Status: Common regular spring and fall migrant east and central, uncommon, locally common, and erratic west. Common, locally abundant, regular breeder east and east-central, uncommon west-central and west. Rare casual winter visitor south and east.
Documentation: Specimen: UNSM ZM12132, 22 May 1895 Lancaster Co.
Taxonomy: No subspecies are recognized (Pyle 1997).
Spring: Apr 15,15,18 <<<>>> summer (southeast), Apr 30,30, May 2 <<<>>> summer (north), May 17,18,18 <<<>>> summer (west)
Migrants arrive in late Apr, entering Nebraska via the southeast. A few very early undocumented reports from the southeast may be of wintering birds, if correctly identified: 5 Mar 1977 Otoe Co, 29 Mar 1980 Douglas-Sarpy Cos, 31 Mar 2016 Hall Co, 4 Apr 1980 Lancaster Co, 7 Apr 1943 Jefferson Co, and 8 Apr 2017 Douglas Co. By late May the expected summer range is occupied.
Migrants are rare in the Panhandle, which is outside the expected breeding range; arrival there is generally in late May and Jun (see Summer). One at Crescent Lake NWR, Garden Co 14 May 2010 was an early date that far west.
High counts: 76 in Sarpy Co on 13 May 1995, 55 in Johnson Co 22 May 2017, and 50+ in Otoe Co 17 May 2011.
Summer: Dickcissel is a common, locally abundant, breeder in the southeast, and common elsewhere east of the Panhandle. In the west, its abundance is highly variable from year to year, being common in some years and absent in other years. There is little information on historical occurrences in the west, but the few records suggest that occurrence there, including a few old breeding records, has always been highly variable (Ducey 1988, Bruner et al 1904).
Major incursions into western Nebraska occurred in 2005, 2006, and the years 2008-2011; the years 2012-2017 saw a return to the normal low numbers of reports in the west. The reasons for these incursions are not understood; much marginal agricultural land was put into crop production from around 2005, perhaps causing male Dickcissels to search suitable habitat westward. Finck (1984) found that territorial display in Dickcissels functions in male-male competition for habitat rather than to attract females, suggesting that habitat availability is indeed a factor in male distribution.
During incursion years, reports are throughout the Panhandle, including the southwest and Pine Ridge. Mollhoff (2016) showed the species occurred statewide during the second BBA period 2006-2011, including most of the incursion years listed above, but was largely absent from the southwestern Panhandle and northwestern Nebraska during the first BBA, 1984-1989 (Mollhoff 2001). BBS trend analysis shows the species has declined 1.82% (95% C.I. 0.40, 3.03) statewide 1966-2015.
Numbers increase throughout the expected breeding range during incursion years; in 2006, broods were present by 4 Jul in Clay Co when usually adults are not seen until Jul, and, despite not arriving at Valentine NWR, Cherry Co at the northwest edge of the expected breeding range until 5 Jun, they were “extremely common” by 15 Jun, including two nests found. During the same year, numbers were high in the core range; 75 were counted in Cedar Co 21 Jun 2006, and point counts in a southeast Nebraska Henslow’s Sparrow study area in 2006 (Silcock and Jorgensen 2007) yielded an estimated density of 80 Dickcissels per 100 acres.
In the 2008 incursion year, at the west edge of the expected range, Dickcissels were “everywhere” in Keith Co 17 Jun, where the observer surmised that wetter conditions allowed for more weeds, and “abundant” in Lincoln and Custer Cos where a BBS route recorded them at 25 of the 50 stops. A BBS route as far northwest as Crawford, Dawes Co had a count high of 12 on 5 Jul during the 2011 incursion year.
Major incursions usually become apparent in the west in early Jun and consist almost entirely of unpaired males. Rosche (1982) indicated that he had “never observed a female nor any courtship or possible nesting activity,” and that singing males “often did not arrive until mid-Jun or even mid-Jul, sang for a week, and departed.” Of the surprising 30+ on a BBS route in Cheyenne Co 4 Jul 2009, most were males; only one pair was seen. Fretwell (1977) documented an unequal sex ratio in favor of males, which was thought to account for the many unpaired territorial males. Data from Kansas (Zimmerman 1982, Finck 1984) showed this absence of mates for males occupying much of central and western Kansas. The arrival during incursion years of males in the west occurs about a month later than in the expected breeding range, and reinforces the idea that these birds are unmated males; it has been suggested that Dickcissels may nest earlier in the southern portions of the breeding range and then shift northward, perhaps nesting a second time (Basili et al 1997).
The vast majority of reports west of the expected breeding range occur during incursion years; at these times there are reports throughout the area, including the area south of the North Platte River Valley and the western Sandhills.
Dickcissel nests are frequently parasitized by Brown-headed Cowbirds, a factor that limits Dickcissel reproductive success. Hergenrader (1962) found that 52.9% of the roadside nests he found in eastern and south-central Nebraska contained 1-3 cowbird eggs. Zimmerman (1982) found that in Kansas parasitism was significantly higher in grassland than in old fields and parasitism contributed significantly to lowered Dickcissel productivity in grasslands.
