Nick Altena schreef op zaterdag, 8 januari 2005, 0:48:
> Hoi,
> Op een van de vele paarden site´s zag ik het volgende stukje
> waardoor er bij mij een vraag naar boven kwam...
> kijken , iets wat ik deze keer nou eigenlijk wel eens had willen
> doen...
> Wie weet hier wat zinnigs over te vertellen?
>
IK NIET! Maar Mariner en Alexander doen er onderzoek naar in Z-Afrika:
#Coprophagy as an avenue for foals of the domestic horse to learn food preferences from their dams
Marinier S. L., and Alexander A. J.
Journal of Theoretical Biology
Volume 173, Issue 2 , 21 March 1995, Pages 121-124
Abstract
Observation of foal development shows that the appearance of adult-type motor grazing behaviour, selection of grass vs. non-grass and the avoidance of poisonous plants occur concurrently between the ages of 4 and 6 weeks. Suckling behaviour and close association of foal with dam change with time but show no particular coincidence with grazing behavioural changes. Coprophagy of the foal on maternal faeces does, however, correspond chronologically with the foal learning to graze selectively. This correspondence suggests that, as well as other uses, in domestic horses coprophagy may function to imprint on the foal the food-selective values of its dam.
Volgens M&A leert een veulen dus al snel (4-6 weken oud) d.m.v. coprofagie - het eten van de poep van moeders - welke planten moeders gegeten heeft en welke niet. HET ONDERLING GEDRAG GEEFT GEEN CORRELLATIE.
Toch komt er naar mijn verwachting meer bij kijken in dit leerproces, nl: associatie en categorisering.
Toch is jouw hypothese alsdat paarden vervreemd raken (of "dom" worden) ook binnen deze context zo gek niet. Ik denk dat dát klopt, en in extrema samenhangt met het feit dat met domesticatie zo een gigantische terugval in hersenvolume samen gaat. M&A hebben er ook, in een ander artikel, iets over te zeggen:
#Selective grazing behaviour in horses: development of methodology and preliminary use of tests to measure individual grazing ability
S. L. Marinier and A. J. Alexander
Applied Animal Behaviour Science
Volume 30, Issues 3-4 , May 1991, Pages 203-221
Abstract
Methods are described to assess horses' selective grazing ability that includes choosing, sorting and the adaptive value of this behaviour. Choosing ability was tested by the experimenter presenting pairs of cut plant species that were then alternated at each presentation until the test horse had taken three bites of one of the plant pair. The results were analysed in relation to five measures of choosing behaviour: (1) the strength of the choice; (2) correspondence between first bite and the final choice; (3) constancy of the choice over a number of trials; (4) the comparison of the horses' ranking of the species over a number of trials; (5) the constancy of the linear arrangement of the plants over a number of trials. Sorting ability was tested using two methods. A mixture of two plant species was presented either in a clamp or loose in a trough. Results were based on number and weight of plant residues. The adaptive value of the behaviour related to the bitterness of toxic plants. This bitterness was represented in testing by quinine sulphate and a poisonous Senecio species. An extremely bitter substance "Bitrex" was also used in this context but was totally accepted by the horses. The horses' reactions to these substances were monitored using a behavioural score chart.
The results from 12 horses revealed that the horses differed individually in their grazing ability. On this basis, the horses were classified as efficient, semi-efficient, or inefficient grazers. This finding has practical implications in deciding which horses may safely graze on pastures infested with toxic plants.
Er zijn/ontstaan dus wel degelijk kampioengrazers en sukkels. Dit kun je testen, wat me zeker interessant lijkt waar het JKK aangaat.
Wat me daarop een niet onlogisch vervolg lijkt, is bij "dommerikken" proberen uit te vinden of alsnog leren JKK te mijden d.m.v. conditionering betrouwbaar is.
Groeten, Egon
Warboel
