Over the years we have been contacted repeatedly by rescuers and lay people, who were caring for corvids such as magpies, jackdaws and crows, and who observed that their foster birds showed difficulties with flying despite appearing otherwise fit and healthy. Some of these birds demonstrated abnormal flight feathers and showed an unusual or even abnormal behaviour not normally expected in wild birds. A closer assessment of the plumage showed quite quickly that these birds had been wing clipped.
What is feather or wing clipping, and why is this being done?
At this time of the year we are contacted on a daily basis by members of the public, who have found, rescued and raised a corvid fledgling, all with good intentions of course. If we are not being contacted at the very beginning of a rescue journey, mostly for advice about the diet of corvids, then it is usually at the point where people feel that their foster bird might be ready for release soon. Unfortunately, our advice is often a disappointment if not a shock to many of these hobby rescuers, as in most cases the desired immediate release is not an option, or at least not an option which gives the foster bird a sufficient chance of survival. We do understand that circumstances will differ greatly, and that expert help is not always at hand. Therefore it is also important that the rescuer understands, that the likelihood of survival will differ greatly as well, as corvids are not belonging to those bird families, which can be hand raised by their own and hard released immediately after they have fledged. There are of course certain ways to ensure that the rescue bird gets the best second chance he or she deserves. However, to achieve the best possible outcome, decisions should ideally be made before a bird is being hand raised without appropriate company.
Jackdaws are probably the most common corvid species rescued and cared for in captivity, which is mainly due to the fact that they have adapted very well to an urban lifestyle and that they are often nesting in very close proximity to us humans. Jackdaw babies are also often perceived as being irresistibly cute in the eyes of many humans, which seems to persuade even completely unexperienced people to raise a jackdaw nestling or fledgling by themselves. Therefore it is not surprising that jackdaws are the most frequently imprinted corvid species. Before going into more detail about what imprinting means and what the consequences of imprinting are, it might be useful to look into some aspects of the natural behaviour and some of the normal social interactions of jackdaws.
Imprinting of rescue bird is an often hotly debated topic amongst bird lovers, wildlife rehabilitators and rescuers, where voiced opinions range considerably. One extreme approach to this topic suggests that imprinted birds are principally unreleasable, and that once a bird is imprinted that this situation cannot be reversed. The other extreme opinion considers all imprinted birds as releasable and implies that these birds have similar survival chances in the wild compared to birds who have not been imprinted. However, own experiences and those of fellow rehabbers have shown that, and this should actually not be unexpected, the truth lies neither in the middle nor is it to find in one or the other extreme. To find an answer, it seems worth to explore some basic underlying processes, like imprinting, learning, conditioning and habituation.
Blackbird Marcia came to us three weeks after been rescued by a well meaning person, who found the bird as a nestling being out of the nest on the ground. Unfortunately, a wrong diet has been fed to the bird, which led to a very poor plumage and delayed general development. Marcia suffered also from an untreated coccidia infection worsened by a generally weakened immune system due to lack of nutrients, vitamins and minerals. Additional plumage damage has been inflicted by keeping the fledgling bird in a metal cage. Marcia appeared also clearly imprinted, as she has been raised by her own. Luckily, the finder didn’t release Marcia as initially intended, but only because of concerns regarding cats visiting the garden. This was the main reason why Marcia has been brought to us eventually, which saved her live and gave her another chance.
Although Marcia’s plumage might not look too bad at the first glance, one should not forget that most plumage related problems will manifest themselves at a later stage. Feathers and flight are the primary facets of bird rehabilitation, which are sometimes overlooked by inexperienced and even seemingly experienced rescues and rehabbers. Feather condition is as critical during the course of release for birds as is the ability to fly. Any type of damage to the feather structure will impede a bird’s ability to fly, to be waterproof and to thermoregulate. In short, birds with compromised feather condition have a low survival rate following being released. To further compound the problem, the majority of birds have only one annual moult, the first complete one usually occurring in their second year.
Update – 28/05/2017
It took Marcia five months to replace all damaged and prematurely lost feathers. Marcia was unable to fly for many weeks, which would have been her death sentence in the wild. She would have been unable to protect herself from the elements, rendering her unable to maintain her body temperature and unable to forage. Marcia has spent most of the time in our sheltered soft release aviary, where she could exercise and explore freely, but where she also had the chance to find shelter and warmth when needed.
Update – 22/09/2017
Today blackbird Marcia has been successfully released. Stay safe Marcia!
