5.2.6 Abnormalities It is worth noting unusual coloration, injuries or deformity to re-identify individual animals and monitor changes or healing processes. A number of bats are seen that have had serious tears to the wings, but which have healed. Bite marks are sometimes apparent. 5.3 Measurements Measurements are generally only of value when taken as part of a larger project studying some aspect of bat morphology or for the field identification of certain species. Research projects may involve recording growth rates or assessing the normal and expected range of variation in size. If weight studies are being undertaken, it is useful to record at least forearm length to relate the weight to the size of each animal. All measurements should be in grams and millimetres. Forearm measurements (by far the most useful), should ideally betaken with callipers, although a short steel ruler with a stop end can be used. CHAPTER 5 EXAMINING BATS 52 All other measurements should betaken with vernier or dial callipers. When measuring, rotate the callipers or animal slightly along the axis of the callipers to ensure that you have the maximum measurement. For right-handed people, it is best to control the bat in the left hand, leaving the right hand for the more delicate manoeuvring of the callipers.