From Wikipedia, the free encyclopedia
Grouping of eggs in a nest
A
clutch
of
eggs
is the group of eggs produced by
birds
,
amphibians
, or
reptiles
, often at a single time, particularly those laid in a
nest
.
In birds, destruction of a clutch by
predators
(or removal by humans, for example the
California condor
breeding program) results in
double-clutching
. The technique is used to double the production of a species' eggs, in the California condor case, specifically to increase population size. The act of putting one's hand in a nest to remove eggs is known as "dipping the clutch".
Size
[
edit
]
Clutch size differs greatly between
species
, sometimes even within the same
genus
. It may also differ within the same
species
due to many factors including
habitat
, health, nutrition, predation pressures, and time of year.
[1]
Clutch size
variation can also reflect variation in optimal reproduction effort. In birds, clutch size can vary within a species due to various features (age and health of laying female, ability of male to supply food, and abundance of prey), while some species are determinant layers, laying a species-specific number of eggs. Long-lived species tend to have smaller clutch sizes than short-lived species (see also
r/K selection theory
). The evolution of optimal clutch size is also driven by other factors, such as
parent?offspring conflict
.
In birds, ornithologist David Lack carried out much research into regulation of clutch size.
[2]
In species with altricial young, he proposed that optimal clutch size was determined by the number of young a parent could feed until fledgling. In precocial birds, Lack determined that clutch size was determined by the nutrients available to egg-laying females. An experimental study in Black Brent Geese (Black Brant), which rarely lay more than five eggs, found that the probability of an egg successfully leading to a fledged gosling declined from 0.81 for two-egg clutches to 0.50 for seven-egg clutches, whilst the nesting period increased with the increasing number of eggs laid. This suggests that there is no benefit for female Black Brant to lay more than five eggs.
[3]
Gallery
[
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]
See also
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]
References
[
edit
]
- ^
Lack, David
(1947): The significance of clutch-size (part I-II).
Ibis
89
: 302-352
- ^
Lack, D. (1947). "The significance of clutch-size, parts I and II".
Ibis
.
89
(2): 302?352.
doi
:
10.1111/j.1474-919X.1947.tb04155.x
.
- ^
Leach, A. G.; van Dellen, A. W.; Riecke, T. V.; Sedinger, J. S. (2017). "Incubation capacity contributes to constraints on maximal clutch size in Brent Geese
Branta bernicla nigricans
".
Ibis
.
159
(3): 588?599.
doi
:
10.1111/ibi.12475
.