On Sunday 31st August 2014, our satellite-tagged Osprey, 30(05), set off on her long migration south to her wintering grounds in West Africa. Just over eleven days later, she arrived! It took her exactly the same amount of hours as last year (267), and the route she took was almost exactly the same!
In the photograph above you can see the three lines indicating 30’s three tracked journeys to and from Rutland and Senegal. The red line is this year’s migration – autumn 2014. The green line is her autumn migration of last year, 2013. The yellow line is her spring migration back to Rutland in March 2014. Below is a table that shows the total distance 30 travelled on all three of her tracked migrations. They are remarkably similar!
|Autumn 2013 (green line)||Spring 2014 (yellow line)||Autumn 2014 (red line)|
|Total distance travelled (km)||4624||4895||4686|
|Total distance travelled (miles)||2873||3041||2911|
It is incredible how Ospreys know where they are going, and how they stick to a similar route each year. We imagine that they must use significant land marks and remember them to guide them on their way. In reality, we’ll never really know how they do it, it will remain something that we cannot possibly ever fully comprehend. But that doesn’t matter, we don’t need to know everything, what matters is that we can appreciate the intricacies and complex abilities of nature, and feel awed and inspired by them!
30’s autumn migration this year is without doubt an awe-inspiring thing. During her eleven-and-a-bit days of migrating, she travelled a total of 4686km (2911 miles), averaging 424km a day (264 miles), at an average speed of 36kph (22mph). Out of her 267 total hours of migration, she spent 130 hours actually flying, which is just under 50% of her time, and averages at 12.8 hours per day of flying.
The photograph below shows 30’s complete, and incredibly direct, migration to Senegal this autumn.
The table below shows how far 30 travelled each day and at what times, and total hours each day.
|Day||Distance (km)||Distance (miles)||Time migrating||Total hours|
|1||521||324||08:00 – 19:00||11|
|2||508||315||05:00 – 19:00||14|
|3||516||320||05:00 – 18:00||13|
|4||259||161||08:00 – 19:00||11|
|5||413||256||05:00 – 19:00 (1hr resting)||13|
|6||536||333||06:00 – 20:00||14|
|7||354||220||08:00 – 19:00||11|
|8||561||349||07:00 – 17:00||10|
|9||351||218||09:00 – 20:00||11|
|10||165||103||09:00 – 18:00||9|
|11||449||279||09:00 – 20:00||11|
|12||53||33||06:00 – 11:00 (but 2 hours migrating)||2|
Migration is truly mind-blowing, and not fully understanding how it is done just serves to make it even more admirable. Just look at what this 1.9kg bird has accomplished this autumn, in just over a week and a half. It doesn’t get much more amazing than that.