How to tell male and female ospreys apart

How do you tell male and female ospreys apart?  And how can you tell the difference between our resident Loch Arkaig pair, Louis and Dorcha, and other local birds?

Louis and Aila were the original pair who made our Loch Arkaig nest their home between 2017 and 2020. In 2021, Aila didn't return from migration and Louis has been paired since then with Dorcha. Our live nest cam has caught all the action and we'll be watching closely for this year's activity.

To help you recognise our ospreys, we've put together some handy identification tips. Massive thanks to Mary Cheadle and Liz Bracken of the Friends of Loch Arkaig Ospreys group, who pulled together the photos illustrating the main identifying features.

Look at the size of the osprey

Female ospreys are up to 20% larger than males. This is handy if you have a pair sitting together, but not so helpful if you only have one bird in view.

Check the osprey’s chest markings

The main useful visual clue is the 'bib' or 'necklace' marking on the osprey’s chest. Adult females tend to have quite pronounced brown necklaces while adult males have a lighter marking, sometimes fading to virtually nothing.

Our original pair look fairly typical. Aila had a very pronounced brown necklace and Louis has much lighter markings, although he is at the darker end of the male range.

Take note of any unique marks

Individual ospreys can often be identified by a number of unique markings. For our pair, the main features to look for are:

• stripes running from their eyes
• front and back head markings
• under-wing colourings.

Dorcha has some very pronounced individual features, including a strong line of dots running under her wing and arrow shapes on the front and back of her head.

Louis is only lightly marked under his wing and has a darker head overall.

Telltale signs for Louis include his pale male chest, head colour, eye stripe and light underwing markings.

Can you identify Louis and Dorcha?

As the nesting season gets underway at Loch Arkaig, there are often a few birds already around and much debate over who is who. Everyone is anxious to confirm that our resident pair made it back safely!

In theory you should now be able to confidently ID Louis and Dorcha – but remember, the first arrivals sometimes only offer quick glimpses of themselves as they swoop in. You’ll need to work fast!