By Krista Ruppert, Texas A&M WFSC
‘16
For
much of the time that bobwhites have been studied, it was assumed that upon
breaking off from their covey into pairs for breeding season, the pair would be
monogamous and work together (to a certain degree) to raise a single clutch of
eggs, or perhaps two if the first nest was not successful. More recent studies
have revealed that the breeding habits of bobwhites are not quite as
straightforward as once believed. Re-nesting may not be exclusive to failed
nests, multiple brooding may not be as rare as previously thought, and
polyandry (a female mating with multiple males) over a breeding season may
actually be the standard rather than an exception.
Re-nesting
is when a bird lays more than one clutch in different nests at different times
during a single breeding season. For bobwhites, it was a long held belief that
this was an uncommon practice, only occurring if a pair’s first brood was laid
early in the season and was unsuccessful. Taylor (1991) provided the first
direct documentation of re-nesting when he found hens to begin laying their
second clutch approximately seven days after losing contact with the first
brood. Burger et al. (1995) discovered differently; they found that females
incubated an average of 1.8 nests per season, and that 58% of females would re-nest
if their first nest failed. Additionally, 26% of females would attempt a re-nest
if their first brood was successful. Based on these data, it becomes evident
that the majority of quail, whether successful with their first brood or not,
will re-nest. Since bobwhite nests have a relatively low rate of survival, the
re-nesting process gives birds another chance to produce viable offspring,
potentially doubling their production rate. Some hens have even been observed
re-nesting twice, totaling three nests for one hen during a single season.
Success of all three nests during this scenario has yet to be observed, but
would not be statistically impossible. According to Cox et al. (2005), 74% of
females and 26% of males were recorded to have hatched a nest by the end of the
season, with the success of the nest independent of the sex or age of the quail
hatching it and whether it was an initial attempt as opposed to a re-nest.
 |
|
There is not
a sure way to tell whether a brood is the product of an initial nesting attempt
or a re-nesting attempt unless the female was wearing a radio-collar and her
nesting activity was monitored throughout the nesting season.
Photo from Texas A&M AgriLife Extension
|
Interestingly enough, however,
Guthery and Kuvlesky (1998) found that the overall production between coveys
exhibiting re-nesting and those not exhibiting re-nesting to be similar. Their
conceptual data based on modeling and previous studies discovered little
difference between the age ratios of the two groups under a typical probability
of success. While conceptual data should be treated differently than empirical
studies, their conclusions appear to be logical; areas not exhibiting
re-nesting behaviors were typically found at higher latitudes, where bobwhites
have been proven to be more productive in order to compensate for a shorter
breeding season. Less productive hens at lower latitudes, such as in Texas,
have a longer breeding season and the opportunity to re-nest at least once in
order to match the overall production rate of northern hens. Additionally,
clutch size appears to decrease as the season progresses, further balancing any
potential differences between the two groups.
 |
|
Re-nesting
allows quail a second chance to produce offspring when their initial nests
fail, and the chance to produce more offspring when their initial nests succeed.
|
Multiple-brooding, on the other
hand, is when a hen lays a clutch of eggs for a male to incubate, then
immediately lays another for herself to incubate as well, thus doubling the
amount of eggs being brooded during the same period of time. Multiple-brooding
is much more likely to occur during re-nesting than during an initial nesting
attempt. Out of all the nesting attempts in a breeding season, Burger et al.
(1995) found that 6% were multiple-brooding nests. Even outside the realm of multiple-brooding,
it is not uncommon for males to incubate a nest. It is estimated that 15-30% of
all bobwhite nests are incubated by males, whether due to multiple-brooding,
nest abandonment, surrogate parenting, or other factors.
Though some bobwhite exhibit strong
pair bonds which last throughout a breeding season, many are not monogamous
even during a single nesting attempt; around 40% of female bobwhites exhibit
polyandrous behavior during a single nesting attempt. When the scope is
expanded to cover an entire breeding season, Burger et al. (1995) found that
about 74% of female bobwhite exhibit polyandrous behavior (mating with more
than one rooster). This is a far cry from the lifetime bonding that was once
thought to occur! Monogamy is not without its benefits for quail, as it could
reduce courtship times, thus potentially allowing multiple broods to be hatched
and therefore increasing the overall chance of producing at least one
successful nest.
 |
|
Both female
(left) and male (right) quail incubate nests to optimize the survival of young.
|
So how can managers maximize the
breeding success of quail through re-nesting and multiple brooding? According
to Cox et al. (2005), the most important step is to ensure that there is plenty
of early nesting season cover. Proper cover provides temperature control,
protection from predators, and a safe place for quail to lay eggs. Better cover
leads to a higher chance of nest success, an especially critical aspect to
consider during the beginning of the nesting season when clutch counts are
highest. Additionally, it offers the opportunity for quail to have multiple
successful nests during the season. To learn more about provide an ideal
nesting habitat for bobwhite, see the following Texas A&M AgriLife
Extension resources:
Blog articles:
YouTube videos:
Literature
Cited
Burger, L. W., M.
R. Ryan, T. V. Dailey, and E. W. Kurzejeski. 1995. Reproductive Strategies,
Success, and Mating Systems of Northern Bobwhite in Missouri. Journal of Wildlife Management
59(3):417-426.
Cox, S. A., F. S.
Guthery, J. L. Lusk, A. D. Peoples, S. J. DeMaso, and M. Sams. 2005. Reproduction
by Northern Bobwhites in Western Oklahoma.
Journal of Wildlife Management 69(1):133-139
Guthery, F. S.
and W. P. Kuvlesky Jr. 1998. The Effect of Multiple-Brooding on Age Ratios of
Quail. Journal of Wildlife Management
62(2):540-549.
Roseberry, J. L.
and W. D. Klimstra. 1984. Population Ecology of the Bobwhite. Carbondale :
Southern Illinois University Press.
Sermons, W. O.
and D. W. Speake. 1987. Production of Second Broods by Northern Bobwhites. Wilson Bulletin 99(2):285-286.
Taylor, J. S.
1991. Aspects of northern bobwhite reproductive biology in South Texas. Thesis.
Texas A&I University, Kingsville, Texas.