Osprey Diary Thurs 29th August
Posted on August 29, 2013 by rangeremma
Not a lot of action on the osprey nest today – in fact we spent most of the morning watching the flies on a rather unsavoury left over fish tail in the nest! This in itself is a good sign though- it means neither of our two remaining ospreys are going hungry, or they’d have been back for it, flies not withstanding. The adult male did bring a fish in for our chick Blue YZ this afternoon so we know she isn’t too hungry.
Q: Why do ospreys sometimes eat the fish tails and sometimes not?
A: It depends on how hungry they are, and the type of fish ( some have larger stiffer tails). I have found a pile of fish tails below an ospreys favourite feeding perch before, and at Loch of the Lowes, most nights a fox wanders past the base of the nest tree looking for any dropped tidbits.
Q: Do ospreys produce pellets like owls?
A: Great question! All raptors ( birds of prey) and many other predatory or scavenger birds ( like large gulls and Skuas) all produce pellets. These are regurgitated inedible remains of their prey, such as fur, hair, bones and beaks. As ospreys only eat fish, and fish scales are digestible and their bones are cartilaginous ( rubbery) and easy to digest, they do not need to produce pellets.
Q: How long does an osprey take to kill a fish and how is it done?
A: This depends on the birds catching technique. Sometimes, if the bird gets a good hold on the fish in the water , it can pierce the fish’s brain or vital organs with its talons and it dies almost instantly. If not, it often quickly suffocates when it is taken from the water, as the bird carries it away. Occasionally if the bird returns to a nearby nest quickly, the fish will still be alive, and we have all seen this on the Lowes nest. In this case, the osprey invariably start eating the head first so this quickly kills the fish.
And the BIG question of the week…..
Q: How much longer will the ospreys be at Loch of the Lowes this year?
A: We don;t know exactly as every year their leaving date is a little different. Most often they leave around the end of August, or the first week of September, We have had juveniles still here into the second or even third week of September but this is less common. It can be influenced hugely by weather- a good northerly breeze and high pressure are ideal for southwards migrations so check your weather forecast!
My advice is that if you wish to see the ospreys this season, come and visit Loch of the Lowes this weekend and wish them safe journeys!
The 2 juvies from the other nest
http://www.strathspey-herald.co.uk/News/Loch-Garten-ospreys-on-their-way-to-sunnier-climes-28082013.htm The other 2 juvies from the Loch Garden have gone, both with transmitters and you can track them. Story here
