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.
Continue reading “Some Thoughts About Animal Learning And Imprinting”Animal Emotions – Joy, Happiness and Play
This short videoclip shows one of those beautiful occasions, where we were privileged to be part of the daily lives of our wild non-human animal neighbours. Just by chance we have been able to document and record a fascinating playful interaction or variation of social play occurring between a wild young rook and a mixed group of rooks and jackdaws as well as a small flock of residential pigeons circling the area. Just a few seconds after the rook had drawn the attention of one of the approaching jackdaws, the rook decided to disengage and to follow the leaving birds.
” Social play is an excellent example of a behavior in which many animals partake, and one that they seem to enjoy immensely. Individuals become immersed in the activity, and there seems to be no goal other than to play. As Groos (1898) pointed out, animals at play appear to feel incredible freedom. ” 1
Social play observed amongst non-human animals including corvids plays an important part in the emotional lives of many non-human animal species. During our daily interactions with our corvid patients, residents and visiting wild birds, we are frequently able to observe many of these intricate nuances of their fascinating emotional lives, and even get sometimes involuntarily involved in their playfulness and cheekiness. Although many encounters we are able to witness may serve a specific purpose, a purpose we may or may not fully understand, some incidents like the playing rook in the video clip, might just be what it seems – a bird having a bit of fun, nothing more and nothing less.
Bibliography
- Bekoff, M. (2000). Animal Emotions: Exploring Passionate Natures Current interdisciplinary research provides compelling evidence that many animals experience such emotions as joy, fear, love, despair, and grief—we are not alone. BioScience, 50(10), 861-870. ↩︎
Crows To Clean Up Cities – Ignorance Versus Intelligence
The list of animal exploitation is long and includes the abuse of animals for food, clothing, entertainment and experimentation as well as as companions and workers. Right now, there is a new scientific project making its rounds through the media, which is suggesting a new method to keep our cities clean. The idea has been developed by Dutch scientists und is focussing on the utilisation of specific traits of an animals species, which could theoretically help to tackle one of the biggest human evolutionary shortcomings – to be willing to live in harmony with nature and the environment. The project design incorporates a machine and is recruiting and training city crows, who would take care of recklessly discarded cigarette butts.
It is known that cigarettes take between ten and twelve years to decompose. The scale of this waste problem is huge, as it is estimated that every year approximately 4.5 trillion cigarettes are discarded with no regard for the environment. The project is using a so called ‘Crowbar’, which is based on a design created by an American inventor. The device has a large funnel, where cigarette butts can be deposited, and a dispenser for releasing peanuts as a reward. The hope is that crows get busy cleaning up the streets in exchange for some easy food. This idea is trying to utilise the generally acknowledged fact that crows are very intelligent and adaptable being known for their ability to solve complex problems and also to create and use tools.
Before looking at ethical questions related to this idea, there are at least two ‘technical’ problems to address, which the inventors might not have fully thought through. First off all, it is very likely that crows will always have a food choice in our crowded cities, meaning that peanuts may not be that much attractive as a food reward. Secondly, our crows are usually territorial, which means that only one territory holding pair is going to use that machine, which doesn’t seem very efficient, when it comes to cleaning up our large cities. These two problems alone are likely to be sufficient enough, to put this questionable idea to rest.
However, without a doubt, this project raises also several ethical issues, the most important ones being the egocentric and anthropocentric way of human thinking and attitude. Obviously, common sense tells us that the far simpler and cheaper way of solving the cigarette butt problem is to educate people, in this particular case smokers. Instead of constructing, deploying and maintaining machines, which are leaving a noticeable carbon foot print behind, one should rather educate and encourage smokers to quit smoking, or at least to discard their waste products appropriately, which is the least one could expect from a grown up human being.
However, the problem is far more complex than that. Firstly, as mentioned already, the suggested solution is based on an anthropocentric view point. Humans have long tested animals to see how smart they are by seeing if they can do human-like tasks. We are too quick to judge animals by our own human standards, instead of testing within the limits of the animals’ natural behaviour and within their natural setting. By any standard used, we all know that corvids are clever enough to be able to fulfill this particular task, but so are other sentient beings, like toddlers too. And this leads to the second problem.
Humans do not treat sentient and intelligent beings like crows as equals, meaning we treat them differently, and by far not the way we would want to be treated, despite that there is a general agreement about the fact that humans and crows are both, sentient and intelligent. It is actually even worse, the anthropocentric view point is so deeply rooted, that many humans are often tend to focus on the level of animal intelligence (compared to humans) rather than sentience, when it comes to decide how to treat an animal, ignoring completely the fact that humans are not unique in possessing the neurological substrates that generate consciousness.
