Lecture 8 - Lecture 8 How animals deal with extreme cold. -...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 8 How animals deal with extreme cold. - Solution A: dress for the occasion - Mammals (ie. Fox) – add extra layers of fur o Guard Hairs grow longer and thicker (ie Moose) Dense UNDERFUR - Birds grow bulkier feathers o Longer and denser called CONTOUR FEATHERS on the outside and DOWN feathers underneath (ie black-capped Chickadee) o Tend to be 50% more dense than summer coat - Animals also add extra layers on the inside. Mammals have two types of fat: o Layer just under the skin: SUBCUTANEOUS FAT for insulation = warmth o Fat around internal organs (ie. Heart). The fat is brown in colour This type of fat when burned provides more heat than white fat (subcutaneous fat) Only mammals have BROWN Fat - Birds add subcutaneous fat for FUEL not warmth and do not make BROWN fat o They SHIVER to generate heat; this is the muscle shivering to generate heat which is than trapped by the feathers o Birds fluff up their feathers to trap more heat (ie. Gray Jay) o Colour can help to stay warm. White colour is better than darker because the hairs
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

Lecture 8 - Lecture 8 How animals deal with extreme cold. -...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online