tag:blogger.com,1999:blog-5204430743209912348.post6154113511091650319..comments2023-12-04T09:12:04.628+00:00Comments on <img src="http://www.gwct.org.uk/media/361898/gwctlogo.jpg"> GWCT News & Advisory: Corvid control - research & useGWCThttp://www.blogger.com/profile/10926927246833909130noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-5204430743209912348.post-4250286424756761352015-04-27T13:41:18.403+01:002015-04-27T13:41:18.403+01:00It really is not very scientific to make a stateme... It really is not very scientific to make a statement linking two events and presenting them as accepted wisdom. Corvid numbers have increased but it is too big a leap to claim that this is a consequence of "relaxed" corvid control. It is a fact that crow numbers have increased but according to the BTO “there are few specific studies providing evidence for the causes of the increase in this species, although evidence presented shows that increases in breeding success have been important. Ecological causes of this could be increases in food availability and the increasing suitability of urban areas (driving the species' expansion there), although specific evidence supporting these hypotheses is limited”. It is a similar picture with the other most common corvid, the magpie. A substantial increase from 1970 until 1990 and then stable with the biggest increase in suburban and urban areas. With most corvids (and other predatory birds), it should also be recognised that any increases are from a much lower base which was created by intense persecution from the latter half of the 19th Century until the First World War, related to management of land for shooting.<br /> <br />This is probably inconvenient evidence for those that need to reduce predator numbers to produce sufficient numbers of game birds for shooting purposes and try to justify it by portraying a countryside awash with predators with predator control required to restore balance. Any scientific analysis of the impact of predators and the effectiveness of predator control, has to consider more than local impacts, especially for an understanding of long term bird population change. <br /><br />For thinking outside the Larsen Trap box, how about more goshawks as a cheaper and more effective long term solution to controlling crows. Now that would put the W into GWCT. <br /> Ian Whittakerhttps://www.blogger.com/profile/17253402995639692812noreply@blogger.com