A Pallid Harrier (Circus macrourus) named ‘Selja’ satellite-tracked from Finland died in southern Morocco last January. The cause of death is most likely not electrocution as was feared initially.
Selja was fitted with a satellite transmitter in central Finland in June 2018 as part of the research on Pallid Harrier carried out by Ari-Pekka Auvinen for the Finnish Natural History Museum (LUOMUS).
She arrived to Guelmim in southern Morocco on 13 November 2018. She would spend here the whole winter until 21 March 2019 when she started her northward migration. She became the first Pallid Harrier to winter in Morocco.
Once arrived to Finland, instead of nesting in the same area as in 2018, she chooses to settle in the north-west near the Swedish border where she paired with a new male. The pair successfully raised their chicks. Dutch harrier specialist Ben Koks and journalist Elvira Werkman visited her breeding area and took the following photos (Selja, her male and the ringing of one of her chicks by Ari-Pekka Auvinen). More about their visit on this link (in Dutch): Op zoek naar Selja.
Wintering in Morocco for the second year
This season, Selja arrived at the same wintering ground in the Guelmim region in early December 2019. After a month or so, Ari-Pekka Auvinen informed us that she most likely died on 9 January 2020. The cause of death was not known at the time, but we strongly suspected electrocution was the likely cause. The problem of bird electrocution is so serious in this region that we talked about it even when nothing actually happened to Selja in her first winter.
To find out what happened and try to retrieve the transmitter, I contacted our friend and colleague Ali Irizi from the Association of Friends of Raptors (ASARA). Fortunately, he agreed to volunteer and headed south to Guelmim on 6 February 2020.
His observations suggest that the cause of Selja’s death was probably not electrocution (e.g. no visible injuries on feet or wings). She was more likely attacked by a predator, with the likely ‘culprits’ include mammals such as African Golden Wolf (Canis anthus). Or maybe, it was killed first by a bird of prey such as Pharaoh Eagle Owl (Bubo ascalaphus) and finished off by a mammal later (note the partially crashed head). The photos below are reminiscent of those of an English Osprey who was also predated by Pharaoh Eagle Owl or a mammal in the same general region some years ago (see below the first photo in that link).
Sadly for Ari-Pekka Auvinen and his research, Selja was not the only Pallid Harrier to die this year. Another bird named ‘Hippus’ also died in Northern Nigeria (I can’t add more details). Unlike Selja, Hippus used the easterly route through Russian, Greece and Libya to reach the Sahel, see her full track here.
Some good luck is needed
Here are some anecdotes which I think we should keep in mind when we try to find a dead bird carrying a satellite transmitter. Children can stumble upon the birds and destroy their transmitters out of curiosity.
In the case of Selja, despite her carcass – with her transmitter – was laying there on the ground for almost a month, Ali Irizi found everything intact. It’s a different story in more density areas in the north where children can be found everywhere. A Moroccan colleague, studying another raptor species, has lost a few satellite transmitters because the children arrived before him. So luck is very important in some cases like these (more details when he publishes his results).
But it’s not always like this. A small girl found an electrocuted Spanish Imperial Eagle (Aquila adalberti) in the Rif region last year, and guess what, she informed her father about her find. When our friend Mohamed El Andaloussi from ‘AZIR Association’ went there later, he found the transmitter safely stored in the family’s house.
Adults can also find the transmitters first, and the diplomacy is needed in these cases to convince them to cooperate (happened with this White Stork in northern Morocco).