Ethical Methods Of Feral Pigeon Management
The truth is that this machine, when it would actually work, would exploit crows, ignoring the fact that it is morally wrong to use or exploit sentient beings in any way. Even worse, this machine is putting these birds at an additional risk by encouraging and rewarding them to handle toxic and also possibly still burning cigarette butts, which might even end up in a place, where we might not want them to be. Furthermore, at least to a certain degree, these birds will be made dependent to rely on human handouts. Based on the natural behaviour of corvids, they will also cache their food, or potential valuables like cigarette butts, as they might want to trade them in later. The result will be that litter will not only be removed, but also be distributed in a different, not nessarily desired pattern. It is also to expect that crows will test the built in scanner to its limits, simply to find out, if other items like pebbles or pieces of paper also trigger food rewards, something which will put the whole machine to a test.
Sadly, even some bird and corvid lovers seem to find this idea fascinating, as they feel that this approach spreads the word and is helping to change and improve the traditionally bad reputation of corvids. It might even do that, but by disregarding the rights of an individual sentient being and by supporting exploitation. Luckily, regardless of all ethical issues, and purely due to technical problems alone, it remains doubtful that this machine is ever going to work.
Top 10 Mistakes Made In Corvid Rescue And Rehabilitation
During many years of corvid rescue and rehabilitation we came across a number of serious mistakes being made by presumably experienced and unexperienced individuals or rehabbers alike. We would like to share our observations and experiences in the hope that these sometimes fatal mistakes will not be made again, hopefully saving the lives of many corvids in need of help.
Overestimation of one’s own capabilities
Raising an orphaned baby corvid is often seen as easy and very tempting, in particular as the finder is often ‘persuaded’ by the cute and interactive attitude of baby corvids. Lay people, but sometimes even rehabber with some degree of experience with other bird species, ever so often get into the trap of ‘giving it a go’, even when expert help and advice is being at hand. Despite meaning well, it is sadly rather more often about the own ego than the genuine wish to give the bird the best possible second chance he or she deserves. One of the common mistakes being made is that the effort and financial implications needed to raise a corvid are often greatly underestimated, and so are the needs of a sentient being, who is being degraded as an object of experimentation. Ever so often birds will be inadvertently imprinted on humans and prematurely released by choosing an insufficient release method, the wrong release site or the wrong release time.
Raising corvids as sole individuals without adequate company
Raising a nestling corvid by his or her own will without exception result in some degree of imprinting on humans, the human habitat or pets. However, it would be wrong and one of those mistakes to believe that imprinting is a negative or undesired feature. Imprinting as such is essential for life and survival. But the question is to whom the animal is being imprinted on. Birds are ‘hard-wired’ to many things in their future lives, but they also need to learn the art of feeding, catching prey or social interactions and behaviours from their parents. Songbirds can sing by default, but they do need to ‘learn the tune’ from those around them, those normally being their parents. Imprinting in animals in general can involve more than one sense. It can involve sight, sound and smell. Furthermore, the imprinting becomes stronger when the animal is under stress, which is in no doubt a survival mechanism. Imprinting is an interaction between instinct and learning. The irreversible and species specific process of imprinting occurs only in a fixed time window. This is the critical period, learning after this period has different weaker effects. To counteract the risk of imprinting, company of a same or similar species bird is crucial, meaning that corvids in particular should never being raised by their own. As many of these young patients are in need of long-term rehabilitation, it is also crucial to understand and to recognise their social needs during the process of maturing, a process which takes many months if not years. One of the mistakes commonly made is that the importance of the help provided by releasable and also unreleasable wild adult birds is underestimated, or not utilised at all, which in fact is an essential tool to teach young birds necessary social skills and behavioural patterns they require for their survival.
Inadequacy of rehabilitation facilities
The fact that corvids should not be raised by their own, the species specific needs and the common requirement for long-term rehabilitation facilities with adequate company, which includes the interaction with unreleasable adult possibly disabled birds, is a challenge in itself, which is often completely ignored or at the very least underestimated. One of the common mistakes being made in this context is that the facilities provided are usually too small and inadequately equipped to be fit for purpose, which is leading often to injuries, chronic diseases like bumble foot or damaged plumage. Corvids are very inquisitive and destructive. The materials to be used in an corvid aviary have to be safe and need to be checked and monitored constantly for wear and tear to eliminate a potential cause of injury. Although it is possible to combine different corvid species, one should always bear in mind, that the artificially created corvid society is a fragile and dynamic element, which needs constant monitoring and which is subject to frequent and sometimes rapid change at any time. Maturing, pair formation, hierarchical disputes, mood and hormonal changes during breeding season and moulting are only a few of the causes influencing the stability of a mini flock. CCTV monitoring is an expensive but very useful tool, which allows undisturbed and unbiased observation of behaviour and social interactions between birds, allowing early interference before problems occur. Sound knowledge and understanding of corvid species specific behaviour is the key, which unfortunately is often completely lacking, being ignored or at least regarded as unimportant.
