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Walt Koenig's Research

My research spans the fields of behavioral ecology and cooperative breeding, population ecology of birds, spatial synchrony of ecological phenomena, and the evolutionary ecology of variable reproduction (masting behavior) in trees.

A full list of publications along with more pdfs of papers is available here. I have copies of most of the others; feel free to email me if you need one.

Behavioral ecology of cooperative breeding 

Evolutionary ecology of variable reproduction in plants 

Population ecology of avian populations  

Spatial synchrony of ecological phenomena  

New publication:

Cooperative Breeding in Vertebrates: Studies of Ecology, Evolution, and Behavior, W. D. Koenig and J. L. Dickinson, editors (Cambridge University Press), 2016.

Behavioral ecology of cooperative breeding

Since 1974 I have been involved in a long-term study of the ecology and evolution of social behavior in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus) at Hastings Reservation in central coastal California, currently in collaboration with Dr. Eric Walters (Old Dominion University) and Dr. Joseph Haydock (Gonzaga University). The mating system of this species is one of the most complex of any vertebrate, with social units consisting of up to seven related males competing for matings with up to three related females, all laying eggs in a single nest, and up to 10 nonbreeding helpers of both sexes (offspring from prior years). Our current work focuses on understanding the formation of coalitions and implementing an automatic tracking system using solar-powered 'nanotags' whose signal is picked up by a series of base stations located throughout the study area. My work on cooperative breeding in acorn woodpeckers has been supported by a series of grants from the NSF going back over 30 years. Recent publications related to this project include:

Koenig, W. D., E. L. Walters, and J. Haydock. 2009. Helpers and egg investment in the cooperatively breeding acorn woodpecker: testing the concealed helper effects hypothesis. Behavioral Ecology and Sociobiology 63: 1659-1665. pdf

Koenig, W. D., E. L. Walters, and J. Haydock. 2011. Variable helper effects, ecological conditions, and the evolution of cooperative breeding in the acorn woodpecker. American Naturalist 178: 145-158. pdf

Koenig, W. D. and E. L. Walters. 2011. Age-related provisioning behaviour in the cooperatively breeding acorn woodpecker: testing the skills and the pay-to-stay hypothewses. Animal Behaviour 82: 423-424. pdf

Koenig, W. D., E. L. Walters, and J. Haydock. 2011. Fitness consequences of within-brood dominance in the cooperatively breeding acorn woodpecker. Behavioral Ecology and Sociobiology 65: 2229-2238. pdf

Koenig, W. D. and E. L. Walters. 2012. Brooding, provisioning, and compensatory care in the cooperatively breeding acorn woodpecker. Behavioral Ecology 23: 181-190. pdf

Koenig, W. D. and E. L. Walters. 2012. An experimental study of chick provisioning in the cooperatively breeding acorn woodpecker. Ethology 118: 566-574. pdf

Rusk, C. L, E. L. Walters, and W. D. Koenig. 2013. Cooperative breeding and long-distance dispersal: a test using vagrant records. PLoS One 8(3): e58624. pdf

Koenig, W. D. and E. L. Walters. 2014. What we don't know, and what needs to be known, about the cooperatively breeding acorn woodpecker Melanerpes formicivorus. Acta Ornithologica 49: 221-232. pdf

McMahon, D. E., I. S. Pearse, W. D. Koenig, and E. L. Walters. 2015. Tree community shifts and acorn woodpecker population increases over three decades in a Californian oak woodland. Canadian Journal of Forest Research 45: 1113-1120. pdf

Koenig, W. D. and E. L. Walters. 2015. Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker. Proceedings of the Royal Society of London, Series B 282: 20151742. pdf

Koenig, W. D., E. L. Walters and J. Haydock. 2016. Acorn woodpeckers: helping at the nest, polygynandry, and dependence on a variable acorn crop. Pp. 217-236 in Cooperative Breeding in Vertebrates: Studies in Ecology, Evolution, and Behavior. (W. D. Koenig and J. L. Dickinson, eds.). Cambridge University Press, Cambridge. pdf

Koenig, W. D., J. L. Dickinson and S. T. Emlen. 2016. Synthesis: cooperative breeding in the 21st century. Pp. 353-374 in Cooperative Breeding in Vertebrates: Studies in Ecology, Evolution, and Behavior. (W. D. Koenig and J. L. Dickinson, eds.). Cambridge University Press, Cambridge. pdf

Koenig, W. D. and E. L. Walters. 2016. Provisioning patterns in the cooperatively-breeding acorn woodpecker: is feeding a signal, and if so, to whom and why? Animal Behaviour 119: 125-134. pdf

Shen, S.-F., S. T. Emlen, W. D. Koenig, and D. R. Rubenstein. 2017. The ecology of cooperative breeding behavior. Ecology Letters (in press).

