18 Nebraskaland • August-September 2021
IN THE FIELD
By Joel G. Jorgensen
MISSING BLUEBIRDS?
If you think you are seeing fewer eastern bluebirds in 2021,
you are not imagining things, and you are not alone.
Eastern bluebirds are familiar, popular and, usually, fairly
common songbirds that inhabit many of Nebraska's rural
landscapes in summer. Even when not enjoyed visually, a
male bluebird's cheery song is a delight to the ear. Eastern
bluebirds declined during the mid-20th century, in part
because of competition for nesting cavities from introduced
European starlings and house sparrows. Nest-box campaigns
that began in the 1960s and 1970s have helped bolster
bluebird numbers. The species has increased by about 2%
annually in the state since 1966, according to the national
Breeding Bird Survey.
So, what happened to bluebirds in 2021? Harken back to
the intense February cold spell. That extreme and unusual
weather event descended from Nebraska all the way south
into Texas and Mexico and remained in place for an unusually
long period. Eastern bluebirds are a semi-hardy species
that does overwinter in Nebraska in small numbers, but
adequate food resources are essential for fending off chilly
temperatures. Blue birds become vulnerable to extremely cold
weather when food resources are limited, and, presumably,
this susceptibility surfaced this past winter.
While a complete picture of their dramatic decline in 2021
may not be fully understood for some time, initial estimates
and anecdotes suggest numbers may be down more than
80%. It is also too early to be certain whether other factors
may or may not have contributed to the decline.
The absence in many places of such a delightful avian
species is disappointing. Long-time bluebird enthusiasts with
Bluebirds Across Nebraska have stated they have never seen
a steep drop in numbers like this one. These observations are
not just limited to Nebraska, as similar reports have come in
from nearby states. Furthermore, several other species that
overwinter in the southern U.S. and summer in Nebraska, such
as eastern phoebes and tree swallows, also appear down.
The 2021 decline in numbers of bluebirds and other species
requires attention going forward to ensure some other factor
may not be affecting these birds. Even if the cold spell is
the sole culprit, it likely will take several years for eastern
bluebird numbers to recover.
Joel G. Jorgensen is the Nongame Bird Program Manager for
the Nebraska Game and Parks Commission.
Eastern bluebird at Pawnee State Recreation Area in Lancaster County. CHRIS MASADA
