Inbreeding Lovebirds & Other Questions
Adrienne Stephens
They currently have a nine week old baby and the female is sitting on a
new clutch of five eggs. If I keep them together as a family , will it
cause problems when the young mature and start to breed? I know that
inbreeding is bad for dogs etc. but don't know about birds.
Also, the 9 week old baby who has been parent fed seems to be eating on
his own but the father still feeds him on occasion. Is he old enough to
be on his own? The mother bird is quite agressive while sitting on her
eggs and I don't want her to injure the big baby. Can I put them all
together again after the new eggs hatch? Will the big baby be too
lonesome by himself at this age? If the 9 wk. baby is too young to be
alone, would it hurt if I moved them all, Including the new nest into a
bigger cage while the mother is still brooding?
Obviously, I am new to bird breeding, but I love them and want to do
well by them. Any help would be appreciated as the books I've read don't
seem to answer my questions.
Adrienne, San Jose, Ca.
Steve DeGroof
>I have a pair of apparently prolific peach faced Dutch Blue lovebirds.
>They currently have a nine week old baby and the female is sitting on a
>new clutch of five eggs. If I keep them together as a family , will it
>cause problems when the young mature and start to breed? I know that
>inbreeding is bad for dogs etc. but don't know about birds.
As far as I know, all complex organisms are affected by inbreeding. Inbreeding
can bring out undesirable mutations through reinforced recessive genes. Some
breeders of livestock will use inbreeding to bring out desirable mutations.
This is done by separating the animals into small groups, letting them inbreed,
and culling any animals with undesirable characteristics. Any animals left over
are collected into a new breeding pool and the process starts over. This sort
of process can produce dramatic results in a short period of time. The major
problem is that it can cause mutations that may not be immediately apparent:
reduced lifespan, susceptibility to disease, that sort of thing.
Does anybody know if bird breeders engage in this practice? It would explain
why lutino 'teils have bald spots.
SD
DeeAnna Weed
mutation as an example. The lutino mutation, however, in cockatiels at
least, is not a simple recessive trait as Scott presented it. It's a
sex-linked color. If X is the male chromosome and Y is the female, then
male 'tiels have two male chromosomes or XX. Females have one male and
one female or XY. This is the opposite of mammalian genetics where males
are XY and females are XX.
To be feathered in a sex-linked color like lutino, cinnamon, or pearl, a
male 'tiel baby MUST inherit two X chromosomes that carry the sex-linked
color. If he only gets one with the sex-linked color gene, the baby will
be a normal grey (or maybe some other non-sex-linked color, like pied,
white-face or fallow). Female 'tiel babies only need to inherit one X
chromosome carrying the sex-linked color to show that color. That's why
breeders sometimes know what sex a 'tiel baby is right out of the egg.
If the father is a normal grey, for instance, and the mother is a
lutino, then all the babies will inherit one copy of the lutino gene.
Since females only need one copy to be a lutino, while males need two
copies, all lutinos from that set of parents *have* to be hens.
It is my understanding that the baldness associated with lutino 'tiels
was indeed caused by breeding lutino birds into a line of 'tiels that
carried a bald spot. It's also possible, I suppose, that this genetic
baldness may be attributable to the lutino mutation itself. My oldest
lutino 'tiel, Miss Max, is "thin" on top, but not really bald, but the
lutino offspring of her and my whiteface/lutino male, Pip, are bald.
(Whiteface/lutino means that Pip is visually a whiteface 'tiel, but he
carries one lutino gene. Some of his and Miss Max' male babies are
lutino.)
In _Keeping and breeding cockatiels: A complete guide_ by Dulcie and
Freddie Cooke, 1987, Blandford Press, London, ISBN 0-7137-1961-3, the
first lutino cockatiel was born in 1958 from two normal grey 'tiels
owned by Cliff Barringer of Florida, USA. Lutinos were introduced to the
UK in 1968 from the aviary of Mrs. E. L. Moon, who bought the original
lutino birds from Barringer and developed the mutation. Perhaps it was
Mrs. Moon who inadvertently bred the baldness trait into the lutino
line, but I don't know that for a fact.
BTW, the book I refer to is a good one if you are interested in basic
info on 'tiels. The authors talk about aviaries, brooders, the color
mutations, basic genetics, basic nutrition, etc. Lots of color photos of
the different color mutations. I would NOT take the authors too
seriously about what specifically to feed 'tiels or how to provide first
aid or medical treatment. So much more is known about avian nutrition
and medicine now that this information in their book is dated, or just
plain wrong.
--
DeeAnna Weed Fear loss of meaning
Ag & Biosystems Engineering dee...@iastate.edu beyond all other losses,
Davidson Hall, Iowa State Voice: (515) 294-6286 because without it
University, Ames, IA 50011 FAX: (515) 294-2552 one can love nothing
Cathy Quinones
>
>Does anybody know if bird breeders engage in this practice? It would explain
>why lutino 'teils have bald spots.
