One summer, as part of my training, I accompanied one of the wildlife workers out for the re-release of four orphaned bunnies. (The call had come in a few weeks prior that these newborn bunnies had been orphaned.)
I accompanied her as she drove the bunnies back to the area
where they had originally been collected; and as she trudged around in the tall dry grass opposite a new sub-development, looking for the best release location; and as she scooped them up and set them free.
Standing at her side as we watched them hop away through the field, I said:
Standing at her side as we watched them hop away through the field, I said:
“Do you think they’ll be okay?” (Unprepared to be met with the first of what would soon become a surplus of harsh realities learned.)
“When it comes to rabbits, you need to keep in mind that they are basically just nature’s food," was her reply.
Often, too often, we would get
calls about orphaned goslings. Poor mama and papa goose having been hit by cars in tragic Goosespearean scenes of one rushing to the other's side after he/she had been struck, and then, well, you get the picture.
In these situations, the goslings didn’t require a stint at a rehabilitation facility, we could simply pack them up, take them to
the nearest pond and search out a goose pairing with goslings of a similar age.
Inevitably, curious onlookers would gather around, which in this case was welcome, as opposed to those times when I was trying to catch an injured raccoon or hawk or possum.
I’d wait for the goose family to come ashore and place my downy additions at the end of the line, and without fail, they’d be instantly incorporated into the family.
Inevitably, curious onlookers would gather around, which in this case was welcome, as opposed to those times when I was trying to catch an injured raccoon or hawk or possum.
I’d wait for the goose family to come ashore and place my downy additions at the end of the line, and without fail, they’d be instantly incorporated into the family.
When I attended my first training session at a wildlife
rehabilitation facility it happened that they were caring for an orphaned baby otter, which
is basically among the top 10 cutest things on earth. The rules were very
strict (and very difficult for me to abide by). No talking or cooing or
cuddling or any of those things you are naturally inclined to do. The place was
starkly silent. But the rules were strict for a reason.
Certain animals, otters among them, can very quickly form attachments. And our involvement, our purpose of presence was to provide the essentials (food, water, shelter & medical attention), anything beyond that might risk jeopardizing the animal bonding with the same-species mother in whose care he/she was intended to be placed.
Certain animals, otters among them, can very quickly form attachments. And our involvement, our purpose of presence was to provide the essentials (food, water, shelter & medical attention), anything beyond that might risk jeopardizing the animal bonding with the same-species mother in whose care he/she was intended to be placed.
I never had the experience of matching orphaned wildlife to mothers of a different species, our aim was always to match up orphans with same-species mothers, the ultimate goal for wild-life being eventual re-release into the wild. That said, it has been observed to occur spontaneously in the wild:
FILIAL IMPRINTING is the phenomenon exhibited when the newborn of a species follows and becomes bonded to the first moving object they encounter. [1]
- Imprinting is an example of how some animals are genetically hard-wired to quickly learn key behaviours essential for the survival of the species. [1]
- Birds may be built for flight &/or song, but need to be taught migratory routes and specific melodies. [2]
- Imprinting can involve more than one sense: sight, sound, smell; and is stronger when the animal is under stress. [2]
In the 1930's the Austrian naturalist Konrad Lorenz was among the first to describe how imprinting occurs. [3][5] Working with incubator-hatched graylag geese, he observed that hatchlings would imprint on the first moving thing they saw within the first 36 hours of life. [2]
One of the groups was hatched by their mother and immediately began following her around.
The second group was hatched in an incubator (in the mother's absence), and began to follow Lorenz.
When Lorenz placed all of the goslings together inside a box and then released them, the goslings moved toward their mother or Lorenz, according to whom they were first exposed. [1-3][5]
Based on his observations of these hatchlings in their natural environments, Lorenz proposed the following points which differentiate filial imprinting from *associative learning: [1]
- there is a stringent critical period for imprinting to take place;
- the imprinting process is irreversible;
- the phenomenon is species specific as opposed to being an individual memory process.
*“Associative
learning is a form of conditioning, a theory that states behavior can
be modified (or learned) based on a stimulus and a response. This means that
behavior can be learned or unlearned based on the response it generates. For
example, a student might know that if she misbehaves in class (stimulus), she
will not be permitted to go out for recess (response).” [19]
FILIAL IMPRINTING & THE BRAIN
Studies into the neural mechanism of filial imprinting in chicks have implicated the intermediate and medial part of the hyperstriatum ventrale
(HCV) as the likely site for memory storage. [1][4][6][11-12]
Bilateral lesions of the HVC prevented both the acquisition [7] and retention [8] of an imprinted preference. Whereas, lesions of other forebrain regions, did not affect imprinting. [6][7-10][13]
Birds hatched in captivity
need to be taught their traditional migratory routes.
