Overview and ‘microview’

Since the last update on UV he has continued to spend his days in a few familiar places but without having a settled routine. Sometimes he is at the coast for most of the daylight hours, occasionally he is barely recorded away from a roost area. An interesting aspect is where he still hasn’t been – no recent recorded activity on the south spit of the Langue de Barbarie, no travel to the southern end of the National Park where the river mouth used to flow into the ocean. His foraging areas have varied but before looking at a couple of examples an ‘overview’. Paul has prepared a migration map which will go up in A2 and A3 versions at Kielder Castle. It is also in the Location Maps section of the blog. 

courtesy Paul Wildlifewriter

courtesy Paul Wildlifewriter

Whilst in ‘overview’ mode the daily MODIS weather satellite data for 20 November showed a red dot at the top of this graphic indicating thermal activity very near Djoudj National Park.

courtesy Paul Wildlifewriter

courtesy Paul Wildlifewriter

The smoke billowing out to sea covers as large an area as the patchy cloud near the Senegal River mouth. The red dot is in an agricultural area and the likeliest explanation is that the crop is sugarcane. Sugarcane field burning commences in November, the start of the dry season. The fires burn the leaves off the stalks which makes harvesting the sugarcane easier.

Back to UV. His foraging activity has  ranged from just offshore to around 4.75 km out over the ocean. On 25 November he went further south offshore than usual.

checking different areas of the ocean

checking different areas of the ocean

When there are one minute fixes the change from slower foraging to moving on to try a different area is clear. After speeding south UV slowed down from 15.14, when he circled over a spot before carrying on south then east and north to a shallower area.

In contrast many of his forages look more like the image below.

another fishing trip?

another fishing trip?

That shallow area is a popular one.

Data arrived as this blog was being finalised. UV had two excursions today into the deep blue of the ocean, about 3.25 and 4.75 km offshore. Where tomorrow, UV?!

This entry was posted in Abroad, Blue UV, Migration, Osprey updates and tagged , . Bookmark the permalink.

7 Responses to Overview and ‘microview’

  1. JW4926 says:

    Thank you once again for a super update on the lad Joanna ….. and the graphics and maps really are so interesting Paul.
    One question – if I may – is it usual for migrants to travel so far offshore – or is this no distance whatsoever when compared with other birds?
    (1) Does this give an indication of the fish stocks nearer land
    (2) Is it more likely that UV is investigating further afield – because he can and because he seems to do this at home – for reference ….

    • Since arriving back in Senegal, UV has done most of his hunting within 2000m of the shoreline. But on other days he has ventured out to around 6000m. Purely in terms of distance flown, none of this is an issue: during the breeding season we regularly see nesting males in GB that undertake fishing trips of 10, 15, 20 km and more.

      By the standards of other bird species, ospreys generally are “local operators” – gannets and other seabirds can cover much larger distances in search of a meal for themselves or their offspring.

      UV’s behaviour is almost certainly a response to the conditions and fish movements on any given day. As he returns more data during the winter, we will be doing a more structured analysis of his hunting patterns and the results will be presented here.

  2. Vivien Finn says:

    Thank you Joanna, another interesting update on UV’S fishing activities. Interesting to read about the sugar cane crop being set alight to make it easier to harvest, also to see the effect of the smoke drifting out to sea.

    Paul your migration map really does highlight UV’s epic Spring 2016 migration compared with his autumn migrations. Thank you. It will be interesting to see the route of his Spring 2017 journey.

    • joannadailey says:

      Hope UV takes a rather more direct route next Spring, Viv! But as long as he is safe, that is what matters.

      • JW4926 says:

        Yes – his Spring trip was certainly a little ‘different; ….. but his wandering return journey seemed to tie in with his general inquisitiveness when back at home ….. hindsight and all that!

  3. Cirrus says:

    I’m with you there Joanna. Really do hope UV is learning best and better routes . Thanks to you and to Paul. Always interesting maps.

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