backpack units up to a laptop to obtain movement data and then transferring the data onto GIS for spatial analyses. We hope that, come springtime, the project will be able to recover the additional birds that we were not able to capture this season.
While we are sad that this research season is soon coming to an end, we are nonetheless pleased to have been a part of such an incredible project. We greatly appreciate all of the support and encouragement everyone has given us, and we hope that we have effectively laid out the groundwork for all future efforts.
Click below to view the different periods of history of the RhWR at CCESR. Some of the content are reprints from “The REDHEAD”.