Spoiling their EGGs is a Reasonable Solution.
Click Images to Enlarge.
Each Fall and Winter Veterinarians and Wildlife Rehabilitaters in many States
may have Multiple Calls about Young Mute Swans found in Distress.
Some Young Swans are Found by the General Public..
Maybe in their Yards. Maybe along the Road. Maybe on their Ponds.
The Young Swan Below was on the Property Owner’s Pond when she came Home from Work.
I get Several Calls every Year from Folks who are Excited they have a Lone Surprise Swan.
Now they want to Find a Companion/Mate for this Swan. They have NO Idea of the Age or Sex.
I Explain what Needs to be Done.
Feed-Gain Trust, Catch the Swan, Clip One Wing and Send a DNA Sample to Learn the Sex.
So Far, Few Free Flying Rogue Swans has been Caught or Stayed with them.
Some Swan will Come and Go, Gone for a While, Returning at Random..
These 7-8-9 Month Old Rescued Cygnets Below were Likely Chased Away by their Parents,
when the Adults were Getting Ready for their Spring Nesting Season.
These Growing UnPinioned Cygnets have Nowhere to Go.
They are Chased into the Larger World Totally Unprepared.
No Idea how to Care of themselves.
Young Cygnets are very Vulnerable to Predators and Dog Attaches when Feral..
When Rescued.. Many are Injured, have Wounds and Broken Bones.
Sadly, many will be Euthanized.. This was the Fate of the Young Swan Below.
Evaluated at an Animal Clinic.. Advanced Infection, Wounds Full of Maggots.
Unknown Blood Loss, Badly Mangled Foot.. Euthanized to End Suffering.
Many Rescued Swans are UnderWeight..
During Fall and Winter there are Few Natural Foods for them to Eat, if they can Find any.
The Cygnet below was Very Scared when Brought to a Rescuer’s Home..
As I have been Reading various Article about Department Natural Resources
WildLife Services ( Different States ) Mute Swan Management Methods.
I have come across a Number of Very Disturbing, Cruel Practices.
It is Far Worse to Allow a Cygnet or Swan to Fly Away to be Abused and Destroyed.
Slaughtering these Helpless Swans can not be much Enjoyment for the WildLife Services
who are Trained and Employed to Protect WildLife.
I Feel it would be MUCH more Ethical to Prevent Cygnets Hatching
then to have them Endure the Perils of being Feral and the Potential End
of their Lives by the WildLife Agencies various Cruel Slaughtering Practices.
Having Cygnets every Year can be Demanding – They are Cute and Work.
They NEED to be Pinioned.. DNA-Sex Determined..
and New Adoptive Homes Arrange between 4-9 Months Old.
It MAY be Tempting to just let the Cygnets be Chased off..
Out of Sight…Out of Mind.. Now Someone Else’s Problem.
Being a Responsible Swan Keeper.. YOU will Not Let this Happen.
Or Maybe you just want to “Take a Year OFF..”
Prevent Cygnets Hatching in Years that other Things in your Life have Priority.
And just Enjoy your Graceful Adult Swans on a Peaceful Summer Pond.
OR Maybe your Pond is Really NOT Suitable for a Large Brood of Eating-Pooping Cygnets.
Maybe Limit the Number of Cygnets that Hatch.
The 0.48 Acre Retention Pond Above & Below became FOULED with Swan Cygnet Poop.
Neutering or Spaying is NOT an Option with Swans..
DO NOT Spay or Neuter Swans
I did some Reading about Hormone Implants for Birds.
This is Expensive, May Not be Effective, Needs to be Repeated Frequently.
The Article Below was Informative.
Hormone Implants for Avian Species. … ARE NOT Practical.
DO NOT JUST REMOVE OR BREAK the EGGS !
Removal of All the Eggs or Breaking the Eggs will cause the Pen
to Lay a Second Clutch of Eggs.
This will Deplete her Body more then Necessary… and Extend the Nesting Season.
Having to lay Extra Eggs may/will Deplete the Pen of the Nutrients
to Regrow Healthy Feathers after her Annual Moulting.
