18 Jan 2012

Castro Marim - February 1989

The reserve at Castro Marim takes its name from a small town nearby, and includes a series of shallow lakes and lagoons, many of which are commercially exploited for salt. It is used by many water birds on migration during the winter. The emblem of the reserve is the black winged stilt the area is said to have the largest colony of this species in the country.

We arrived in the area with just enough daylight left to find the old buildings that Glenis suggested as a campsite. This was next to an area of open water with a dozen of so little grebe fishing close by and three or four hundred coot flying in circles looking like huge moths fluttering on and off the water surface. At least half were in the air at any one time and the whole group moved slowly past us.

Five large birds flew over as it was almost too dark to see. Jim pronounced flamingos, so I grabbed my binoculars for a look and saw strange shaped pinkish birds with dark flight feathers.

The next morning we drove around the saltpans and found one with a track nearby so we could watch from the van. From our vantage point we could see that people jogging or walking dogs along the road caused more problems for birds than motor-bikes or cars. However, the greatest disturbance came from a shepherd letting his flock of sheep and goats out of the shed where they had spent the night. Most of the livestock anywhere in Portugal seemed to graze open fields, orchards or scrub during the day, with one or two people and their dogs in attendance, then all were shut up at night.

Amongst the people walking along the road was a man with a cat and a dog. Apart from climbing a tree, the cat acted more like a dog, following its owner and coming to heel when called. When they got back to the village the trio climbed a path up a hill to what looked like a chapel and sat down on a bench outside in the sun.

The birds were, as usual, more interesting that the people. The saltpan we were watching contained two black-tailed godwit plus ruff, redshank, spotted redshank and a few stilt. In the next pan there was a flock of about thirty godwit. If any of the flock tried to land in the first saltpan they would be vigorously chased off by the two resident godwit. One of these was particularly active, he stopped feeding and crouched in readiness to attack if another bird even flew over, and if it looked like landing the bird would chase it off with a war cry of ee ya da cha cha cha (according to Jim).

The second godwit occasionally chased others off, especially if several tried to land together. Even when all the waders in the first saltpan were put to flight the two godwit would be the first back and defending their patch again. They also expelled intruders venturing into the small saltpan next to the one they were feeding in, but showed no interest in any of the other wader species. A godwit who tried to sneak in on foot was also chased off.

Two ruff caused us some problems in working out their plumage. They were slightly bigger than redshank which made them both males, and both had the pale fore face indicative of adult birds, but one was buff and the other grey. The buff bird had feathers with brown centres, black subterminal marks and broad pale fringes, with the grey bird had dark feathers with narrow grey-white fringes. It also had white underparts when compared with the other; the variability of ruff obviously extends to winter as well as summer plumage.

There were more and more people about with dogs, motorbikes etc so we moved on, and found ourselves another track among the saltpans. Some dis¬tance along this track Jim saw a godwit in a wet area farm effluent on his side of the road so we stopped to photograph it. It was in winter plumage and close enough that we could see the dark feather shafts quite clearly. The day was quite windy, the bird seemed to have its legs braced and was reluctant to move.

Going back along the track we found another godwit in a more pleasant area of water. This one was in summer plumage. It spent some time preening and oiling: wiping the middle section of its bill on the preen gland then wiping the oil onto its breast feathers. Its toilet complete the bird yawned, scratched its head and flew off.

We moved on down to the coast, to where a long sea wall protects the mouth of the Guadiana River from wind blown sand. There was a force six westerly blowing during the afternoon and even with the windows closed, a lot of fine sand worked its way into to the van.

Two dozen little terns were feeding off the mouth of the river. Seeming to make slow progress into wind, they allowed it to toss and flip them back to the beginning of their feeding run. Then they bobbed up and down like yo yos to pick items from near the water surface until they were ready to do it all again. The nearby sandwich terns looked huge and cumbersome by comparison.

Other birds out in the gale included thirty balearic shearwaters, sixty common scoter, a handful of razorbills, two bonxies and a variety of gulls.

We headed back for another night at Castro Marim, to get some shelter from the wind and sand. This morning we found a little egret that had taken shelter in a burnt out shed. Its white plumage was covered with fine soot, and it looked generally quite miserable. It was almost reluctant to leave the place, but eventually we persuaded it to go out into the sun, where it stood outside the building as if waiting to go back in. There was nothing obvious wrong with it, and we left it to its own devices.

A pale phase booted eagle flew high overhead; followed later by a dark phase bird, flying much lower and showing off all flight identification points.

Time to move on again, and we were looking forward to the Coto Doñana.