A poster describing the bizarre social behavior of the acorn woodpecker is available on the Hastings Reservation web site here.

*** This study is funded by the National Science Foundation ***

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Evolutionary ecology of variable reproduction in plants

This project includes several main parts. The first, in collaboration with Dr. Jean Knops of the University of Nebraska, Bill Carmen of Mill Valley, former postdoctoral scholar Ian Pearse, and current postdoc Mario Pesendorfer, focuses on the behavioral ecology of variable seed production by California oaks and involves a long-term study of the reproduction and growth of over 1,000 trees throughout California currently funded by an LTREB grant from NSF. This part of the project has its own website (The California Acorn Survey) and its own annual newsletter, the California Acorn Report, the most recent edition of which can be found at the California Acorn Survey website.

Second is a project on gene flow and the genetic ecology of valley oaks (Quercus lobata) in collaboration with Dr. Mary Ashley at the University of Illinois, Chicago. Third is a more general interest in the evolution of masting behavior and growth of forest trees. Recent papers related to these projects include:

Koenig, W. D. and M. V. Ashley. 2003. Is pollen limited? The answer is blowin’ in the wind. Trends in Ecology & Evolution 18: 157-159.pdf

Koenig, W. D., D. Kelly, V. L. Sork, R. P. Duncan, J. S. Elkinton, M. S. Peltonen and R. D. Westfall. 2003. Dissecting components of population-level variation in seed production and the evolution of masting behavior. Oikos 102: 581-591. pdf

Koenig, W. D. and J. M. H. Knops. 2005. The mystery of masting in trees. American Scientist 93: 340-347. pdf

Knops, J. M. H., W. D. Koenig, and W. J. Carmen. 2007. A negative correlation does not imply a trade-off between growth and reproduction in California oaks. Proceedings of the National Academy of Sciences (USA) 104: 16982-16985. pdf

Koenig, W. D. and J. M. H. Knops. 2007. Long-term growth and persistence of blue oak (Quercus douglasii) seedlings in a California oak savanna. Madroño 54: 269-274. pdf

Kelly, D., W. D. Koenig, and A. M. Liebhold. 2008. An intercontinental comparison of the dynamic behavior of mast seeding communities. Population Ecology 50: 329-342. pdf

Koenig, W. D., J. M. H. Knops, W. J. Carmen, and R. D. Sage. 2009. No trade-off between seed size and number in the valley oak Quercus lobata. American Naturalist 173: 682-688. pdf

Koenig, W. D., J. M. H. Knops, and W. J. Carmen. 2010. Testing the environmental prediction hypothesis for mast-seeding in California oaks. Canadian Journal of Forest Research 40: 2115-2122. pdf

Abraham, S. T., D. N. Zaya, W. D. Koenig, and M. V. Ashley. 2011. Interspecific and intraspecific pollination patterns of valley oak, Quercus lobata, in a mixed stand in central coastal California. International Journal of Plant Sciences 172: 691-699. pdf

Koenig, W. D., K. A. Funk, T. S. Kraft, W. J. Carmen, B. C. Barringer, and J. M. H. Knops. 2012. Stabilizing selection for within-season flowering phenology confirms pollen limitation in a wind-pollinated tree. Journal of Ecology 100: 758-763. pdf

Barringer, B. C., W. D. Koenig, and J. M. H. Knops. 2012. Interrelationships among life-history traits in three California oaks. Oecologia 171: 129-139. pdf

Knops, J. M. H. and W. D. Koenig. 2012. Sex allocation in California oaks: trade-offs or resource tracking? PLoS One 7(8): e43492. doi:10.1371/journal.pone.0043492 pdf

Koenig, W. D. and J. M. H. Knops. 2013. Large scale spatial synchrony and cross-synchrony in acorn production by two California oaks. Ecology 94: 83-93. pdf

Koenig, W. D, M. Díaz, F. Pulido, R. Alejano, E. Beamonte, and J. M. H. Knops. 2013. Acorn production patterns. Pp. 181-209 in Mediterranean Oak Woodland Working Landscapes: Dehesas of Spain and Ranchlands of California (P. Campos, L. Huntsinger, J. L. Oviedo, P. F. Starrs, M. Díaz, R. B. Standiford, and G. Montero, editors). Springer Landscape Series vol. 16.