The Swans Above and Below Lost their Early Spring Nests to the Creek Flooding Twice.
We could only Guess… she may have Laid around 20 Eggs that Year.
Nest #1 > 8 Eggs – Nest #2 > 7 Eggs – Nest #3 > 5 Eggs. ca. 15 were Lost to Flooding.
They ReCycled.. the Pen Laid 5 more Eggs ( Third Clutch ) Nesting into Mid-July.
One Egg Cracked and I Removed it. ??? Maybe the Shell was Thinner.
One Egg was Stolen by a Raccoon.. Then there were just Three Eggs.
We were Helpless to do Anything since these Swans were Living Feral..
After a Very Long Nesting Season, Three Tiny Cygnets Hatched on July 14-15th.
In 2022, We Still have the Pale Brown Cygnet on the Left.. He is our “Meadow.”
During the Late Winter and Very Early Spring Months,
Roughly THREE Weeks before a Mute Pen begins to Lay her Eggs..
YOU WILL Typically SEE the Pen EATING – EATING – EATING..
Preparing her Bodies to Lay a Clutch of BIG Eggs. ( Average 4-8 )
Natural Egg Production is Stressful for Female Birds/Swans.
It Depletes their Nutritional Stores, and Predisposes them to Malnutrition,
Osteoporosis, and Life Threatening Illnesses.
They Benefit from a Proper Diet during the Winter Months.
It is a BAD Idea to Catch or Disrupt your Pen’s Egg Laying Process.
Catching your Pen during the Days that she is Laying her Eggs
may STOP an Egg from Moving through her
Uterus > Shell Gland > Vagina > Cloaca and being Expelled into her Nest.
Risking the Pen becoming EGG BOUND with all the Risks
and Serious Complications an Egg being Stuck
in the Pen’s Uterus-Shell Gland may Cause.
BEST to WAIT and Allow your Pen to Naturally Lay her Full Clutch of Eggs,
Allow her to “Sitting” to Incubate her Clutch for at Least 7-10 Days
before you do ANYTHING with your Pen during her Nesting Sequence.
You WANT to be sure she is Finished Laying Eggs.
Black Australian Swans Nest Twice a Year..
It can be Challenging to Raise these Cygnets during the Winter Months.
These Last Season Cygnets will Need to be Shelter-Raised in Cold Regions.
Maybe you Want to have just One Brood during the Warmer Months.
Here I will State: I have No Experience with Spoiling Swan Eggs.
I have not “Actively” Spoiled any Swan Eggs with Plain Corn Oil..
So my Information is NOT Hands-On.. Just from Reading.
I have Talked with a Number of Folks who have Used Spoiling Methods
to Control other Types of Waterfowl.. Example Muscovy Eggs.
We have used Replacement Eggs most Years… Successfully.
At First Real Mute Swan Eggs, Drained, Cleaned and Filled.
But without a Doubt the Wooden Reusable Eggs have Worked Well.
SWAN REPLACEMENT EGGs
We can use them to “Swap-Out” the Real Eggs to Prevent Cygnets Hatching.
OR they are Ready if Eggs are being Stolen from a Fertile Swan Nest.
OR if there are Eggs that are Not Developing and Start to STINK ! !
I Know there is a Need for this Information about Spoiling to be Available.
I am going to RELY on Reading a Number of Articles and Compile General Information.
I Suggest you ALSO Read a Variety of Articles.
If the Articles seem to make Sense.. Gathering Information is Best.
I did Call our State’s Waterfowl Specialist and Ask for Information..
I am Including this in the Text Below.
I hear People Troubling with the Ethics of Killing the Embryos..
They want to Remove or Oil the Eggs VERY Soon after they are Laid.
Before there is much Development..
I have Searched without Success for a SWAN Embryo Development Chart.
Chicken Chicks Hatch in 20 Days.. Swan Cygnets Hatch at 37 Days.
Each Stage on this Chart would be Almost 2 Days for the Developmental Stages of a Cygnet.
AT 7-10 Days of Incubation the Cygnet Embryos would be at 4 to 5 Days on this Chart.
