LECTURE 21/22/23 - Parental Care (Birds) Flashcards
There are two forms of paternal care in birds describe the two.
Biparental care (90%) Female only parental care (10%)
Making eggs takes a lot of ___ and ___.
time / energy
Shells require a lot of _____
calcium
Ducks grouse and sandpipers have what size of eggs in comparison to songbirds?
Ducks Grouse + Sandpipers = Large with 40% yolk
Songbirds = Small with 25% yolk
Duck and grouse hatch as ____ chicks.
precocial (mobile chicks)
Precocial chicks usually have what?
A longer development time spent in the egg.
Altricial nestlings usually do this.
Stay in the nest
Nests are usually mad up of local materials because of these two factors.
Less energy to get materials easier to camouflage the nest.
The outershell of the nest often has _____.
Camouflage
Name the two types of cavity dwellers. Give examples of both.
cavity excavators (Woodpeckers) cavity adopters (Owls/Birds)
Birds that nest in cavities _____their chances of success for their babies. What does this mean for cavity excavators?
Increase
Cavity excavators have an even higher success rate.
Why is cavity excavating such an advantage?
- Because you can choose where you want your home.
- Can custom fit the hole size to fit their bodies.
- Predators don’t know about the holes.
- Tools for excavating are also weapons
The Great Crested Flycatchers are cavity adopters what do to discourage predators?
Hand a cast snakeskin by their cavity
What do Red Breasted Nuthatches put on the exterior of their cavity for extra protection?
Rub a blister beetle on the outside of their cavity because of the beetles chemical defense called cantharidin (terpenoid)
What do White Breasted Nuthatches put on the exterior of their cavity for extra protection?
Resin (terpenoid)
Using cast snakeskins / resins and cantharidin on the exterior cavity all are forms of ___ ____.
Nest Protection
European Starlings add green material to the exterior of their nests. There are a lot of hypothesis about why they do this but what is the most compelling one.
The Nest Protection Hypothesis
Tannins and other plant defenses discourage nest parasites.
Plants release chemicals that reduce the number of mites and is a form of Nest sanitation/chemical hygiene.
Incubation does what lol.
Keep the egg warm
What are brood patches? What animals have them?
Featherless spots on the bird with lots of blood vessels that make contact with the eggs.
Female Grouse + Female Ducks
Out of the following animals which ones will both the female and male have brood patches and which ones will only the female have brood patches.
- Killdeer
- Grouse
- Ducks
- Northern Flickers
- Woodpeckers
Killdeer = both Grouse = female Ducks = female Woodpeckers = both Nothern Flickers = both
How can you tell is a male is incubating or not?
It will have Brood Patches
What is the bird where only the male incubates the egg.
Phaloropes
- females are more colourful
- exhibit polyandry (female with multiple males)
What is cuckoldry?
When birds have their main mate but one of the eggs is fathered by another dad.
Describe the purple martin colony set up.
What is a product of this set up?
Dominate male will start the colony and will reproduce with the females of every pair that joins the colony.
Extra pair copulations that almost double the number of the dominant males offspring.
Female Scarlet Tanagers also solicit extra pair copulations, what does this system provide?
They mate with males wandering from distant territories’ for more genetic diversity.
When do precocial/altricial birds hatch
Precocial Birds = Ready to move out the nest) = Synchronous Hatching
Altricial = Nestlings in the nest = Synchronous Hatching
What to mother do to ensure synchronous hatching?
Will delay incubation until all eggs are laid.
What time do birds usually lay their eggs? Why?
Morning so the females arn’t carrying around an egg all day.
Baby birds also do something to contribute to synchronous hatching. What is this?
Communication through chirping
Describe why the short-eared owl might use asynchronous hatching.
might lessen feeding stress on parents
reduces the odds of losing entire brood
ensure the survival of some young in times of food stress
Describe the 4 things that are included in external parental care for birds.
- Nest Sanitation
- Removing nest droppings
- Feeding the young
- Nest Defense
Describe what birds do with the leftover egghells and why.
Removing of eggshells and moving them far away.
Eggshells could injure hatchlings /make brooding difficult / reduce nest hygiene / increase predator risk / interfere with unhatched eggs
What is produced by altricial birds that help parents remove their fecal matter.
Fecal sacs
Describe how feeding the young is parental investment.
Feeding the young is a investment of time and energy. Baby Birds are fed approx. 12 times an hour.
Altricial birds usually involve ___ ___
Biparental care (90% of species)
How do altricial birds compete for food?
By begging and stretching
What also helps the bird parents choose where to put the food?
Bright coloration of babies mouths.
Bright coloration = healthier.
List the 5 nest defenses
Mobbing Talons Leading the babies to safety Distraction displays Feigning injury distraction displays
What animal does a feigned injury distraction display and even has fake blood!
Killdeer
What do small ground nesting birds do to lead predators away? Name a type of bird that does this.
Rodent run / Sandpiper
When do nest defenses increase?
When the parents have more to lose and more of an investment has been made.
When is the strongest defense for altricial birds?
Just before fleeing the nest
When is the strongest defense for precocial birds?
Just before the eggs hatch
For both precocial and altricial birds the strongest defense is around the ____ day.
28th
Duck and geese sometimes have extremely large broods due to ___ ____.
Brood Amalgamation
What is a large group of babies called
A creche
How do creches happen? Why?
A mom will leave her babies with another mom.
Safety in numbers for both parties (donors and recipients).
What is egg dumping/Facultative Brood Parasitism?
When another female drops an egg off in their neighbors nest.
Give an example of a bird that egg dumps. Why would they do this if they have their own nest?
Black-Billed Cuckoo
As an insurance policy
Determine the difference between Intraspecific brood parasitism and Interspecific brood parastitism.
Intra = black billed cuckoo into a black billed cuckoo’s nest
Inter = black billed cuckoo into a yellow billed cuckoo’s nest
What are Brown Headed Cowbirds?
Obligate Brood Parasites.
State the difference between obligate/facultative brood parasitism. Give an example of an bird for each
OBP = Brown Headed Cowbirds FBP = Black Billed Cuckoo
Brown Headed cowbirds never do what?
Build Nests
Feed Babies
Incubate Eggs
Very effective
How do female cowbirds find their host?
Sit on a high perch and silently watch for nest building
Walk on the ground and silently watch for nest building
Dive Bird! Fly into shrubs and leaves noisily flapping their wings to scare parents away from the nest.
What adaptations do cowbirds have for their obligate brood parasitic lifestyle? (5)
- Fast egg laying
- Thicker egg shells (bumpy egg laying)
- Fast Hatching (10 days)
- Removal of a hosts egg prior
- Babies can outcompete nest mates (crush them or knock them out of the nest)
Why is the cowbird strategy good?
A lot of birds have not evolved to recognize the cowbird egg!
Some birds recognize the cow bird egg. What are the three ways they can get rid of it?
Build a nest on top of itif they cant remove the egg (Yellow Warblers)
Toss the egg out with their bill (larger birds)= Grasp Ejectors
toss egg out by poking a hole (smaller birds) = Puncture ejectors
what is a drawback of puncture ejecting?
Can make your own nest messy + beak could hit your own egg when pecking at it.
What is the mafia hypothesis?
That if a bird dosen’t accept a cowbird egg the cowbird will come back and break all the eggs.