Pearse, I. S., W. D. Koenig and J. M. H. Knops. 2014. Cues versus proximate drivers: testing the mechanism behind masting behavior. Oikos 123: 179-184. pdf

Pearse, I. S., W. D. Koenig and K. A. Funk, and M. B. Pesendorfer. 2015. Pollen limitation and flower abortion in a wind-pollinated, masting tree. Ecology 96: 587-593. pdf

Koenig, W. D., J. M. H. Knops, W. J. Carmen and I. S. Pearse. 2015. What drives masting? The phenological synchrony hypothesis. Ecology 96: 184-192. pdf

Pérez-Ramos, I. M., C. M. Padilla-Díaz, W. D. Koenig, and T. Marañón. 2015. Environmental drivers of mast-seeding in Mediterranean oak species: does leaf habit matter? Journal of Ecology 103: 691-700. pdf

Ashley, M. V., S. T. Abraham, J. R. Backs, and W. D. Koenig. 2015. Landscape genetics and population structure in valley oak (Quercus lobataNée). American Journal of Botany 102: 2124-2131. pdf

Funk, K. A., W. D. Koenig, and J. M. H. Knops. 2016. Fire effects on acorn production are consistent with the stored resource hypothesis for masting behavior. Canadian Journal of Forest Research 46: 20-24. pdf

Pesendorfer, M. B., T. S. Sillett, W. D. Koenig, and S. A. Morrison. 2016. Scatter-hoarding corvids as seed dispersers for oaks and piunes: a review of a widely distributed mutualism and its utility to habitat restoration. Condor: Ornithological Applications 118: 215-237. pdf

Pesendorfer, M. B., W. D. Koenig ,I. S. Pearse, J. M. H. Knops, and K. A. Funk. 2016. Individual resource-limitation combined with popluation-wide pollen availability drives masting in the valley oak (Quercus lobata). Journal of Ecology 104: 637-645. pdf

Pesendorfer, M. B., and W. D. Koenig. 2016. The effect of within-year variation in acorn crop size on seed harvesting by avian horders. Oecologia 181: 97-106. pdf

Koenig, W. D., R. Alejano, M. D. Carbonero, P. Fernández-Rebollo, J. M. H. Knops, T. Marañón, C. M. Padilla-Díaz, I. S. Pearse, I. M. Pérez-Ramos, J. Vázquez-Piqué, and M. B. Pesendorfer. 2016.Is the relationship between mast-seeding and weather in oaks related to their life-history or phylogeny? Ecology 97: 2603-2615. pdf

Pearse, I. S. W. D. Koenig, and D. Kelly. 2016. [Tansley review] Mechanisms of mast seeding: resources, weather, cues, and selection. New Phytologist 212: 546-562. pdf

Pesendorfer, M. B., and W. D. Koenig, 2016. Competing for seed dispersal: evidence for the role of avian seed hoarders in mediating apparent predation among oaks. Functional Ecology31: 622-631. pdf

Koenig, W. D., J. M. H. Knops, W. J. Carmen, and M. B. Pesendorfer. 2017. Testing the terminal investment hypothesis in Caifornia oaks. American Naturalist 189: 564-569. pdf

A poster that talks about some of our work on acorn production in California oaks is available on the Hastings Reservation web site here.

*** This study is funded by the National Science Foundation ***

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Population ecology of avian populations

I have done considerable work investigating various aspects of avian ecology, often using large-scale public datasets such as the Audubon Christmas Bird Counts (CBC), the North Ameriocan Breeding Bird Surveys (BBS), and the Lab of Ornithology's Project FeederWatch. The focus of this work has varied depending on the questions involved, but has generally involved identifying and explaining large-scale spatial patterns in population numbers and trends. Recent papers in this area include:

Koenig, W. D. 2003. European starlings and their effect on native cavity-nesting birds. Conservation Biology 17: 1134-1140. pdf

Koenig, W. D. and A. M. Liebhold. 2005. Effects of periodical cicada emergences on abundance and synchrony of avian populations. Ecology 86: 1873-1882. pdf

Monahan, W. B. and W. D. Koenig. 2006. Estimating the effects of sudden oak death on oak-dependent birds. Biological Conservation 127: 146-157. pdf

