Lecture 7

Question 1

What is an issue with birds laying their eggs earlier?

Answer 1

For some populations advancing times of egg laying my other environmental timing cues appear to be becoming desynchronised

Question 2

How did the BTO organisation, one of the first researched into showing that climate change changed the time of breeding, research this?

Answer 2

Got people to send in data allowing changes in time to be assessed

Question 3

Give an example of a bird where climate change has meant that egg laying has become desynchronised with environmental cues

Answer 3

Dutch great tit population

Question 4

What are ultimate factors?

Answer 4

The evolutionary forces that are causing birds and other animals to breed at a particular time of year

Question 5

How did they study temperature effects on breeding in starlings in semi-natural conditions and what were the results?

Answer 5

. The birds were in avaries exposed to natural changes in day length and temp and compared it to another group of birds that had the same annual changes in day length
. Starlings exposes to natural photoperiod and either constant temps of 20 or 5 degrees (and natural temp control) through the breeding season
. No differences in timing of testicular growth
. Testicular regression and mould occurred earlier at higher temps
. Permissive window for breeding is reduced at higher temps
. Experimental evidence for a physiological effect of temps

Question 6

Describe field endocrinology (environmental endocrinology) (positives, negatives)

Answer 6

. Developed 1970s
. Good in a lab because you can control the environment
. However, probably won’t give you the full information about how animals respond to the environment in the field conditions
. For a true understanding of ecophysiology need to go into the field and study the animals in their natural environment

Question 7

Give the field endocrinology techniques

Answer 7

. Mist netting 
. Blood sampling 
. Weighing- body mass
. Fat scoring 
. Moult scoring 
. Ring (‘banding’ in the US)

Question 8

How does the field endocrinology technique mist netting work?

Answer 8

Used on small birds.

Put up a very fine net and the birds will fly into it and become temporarily entangled in it

Question 9

How does the field endocrinology technique fat scoring work?

Answer 9

Is when feathers are moistened to allow them to be pulled apart and you can see how thin birds skin is and give a number to the amount of fat a bird has under its skin at a particular point of the body

Question 10

How does the field endocrinology technique moult scoring work?

Answer 10

Is particularly with the primary flight feathers particularly after the reproductive period the birds will lose feathers in a sequence that is sort of symmetrical so we can look at feathers at different stages of growth and again give them a number based on the stage of development it is

Question 11

What does the field endocrinology technique ringing allow you to do?

Answer 11

Allows you to identify through binoculars what individual it was without having to catch it again

Question 12

What are the 2 hypotheses the artic-breeding birds evolved neuroendocrine and behavioural adaptions to cope with a breeding environment that can be unpredictable? (This environment does provide a very high level of biomass with larvae for birds to feed their young on over a very brief period of time and by the end of the breeding season the environmental conditions can be very variable)

Answer 12

. The need for a rapid transition from sexual to parental behaviour is associated with an altered relationship between testosterone and reproductive behaviour
. The adrenocortical response to stress is adjusted to allow nesting to begin in adverse environmental conditions e.g. storms (modifying factor)

Question 13

How does testosterone link to reproductive behaviour? And what trade-off is testosterone related to?

Answer 13

. Testosterone is correlated with aggression during social instability- the “challenge hypothesis” (individuals with high levels of testosterone tend to have a benefit in winning competitive encounters)
. Maintaining high testosterone incurs costs (e.g. injury, reduced parental care, immunosuppression- so may be more prone to getting diseases)
. Trade-off between territorial behaviour and parental care- seems to have been adapted in birds that a living in these more extreme Artic environments

Question 14

What latitude birds have a strong correlation between testosterone so aggressive behaviour?

Answer 14

Mid-latitude birds

Question 15

In what birds has the strong correlation between testosterone and aggressive behaviour been lost in?

Answer 15

High latitude breeding species

Question 16

Why has the strong correlation between testosterone and aggressive behaviour been lost in high latitude breeding birds?