It is Up to You.. when you Decide to Spoil the Eggs.. 7th Day or the 25th Day..etc.
BUT, I do think it is Wise to Wait until the Pen is “Sitting” Full-Time for at least a Week..
JUST to be Sure her Clutch is Finished !
True Story: One Swan Keeper saw his Pen “Sitting” on Four Eggs.
He “Swapped-Out” Two Real Eggs for Two Replacement Eggs he made.
Goal to Allow just Two Cygnets to Hatch.. Manageable for their Enjoyment.
SURPRISE > > > SIX Tiny Cygnets Hatched.. Explanation.
Four more Fertile Eggs were Laid after the “Swap-Out.”
COMMONLY USED METHODS for Spoiling or Reducing:
ADDLING – Addling is a Wildlife Management Method of Population Control
of Various Bird Species that are Increasing in Numbers.
Eggs are Temporarily Removed from the Nest, the Embryo Development is Terminated
and the Eggs are Returned to the Nest.
Methods that Terminates Embryo Development are by Oiling, Shaking
or Puncturing the Eggs and then placing the Eggs Back in the Nest.
It is Important Not to Change the Odor, Appearance or Texture of the Eggs.
This Allows the Nesting Female to Continue her Nesting Process..
By Disrupting the Yolks from Developing there will be No Cygnets.
AS I was Reading, One Person Leaves the Parent Swans One ”Good Egg” to Care for.
Personally, a Cygnet Raised Alone is a Little Sad.. Maybe Leave them Two Fertile Eggs.
OILING: It is IMPORTANT to ONLY USE a FOOD GRADE OIL.
AS I Searched for Information,
I came Across the Same Field Study Article Several Times.
“Spraying Corn Oil on Mute Swan Cygnus olor Eggs to Prevent Hatching.”
1996-1997 Larry J. Hindman, William F. Harvey, IV, & Linda E. Conley
Corn Oil is an Effective, Nontoxic Method of Reducing Mute Swan Eggs Hatching.
Spraying an Oil/Oil Flour Product on the Eggs will Cut Off the Oxygen Exchange
through the Tiny Pores in the Shell. This will Stop the Embryos Developing.
My Best Guess is that Eggs Coated with Plain Corn/Vegetable Oil
should Not be Soaked and Slimy.. The Oil can be Sprayed or Rubbed on with a Rag.
Be Sure to Coat the Entire Surface of the Egg.
It Occurred to me that this Oil might Interfere with the Pen’s WaterProofing.
She would be Sitting on the Eggs and get the Corn Oil on her Abdomen Feathers
and then Preen the Oil ALL OVER. Hummm !
*** I am Going to see if I can Learn More.
These Oil Spoiled EGGs will Start to Rot and Stink by the End of 42 Days.
EGG SHAKING: This Method of Waterfowl Population Control has been the Standard.
Used for Decades by Fish and Wildlife Services
and has the General Approval of the Atlantic Flyway Council.
Eggs are Vulnerable to Vibration Type Injuries Early in Incubation.
Shaking or Jarring can Kill the Developing Embryo either Directly
or by Rupturing the Yolk.
The Yolk of an Egg is Suspended between two opposing Filaments of Protein
called the Chalazae. Shaking can Dislodge the Chalazae.
Brisk Vigorously Shaking beyond the Point of Breaking the Chalazae,
will Start to Break-Up the Yolk and No Embryo will Develop.
These Spoiled Eggs will Start to Rot.. ( PPPe-UUU )
There “Might” be a Small Percentage that Survive Shaking.
June 2022… I am ADDING this Personal Note:
Last Weekend I was Preparing a Casserole that Calls for 6 Eggs..
I Thought I would SHAKE these Raw Eggs and See if they would be Scrambled
when I Cracked them into my Recipe.. I SHOOK and SHOOK.. Very Hard.
I Could Hear the Liquid Inside each EGG Rattling as I SHOOK….
I Shook Harder and Longer with Each Egg.. NOT ONE had a Broken Yolk.
ALL 6 Eggs were in Perfect Condition when I Cracked them.
