Osprey Q and A : 23rd May

 Some more of your Osprey questions answered: please check our FAQ section at the top of this page and if you can’t find your answer there, email ospreys@swt.org.uk

Q:Is the chicks wobbly head normal – it seems very uncoordinated and weak?

A: This is perfectly normal: newly hatched ospreys are very wobbly at first as their heads and feet are too big and their muscles haven’t developed yet. They have just spent 6 weeks cramped in a shell too, so need time to adjust. Everything we’ve seen of this wee one so far indicates he is strong and healthy.  

Q: Why is the female panting, rapid breathing and gaping- is she poorly?

A: Our bird is hot- it unseasonable warm this week and as Osprey cannot sweat, like your dog, they pant to release heat. She is also a little more ‘fluffed up’ than usual as she tries to maximize air circulation through her feathers to cool herself. We have seen nothing that would indicate she is unwell or distressed though.

Q: Her feathers look different from the males- why?

A: She is molting- the relatively inactive period on the nest during incubation and chick rearing is an ideal time to re-grow old and tattered feathers (something all birds do, usually annually, some all at once, some gradually). If you look closely you will notice older feathers are a bit threadbare, sun bleached and have frayed edges, whereas the new ones just growing through are a darker chocolate colour and have clean sharper edges. By contrast our male bird is sleek and in top form (he has to be as he is this is his busiest time of year) and it is presumed that the male ospreys molt in winter.

Q: I noticed on the female last night a bald patch on her chest and a bulge on her neck- what are these?

A: The bulge  is the birds crop where all birds store their food pre-digestion- it was very full indicating she had just eaten a good meal.

The bald patch is known as her brood patch- an area on the chest on all birds where the veins are very close to the skin to make it warmer and designed to be a ‘hotspot’ to keep the eggs against. Interestingly, both genders of birds have them, and they are usually hard to see as the feathers close over them when they stand, but as our female was very ‘fluffed-up’ it was more obvious than usual.

Q: Is it possible that some of our young Ospreys may return to the UK but never find and mate or a nest of their own?

A: This is possible but unlikely. Most young ospreys will come back to their home areas, and if not successful after a year or two in finding a nest, they will probably spread out wider to try new areas- this is how new areas of the UK are being recolonised by ospreys currently. This process is being encouraged by the provision of nest platforms in new areas (like a starter kit home for ospreys, where natural nesting sites are in short supply) that gives young birds a head start. This crucial technique has been enormously successful in recent years in expanding the osprey population into new areas such as the Scottish Borders, Dumfries andGalloway, Northumberland etc.

Q: Is there such a thing as Osprey Menopause?

A: We don’t yet know- though in most animals, they continue to breed until the end. We presume that there may be some drop in fertility at an advanced age, but as there are so few Ospreys breeding into their 20’s this has been little studied. If our female is anything to go by, there is no sign of her being less fertile yet! In most cases, older Ospreys simply fail to cope with the rigors of migration, and don’t make it back to breed.

Q: Has there been any sign of the old male( last years green 7Y)?

A: No, I’m afraid not- he failed to turn up at Loch of the Lowes this year and has not been reported anywhere else either. It is most likely he has perished with over winter in Africa or on the hazardous migration route. We held out hope for him returning late but alas I think we must now presume the worst.

Q: What happenes to the egg shells once the chicks have hatched?

A: the female usually pushes them to the edge of the nest ( you may have noticed her doing this last night) from where they often go over the side- ospreys are notoriously clean and hygienic on their nest and remove the shells, which are bloody, to keep from attracting flies etc. If they do not go over the side, the egg shells usually get broken and crushed into the nest fabric. Very occasionally you will see a female osprey consume the egg shell to recycle the calcium, but this is much more common in smaller birds more likely to have a  calcium deficient diet.

Q: What height is the osprey nest in the tree?

A: We estimate the height of the mature Scots Pine our Ospreys are nesting in  to be between 60 and 80 feet ( approx 20 -25 meteres) , whilst the nest itself is approxiamtely  4-5 feet deep.

Q: Can you publish a list of dates and significant events on the nest at the end of the season?

A: Yes we will be happy to do this for you- whatch the blog later in the summer.

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 Some more of your Osprey questions answered: please check our FAQ section at the top of this page and if you can’t find your answer there, email ospreys@swt.org.uk Q:Is the …

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