Basin Notes - October 2007

Guesstimating Geese

If you live in or around Montrose you can't help but notice that the Pink-footed geese are on the basin in large numbers this month.

Montrose Basin is an important roost site on their southward migration from Greenland and Iceland to their winter haunts around Scotland and England.

One of the questions that we are always asked at the Montrose visitor centre at this time of the year is "How do you count the geese?", especially when visitors read on the 'Bird Arrivals Board' that there are now 26,661 pink-footed geese roosting on the basin.

Goose counting, mainly of the grey geese at Montrose (i.e. Pink-footed and Greylag geese) is one of the favourite seasonal events for the staff and volunteers at the visitors centre, we try to carry out two counts per month if possible. These counts will include three national goose counts for the Icelandic-Breeding Goose Census, which are carried out on the same weekend nationwide and aim to count geese at all known goose roosts.

The results of these counts are used to work out national and international populations of Icelandic-breeding geese.

The best time to carry out a goose count is at the time of the month when there is no moon (New moon), or the nearest Sunday to this event. This is because fewer geese will tend to leave the roost to feed in the fields on these dark nights, than on nights that are lit by the moon. Therefore we get a more accurate count of the numbers of geese using the basin as a roost.

The count itself normally starts with the 'goose counters' meeting at the centre (under the cover of darkness), around an hour and half before sunrise. After the obligatory cuppa, the counters move off with military precision around the edge of the basin, armed with radios, clickers, scopes and notebooks. Each counter will have their own section of shoreline, where they will count all geese crossing inland through that section (but not geese flying within the basin itself).

Counting geese flying over in skeins is relatively easy as long as the skeins are small and well spaced out. The method used to count larger or faster skeins (or large groups of birds on the ground) is to start at one end counting (or estimating) in 10s, 50s, 100s or 1000s birds (depending on how large the skein is), you then put this suitable number in an imaginary 'box'.

This box can then be used to move over the large or fast moving skein to give you an estimate of the total number of birds passing over, this method is only used in situations where it would be impossible to count each bird individually.

So back to the 'counters', who will be sitting in their hides or cars by now waiting for enough light to start the geese moving inland to feed. This time of the morning, the 'half-light' is one of the best times to see the other wildlife of the basin. Some of the most memorable wildlife sights I've seen have been while waiting for the geese to flight inland.

One morning I watched two young foxes come charging out from the Sleepyhillock side into the mass of geese on the ground, they were unable to catch hold of a single goose and sat there on the mud back-to back surrounded by the now vigilant geese for twenty minutes. And on our last goose count a number of counters had great views of our latest visitor, the White-tailed Eagle as it came soaring over the trees at Sleepyhillock encircled by crows (it reminded me of a manta ray with cleaner fish in attendance, off the TV of course).

The goose count always starts slow, with ones, two and family groups moving early before the larger skein start to move. But on some counts very large skeins containing several thousand birds can all move at once giving the counter where they cross 'some problems' with their counting, this is when the knack of guesstimation comes in handy.

Once most of the geese have left (some will always sit tight), the remainder on the ground will be counted and the rest of the counters will head back with their results for more tea and bacon rolls at the centre, where all the area counts will be brought together for the final total, and that's how we get pink-footed geese of 26,661 on our board!

If you fancy get out early to watch the pink-footed geese flight inland to feed why not come along to the Montrose Basin Visitor Centre on Sunday, November 4 at 6.30am and join the rangers and staff for the 'Goose Breakfast', a free event (with only a small charge for breakfast, after the flight has ended). Booking is essential on (01674) 676336