In 1986, perhaps the best known example of imprinting facilitated assisted migration occured when orphaned Canada geese were trained to follow their normal migration route by the Canadian ultralight enthusiast Bill Lishman. A rendering of his story was told in the film, Fly Away Home. [15][18]
 |
| Moullec flying with geese in Dahlem, Germany (2007) |
In 1990 ornithologist Christian Moullec
completed a 2,000 km flight from Sweden to Germany followed by 30
geese. [18]
(The two videos that follow are of Moullec and his geese.)
(The two videos that follow are of Moullec and his geese.)
 |
| Angelo d'Arrigo guiding Siberian Cranes on a 5300 km migration from Siberia to the Caspian Sea. |
- Studying imprinting within the laboratory in the 1950's, psychologist Eckhart Hess and biologist A.O. Ramsay observed that hatchlings would follow colored spheres, with imprinting being stronger for blue spheres than for white ones. [3]
- In a series of experiments (2009), newly hatched domestic chicks were reared with five identical objects. [14]
- When the chicks then watched the visible transfer of these objects from behind one opaque screen to the other, they demonstrated basic counting skills by figuring out behind which screen were hidden the most objects.
Except where othewise specified, the points below are from the paper Mechanisms of avian
imprinting: a review (1991): [4]
- The end of the critical period for imprinting is likely to be a result of the imprinting process itself.
- There is little evidence for a direct role of hormones in the learning process of imprinting.
- Filial imprinting is reversible. (Contrary to what Lorenz had proposed.)
- The first stimulus to which the young animal is exposed may exert a greater influence on filial preferences than subsequent stimuli.
In, The importance of being first: a primacy effect in filial imprinting (1990), the authors found that the reversal of filial preferences was not necessarily permanent: [13]
When presented with a simultaneous choice of different objects prior to and following a series of experiments in which chicks had been sequentially exposed to each of the objects for an equal amount of time, the chicks would ultimately return to what had been their first choice.
- Filial preferences are formed not only as a result of learning through exposure to an object, but also under the influence of visual and auditory predispositions.
In this 1994 study, [14] researchers set up three experiments involving 208 chicks to investigate the conditions under which auditory cues may function to enhance imprinting preferences.
They found that the simultaneous presentation of a visual and an auditory stimulus enhanced the chick’s preference for the visual stimulus when the auditory stimulus was absent.
But that additional exposure to the auditory stimulus either prior to or after the combined presentation of stimuli reduced the chicks preference for the visual stimulus.
CAN BIRDS SMELL HUMAN SCENT? [16][17]
The wildlife trainer was not one of the, 'there's no such thing as a stupid question', variety, and the look she gave me when I asked:
"Will a bird abandon her chicks if a human handles them?"
“Birds don’t have noses; they can’t smell.” In the tone of, dumbass.
Well, I have had occasion to do a bit of
reading up on the subject through the course of this week's subject matter. And I have found that she was partly right: they may not
have noses per se, but they do have olfactory bulbs and nasal conchae, and so
yes, birds do possess a sense of smell.
That said, the implication of her snarky tone was correct: The combination of strong parental drive (killdeer and ducks will feign a broken wing to lure a predator away from their babies), and relatively weak sense of smell (as in, too weak to detect human scent), make it highly unlikely that a bird would abandon its young as long as the nest was left undisturbed.
That said, the implication of her snarky tone was correct: The combination of strong parental drive (killdeer and ducks will feign a broken wing to lure a predator away from their babies), and relatively weak sense of smell (as in, too weak to detect human scent), make it highly unlikely that a bird would abandon its young as long as the nest was left undisturbed.
There are very few birds with extraordinary olfaction. Two examples are turkey vultures and starlings: [16][17]
- Turkey vultures are attracted to methyl mercaptan, a gas produced by decaying organic matter.
- Starlings can detect insecticidal compounds in vegetation, which they utilize to keep their nests bug-free.
UPDATES / RELATED
Seabirds May Navigate by Scent / Science News / July 3, 2015
***
FIN
lpmangas via YouTube
REFERENCES
[2] The
Psychology of Imprinting: Does imprinting explain why we are attracted to
certain types of people? / By Adrian
Furnham Ph.D. / Apr 12, 2015 in A Sideways View
[4] Bolhuis
JJ1. Mechanisms of avian imprinting: a review. Biol Rev
Camb Philos Soc. 1991 Nov;66(4):303-45.
