Today both units have been switched on for the first time after the new December moon. There is always some trepidation until the alignment completes, especially after both units have spent a couple of weeks out there in the rain and unusually turbulent weather. Luckily…both units aligned without any difficulty.
Fingers crossed for some good weather – let us see what will turn up this month.
Another of those tiny gems. This one fluttered across more than 45 frames (1.5 seconds) on the upper part of the moon. Something about its flutter and long wings makes me think of a quail. Any ideas?
Amongst a zillion faint sightings, sometimes the patient moonwatcher gets rewarded with tiny gems of unusual sightings – perhaps a sighting that is in focus, or a bird that can be mapped to some species perhaps. Or something like this double shot, for instance.
And were it not for the possibility to view this in slow motion it would have been hardly possible to realise that there are actually two birds in this clip…
November moon season is officially closed as of today as the moon is now too small for any relevant observations to be made. So, there is little left to do other than to wait for the new moon to grow – weather permitting we should restart observations around 8th December.
In the meantime, time to revisit one of the highlights from a few weeks back…
It is a pity that over the past week or so we have not been very lucky with the weather. Even though the sky was generally clear, most nights were blighted with the passage of high clouds. The current scanner software can filter out and distinguish proper dark cloud cover…but it is quite difficult to distinguish the passage of high clouds from the passage of bird silhouttes.
And the consequence is a lot of false positive readings ….
Now if only that was migration!! Having actually reviewed some of the trajectories it was surprising to actually find a couple of real sightings!
I guess its time to use the next moon break to roll up those sleeves and put some fixes to that software!
Last week we were kindly invited to deliver an overview of the Lunaves initiative to the Birdlife Malta ringers group – lots of good and encouraging feedback received.
According to Wikipedia ‘Aeroecology is the discipline for studying how airborne life forms depend on the support of the lower atmosphere’.
There is also a Facebook group dedicated to this ‘ology’ as well: https://www.facebook.com/pages/Aeroecology/359062474194572
And although it has far less ‘likes’ than the Justin Bieberhood facebook site, rest assured that you will find a lot of more interesting material, particularly if you are interested in nocturnal migration:
The sky has just started clearing up across the Malta. Both Hamrun and Zurrieq station have clear views and are tracking. It does seem, from a distance, that it is quite windy, so the prospects for good migration for tonight seem to be quite low at the moment…
And even that might be very short-lived – a sandstorm seems to be on its way, straight from the Sahara:
Since the start of the project, the main objective has always been that of being able to report on nocturnal migration, more or less as it happens. It has taken a while to get there…but here is the first, of hopefully many posts, where we are reporting on nocturnal migration….as it happened last Saturday!
The night was calm, hardly any wind and most importantly, not a cloud in sight. Luckily the Zurrieq station was all set – we had just finished a scheduled round of maintenance that same afternoon (cleaning of the scope, resetting the motor and doing minor realignment).
These are the sightings as detected by the lunaves scanner for Saturday (every 30 mins):
Three observations worth noting:
1. Unlike previous September nights, we had uniform migration across all night. In September most of the sightings were concentrated between 22.00 and 23.00. For instance we had a lot like this type of pattern a month earlier:
2. Unlike September sightings where we used to have a mix of small/bigger birds, this time round we had only smaller sightings. So either all birds were flying very high or else it was mainly a migration of smaller passerines (we are still working on getting a better reading of the distance of sighting) . Here and here and are a couple of videos for the record (keep your eye below the white trajectory line, video has slow motion)- nothing spectacular really, but they are just as valid!
3. We compared notes with captures made during a ringing session on Sunday morning (worth noting that this was the same session where the first Malta record for the Red-flanked Bluetail was recorded, much to the delight of ringer Joe Mangion). The main observations from the ringing session were:
- Normal numbers of passerines observed in the area – so, we were either very lucky with the sightings (there were more than 40 in all, which for moon watching can be considered to be high) or most of the migrants continued with their migration. Most of the captures had low fat/muscle score which indicates that they stopped only because they had little choice other than to stop to refuel.
- There were three species of smaller passerine species captured (Robins, Blackcaps and Chaffinches) with a handful of Song Thrush sightings – this seems to tally with the smaller passerines moonwatching sightings.
Moonwatching is like birdwatching with a pair of blinkers.
Just how restricted is the view?
Earth and moon are about 397,000km apart and the diameter of the moon is 3500 km. What this effectively means is that at a point that is 240 metres away, your window of opportunity is merely 2m x 2m. In the best case scenario (good visibility and big birds) at a distance of 3000m, the window of opportunity widens to 26m x 26m. Given that most birds are unlikely to fly at that maximum altitude, when the moon is vertically above, that window of opportunity reduces itself to 17m x 17m.
The following is a chart of sightings for the night of 14th September 2013 (you will see this day being quoted across a couple of other posts) at one of the stations. We had 72 sightings recorded in just 1.5 hours.
Calculating the effective area being scanned is difficult as the different sightings would have come across at different planes. Assuming an average window of 17m x 17m and assuming even distribution (we do not have the readings from the other site on this day, but we have seen good correlation in general) that leads to the next question : if we have recorded 72 sightings in an area of just 17m x 17m what was the flow of migration across a whole kilometer? Or what was the flow of migration across the whole West to East axis of 27km of Malta?
And if all logic holds, that equates to an interesting migration front that would have otherwise been simply missed.