PERSONALLY >>> I would not Try this Method..
The Cygnet Above was a BIG SURPRISE.. ( A Happy Surprise ! )
It was Day 42… We are there to Take All the Eggs Away ! !
CULLING: The Word seems to have Various Meanings..
Here I am Using Culling.. as Reducing the Number of Eggs.
If a Swan has a Clutch of 8 Eggs.. Up to 5 Might be Removed
to Reduce the Number of Cygnets that will Hatch..
Removing Some or All of a Clutch.. ( REPLACE Some with Replacement Eggs.)
Leave the Pen at Least 3 Eggs to “Sit.” Spoiled or Fake or Fertile.
If you Remove Several Eggs from the Clutch.. Put them in a Container
to keep them Safe and Refrigerated.. You might Need them for Replacements.
PUNCTURING: I Tried Several Key Word Searches.. and I could not
Find much about Puncturing Eggs to Prevent Hatching.
I would think this Method would NOT be a Foremost Method.
Piercing with a Thin Hat Pin and Stirring the Content.. Breaks the Yolk.
From a United States Department of Agriculture
Animal and Plant Health Inspection Service WebSite:
Puncturing—To Puncture the Egg, hold it securely in your hand, Braced against the Ground.
Insert a Long, Thin Metal Probe into the Pointed End of the Egg.
Best Results are by placing Slow Steady Pressure. ( If the Egg Breaks-Cracks, Remove it. )
Once the Probe Passes Through the Shell, Place the Tip against the Inside of the Shell,
and Swirl with a Circular Motion. Swirl Several Times to Ensure the York is Broken.
Puncturing the Shell would Introduce Bacteria and Dirt.
One of the Most Common Causes of In-Shell Deaths for Forming Embryos
is a Bacterial or Viral Infection Entering through a Crack in an EGG.
As the Pen Turns her Clutch Several Time a Day, I would Expect the Albumin
to Start to Leak from the Eggs. That would Attract Insects.. and be a Sticky Mess.
As the Egg Contents Degrades the Leaking would Increase.
If you Spoil your Pen’s EGGS…
DO NOT Allow her to “Over-SIT” Incubating Eggs that will Never Hatch.
She Needs to be Able to Start Eating..
Remove the “Eggs” from the Nest at 42 Days.
Another Plan to Consider:
Contact a Swan Breeder who might Want the Fertilized Swan Eggs.
Talk with them about when to Remove Some of the Fertile Eggs Under your Pen.
Only Remove a Few of the Clutch…
Leave the Pen some Eggs to “Sit-On”.. Or “Swap-Out” with Replacements.
IF you PLAN AHEAD : Arrange for Another Person to Raise your Cygnets.
Before the Cygnets Hatch.. See if you can Arrange for Another Person
to Raise the Cygnets. Be Sure they have a Proper Environment to do this.
A Protected Pond and a Shelter for Night Time Safety.
Decide Who will Pinioned the Cygnets before 21 Days Old.
Hand Raised Cygnets have a Better Survival Rate then Cygnets Raised
by their Parent Out on an Average Pond.
All Ten of the Cygnets Above – in 2022 are Mature Swans in Homes that Love them.
I like the Replacement Eggs the Best.. Zoos use them.
The Real Unfertile or Spoiled Eggs will Start to Rot..
They Smell Terrible, Attract Flies and Some Explode.. Stink BOMBs – BIG Mess !
AND with the Sneaky Raccoons Stealing so many Eggs..
It is SO Helpful to have the Replacement Eggs.. Real Eggs Refrigerated or Wooden Fakes.
We have been using the Wooden Replacement Eggs for 5-6 Years..
They have been so much LESS Worry… Ready when Needed..
And our Pens have Accepted them without any Problems.
( All but One Egg. )
I Never Figured-Out Why this One Egg was Rejected Repeatedly.
I Must Decline ANY Request to Make Replacement Eggs for you Folks.
I would have to make Hundreds for All the People who have Asked.. (-;
SPOILING the EGGs in a Swans’ Nest.
This is a Helpful Procedure if you Do NOT want to have Swan Cygnets every Year.
