Wednesday 6 December 2017

Morgan the killer whale has become pregnant - would her calf be a be a hybrid.


Morgan at Loro Parque in Tenerife.
Photo copyright  Loro Parque



The paper makes it clear that the Icelandic and Norwegian killer whale populations were a single panmictic population; this term means random mating where all individuals are potential partners. 

The recent news that Morgan the killer whale (
at the Spanish zoological collection Loro Parque at Puerto de la Cruz on Tenerife) has become pregnant has led to a number of people making allegations that the calf would be a hybrid.  

Morgan is believed to be an animal from the Norwegian killer whale population but the animals she lives with, whilst all captive-bred, are derived from animals from Iceland. 

In a paper published in 2014, an overview is given of the North Atlantic killer whale population and what is known so far.

The paper makes it clear that the Icelandic and Norwegian killer whale populations were a single panmictic population; this term means random mating where all individuals are potential partners. 

Whilst it is clear that animals within the North Atlantic population do follow specific feeding patterns which have in turn shaped their behaviour, the idea that Morgan's calf would be a hybrid - and as such this would be detrimental to the animal's welfare or conservational used in the future - is not based all our current scientific understanding of these animals in the wild.
The North Atlantic populations are currently considered the same species but with possible different ecotypes.

Moreover, hybrids only occur across species. There have been hybrid whales and dolphins in both captive care and the wild.  Perhaps the most well documented is the w
holphin which is a cross between a bottlenose dolphin and a false killer whale.


Reference and significant quotes.

North Atlantic killer whale research; past, present and future (2014) Andrew D. Foote, Sanna Kuningas and Filipa I.P. Samarra

"Further light has been shed on the relationship between Icelandic and Norwegian herring-eating killer whales by genetic investigations. Early genetic studies typically used DNA from captive Icelandic killer whales as outgroups for studies focused on North Pacific killer whales (e.g. Stevens et al., 1989). Only recently, have studies used larger sample sizes from across the North Atlantic using both mitochondrial and nuclear genetic markers. Allele frequencies of 17 polymorphic microsatellite loci indicated individuals from the Norwegian and Icelandic herring grounds were a single panmictic population; however, there was significant differentiation between the two regions based on mitochondrial DNA (Foote et al., 2011). Stable isotope ratios differed significantly between Icelandic and Norwegian killer whales assigned to this panmictic population, suggesting some differences in ecology, such as spatial distribution or trophic position (Foote et al., 2012)"

"The effectiveness of these large shared datasets was recently demonstrated in an unusual scenario, when a young killer whale became stranded off the coast of The Netherlands. No photo-identification matches were made, but sequencing of informative regions of the mitochondrial genome suggested that the whale belonged to the lineages that follow the *NSS herring. This was then further supported by the matching of several stereotyped call types produced by the whale and those recorded by groups feeding on herring in northern Norway (Samarra et al., 2010)"
*NSS: Norwegian spring spawning.

More details on Morgan's rescue can be found here. 
Morgan - The Rescued Female Killer Whale