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Lecture 8

ANSC 3180 Lecture Notes - Lecture 8: Altricial, Puggle, Crop Milk


Department
Animal Science
Course Code
ANSC 3180
Professor
Esther Finegan
Lecture
8

This preview shows pages 1-3. to view the full 12 pages of the document.
Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017
12:24*PM

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Searching for food for young
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017 12:24*PM

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Sperm
Egg (mammal and bird)
Foetus
Enlarged reproductive organs (testes, ovary/oviduct, uterus, mammary glands)
Milk
Heat for egg incubation
Territorial establishment and defense / courtship
Nest/burrow construction
Searching for food for young
Energy and nutrients are required for:
Testicular growth -minimal energy and protein requirements
Sperm productions -minimal energy and protein requirements
Ex. Manes in lions; horns/antlers on cattle/deer -->protein/calcium requirements
Males:
Ovary and oviduct growth -minimal energy and protein requirements
Water content decreases; protein, fat and mineral content increases
Foetal growth: ~80% growth occurs during the last 40% of gestation
!
Gravid uterus growth (uterus + foetus)
Mammary growth
Total energy expenditure by lactating mammals: 4-7 x BMR
!
Milk is produced by all mammals (eutherians), marsupials and
monotremes
!
Lactation
Protein -12.5%
!
Ash (mineral) -2.7% (mostly in skeleton)
!
Seals: ~9-12% fat (cold ambient temperatures; short lactation)
Guinea pig: ~10% fat -used immediately
Human: ~16% fat
Fat - 2.1% …except:
!
Body composition (averages) of the mammalian neonate:
Mouse (altricial: naked, blind, immobile)
!
White-tailed deer (precocial: pelage/plumage, sighted, mobile)
!
Low fat of most neonates (~2%)-both precocial and altricial species
17-35% higher than non-pregnant
!
Daily expenditure of pregnant mammals: 2.7-3.1 x BMR
Females:
Energy Reproduction in Mammals:
*monotremes -egg laying mammals (young echidna -puggle)
Fed as only food for first 3 days and then is gradually mixed with other
food (production for 3-4 weeks)
!
Under control of prolactin
!
Pigeons and doves (both parents) produce 'crop milk' (sloughed, crop-wall
epithelial cells) rich in fat (35%) and protein (60%)
Male emperor penguins: feed newly hatched chicks a secretion from oesophageal
epithelial cells
Greater flamingoes: feed hatchlings with a secretion from oesophageal mucous
glands
'Lactation' -oesophageal/crop secretions fed by a few bird species to hatchings
Energy Reproduction in Birds:
To the foetus only in utero (primates, guinea pigs, rabbits)
1)
To the foetus both in utero and from colostrum (rats & mice -16-20days;
cats, dogs)
2)
Have heavy barrier in placenta -require milk for disease
control
!
Will appear in blood rapidly
!
Ungulates (24-36 hrs): hooved mammals, perissodactyls (equids,
tapirs, rhinos), and artiodactyls (pigs, hippos, camelids, ruminants)
Marsupials (macropods: 170-200 days)
Mink (8 days)
To the neonate only in colostrum (for as long as intestine is permeable to
immunoglobulins)
3)
Maternal immunoglobulins may be passed:
Colostrum -first milk produced each lactation; may contain IgG immunoglobulins to
provide passive immunity to the neonate
Water, minerals, protein (e.g. casein), fat, carbohydrates (lactose in
eutherian mammals)
!
Composition:
Equids/black rhino: 90-91% water
!
Seals: 30-48% water
!
Concentration (dilute -very concentrated)
Equids/black rhino/ primates: <2% protein
!
Some seals/lagomorphs: 10-15% protein
!
Protein Content:
Equids/black rhino/primates: <2% fat
!
Seals: 39-61%
!
Fat Content:
Equids/black rhino/ primates: 6-8% sugar
!
Seals: <1% sugar
!
Sugar Content:
Equids/black rhino/primates: <1kcal/g
!
Seals: 4-6 kcal/g
!
Energy Content:
Dilute (76-83% water) --> Concentrated (65-74% water)
Low fat (2-5%) --> moderate fat (13-16%)
Low protein (3-6%) --> moderate protein (7-15%)
High sugar (6-11%) --> moderate sugar (2-5%)
Low energy (<1kcal/g) --> higher energy content (1.5-2 kcal/g)
Period 1 (young is confined to pouch )--> Period 2 (young can leave
pouch)
!
Marsupial Milk:
Concentrated, high fat, high energy milk
!
May compensate for high heat loss by neonates in cold environment
