tag:blogger.com,1999:blog-4819377074550717188.post347465434430066812..comments2023-12-24T02:53:29.472-08:00Comments on Syrphing Time: Data requirements for occupancy modellingRoger Morrishttp://www.blogger.com/profile/18319989613630200252noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4819377074550717188.post-69849084185576841442018-11-05T21:04:16.992-08:002018-11-05T21:04:16.992-08:00This comment has been removed by a blog administrator.Ecosenshttps://www.blogger.com/profile/00798230262379768484noreply@blogger.comtag:blogger.com,1999:blog-4819377074550717188.post-71907568969184131222018-05-24T13:16:58.136-07:002018-05-24T13:16:58.136-07:00With occupancy models, we can estimate the total n...With occupancy models, we can estimate the total number of species (or taxa) present, for example, using multiple season multi species occupancy models. Not only can these models help with false absences but they can help us with false positives too. Improving coverage and species identifications will increase accuracy when there is an associated increase in the number of surveys, and similarly it will help to record the common as well the rare species.<br /><br />A really important consideration is the number of repeat surveys at our sampling sites of interest: the accuracy of the estimates can be improved more effectively by repeating more surveys at a single sampling location rather than by spreading fewer surveys across many sampling locations. The exact number of surveys required will depend on the detection probabilities of the species involved, their occupancy rates and available resources.<br /><br />Another key feature of occupancy models is that they allow us to account for the different abilities and detection rates of different observers. This has the potential to help with observers that are more likely to record some species than others. <br /><br />Darryl MacKenzie et al (2018) have published a 2nd edition of Occupancy Estimation and Modelling, which is a useful update on these methods, and there are some good packages in R that can be used to help with any analysis.<br /><br />Apologies, I was unable to comment on the UK Hoverflies Facebook post, so hope it is ok to discuss on here.nrbflodhttps://www.blogger.com/profile/10933016525067274554noreply@blogger.com