I have always been fascinated and touched by the devotion of Emperor Penguins and their rearing of a single chick in possibly the remotest and severest of environments on the planet.
They breed in the depth of the Antarctic winter during 24 hours of darkness in temperatures which range from –20 C to – 50C where wind speeds can reach in excess of 124 mph and where blizzards cause complete whiteouts.
How is it then that in these conditions which are difficult enough for them to survive do the females manage to locate over such large distances the huddled male incubation groups and within that group the individual male and chick?
The single egg is laid between May and June and the female then leaves the group and will be away until July.
At this point there are several elements that will come into play.
The first is ‘distance’ location.
Jim Andrews has explained the methods employed by the Romans to build straight roads. By using this same straight line ability the female is able to locate from whatever distance the direct bearing of the male incubation group. She will do this by either focusing on the historic established breeding site ( similar to homing pigeons) or possibly by focusing on her mate or chick. I would favour the link to the historic breeding site which would have a very strong ‘signature’.
This can be done in any conditions, darkness, whiteouts and from any distance. Even when the female is at sea collecting the food required for the chick she will be aware of the precise direction of the breeding ground.
The second element that comes into play is ‘ground’ tracking.
When the female has collected sufficient food she will leave the open sea and start her long trek towards the incubating group.
She will have used the ‘distance’ tracking to get to the shore or ice line and once ashore she will be able to locate the ‘ground’ tracking element.
This in all probability will be her own ‘signature trail/track’ or maybe her partner’s ‘signature/ track’ when they both made their way up to the breeding grounds. This track will be individual and unique and although there are many thousands laid down not only during this season but in countless seasons before over many years ( I have found all ground tracks made by animals or humans seem to last indefinitely) she will be able to follow it regardless of the conditions, and shuffling forward will use this ‘ground’ tracking together with occasional ‘distance’ tracking to home on the incubation group.
When she eventually arrives at the male incubating group there will be many hundreds if not thousands of males all huddled in a large slowly rotating group, possibly in the severest of conditions.
It is at this point she will use the third element which is the element which enables her to locate her mate and newly hatched chick. Although not hatched before she left the fertilised egg containing the chick was very much part of her and it would make no difference the chick being in the egg or out of it.
I have found that by holding both hands of a mother it is possible to locate the direct line bearing of any off her offspring whatever the distance.
This third element is the ability which is related to distance tracking and allows her to locate at close range her mate or chick. She will be able to switch between either of them at will.
Each of them will have a unique individual signature which is as specific as DNA and these ‘signatures’ will be recorded within her to be recalled as and when necessary.
Her mate will also have the ability to locate her once he has been alerted that the females are returning. He will no doubt have always been aware of her direct line bearing whilst she has been away. It is also possible that he might also have been aware of the distances separating them. Just as we are able to calculate distances when taking straight line bearings and the distances/depths involved when locating underground streams etc.
However current academic thinking is that this pairing up again is achieved by recognising a distinctive call.
This may in part be so, but it is difficult to understand how it might be that distinctive in such a large noisy group ( which it must be) when all the females are returning and in possible adverse weather conditions which may well involve winds in excess of 100 miles per hour and driving snow!
The male then leave the group after handing over to the female. To build up his reserves he then returns to the sea which could be up to 250 km away and might take several days to reach. He will be using the ‘ground’ tracking ability, following the same ‘ trail signatures’ as the female had done but in reverse. He will choose a particular ‘signature’, most possibly his own or perhaps his mate’s in order to find his way down to open water.
When the male has built up his strength he will return to the female and then both parents will leave the chick in the ‘crèches’ and go back and forth to the sea to collect food.
At this point they will both be using their ‘distance’ and ‘ground’ tracking abilities and be aware of each others location be it on land or at sea but most importantly homing in directly on the chick’s ‘ individual signature’ regardless of distance to enable them to continue to feed and sustain their sole offspring.
Malcolm Bransgrove, February 2012.