Message from the Board
Camas National Wildlife Refuge 2023 Bird Banding Summary and Highlights
By Austin Young and Jay Carlisle
Sage Thrasher held by a bird bander. A total of 84 Sage Thrashers were banded in fall 2023. This is a substantial increase from the 2005-2007 banding effort when only 2 Sage Thrashers were banded across two spring and two fall migration seasons!
Roughly 4 billion birds migrate annually in the United States (Dokter et al. 2018). They are highly vulnerable to environmental change because change can occur on the breeding grounds, winter range, or the thousands of kilometers in between that are used during migration. To accomplish the impressive journey many migratory birds take, most use a combination of endogenous reserves, i.e., what they can store in their bodies, and stopover locations to rest and refuel along the way. Unfortunately, stopover sites appear to be changing, for example the cottonwoods and other deciduous trees and shrubs at Camas National Wildlife Refuge (NWR) are undergoing senescence due to heat, drought, and increased agricultural water use of upstream portions of Camas Creek.
In response to environmental change over time, some behavioral and morphological features of some species appear to be undergoing change. For example, Zimova et al. (2023) found that many birds appear to be decreasing in size and increasing in wing length over the last 40 years. Because of the dramatic habitat changes at Camas NWR that have occurred since a prior study of songbird migration and stopover (Carlisle et al. 2008), this provides an opportunity to examine how migrating songbirds might be responding to stopover site changes. The goal of the Camas NWR bird banding project is to measure physical, behavioral, and abundance data on birds migrating through Camas NWR and then to compare the results to historical records (Carlisle et al. 2008). Not only will we compare numbers for each species across time, we’ll also examine important metrics of stopover ecology such as body condition and stopover duration.
Importantly, we hope these observations will be useful in understanding the stresses being experienced by migrants and to help guide conservation actions to preserve these species and their broad-scale ecological function. In order to carry this out, we operated 10 mist nets for five hours a day, weather allowing, from April 16 to June 15 and again from July 21 through October 15 during 2023. The same will be done next year, 2024.
Overall, we found a decrease in total captures of migratory birds between years as well as some striking differences in certain species capture totals. In the spring season we captured 1,412 individual birds comprising 65 species. This is approximately 25% less compared to historical numbers from the 2006 and 2007 spring migration banding seasons. Species with substantially lower capture totals, some with up to 67% lower abundances, included Hermit Thrush, Wilson’s Warbler, MacGillivray’s Warbler, Lazuli Bunting, Yellow-rumped Warbler, and Hammond’s Flycatcher. In contrast, we captured some species more often in 2023 and these included Dusky Flycatcher, White-crowned Sparrow, Red-winged Blackbird, Black-billed Magpie, Cliff Swallow, and Northern Flicker. Interestingly, we also captured more hummingbirds in 2023 than in prior spring seasons. Some noteworthy species for the spring season were Black-throated Green Warbler, which was likely Idaho’s 3rd confirmed record (!), Ovenbird, Least Flycatcher, and several White-throated Sparrows.
Over the course of the fall season, we captured a total of 3,930 individual birds comprising 73 species. This is approximately 12% less than the 2005-2007 historical average of captured birds. Some of the species captured much less frequently in fall 2023 were Wilson’s Warbler, Ruby-crowned Kinglet, and MacGillivray’s Warbler,
Hermit Thrush, Yellow Warbler, Hammond’s Flycatcher, and Northern Waterthrush. A number of species were more numerous in fall 2023, including White-crowned Sparrow, House Sparrow, Yellow-rumped Warbler, Sage Thrasher, Lark Sparrow, Vesper Sparrow, Loggerhead Shrike, Western Kingbird, Red-breasted Nuthatch, and Common Nighthawk. Noteworthy species include a Blackpoll Warbler and a surprising 7 White-throated Sparrows.
The capture totals of 2023 compared to historical numbers seem to track the fact that the wooded habitat around the refuge headquarters has experienced a decrease in live foliage, including 1-3m above the ground where we set our mist nets. We captured many more open country birds, such as Sage Thrashers and Vesper Sparrows, in 2023 and one of the biggest surprises was how many House Sparrows (a non-native species) we captured during fall 2023 – as astounding 347 individuals when we’d caught a single individual across the fall 2005 and 2006 seasons combined! The House Sparrows were mostly concentrated in late July and early August, presumably a post-breeding dispersal phenomenon.
In contrast to an increase in captures of open country species, we captured many fewer individuals of a suite of woodland-reliant species such as Wilson’s Warbler, MacGillivray’s Warbler, Ruby-crowned Kinglet, and thrushes, all of which prefer dense, live foliage. A broader, continental-scale decline in songbirds has been documented in recent years (Rosenberg et al.2019) and this could certainly be a factor in some of the apparent declines we observed in 2023, but the habitat at the Camas NWR banding site specifically appears to be changing in a way that’s not favorable for woodland migrants.