Underestimation of the importance of hygiene
The necessity of keeping a larger group of corvids in a confined area for a longer period of time harbours another challenge, which is to maintain a basic hygiene and cleanliness system. The problem increases exponentially with the number of animals cared for and the good intentions to create a small artificial habitat, which should ideally allow the animals to behave and act naturally. It becomes apparent, when testing corvid patients, that almost all of them are carriers of coccidia and worms. Although it is possible to treat these birds individually, it becomes a bigger problem and challenge when birds are residing in a larger communal aviary, where flock treatment is the only option. It is also impossible and actually not advisable to completely eliminate these diseases, but is seems necessary to keep infection levels as low as possible. Therefore a larger communal aviary will always be a compromise between the ideal case scenario of a species specific nature habitat and a place which can be easily cleaned and maintained to minimise the potential infection risk due to the build up of infected faecal material in areas created for foraging and food caching as well as due to the run off of contaminated material into the surrounding environment creating a potential infection source for wild animals like ground feeding blackbirds or thrushes, but also hedgehogs and rodents. This is in particular a problem with coccidia, as the oocysts have resistant cell walls and are discharged unsporulated in the faeces. Oocysts do not survive well at temperatures below -30°C or above +40°C. However, within this temperature range oocysts may survive for more than one year and will sporulate or become infective in as little as 24 hours under optimum conditions in a humid environment between +25ºC and +30ºC.
Raising corvids on an insufficient or suboptimal diet
Although corvids are known to be scavengers and omnivores, the diet of the different corvids species does vary considerably, from species to species and over the seasons of the year. Only about 40% of the rooks’ diet for example consists of animal protein, and those being mainly worms, bugs and larvae. They usually don’t eat carrion, as their beak is not designed and able to rip animal carcasses into manageable pieces. The remaining 60% of the rooks’ diet are plant-based products like fruits, seeds and vegetables. During the winter time, carrion crows prefer seeds, berries and carrion, whilst during the summertime they also do mainly live on animal protein like snails, worms, insects, small mammals and eggs. These species specific facts should be taken in consideration when creating the menu for corvid patients. Nestling corvids should be primarily fed on an insect or adequate animal protein based diet. However, despite the fact that nestling corvids are being fed snails and worms by their parents, these should not be fed to birds when hand raising them, as internal parasites like coccidia or round worms are likely to be transmitted. Tinned dog or cat food is not suitable either and will lead to severe digestive short and long-term problems. Additional vitamin, mineral and calcium supplements are recommended, as corvids are prone to develop calcium deficiencies resulting in rachitis and feather damage. Pellet producing materials like small pieces of fur or feathers should be mixed under the baby food when older than 2 weeks. When the birds are fledged, the species specific diet preferences become more important and should be accounted for.
Misinterpretation of species specific behaviour as imprinting or tameness
One of the most common mistakes made is the wrong interpretation of normal corvid behaviour, mainly due to lack of knowledge and experience, but also sometimes due to anthropomorphistic reasons. Corvids are highly intelligent, sentient and social animals, who are able to interpret good or bad intentions and behavioural patterns of other animals, humans included. There is a big difference between submissive behaviour in a captive environment and being genuinely tame or imprinted. Young corvid nestling and sometimes even fledglings have not learned yet to regard humans as dangerous entities and will cooperate eagerly when being fed. At that point in time the risk of imprinting is at the highest, but has not necessary happened yet. Adult corvids are also able to adapt very well to a captive situation, in particular when realising that the human caring for them is providing food and is easing the pain. They will remain calm when not being restrained and when a minimum amount of privacy is being allowed, at least as long as they are poorly or compromised due to their injuries. Long-term patients often form a close temporary and person specific bond with their carers, which is being cut when the animal feels ready to go. All these behavioural variations have nothing to do with imprinting or tameness and are simply signs of their amazing ability to adapt to these unique situations. It is important to recognise the difference, as this fundamental ability of a good rehabber will decide over the future and the chances of survival of the animal being cared for.
Underestimation of the importance of species identification and age
Animals are sometimes rescued unnecessary, with good intentions, but without good reason. A young bird alone on low-level branches or on the ground has not necessarily been abandoned, as the young of many bird species will spend a couple of days on the ground before their feather development is complete and they are able to fly. Parents will be close by and come to feed the bird as soon as it is safe. However, to make an informed decision, whether an animal has to be rescued or not, one has to find out what species he or she belongs to and how old the animal is. A healthy rook fledgling on the ground, who is unable to get to higher ground, will not be fed by his or her parents and will require help. On the other hand, a healthy carrion crow fledgling on the ground, will usually be attended and defended by his or her parents. However, nestlings of any species, found on the ground, will not survive without human intervention. However, the degree of human intervention varies from stepping back and observing the situation, over taking a fledgling out of a danger zone and putting the bird back onto higher ground, to taking the animal in to human care. Species identification and establishment of the correct age are also crucial for the correct choice of release location and time.
