Highland Foundation for Wildlife

Logie's Winter 2007- 2008
DATE	NOTES
28th Sep	The island of Roxa is one of the outer islands of the Bijagos archipelaga; it is about 20 kilometres long by 10 kilometres at its widest. It is part of a UNESCO Biosphere reserave (see below). A description of the reserve is given below. In 1999, in the first year of our studies of osprey migration using the old style satelitte transmitters, a breeding female from a nest near Glenferness wintered just 18 kilometres west on the island of Bubaque.
29th Sep	The early fixes this morning came from her roosting site.
	Description of the UNESCO Biosphere reserve Boloma Bijagós Biosphere Reserve is an archipelago of 88 islands located on the coast of Guinea-Bissau in western Africa. It was formed from the ancient delta of the Rio Geba and the Rio Grande. There is a high diversity of ecosystems: mangroves with intertidal zones, palm forests, dry and semi-dry forests, secondary and degraded forests, coastal savanna, sand banks and aquatic zones. Many rivers discharge nutrient rich freshwater into the sea with resulting in very high productivity. The archipelago, therefore provides an important feeding and reproduction ground for many species. Fish, crustaceans and molluscs are especially abundant. Among the mammal species are the Nile crocodile (Crocodylus niloticus) and the hippopotamus (Hippopotamus amphibius). In 1996, the Biosphere Reserve had about 27,000 inhabitants living mostly in the cities of Bubaque and Bolama. Because of the colonial history, there is a large ethnic diversity. Depending on their culture, people make their living from rice cultivation stock raising, wild palm tree exploitation, fishing and the collection of molluscs, orchards and horticulture. Several research and education programmes are taking place.
1st Oct	It looks as though she is back at her winter quarters, she has settled down to a routine, fishing in the sea within a half a kilometre of the shore, and ranging within 2.6 kilometres of her main roosts on the wooded island. We will follow her movements during the autumn and bring regular updates, and try to find out more about her wintering home.
2nd-5th Oct	She is now well settled - it is about 600 metres between her main roost and her main fishing site; and her range is only 1.4 by 1.5 kilometres. I wonder how many years she has wintered at this spot in the tropical seas.
12th Oct	Her movements are now very settled, between resting on favourite trees and hunting once or twice a day in the coastal waters. The following map shows the complete migration from nesting grounds in Moray to her winter quarters.
20th Oct	There has been very little movement, most of the time she sits in the same roost tree, and when hungry flies about 400 to 600 metres to the sea to catch fish. The night time roost is about 350 metres further inland in the island woodland. Today, she travelled the furthest distance record since arrival; 3.5 kilometres to the NE, flying SE at 48kph just 26 metres above the sea at midday. Presumably making a longer trip to catch fish or flying with wintering local ospreys.
11th Nov - 10th Dec	She is still at exactly the same location. The fishing locations are mainly 500 metres from the main roost tree, with one as far out to sea as 800 metres from the roost. She has a favourite morning roost on the shoreline , possibly a fallen tree in water, 400 metres to the north, and the only other movement was 300 metres south. Her wintering home range is all within one square kilometre. She has a very settled winter home range.
22nd Dec	Still in exactly same location, nearly all of her time spent perched in the same large tree a few hundred metres from the ocean, while day time signals are often from a position about 150 metres offshore, where there is probably a good perch such as a beached tree trunk.
3rd Jan	Most of the time, she is still roosting in the same tree on Roxa Island. Between Christmas and today she has been within one kilometre of her roost, except on 2nd January when she was 2.7 kilometres NNE at 9am. She had probably gone there to fish in more sheltered water, as the winds are light to fresh NE. Today it's cloudy skies with good visibility in the islands, temperature of 16C and 42% humidity.
19th Jan - 8th March	Logie is still spending most of her time at her main roost. Twice she has roosted overnight some distance away; 700 metres NW (13/14th Jan) and 430 metres NW (18th/19th Jan). Favourite fishing sites about 400 metres offshore, although on 17th January she was 1.06 kms ENE flying east at 32 kph at an altitude of 21 metres - an obvious fish hunting flight.
11th March	Her behaviour is changing in the last couple of days. She is spending more time perched in trees along the shoreline, and yesterday made her longest recorded flight of the winter, when at midday she was 5.5 kilometres to the north, flying west at 41 km/h at 66 metres altitude, while 6 hours later she was 1.5 kilometres south of her main site, flying at 45 km/h towards her main roost tree.
12th March	Logie has started her migration!! She roosted overnight on her usual tree; at 10 am she was perched 500 metres to the south on one of her normal daytime roosts, then back at main roost at 11am. Maybe she had caught and eaten a morning fish, because at midday she was 4 kilometres to the north, very close to her position of 10th, but this time she was flying NNE, at 50 km/h at an altitude of 258 metres. She was off!