I have Found the BEST Items to use to Protect Myself Working by a Swan Nest..
is a Folding Lawn Chair.. I Turn it Around as a Barrier-Shield.
Female Swans MUST “Sit” on their Unfertile-Spoiled Eggs for at least 42 Days.
OR They Will ReCycle and Lay more Eggs.. With or Without a Cob.
They have NO Control over this Timing.. Mother Nature is in Charge..
Normally Fertile Swan Eggs will Mature in 37 Days.. – /+ a Day.
Healthy Cygnets will All Hatch within 24-36 Hours.. 48 Hours at most.
The Pen will usually continue to “Sit” as much as Possible on UnHatched Eggs for 72 Hours..
Then She will take her Healthy Cygnets out to Begin Feeding
and Spend more and more Time away from the Nest.
The Dam ( Pen ) and Cygnets may Return to the Nest for Several Day..
for the Cygnets to take Naps. (Very Cute). And Warm-Up Under their Dam.
Female Swans will Lay One Large Egg every other Day until ALL her Clutch is in the Nest.
She will NOT “Sit” Full Time until ALL her Eggs are Laid.
This may take 2 – 3 Weeks, if she Lays 7 – 8 – 9 Eggs.
During this Time.. the Cob and the Pen will Keep a Close Watch over their Eggs..
Especially if Someone Approaches..One or Both will QUICKLY Head to their Nest..
They may Cover the Eggs at Times. Making it Tricky to Count the Eggs.
You might see the Cob Sitting for Long Periods on the Eggs…
The Female Only a Few Minutes.. Just to Guard and Protect her Eggs from Visitors.
The Cob can not Incubate..
He can Only Protect and Keep the Eggs Warm Once Incubation Begins..
ONCE the Pen STARTs to “SIT” Full-Time.. NOTE this DATE ! !
Incubation of the Entire Clutch will begin. THE 37-42 Days Starts.
37 Days for Fertile Eggs to Hatch..
This way ALL Fertile Eggs should Hatch within a 24-48 Hour Period.
42 Days to Remove UnHatched-Spoiled Eggs.
WAIT for a Few Days, after you KNOW the Pen is “Sitting” Full-Time.
You want to be SURE she is Finished Laying. ( 7-10 Days )
It is VERY Helpful to have Several People to Do these Projects.
Keep CALM and TRY NOT to be LOUD.. Quiet is Less Stressful.
Make Your Plan and Who will do What !! Practice – Be Prepared.
Do a Basic Practice Walk Through..
Have a Spray Can of Baking Spray with Flour READY.
OR a Plain Spray Can of Baking OIL.. Or a Cup of Salad Oil in a Plastic Container.
And a Rag for Applying the Oil. AND some Paper Towels if Needed..
It is Helpful to have your Supplies in a Bucket.
BE SURE the CAN of Baking Spray will Spray Freely..
and that there is ENOUGH Product.
An Older Can from you Kitchen Cabinet, might NOT WORK !
This is Inexpensive and Readily Available where Baking Supplies are Sold.
Most Grocery Stores Carry this. USE a FRESH Full Can.. ANY Brand.
First, Contain the Cob.
He will generally be Hormonal and is EASY to Catch.
( This is a Good Time to Wear White. )
Most Cobs will COME TOWARD you.. Hoping to Chase you AWAY !
Have a Large Net or Large Beach Towel READY. Let him come to you ! !
We put our Cobs into a Transport Carrier placed in a Shady Place.
Turn the Carrier away from the View of the Nest..
Approach the Nesting Pen Slowly.. Give her a Chance to Assess her Risk.
Some will Leave the Nest and Slip into the Water..
and Some Pens will Continue to Sit and Protect their Eggs.
Move Closer Talk Softly, Net or Wrap the Pen in a Large Towel.. Be Gentle.
Hold her Aside from the Nest. Cover her Head if Possible.
Have your Helper Spray the Top Side of EACH Egg..
Turn Over and Spray ALL Sides. COAT the Entire EGG.
Release the Pen…. She will Usually Return to her Eggs.
