How do Birds recognise each other?

finnegan2010

Last night I saw 2 black birds sitting together on one Lamp post and not far away 2 sea gulls. I got home and saw Lovely little gracefull birds eating off my bird feeder all the same breed.
It got me wondering. How exactly do our feathered friends know one another ie "oh look theres another me, must hang with him"
They are not self aware (Google Self awareness test)
So what stops a crow for instance joining a Swan Colony or Sea gull group. Or a duck joining a blackbird group.
Can a blackbird look at a crow and say he looks different to me i dont like him, then see another strange blackbird and say hmm looks like me ill go chat see what the story is?
Yours baffled

Skerries

birds of a feather flock together, i said flock

spiralbound

They imprint on whatever they see when they first hatch.

wildlifeman

thats like saying..how do chinese people tell each other apart.. or white people if you are chinese.

leopardus

Conspecific recognition is pretty intersting in birds. I Hope the following links (and copied abstracts) are of some help in answering your question.

http://www.springerlink.com/content/e2y1bypjrt434gxa/

When birds raised by another species become adults, they (if they are non-brood-parasitic species) usually attempt to mate with birds of their foster species rather than with birds of their own species, a phenomenon called sexual imprinting. Avian brood parasites lay their eggs in nests of other species (the hosts) that rear the young, but the problem of sexual imprinting among brood parasites has generally been neglected, and brood parasites have been considered as an exception among birds. Here, we show, with data from field observations and field experiments, firstly, that adult great spotted cuckoos Clamator glandarius sometimes maintain contact with both older nestling and fledgling cuckoos. Adult cuckoos visited parasitized nests during the last days of the nestling period (5 observations) and, when parasitic chicks left the nest, adult cuckoos maintained contact with the young (14 observations). Adults and fledgling cuckoos communicated vocally (5 observations), and an adult great spotted cuckoo even fed a parasite fledgling in two cases. Secondly, when experimentally cross-fostered in nests of magpie Pica pica hosts outside the parasite breeding range (thus avoiding visual and acoustic communication with adult cuckoos), young cuckoos did not learn to recognize their own species when only one cuckoo chick was introduced per nest, but they learnt to recognize conspecifics when two cuckoos were reared together. This means that young great spotted cuckoos apparently must learn to recognize conspecifics, that is, recognition is not innate. Social interactions between adult brood parasites and young have also been reported in other brood parasites; thus, brood parasites are probably not an exception to the general phenomenon of imprinting, and young brood parasites may need to be imprinted on conspecifics, although more studies on other brood parasite species are needed to confirm this.

http://www.jstor.org/pss/4535509

Video images of pigeons were used to examine the degree to which these images are equivalent to real live conspecifics by analyzing the natural behaviors of pigeons in the presence of each stimulus. Three aspects of courtship display (i.e. bowing, tail-dragging, and vocalizations) were selected and the display duration for each was measured. When videotaped images of female pigeons were presented as stimuli, the display duration by male pigeons was not significantly different from that for the live birds. In contrast, the subjects showed much shorter, or no, displays to the video images of a non-pigeon bird (cockatoo) and an empty chamber. The results suggest that the video images of pigeons contained necessary information to trigger the courtship behaviors. Furthermore, the present study examined which features of the video images were critical for triggering the displays by manipulating the images. Thus, the subjects' behaviors were more vigorous (1) when video images were in motion rather than still, and (2) when the head-only region was visible rather than the body-only region. These results suggest that motion and facial/head characteristics are important features. Collectively, the results indicate that the use of video images as stimuli and courtship displays as measures provide a useful method to study the visual recognition of conspecifics in birds.

http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2010.01013.x/abstract

The divergence of conspecific recognition signals (CRS) among isolated populations facilitates the evolution of behavioral barriers to gene flow. The influence of CRS evolution on signal effectiveness in isolated populations can be assessed by testing the salience of changes in CRS from surviving ancestral populations but founder events are rarely detected. The population history of the North Island (NI) saddleback Philesturnus rufusater is absolutely known following conservation translocations which increased the number of populations from 1 to 15. With one exception there is no gene flow between these populations. The translocations have generated interisland divergence of male rhythmical song (MRS), a culturally transmitted CRS. We conducted an experimental test of behavioral discrimination in NI saddlebacks exposed to familiar and unfamiliar MRS and found that responses were significantly stronger for familiar MRS, consistent with a model of contemporary cultural evolution leading to discrimination between geographic song variants. Significantly, this result demonstrates the rapid tempo with which discrimination of CRS might evolve within isolated populations and supports both bottleneck and cultural mutation hypotheses in CRS evolution. The evolutionary implications of contemporary cultural evolution in the production and perception of CRS merit debate on the time frames over which conservation management is evaluated.

Tiercel Dave

Just a story to ponder on! Years and years ago, living in Dublin, I took a young Magpie from a nest and proceded to hand rear it. Christened him (?) 'Beaky' :eek:! He thrived, much to everybodies surprise, and in time became a bit of a delinquent. Beaky lived free during the day and roosted in the tool shed at night when we just closed the door over. He'd only be put in a cage if there was some sort of 'sentence' to be served out! Lots of stories could be told, However, what is relevant to this thread is the fact that Beaky could recognise me from distances up to 500 yrds away. If I was walking back from the shops he would fly down to me from the rooftops and land on my out-stretched hand or failing that my head. Now I know, that as I was returning to his airspace I might be easy to spot, BUT there was a train station (Dart now) at the end of our road, maybe 300 yrds from the house and as I alighted the train at rush hour, guessing maybe a hundred passengers, six or eight people across, it was quite normal for Beaky to appear out of nowhere and land on me. As he had a bit of a penchant for ears I would try and discourage him from my shoulders much to the amazement of the general public who thought the world must be coming to an end. It was funny to see such a small creature strike so much terror into people. If anyone tried to swat him with a newspaper Beaky thought it was the best game ever invented and would dodge with ease. Walking home he'd be on my head, trying to root through the shopping bags or flying along from chimney to chimney as he kept up with me! Dave