[5] Konrad
Lorenz Experiment with Geese / Uploaded onto YouTube Mar 2, 2009
Project for Developmental Psychology / Category Education /
License Standard YouTube License / Accessed June 29, 2015
[6] Davies
DC1, Taylor
DA, Johnson
MH. J
Neurosci. The
effects of hyperstriatal lesions on one-trial passive-avoidance learning in the
chick.1988 Dec; 8(12):4662-6.
[7] McCabe. B. J.. G. Horn. and P. P. G. Bateson (1981)
Effects of restricted lesions of the chick forebrain on the acquisition-of
filial preferences during imprinting. Brain Res. 205: 29-37.
[8] McCabe, B. J., J. Cipolla-Neto, G. Horn, and P. Bateson
(1982) Amnesic effects of bilateral lesions placed in the hyperstriatum
ventrale of the chick after imprinting. Exp. Brain Res. 48: 13-2 1.
[9] Horn, G. (198 1) Neural mechanisms of learning: An
analysis of imprinting in the domestic chick. Proc. R. Sot. London [Biol.] 213:
1 Ol- 137. Horn, G. (1985) Memory, Imprinting and the Brain, Clarendon, Oxford,
UK.
[10] Horn, G., B. J. McCabe, and P. P. G. Bateson (1979) An
autoradiographic study of the chick brain after imprinting. Brain Res. 168: 36
l- 373.
[11] Horn, G., B. J. McCabe, and J. Cipolla-Neto (1983)
Imprinting in the domestic chick: The role of each side of the hyperstriatum
ventrale in acquisition and retention. Exp. Brain Res. 53: 91-98.
[12] Horn, G., P. Bradley, and B. J. McCabe (1985) Changes
in the structure of synapses associated with learning. J. Neurosci. 5: 3 16 l-3
168. Johnson, M. H., and G. Horn (1986)
[13] Johnson, M. H., and G. Horn (1987) The role of a
restricted region of the chick forebrain in the recognition of individual
conspecifics. Behav. Brain Res. 23: 269-275.
[14] Rugani, Rosa; Fontanari, Laura; Simoni, Eleonora;
Regolin, Lucia; Vallortigara, Giorgio (2009-04-01). "Arithmetic
in newborn chicks". Proceedings of the Royal Society B (London: The
Royal Society) 276 (1666): 2451–60. doi:10.1098/rspb.2009.0044. ISSN 0962-8452. PMC 2690459. PMID 19364746.
[16] Do
Birds Smell? http://www.bto.org/ /Professor
Tom Birkhead (University of Sheffield) / Spring 2012
[17] Fact
or Fiction?: Birds (and Other Critters) Abandon Their Young at the Slightest
Human Touch Does nature's proclivity to nurture override its flight
mechanism?/ scientificamerican.com / By Robynne Boyd | July
26, 2007
[18] Flying With Birds
/ http://www.euronews.com/ May 20, 2013
[19] Associative
Learning: Definition, Theory & Examples Chapter 8 / Lesson 13 /
Accessed July 2, 2015.
IMAGE CREDITS
"Ducks army marching" by Radoslaw Ziomber - Own
work. Licensed under CC BY-SA 3.0 via Wikimedia Commons -
https://commons.wikimedia.org/wiki/File:Ducks_army_marching.jpg#/media/File:Ducks_army_marching.jpg
"Goslings (Clergue GS) 7" by Fungus Guy - Own
work. Licensed under CC BY-SA 3.0 via Wikimedia Commons -
https://commons.wikimedia.org/wiki/File:Goslings_(Clergue_GS)_7.JPG#/media/File:Goslings_(Clergue_GS)_7.JPG
"Greylag Goose - St James's Park, London - Nov
2006" by Diliff - Own work. Licensed under CC BY-SA 3.0 via Wikimedia
Commons -
https://commons.wikimedia.org/wiki/File:Greylag_Goose_-_St_James%27s_Park,_London_-_Nov_2006.jpg#/media/File:Greylag_Goose_-_St_James%27s_Park,_London_-_Nov_2006.jpg
"Birdbrain" by L. Shyamal based on Nottebohm F -
own work based on
http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0030164.
Licensed under CC BY 2.5 via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Birdbrain.svg#/media/File:Birdbrain.svg
"Christian Moullec 4" by Superbass - Own work.
Licensed under GFDL via Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Christian_Moullec_4.jpg#/media/File:Christian_Moullec_4.jpg
"Arrigo" by Original uploader was BatteryIncluded
at en.wikipedia - Transfered from en.wikipedia. Licensed under CC BY 2.5 it via
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