Climate Change And Endocrinology

Question 1

What overall effect is climate change having on birds?

Answer 1

They’re laying earlier in the year

Question 2

Give an example of a bird where the environmental timing cues appear to be becoming de-synchronised:

Answer 2

The Dutch Great Tit

There has been a shift in the abundance of caterpillar- they’re around earlier in the year

So there’s less caterpillars present when feeding their young

Question 3

Describe the results of a study carried out to look at the effect of temperature:

Answer 3

Two group law of starling exposed to natural photoperiod and either 20 or 5 degrees

Testicular regression and moult was found to occur earlier at higher temperatures

The permissive window for breeding is reduced at higher temperatures

Question 4

What technique is used to measure hormones in a small blood sample?

Answer 4

Radioimmunoassay

Question 5

Give some examples of field endocrinology techniques:

Answer 5

1. Mist netting
2. Blood sampling
3. Weighing
4. Fat scoring
5. Moult scoring
6. Ringing

Question 6

What is testosterone correlated with and what are the costs of maintaining high testosterone?

Answer 6

Correlated with aggression during social instability

Costs= injury, reduced parental care, immunosuppression

Question 7

Why is there no association between testosterone and aggression in some birds?

Answer 7

Allows them to breed quickly rather than spending a long time defending territories

Question 8

What is perturbation?

Answer 8

Unpredictable weather

Question 9

How can birds cope with unpredictable weather?

Answer 9

Redirect behaviour e.g. stop breeding behaviour
Seek refuge or move away
Mobilise stores energy reserves: gluconeogenesis
Recovery: return to normal once perturbation finishes