Next, Release the Cob. Open the Carrier.. let him Exit..
He will HOPEFULLY Head to the Water..
Keep Something Between YOU and the Cob..
If the Eggs are Fertile, the Oil-Flour in the Spray will fill the
Tiny Air Exchange Pores in the Egg Shell.. the Embryos will NOT Develop..
Once the 42 Days of “Sitting” Time has Passed..
A few Pens will leave these UnHatched Eggs on their Own.
Some Females will Continue to “Sit” for many more Days..
If the Pen HAS NOT left the Eggs on her own..
For her Health, it is a Good Idea to Remove and Discard the Eggs.
( THEY WILL SMELL and Attract Flies. )
The Pen does Not Realizing the Eggs will Not Hatch.
A Percentage have been known to Stay on the Nest for Weeks.
She is at Risk of Starving to Death. ReMove the Eggs.
It Took us 90 Seconds to Remove the Stinky Eggs from the Nest Above.
In that Short Time – The Pen was So Stressed that she Collapsed – Fainted.
She Scared the Heck OUT of Us.. The Stress Caused her Blood Glucose to DROP !
After about 2 Minutes her Eyes Started to Blink.. and Sloooowly she Lifted her Head.
We Allowed her to Rest – She Stayed with her Empty Nest that Day.
By the Following Morning, she was out on the Pond Eating.. Recovered.
Now I keep a Few Ounces of a Sweet Syrup like Honey with us.
Timing Swan Eggs to Hatching
If necessary do the Same as above.. Contain the Cob..
Encourage the Pen to Leave her Nest.. Be Patient about Half Will.
We had a Small Container of Concentrated Sugar – Honey, Karo or King Syrup Ready.
The Pens have Little Extra Blood Sugar to be Stressed when the Eggs are Removed.
If the Pen becomes Very Weak or Faints.. Put a Little Syrup under her Tongue..
Keep her in a Safe Place.. and Allow her to Recover from the Excitement.
Yes, we have had Pens become Very Weak.. Only One that Fainted.. This was Scary..
Within a Few Minutes, she was Awake and Recovered.. Out on her Pond the Following Morning.
Wear Protective Glove ( the Eggs will Smell )
Quickly put the EGGs in Double Plastic Bags in a Bucket.. ( they may Explode ! )
LEAVE the Swans Alone.
They need some time to Realize the Eggs are gone.
Typically, they may Spend One more Day at the Nest.
The Following Morning most are Out on their Pond Grazing.
The Next Morning the Pen was OUT on her Pond.
After a Few Days.. Remove the Nest Material..
A Decaying Nest will Attract Unwanted Critters.. Insects, Worms, Rodents and Snakes.
Plus Nasty Bacteria and MOLDs..
Better to Supply New Nesting Materials Next Spring.
Female Swans MUST “Sit” on their Eggs for at Least 42 Days..
OR they are likely to Recycle and lay more Eggs..
Nest Mortality is High for the Pens.. So, it is BEST not to have them
Laying a Second Clutch by taking their Eggs away.
We had one Feral Female Years Ago.. She lost Two Clutches to the Creek Flooding..
Both after “Sitting” for Three Weeks.. AND they Started a Third Nest !
Started “Sitting” June 11th with Four Eggs….
Hatched Three Cygnets July 15th. IT was HOT ! ! ! ..
I would take her a Container of Ice Water in the Afternoon and put it on the Side of her Nest.
Getting Flooded Out or having a Raccoon ( or People )
take the Eggs are Common Reasons for Swans to ReCycle..
You will See the Swans Mating Again.. and More Eggs.
Extending their Nesting into the Hottest Period of Summer.
Natural has programmed their Bodies to keep Trying if they lose their Eggs
to Flooding or Predators. We can NOT Control All Situation.
But, it is GOOD to Know your Options.
This Topic Page was Compiled from a Combination of our Experiences
with Feral/Wild and Numerous BackYard Nesting Swans.
And Lots of Online Reading.. and Chats with Other Swan Folks.
Organized in March 2022 (c) Linda M. Sweger