Answer 16

It is an adaptation for breeding because it is a trade-off and the birds that breed in this environment are under a huge amount of time pressure. So if they don’t breed quickly when they won’t get the chance to lay eggs and rear their young their young before the conditions deteriorate and they have to go down to the wintering grounds again

Question 17

What is simulated territorial intrusion?

Answer 17

Is where you catch a male, out it in a cage for a brief period. Put the cage into another males territory so it regards the male as an intruder. He will then voluntarily come up and probably start singing at the intruder and try to get at him though the cage. Researches can then capture the territorial male, take a blood sample and measure their testosterone and can compare this with birds at different latitudes and see how much testosterone there is in a blood sample in birds with territorial intrusion and those without

Question 18

What is the ‘emergency life history stage’?

Answer 18

A specific physiological and behavioural response to perturbation that enhances survival.
It is changes to physiology and behaviour that can happen at any time of the year that can allow them to survive the effects of the disturbance and allow them to recover allowing them to continue what they were doing once it has passed

Question 19

What does the ‘emergency life history stage’ apply to? When can they potentially enter into it?

Answer 19

To birds in general living anywhere on the planet is something the birds can potentially enter anytime if they experience something like a storm.
So can apply to any bird and interrupt any stage of the annual cycle

Question 20

Give an example of when ‘emergency life history stage ‘ may be used?

Answer 20

May be the redirecting of behaviour such as if you were breeding you may temporally stop that and seek shelter if it is short lived if not you might want to move away from that area

Question 21

‘Emergency life history stage’ can be used when there is a disturbance to breeding that is short lived. However, if a disturbance is not short lived such as a snow storm why might you want to move away?

Answer 21

Because you are probably unlikely to be able to breed so you are probably going to have to change your physiology to start mobilising stored energy reserves so may have to go through gluconeogenesis so start breaking down muscle in order to produce glucose temporarily and also use your fat stores

Question 22

When using ‘emergency life history stage’ and the disturbance stops what happens next?

Answer 22

Recovery: return to normal once perturbation finishes (e.g. move back to original habitat and resume breeding behaviour or whatever stage of the annual cycle they were in)

Question 23

What is a stress response?

Answer 23

The body’s adaptions to correct a disruption of physiological balance (something like a storm is a stressor, stress is the effect it has)

Question 24

What are the two components, both ‘non-specific’ (different stimuli trigger same responses) of physiological response to stress?

Answer 24

1. ‘Flight or fight response’- adrenaline (epinephrine)- short term response
2. ‘General adaptation syndrome’- glucocorticoids

Question 25

What is the ‘general adaptation response’ to a stressor?

Answer 25

Glucocorticoids- if you experience a stressor response that is acting over a longer period it helps to counteract the effects of that stressed and different types of stressor can have the same physiological response could be something like injuries might lead to getting increased hormones in your blood that are part of this longer term response the ‘general adaptation syndrome ‘ or could be a physiological stressor

Question 26

How do peacock butterflies use the startle effect when being attacked by blue tits?

Answer 26

The butterflies rapidly flick their wings while revealing the eyespots.
They also produce a hissing noice and this will startle the predator as well and give them a few scones to escape

Question 27

How did they experiment whether the sound and eye spots used by peacock butterflies when attacked by blue tits worked as a startling effect? What did they find?

Answer 27

. They manipulated the eyespots and sound capabilities of the butterfly
. They found that eyespots can startle the predator reducing the likelihood of the butterfly being eaten but the hissing sound has no effect on the predator

Question 28

What is aposematism?

Answer 28

Is a bright colouration which you see in many animals- is usually yellow, red and black.
So is bright conspicuous warning colours that many animals have

Question 29

What is aposematism often associated with?

Answer 29

With toxins of defences

Question 30

Give an example of an animal that uses aposematism that is associated with toxins of defences

Answer 30

Cinnabar moth- eat toxic plants and then are toxic and display this.

Question 31

What is the proposed reason for aposematism evolving?

Answer 31

Believed to have evolved several times independently to be a warning to advertise their unpalatability