APS126 Hemmings Flashcards
How would you relate Tinbergen’s 4 questions to the behaviour of birdsong?
How does the song develop?
What causes the bird to sing?
What is the adaptive function of the song?
What is the evolutionary history of the song? (+did it evolve once or multiple times?)
Which scientist is famous for early research on birdsong?
William H. Thorpe
When a Chaffinch is raised in isolation what happens to its song?
It is recognisable but far simpler than birds raised by and around other chaffinches
When a nightingale is raised in isolation what happens to its song?
It is severely retarded
When a nightingale is raised by other species what happens to its song?
It picks up the song of the other species
In the chaffinch and most other birds, song is partly …. and partly …
innate, learned
What is the short period in which birds learn details of their songs from a tutor called?
Sensitive period
Light penetrates thin bones in birds’ … which stimulates … which cause the release of … triggering the … to start growing. The testes release …, which triggers song production.
skulls, photoreceptors, gonadotrophin releasing hormone (GnRH), gonads, testosterone
Female songbirds do not typically sing, but do if…
injected with testosterone
+ if males injected in winter they sing
Which parts of the bird’s brain are associated with song?
RA (robust archistriatum) connected to HVS (higher vocal centre) and sends nerve impulses to the syrinx
HVC is much larger in …
males
What is the proximate (extrinsic) stimulus for birdsong?
Daylength
What is birdsong produced by?
The syrinx (voice box)
What are the two main hypotheses for birdsong?
Territory defence and mate attraction
Males (sedge warblers) with a more complex song pair..
earlier - gives more time to mate with others as well
Song has evolved 3 times, in…
parrots, hummingbirds and passerines
- different song control areas in the brain
What causes eating?
Hunger
What causes hunger?
Hormones
Which hormones specifically control hunger?
Leptin and ghrelin
Where is leptin released from?
Fat cells - tell body (hypothalamus) it has enough fat - so stop eating - less hunger
If leptin levels are low, what does the hypothalamus tell the body to release, and from where?
Ghrelin from the stomach - more hunger
Hormones play a major role in the … of structures (e.g…….) that play direct/indirect roles in controlling behaviour.
Development, brain and gonads
Hormones have … effects, e.g. altering neural networks that respond to signals
activational
Hormones often underpin the timing of … when conditions are most favourable
reproduction