This winter we expect to thoroughly analyze the data collected from this first of two years of banding. Alongside migrant bird community data, there is extensive morphological and behavioral information to analyze as well. Further, Austin plans to defend his master’s thesis early next spring. The past spring and fall were a big success, and we hope to see you next year as we continue the second year of banding on April 16th!
Acknowledgements
We sincerely want to thank Friends of Camas for funds, support, volunteers, and friendliness towards the banding crew. We would not be here without you! We thank other funding organizations including Idaho State University, Snake River Audubon, Portneuf Valley Audubon, and Prairie Falcon Audubon.
We thank the work put in from the spring and fall banding crews comprised of Victoria Reid, Chan Mendiola-Orizaba, Lucian Davis, Arden Schneider, Mari Wharff, Dylan Hendry, Noah Nei, and Levi Sheridan. We also want to sincerely thank the refuge staff, Brian Wehausen, Andrea Kristof, and Farrel Downs, for their support and help with data collection. We also thank the refuge technicians Josh Selway, Rachel Hughes, Sam Tackett, and Ajna Bower for their help with data collection. We thank the many volunteers who helped during one or both seasons: Tim Reynolds, Lauren Tate, Erika Mittermaier, Lesley Howard, Ryan Healey, Brianna Baiz, Barbara Howard, Don Thoen, Pam Johnson, Christina Garsvo, Andrew Wehausen, Erin Moyer, Dustin Rose, Erika Alderete, Cody Slaugh, Janette (last name unknown), Bruce Mincher, Sterling Mincher, Justin Fry, Lesley Rolls, Erica McMinn, Ryan Gardner, Dan Stephens, Sam Keninger, Sue Holt, Sean Cozart, Dan Taylor, and Bob Davis.
References
Carlisle J, Larrañaga R, Kaltenecker G (2008) Migration Monitoring of Songbirds at Camas National Wildlife Refuge, Market Lake Wildlife Management Area, and Mud Lake Wildlife Management Area in eastern Idaho: 2007 Annual Report
Dokter AM, Farnsworth A, Fink D, et al (2018) Seasonal abundance and survival of North America’s migratory avifauna determined by weather radar. Nat Ecol Evol 2:1603–1609. https://doi.org/10.1038/s41559-018-0666-4
Rosenberg KV, Dokter AM, Blancher PJ, et al (2019) Decline of the North American avifauna.
Science 366:120–124. https://doi.org/10.1126/science.aaw1313
Zimova M, Weeks BC, Willard DE, et al (2023) Body size predicts the rate of contemporary morphological change in birds. Proceedings of the National Academy of Sciences 120:e2206971120. https://doi.org/10.1073/pnas.2206971120
Refuge Manager's Notes
Brian Wehausen,
Camas National Wildlife Refuge
November 17, 2023
The construction projects are getting very near their end and the Refuge staff is excited to see the finishing touches that will be put on in 2024. The ditch lining was completed in October and we are now ready for water that will come this spring. With the weather still holding, we anticipate some more work could be completed before snow stops construction. The main disturbance on the auto tour route for visitors is over, although some minor closures could occur from time to time. One item I am sure folks would really like to see completed is the observation tower and vault restroom on the south end to the tour route.We are currently completing some design changes and looking for final construction to take place in the summer of 2024.
Hopefully many of our visitors had a chance to meet our songbird banding crew and watch them capture and mark birds. The crew we had this year was wonderful at interacting with the public and give folks and up-close view of birds and discuss why we are doing this type of work. This study is a two-year study, and we will have a crew back in April to start the second season. Please plan to come out to see and interact with the crew again in 2024!
The waterfowl migration this year has been very spread out and the timing seems to be later than most years. The weather has been for the most part warmer this fall, seems to reason for this difference. As an example, we typically see Sandhill cranes show up in big numbers in September. This year we did not have big groups of them show up at once, but smaller groups were seen in October and we still have some around this late in November. A good numbers of Swans are in the area and we have seen more ducks lately, however the recent temperatures are causing water to freeze on the smaller bodies of water and these birds will be looking for larger lakes and rivers soon.
Roosting bald eagles is the next event that many visitors come out to enjoy. The weather has not been cold enough for the eagles to start using the trees just yet. If we see some regular overnight temperatures in the teens or below we could see the amazing birds start to roost on Refuge for the winter.
Winter can be a great time to visit so come on out and enjoy the area if you need a break!