Due to the endangerment status of the Hazel Dormouse, they are well protected in the UK. Due to this only a small sample of either hair or blood is likely to be taken so the animal can continue a full and health life afterwards. It is also possible that they will use a sample from a captive animal as they are more use to handling and stress. It would be nice to have a selection of samples from both captive and wild to compare and have a robust average.
The St. Kilda wren is extremely rare, so scientists would be very careful not to harm any while taking samples. They don’t need to use needles, either – a buccal swab (wiping a cotton bud around the inside of the mouth) is often used to get genetic samples for birds.
In order to get enough high quality DNA to obtain a complete genome sequence of a large vertebrate from scratch it is necessary to collect many cells from the same individual. In theory this might be possible by taking a tissue biopsy from a mature individual and then returning it to the wild. In practice however, because the catshark is a model organism frequently reared in the laboratory and is not threatened with extinction tissue will most likely be procured from an animal sacrificed for this purpose. Compared to the millions of sharks which are killed annually by fishermen, either for consumption or as bycatch, the use of an individual catshark for genome sequencing, or indeed any of the other experimental purposes, has no detectable ecological impact. Indeed, it may be one such animal which would otherwise have been thrown back in the sea to die which may be used for this project. It is important to note that, like all experimental practices involving live vertebrates in the UK, any research done on the catshark must be granted ethical approval by a Home Office license. In order to comply with this license any catsharks which are sacrificed for research purposes must be dispatched humanely, using anaesthetic.
As dragonflies (even the Emperor!) are not very big we would need quite a lot of cells to sequence the genome. However the adults die off after the summer anyway, so collecting dead or dying dragonflies is not that hard. We could also try extracting haemolymph (the insect equivalent of blood) using a needle from live animals, as this contains lots of circulating cells with DNA. This likely would not harm the dragonfly at all – they survive with quite a lot of damage through the summer – it is not uncommon for their wings to be quite tattered by the time they do succumb to the cold!