!
Hooded seal: short lactation (~4 days), grows 22-44 kg/4 days
!
Seals:
Mainly plamitic (16:0), oleic (18:1)
!
Lagomorphs, elephants -mainly capric (10:0)
!
Seals -mainly long chain unsaturated FA (18:3, some 18:1, some palmitic)
!
Fatty Acid Composition:
Usually highest in colostrum
!
Taurine -essential for most mammalian neonates (especially carnivores)
Mule deer -yound nurses 2-10x per day
Single fawn drinks 150-200 g/nursing bout
'hiders' -mother returns to 'hidden' neonate several times a day to nurse
!
Mountain goat -nurses ~40x /day
Single young drinks ~50g/nursing bout
'followers' -neonate follows mother and nurses more frequently than
hiders
!
Intake by Neonates:
Milk:
Mammalian Reproduction:
Testicular growth -0.5% BMR, 3.5% maintenance protein
Sperm production -0.8% BMR
Males:
Ovary and oviduct (produce albumen, shell) -growth is 4% BMR, 28%
maintenance protein
Number varies with age of female (young females may lay
fewer eggs)
!
Number varies with food availability (fewer eggs may be laid
when food is scarce)
!
Egg number:
Size inversely proportional to BW (smaller birds lay larger
eggs relative to BW)
!
Size varies with age of female (young females lay smaller
eggs)
!
Size varies with availability of foods (eggs may be smaller
when food is scarce)
!
Egg Size:
Depends on stage of development of embryo at hatching
!
Young show a marked delay in beocming
independent
!
Young often hatched/born naked, blind and
immbobile
!
Ex. Crows, robins. Starlings, rat, mouse
!
Altricial species:
Young show high degree of independent activity
from hatching/birth
!
Young usually hatched/born with plumage/pelage,
sighted and mobile
!
Ex. Chickens, ducks, white-tailed deer
!
Precocial species:
'nest loving'
!
Young remain in nest being fed for a prolonged
period after hatching/birth
!
Nidicolous species:
'nest fleeing'
!
Young leave the nest almost immediately after
hatching, and start searching for food
!
Nidifugous species:
Altricial -precocial (nidicolous -nidifugous)
!
~40% fresh weight egg -precocial (ducks, geese)
~20% fresh weight egg -altricial (crows, robins)
Yolk size is larger in precocial species than altricial to support
more advanced development before hatching
!
Yolk synthesis (in ovary) takes 4-26 days, albumen synthesis
takes 1-2 days as the ova passes through oviduct
!
Albumin -no lipids, protein (7.1-10.1%)
Yolk contains lipids and protein (13.5-18.5%)
!
Yolk lipid content in higher (34.7-38.3%) in precocial species
than in altricial (23.2-28.4%)
!
1.2:1 -ducks and geese (precocial)
3.6:1 -crows and blackbirds (altricial)
4.9:1 -starlings (altricial)
Albumen/yolk ratio:
!
Egg Composition:
Requirement depends on egg number, egg size, egg composition and
laying interval
!
Egg production
29% BMR, 72% maintenance protein
Hawks, owls (semi-altricial) lay 1 medium sized egg per 3-4 days
!
200+% BMR, 220% maintenance protein
Waterfowl (precocial) lay 1 large, high-energy egg per day
!
Fat deposition prior to egg laying
Mobilizing body fat and protein while laying
Increasing food intake
Changing diet to highly nutritious foods (e.g. Insects)
Meeting requirements for egg laying
!
Egg Laying: daily energy and protein requirements
Heat is needed to start embryonic development in the egg and allow it to
continue
!
Clutch size
Insulation provided by nest
BW of incubating adult bird
Ambient air temperature
Heat required depends on:
!
Normal heat loss through the brood patch is sufficient if ambient
temperature is in the birds thermoneutral zone
!
As incubation progresses, the developing embryo contributes an increasing
heat amount
!
Adult incubating bird has less time to feed
!
Penguins, geese -one parent may do all incubating and rely on fat
deposited before nesting
Canada geese, common eider ducks -loose ~45% BW between
arriving at nesting group and eggs hatching
Some species, both parents share incubation or non-incubating parent may
bring food for the incubator
!
Incubation
Females:
Avian Reproduction:
*Seals are born without lactase
--> lactose-intolerant
*Marsupials can
produce milk with
different content in
each nipple if they
have two young in
different periods
Energy: Reproduction
Friday,*February*10,*2017 12:24*PM
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