Koenig, W. D., L. Marcus, T. W. Scott, and J. L. Dickinson. 2007. West Nile virus and California breeding bird declines. EcoHealth 4: 18-24. pdf

Koenig, W. D., W. M. Hochachka, B. Zuckerberg, and J. L. Dickinson. 2010. Ecological determinants of American crow mortality due to West Nile virus during its North American sweep. Oecologia 163: 903-909. pdf

Koenig, W. D., L. Ries, V. B. K. Olsen, and A. M. Liebhold. 2011. Avian predators are less abundant during periodical cicada emergences, but why? Ecology 92: 784-790. pdf

Zuckerberg, B., D. N. Bonter, W. M. Hochachka, W. D. Koenig, A. T. DeGaetano, and J. L. Dickinson. 2011. Climatic constraints on wintering bird distributions are modified by urbanization and weather. Journal of Animal Ecology 80: 403-413 . pdf

Koenig, W. D., E. L. Walters, and A. M. Liebhold. 2011. Effects of gypsy moth outbreaks on North American woodpeckers.Condor 113: 352-361. pdf

Koenig, W. D. and A. M. Liebhold. 2013. Avian predation pressure as a potential driver of periodical cicada cycle length. American Naturalist 181: 145-149. pdf

Koenig, W. D., A. M. Liebhold, D. N. Bonter, W. M. Hochachka, and J. L. Dickinson. 2013. Effects of the emerald ash borer invasion on four species of birds. Biological Invasions 15: 2095-2103. pdf

Strong, C. B. Zuckerberg, J.L. Betancourt, and W. D. Koenig. 2015. Climate dipoles drive two principal modes of North American boreal bird irruption. Proceedings of the National Academy of Sciences (USA) 112: E2795-2802. pdf

Koenig, W. D. and A. M. Liebhold. 2016. Temporally increasing spatial synchrony of North American temperature and bird populations. Nature Climate Change 6: 614-617. pdf

Rogers, K. H., Y. A. Girard, W. D. Koenig, and C. K. Johnson. 2016. Ecological drivers and population impacts ofavian mortality events in band-tailed pigeons (Patagioenas monilis) in California, USA. Journal of Wildlife Diseases 52: 484-494. pdf

Koenig, W. D., E. L. Alters, and P. G. Rodewald, 2017. Testing alternative hypotheses for the cause of population declines: the case of the Red-headed Woodpecker. Condor119: 143-154. pdf

Koenig, W. D. and A. M. Liebhold. 2017. A decade of emerald ash borer effects on regional woodpecker and nuthatch populations. Biological Invasions (in press).

Spatial synchrony of ecological phenomena

I am particularly interested in the patterns, causes, and consequences of spatial synchrony in ecological phenomena. This work, which overlaps with my interests in the reproductive strategies of forest trees and the ecological work on avian populations, has led me to investigate spatial synchrony in growth and reproduction by forest trees, global weather patterns, North American bird populations, and metapopulations of amphibians. Recent papers include:

Koenig, W. D. and A. M. Liebhold. 2003. Regional impacts of periodical cicadas on oak radial increment. Canadian Journal of Forest Research 33:1084-1089. pdf

Trenham, P. C., W. D. Koenig, M. J. Mossman, S. L. Stark, and L. A. Jagger. 2003. Regional dynamics of wetland-breeding frogs and toads: turnover and synchrony. Ecological Applications 13: 1522-1532. pdf

Liebhold, A. M., W. D. Koenig and O. Bjørnstad. 2004. Spatial synchrony in population dynamics. Annual Review of Ecology, Evolution, and Systematics 35: 467-490. pdf

Liebhold, A. M., V. Sork, M. Peltonen, W. D. Koenig, O. Bjørnstad, R.  Westfall, J.  Elkinton, and J. M. H. Knops. 2004. Within-population spatial synchrony in mast seeding of North American oaks. Oikos 104: 156-164.pdf

Koenig, W. D. and J. M. H. Knops. 2013. Large scale spatial synchrony and cross-synchrony in acorn production by two California oaks. Ecology 94: 83-93. pdf

Koenig, W. D. and A. M. Liebhold. 2016. Temporally increasing spatial synchrony of North American temperature and bird populations. Nature Climate Change 6: 614-617. pdf

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You want more?? Are you sure?? For a exhaustive list of Walt's publications, click here (web page)or here (pdf).


 

Photo by Eric Walters

 

Photo by Ron Mumme