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Maternity strategy of seals

One of the studies that our researchers conduct in the Dollard, is to analyse ten seal mothers. Over several years, they look at whether their mothering strategy changes. For example, they look at whether she feeds more or fewer pups from other mothers and whether she always feeds the same pups or whether this varies. In addition, they study whether the seal mothers give milk each other’s pups. These things combined is called maternity strategy. 

Last updated on 03-07-2023
Zeehond - moeder en pup zogen

Allonursing, what is it?

Allonursing means that a seal gives mothermilk to a pup that is not their own. But why would a seal mother give milk to another pup? The causes and function of allonursing in seals remain mysterious, as giving milk takes an enormous amount of energy for the mother seal. There is also an increased risk of transmission of pathogens between mothers and other pups. It is therefore a crucial research subject.

Why do mother seals conduct allonursing?

There are five hypotheses that could explain why seals nurse their other pups:

  1. Allonursing is the result of misguided parental behaviour.
  2. Seal mothers alternate to nurse each other's pups.
  3. Females nurse foreign pups for additional health benefits.
  4. Females feed foreign pups to discharge milk not drunk by their own.
  5. Inexperienced seals spontaneously give milk without reproducing, or because they have lost their young. In order to improve their mothering.

Dit onderzoek doen we tijdens onze observatie in de Dollard: de periode waarin gewone zeehonden hun pups krijgen. Er worden filmpjes gemaakt van de moeders die melk geven. Met photo identification kunnen we de verschillende pups herkennen.