Lecture 4: Applying fertility research to animal conservation

Question 1

Across bird species on average __ of eggs fail to hatch

Answer 1

10%

but in endangered species, failure rates can be much higher

Question 2

why do eggs fail? 2 reasons

Answer 2

• fertilisation failure

- embryo death

Question 3

fertilisation failure:

Answer 3

• failure of sperm to reach then egg
• sperm or ovum dysfunction
• -> poor male/female quality
• female anti-sperm response

Question 4

embryo death:

Answer 4

• male factors
• female factors
• male-female incompatibility
• external factors

Question 5

sperm must be ___ to make it through the vagina

Answer 5

motile

Question 6

dead sperm can progress from ___ to __

Answer 6

uterus to infundibulum but not from vagina to uterus

Question 7

long/short sperm have a competitive advantage in the zebra finch

Answer 7

LONG

Question 8

association between sperm length & velocity in zebra inches

Answer 8

increase length, increase velocity. Till about 70-75 micrometers, after that velocity decreases

Question 9

specific parts of sperm:

Answer 9

head, mid piece, tail.

balanced tail & midpiecee

Question 10

polyspermy in mammals vs in birds

Answer 10

• in mammals: pathological

- birds = normal

Question 11

what method is used to inkectio na single sperm directly into the ovum (human included)

Answer 11

Intra-cytoplasmic sperm injection

Question 12

examining birds eggs provides a unique insight into the

Answer 12

mechanisms of sperm competition & selection

Question 13

Morphological traits are crucial for

Answer 13

sperm success (Across and within species, and within ejaculates)

Question 14

Processes of fertilisation and early embryogenesis differ ____ between mammals and birds (+ probably many other taxa) – expansion of our view of sperm function

Answer 14

markedly

Question 15

consequences for bird conservation?

Answer 15

• Relevant techniques provide a critical tool for investigating reproductive problems in endangered birds
• egg examinations -> causes of hatching failure
• Sperm analysis -> male infertility
• Mechanisms of fertilisation -> assisted reproduction
• – New insights into bird fertility currently informing captive breeding management around the world