Misjudgement of the importance of release area and timing
Hand reared juvenile corvids, but also all long-term patients having been in captivity for longer than 2 or 3 weeks, should always be soft released. Juvenile corvids are not suitable for release until being 5 or 6 months old, which is usually at the end of the summer after their first partial post-juvenile moult. This allows them to reach full growth and to be able to fly strongly. It also allows enough time to reach enough strength allowing normal competition with other corvids, avoiding excessive bullying. The preferred release time in the U.K. is the end of August and during September. Please also note that an offence may be committed under the Animal Welfare Act 2006, if a released animal does not have a reasonable chance of survival. This may include the release at an unsuitable site, in the wrong territory, when being unfit, or when not having learned to hunt, or when done during the wrong time of the year.
Lack of knowledge of species specific behaviour and ecology
The most common mistake made is the wrong species identification combined with the lack of species specific knowledge. Rooks are breeding in colonies or so called rookeries, as they are very social and gregarious animals. Carrion crows are territorial and have well-defined breeding territories, which are very much fixed but tend to shrink and expand slightly during and outside the nesting season. This means that the territory holding pair is using a single nesting site, which will be defended against any intruders. Sometimes another so called third bird, usually offspring from the previous year, is allowed to stay in the fringes of the occupied territory, helping the territory holder pair to defend their grounds. Non-breeding birds form loose groups, which will reside in an unoccupied area. Outside the breeding season and during wintertime, crows become more sociable and tend to sometimes mix with rooks. When releasing juvenile birds or longterm patients, then soft release is the preferred option. For short-term patients or a hard release scenario, the release site should be chosen very carefully. The location where the bird has been found, might not necessarily be the best place for his or her release. Neither crows nor rooks should be released into an occupied crow territory, in particular not during the breeding season. An area inhabited by a non-breeding flock of crows or rooks would make an ideal place for a release. Soft release works best, when the release aviaries are located in an unoccupied crow territory, near a rookery or communal roost.
Misinterpretation of plumage aberrations and their consequences
Leucism is a general term for the phenotype resulting from defects in pigment cell differentiation or migration. It is a condition in which there is a partial loss of pigmentation resulting in white, pale or patchy colouration of skin, hair, feathers, scales or cuticle, but not the eyes. Leucism can be caused by the reduction of all types of pigment, unlike albininism, which only affects the melanin production. Leucism is occasionally found in corvids, which can show a varying degree of white or pale feathers within an otherwise normal appearing plumage. These abnormal feathers are often more prone to wear and tear and make the bird potentially more conspicuous and prone for predation.
Besides primarily genetic causes, dietary deficiency caused by calcium or folic acid deficiency, or as found in Australian ravens due to a circovirus infection, can also result into this phenotype pattern. It has been also found that agricultural pesticides have a direct impact on reducing food and insect availability. Insects are an essential dietary requirement for almost all bird species, which rely on those for at least a substantial part of the nestling phase of their offspring. Pesticides lead directly and indirectly to the search for alternative and often suboptimal food substitutes and may also result into a progressive weakening of the immune system of adult and young birds, which increases mortality in general, but does more often lead to a varying degree of dietary deficiencies with subsequent plumage and skeletal aberrations.
Recognising the difference between inherited and acquired plumage aberrations is crucial, as acquired plumage problems can be corrected, whilst inherited causes cannot.
Anting Behaviour Observed In Crows
Our routine aviary cleaning procedures also involve the cleaning of drinking and bathing facilities of our crows. This is usually seen with great anticipation by all our corvids. Birds in general, but in particular corvids, are very clean birds, and can’t wait to make use of a refreshing bath. We frequently add natural apple cider vinegar to bath and drinking water, which keeps the water longer fresh and has positive health properties for the birds.
The video shows carrion crow Emma taking advantage of a bath in natural apple cider vinegar, before we have been actually able to add drinking water to dilute the vinegar further. This behaviour can be seen as the equivalent to or a variation of anting, frequently observed in the wild.
Anting can take on different forms. Some birds will pick up ants in their beaks and rub them over their feathers, while others will open their wings, lie down and allow ants to penetrate their plumage. Birds seem to prefer using ants that produce formic acid. Formic acid is being used by ants as a defense mechanism.
One theory on anting is that the formic acid could act as a fungicide, bactericide and insect repellent, while others think that it is the vitamin D content in the acid that birds are interested in. However, birds sometimes use alternative anting tools, such as millipedes and fruit, and in our case apple cider vinegar. Some scientists believe that anting is used to preen feathers and helps to prevent the drying out of the plumage. Another suggestion is that anting has an intoxicating effect on birds, as some birds have been seen to shake themselves and seemingly lose control over their ability to walk.