Mark Elgar

Animal Behaviour

Nurture via Nature

Outline

The role of genes and environment in shaping the behaviour of animals

How do we apply evolutionary thinking to explaining why animals behave as they do?

Nests

NestsGolden-headed cisticola:Uses spider silk to weaves leaves together for nesting

Green tree ants:Use silk from larvae to knit leaves together for nesting

How do these animals know how to do this???

Genes & learning

Innate: a behaviour that is performed the first time an animal encounters the appropriate cue for that behaviour

Learned: a behaviour that is modified as a result of the animals experience of its environment

i) Genes

ii) Learning

Innate behaviour of cuckoos

Cuckoos are brood parasites that lay their eggs in the nests of other bird species

Innate behaviour of cuckoos

Cuckoo chicks respond to pressure stimulus on their back

Horsefields Bronze Cuckoo chick

Learned behaviour

Cattle learned to associate the sound of the motorcycle horn with receiving molasses

Digger wasps use landmarks

Female digger wasps lay their eggs in a hole dug in the ground

Provision eggs with insect larvae

Need to be able to relocate hole

The nature vs nurture debate

Nature: behavior is innate and under genetic influences only

Nurture: behavior is learnt, and not influenced by genes

Behaviour is often the result of both genetic and environmental

influences

The nature vs nurture debate

White-crowned sparrowZonotrichia leucophrys

Listen to an audio recording of the White-crowned sparrow from The Cornell Lab of Ornithology, Macaulay Libraryhttp://macaulaylibrary.org/audio/16679

Early juvenile sub-song becomes more complex over time

Question: How much of the song is genetic and how much is learned?

The nature vs nurture debate

White-crowned sparrowZonotrichia leucophrys

Experimental treatments:

i) Raised with parents

ii) Raise in isolation, prevented from hearing anything

iii) Raised in isolation, allowed to hear own singing

iv) Raised in isolation, allowed to hear singing of adults on tape recorder

Adult song is in part due to genetics but juveniles must learn full song

repertoire from parents

Summary

Behaviour is the result of both genetic and environmental influences.

Both genetic and learned behaviours can be explained in an evolutionary context

Slide 1 _MG_2581 peacock spider Maratus volans by Jurgen Otto (http://www.flickr.com/photos/59431731@N05/5521738809/). Reproduced with permission from Jurgen Otto.

Slide 3a) White-browed Sparrow-weaver Nests (http://commons.wikimedia.org/wiki/File:White-browed_Sparrow-weaver_Nests.jpg by Birdman 1 [Own Work] (CC BY-SA 3.0), via Wikimedia Commonsb) Bird nest Fogg Dam (http://www.flickr.com/photos/26768348@N00/10829823) By Stephen Michael Barnett (CC-BY-2.0)c) Bird nest in grass (http://commons.wikimedia.org/wiki/File:Bird_nest_in_grass.jpg) by Fir0002 (CC BY-SA 3.0), via Wikimedia Commonsd) Taveta Golden-weaver nest (http://commons.wikimedia.org/wiki/File%3ATaveta_Golden-weaver_nest.JPG) By Robert Lawton (Own work) (CC-BY-SA-2.5), via Wikimedia Commonse) Allen's Hummingbird Nest (http://www.flickr.com/photos/pazzani/8563916462/) By Mike's Birds (CC BY-SA 2.0)

Slide 4a) Golden-Headed Cis1cola (h4p://www.ickr.com/photos/bareego/8168449319/) By James Niland (CC BY 2.0)b) Weaver ants (Oecophylla smaragdina) nest in Kinnarsani WS (h4p://commons.wikimedia.org/wiki/File%3AWeaver_ants_%28Oecophylla_smaragdina%29_nest_in_Kinnarsani_WS%2C_AP_W_IMG_6012.jpg) by J.M.Garg (CC-BY-SA-3.0), via Wikimedia Commons

Slide 5Eect of drugs on spider web construc1on (h4ps://commons.wikimedia.org/wiki/File%3ACaeinatedSpider.jpg) By NASA.Materialscien1st at en.wikipedia [Public domain], from Wikimedia Commons

Slide 6a) This nestling Horselds bronze-cuckoo (Chalcites basalis) has a slightly hollow back that makes it easier to push eggs or chicks out of the nest of its host, the purple-crowned fairy-wren (Malurus coronatus) By Michelle Hall. Reproduced with permission from Michelle Hall.

b) This series of 4 images illustrates the ins1nc1ve reex of a young cuckoo nestling to push backwards against anything touching its back, that results in other eggs and chicks being pushed out of the nest. The zygodactylous feet (2 forward- and 2 rearward-poin1ng toes) that characterise cuckoos are also visible. By Michelle Hall. Reproduced with permission from Michelle Hall.

Slide 7 & 8a) Ca4le (h4p://www.public-domain-image.com/full-image/fauna-animals-public-domain-images-pictures/cows-and-calves-public-domain-images-pictures/ca4le.jpg-free-stock-photo.html) by Keith Weller (US Dept. Of Agriculture) [Public Domain]

b) Molasses (h4p://commons.wikimedia.org/wiki/File%3AMolasses.JPG) By Tractorboy60 [Public domain], via Wikimedia CommonsSlide 9a) Digger wasp (Ammophila sabulosa nipponica) (h4p://opencage.info/pics.e/large_795.asp by OpenCage.Info (CC BY-SA 2.5)b) Pine Cone Illustra1on Brown (h4p://www.ickr.com/photos/coeeteagastronomy/6428589747/) By Melanie Widmann, CTG Publishing (CC BY 2.0)c) Cartoon Bug Flying Wasp Forest Insect S1ng (h4p://pixabay.com/en/cartoon-bug-ying-wasp-forest-32311/ ) By Nemo [Public Domain] via pixabay

Slide 11 & 12a) White-crowned Sparrow (h4p://commons.wikimedia.org/wiki/File%3AWhite-crowned_Sparrow_57.jpg) by Tim [CC-BY-2.0], via Wikimedia Commons

PAUSE LECTURE LINK OUT TO: h4p://macaulaylibrary.org/audio/16679/zonotrichia-leucophrys-white-crowned-sparrow-united-states-alaska-leonard-peyton)