- Breeding phenology:
Copulation: 30 Jun-11 Jul
Nest-building: 19 May-2 Jul
Eggs: 19 May-18 Aug
Nestlings: 27 Jun-27 Sep
Fledglings: 24 Jul
- High counts: 122 in Johnson Co 13 Jun 2012, 100 at Branched Oak Lake, Lancaster Co 22 Jul 2017, and 82 in Seward Co 9 Jul 2011.
Fall: summer <<<>>> Oct 27,28,30 (east, central), Summer <<<>>> Sep 15,21,24 (west)
Breeding locations are abandoned by the end of Aug, and most birds leave by early or mid-Sep; Oct dates, however, are not unusual in the southeast. A later date is 16 Nov 2010 Harlan Co.
Fall flocks are rare in Nebraska, despite the propensity of Dickcissels to form huge flocks during fall migration (Temple 2002), suggesting that such flocks form to the south of the state.
High counts: 40 in southeast Sherman Co 4 Sep 2016, 35 at Hickory Ridge WMA, Johnson Co, 5 Aug 2016, and 33 in Lancaster Co 31 Aug 2002.
Winter: Reports of overwintering birds are of singles at feeders in the south and east, sometimes with House Sparrows. There are reports as far north as Wayne Co, in 1985-86 (Williams 1986). One was at a Bellevue, Sarpy Co feeder 15 Jan-29 Feb 1988 (Williams 1988) and another was at a Douglas Co feeder 10-17 Jan 1985 (Williams 1985). Very late, possibly attempting to winter, were singles at a Bellevue feeder 11 Dec 2000, at Hastings, Adams Co 12 Dec 1925 (Jorgensen 2012), at Schilling WMA, Cass Co 15 Dec 2018, on the Grand Island CBC 16 Dec 1995, on the Lincoln CBC one photographed 15 Dec 2012, Harlan Co CBC one photographed 20 Dec 2015, at a Lancaster Co feeder 1-31 Dec 1984 (Williams 1985), and a bright male at Alma, Harlan Co 1 Jan 2000.
BBA: Breeding Bird Atlas
BBS: Breeding Bird Survey
CBC: Christmas Bird Count
NWR: National Wildlife Refuge
UNSM: University of Nebraska State Museum
WMA: Wildlife Management Area (State)
Basili, G.D., S.L. Brown, E.J. Finck, D. Reinking, K.L. Steigman, S.A. Temple, and J L. Zimmerman. 1997. Breeding biology of Dickcissels across their range and over time. In Continental-scale ecology and conservation of the Dickcissel. Edited by G. D. Basili. Ph.D. dissertaiton, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Bruner, L., R.H. Wolcott, and M.H. Swenk. 1904. A preliminary review of the birds of Nebraska, with synopses. Klopp and Bartlett, Omaha, Nebraska, USA.
Ducey, J.E. 1988. Nebraska birds, breeding status and distribution. Simmons-Boardman Books, Omaha, Nebraska, USA.
Finck, E.J. 1984. Male Dickcissel behavior in primary and secondary habitats. Wilson Bulletin 96: 672-690.
Fretwell, S.D. 1977. Is the Dickcissel a threatened species? American Birds 31: 923-932.
Hergenrader, G.L. 1962. The incidence of nest parasitism by the Brown-Headed Cowbird (Molothrus ater) on the roadside nesting birds in Nebraska. Auk 79: 85-88; reprinted NBR 30: 20-23.
Jorgensen, J.G. 2012. Birds of the Rainwater Basin, Nebraska. Nebraska Game and Parks Commission, Lincoln, Nebraska, USA.
Mollhoff, W.J. 2001. The Nebraska Breeding Bird Atlas 1984-1989. Nebraska Ornithologists’ Union Occasional Papers No. 7. Nebraska Game and Parks Commission, Lincoln, Nebraska, USA.
Mollhoff, W.J. 2016. The Second Nebraska Breeding Bird Atlas. Bull. Univ. Nebraska State Museum Vol 29. University of Nebraska State Museum, Lincoln, Nebraska, USA.
Pyle, P. 1997. Identification Guide to North American Birds. Part I, Columbidae to Ploceidae. Slate Creek Press, Bolinas, California, USA.
Silcock, W.R., and J.G. Jorgensen. 2007. Henslow’s Sparrow Status in Nebraska. NBR 75: 13-16.
Temple, S.A. 2002. Dickcissel (Spiza americana), version 2.0. In The Birds of North America (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, New York, USA. https://doi.org/10.2173/bna.703.
Williams, F. 1985. Southern Great Plains Region. American Birds 39: 182-185.
Williams, F. 1986. Southern Great Plains Region. American Birds 40: 134-138.
Williams, F. 1988. Southern Great Plains Region. American Birds 42: 282-286.
Zimmerman, J.L. 1982. Nesting success of Dickcissels (Spiza americana) in preferred and less preferred habitats. Auk 99: 292-298.
Silcock, W.R., and J.G. Jorgensen. 2018. Dickcissel (Spiza americana), Version 1.0. In Birds of Nebraska — Online. www.BirdsofNebraska.org