>
The inbreeding is done for the reasons you describe: to accelerate the rate
at which the breeder can find a desirable mutation and hone down on it. What
is usually done is that there are periods of inbreeding, then periods of
out-breeding to counteract the negative effects of the inbreeding. Say you
have a pair of breeding birds and a new color mutation shows up. It could
have been that one of the parents was carrying the mutation without
expressing it, or it could be that the mutation originated in the
offspring itself. So the breeder may breed the offspring back to a
parent, or to its siblings, in hopes that more offspring with the mutant
trait show up. Depending on how the trait is genetically coded, the breeder
may be capable of making the trait "breed true" (say, purple mutants bred with
one another always produce purple birds), in which case the breeder is then
all set to produce the rare mutants. At some point, there will probably be
some outbreeding to do what you said: bring in some "fresh blood" (read
genetic variability) to counteract the negative effects of
inbreeding. Inbreeding basically breeds "same" with "same" therefore you end
up with a bunch of individuals that are very similar genetically: that may
mean, they all are equally defenseless against a certain disease, or that they
all carry a "fault". In the case of the bald spot in lutino 'tiels, I
understand what happened is that a lot of today's baldies :) go back
to an early few lutino mutants that had a genetically determined bald
spot. The market must have been so keen on getting these new yellow
birds that people didn't care the birds also had a bald spot. These birds
were subsequently bred also and the bald spot kept spreading, to the
extent that today one often hears that all lutinos have the bald spot.
I haven't dug around in a lot of lutino crests :) but I have seen some that
patently had a bald spot, others looked like they were feathered normally.
This suggests that the lutino and the bald spot traits aren't necesarily
genetically linked (i.e., if linked, when one shows up, so does the other),
which supports the idea that the high proportion of animals with the bald spot
has to do with breeding practices. I guess what I am trying to say is
that the fact that we have non-bald, healthy, robust lutinos means that at
some point some breeders did some inbreeding (the birds, not the breeders!),
and managed to "create" animals without obvious faults.
Also, I understand cockatoos have a bald spot underneath their crests; does
that mean they all hail back to a "baldie" ancestor or that natural
selection favored a bald spot (to dump heat? or whatever)? I would go on
to comment on how sparsely feathered 'tiel heads are, but if I tried to dig
around Sid's crest he would bite my head off... I leave that experiment to
people with mellow 'tiels :)
--
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////// /\_/\_____ \\ /// quin...@biology.ucsc.edu ////////////////
///// \"."/ \_// /// ////////////////////
/////////////////////////// Poicephalus rule!!!! /////////////////
Scott Lewis
Scott Lewis
>
>Scott Lewis presented a good post on genetics, using the lutino color
>mutation as an example. The lutino mutation, however, in cockatiels at
>least, is not a simple recessive trait as Scott presented it. It's a
>sex-linked color. If X is the male chromosome and Y is the female, then
>male 'tiels have two male chromosomes or XX. Females have one male and
>one female or XY. This is the opposite of mammalian genetics where males
>are XY and females are XX.
>
Yep. I should have done more homework before using lutino as an example.
It is sex-linked. My example and associated Punnett squares works for
simple, Mendalian, non-sexlinked traits. For example, brown eyes versus
red in many species.
Here's how it works for lutino in cocatiels. I am paraphrasing from an
article in the newsletter I edit by Dr. Darrel Styles.
Birds are different in that their male and femal sex gene roles are
reversed from mammals, meaning the the female is heterozygous
(different or "split") and the male is homozygous (same). In birds, we
use Z and W for the sex chromosomes insteda of X and Y. (The letters
refer to the shape.) A male bird is ZZ; a female is ZW. (Human males are
XY, females are XX.) In this discussion gentoype is the genetics of the
bird and phenotype is how the gene combinations are expressed. Also, we
will use Z(l) for a Z chromosome carrying the lutino mutation. The lutino
mutation cannot be carried on the W chromosome. Note that lutino is a
recessive trait.
Bird Genotype Phenotype
--------------------------------------------
Grey male (not split) ZZ grey
Grey male (split) Z(l)Z grey
Lutino male Z(1)Z(1) lutino
Grey female ZW grey
Lutino female Z(l)W lutino
--------------------------------------------
Case 1 above male ZZ, the male is grey. Lutino mutation not present.
Case 2 male Z(1)Z, the male is grey. Lutino mutation present but not
expressed because it is recessive.
Case 3, male is lutino Z(l)Z(1) becauase recessive lutinot mutation is
present on both chromosomes.
Case 4, female is grey ZW because lutino mutation is not present.
Case 5, female is lutino Z(1)W because lutino mutation is present on Z
and W does not carry a corresponding color gene to mask it. If the lutino
mutation is present in a female, it is always expressed.
To get 100% lutino babies, you still must cross lutino x lutino. I won't
work out all the yields on all the possible crosses. Consider it an
exercise in beginning genetics.
Regards,
Sarah Folkes
One thing no one picked up on! DONT leave that bay in there, chances are
the parents will kill it, if not before the next clutch hatches, then
shortly after it fledges! Lovebirds are aggressive! you dodnt mention <I
dont think> what size cage they were in!
Sarah