Plegadis falcinellus x chihi
Status: Rare regular spring and summer visitor statewide.
Records: At least 44 presumed hybrids had been reported in Nebraska through summer 2022 since the first was photographed in Fillmore Co 21-22 May 2004 (Silcock 2004). There have been five further records 2023-2024. Almost all records are in Apr and May, with early dates 13, 13, and 14 Apr. Records after May are 9 Jun 2021 Crescent Lake NWR, Garden Co, 15 Jun 2018 Garden Co, 17 Jun 2023 Crescent Lake NWR, 21 Jun 2022 North Platte WTP, Lincoln Co, 5 Jul 2020 Morrill Co, 7 Aug 2021 Crescent Lake NWR (Manning, eBird.org), and 2 Sep 2019 Garden Co.
A surprising 11 hybrids were reported in spring 2020 along with 22 Glossy Ibis.
Comments: Presumed hybrids with White-faced Ibis (P. chihi) occur with some regularity on the Great Plains, complicating identification (Arterburn and Grzybowski 2003). Oswald et al (2019) found weak reproductive isolation between the two species and no selection against hybrids; many individuals that had mixed ancestry were later generation hybrids, suggesting that hybrids were not selected against and were fully capable of breeding and producing offspring.
The number of hybrid ibises reported in Nebraska and elsewhere has lagged behind the increase in reports of Glossy Ibis, suggesting hybridization may only occur infrequently (Jorgensen and Silcock 2015) although Oswald et al (2019) found little evidence for assortative mating. It is likely that hybrids and introgressants may be under-reported as observers tend to study these birds less critically as time passes.
Images
Literature Cited
Arterburn, J.W., and J.A. Grzybowski. 2003. Hybridization between Glossy and White-faced Ibises. North American Birds 57: 136-139.
Jorgensen, J.G., and W.R. Silcock. 2015. First Nesting Record and Status Review of the Glossy Ibis in Nebraska. NBR 83: 139-149.
Oswald, J.A., M.G. Harvey, R.C. Remsen, D.U. Foxworth, D.L. Dittmann, S.W. Cardiff, and R.T Brumfield. 2019. Evolutionary dynamics of hybridization and introgression following the recent colonization of Glossy Ibis (Aves: Plegadis falcinellus) into the New World. Molecular Ecology 2019: 1-17.
Silcock, W.R. 2004. Spring Field Report, March-May 2004. NBR 72: 38-58.
Recommended Citation
Silcock, W.R., and J.G. Jorgensen. 2024. Glossy x White-faced Ibis (hybrid) (Plegadis falcinellus x chihi). In Birds of Nebraska — Online. www.BirdsofNebraska.org
Updated 29 Jun 2024