Moorhen 2009 (Part 2)

June 6th, basin B: second brood of 3 chicks.

The following information is based on an observation period of 8 months (from early May 2009 to mid-December 2009), during which 5 different irrigation basins in the municipality of Tazacorte were regularly monitored.

As stated in the previous post, the Moorhen (Gallinula chloropus) is a prolific breeder, but mortality rates are high due to a number of factors:

• Unpredicatble, drastic changes in water levels of 1 - 3 metres, dictated by irrigation requirements, can render nesting sites and available cover untenable.


• Chicks are easy prey for opportunistic predators such as cats, rats, Grey Heron, Little Egret and Common Kestrel.


• Inadequate breeding sites sometimes chosen by parent birds (basins with insufficient food resources, or with high, vertical sides and lack of floating material, so that flightless chicks are unable to leave the water once in).

The number of broods per basin is listed below, together with the number of chicks per brood, and the number of successfully-reared birds. Figures are given for breeding success in each basin, and for the overall breeding success in all 5 basins, expressed as a percentage.

Basin A had 3 broods of 4(June), 7 (July) and 5 (Sept) chicks.

None of the 16 chicks survived more than a few days.

Breeding success = 0%

Basin B had 3 broods of 5 (May), 3 (June) and 2 (July) chicks.
1 chick was successfully reared from the first brood and 2 from the third.
Breeding success = 3/10 = 30%

Basin C had 2 broods of 4 (May) and 1 (July) chicks.
1 chick was successfully reared from the second brood, none from the first.
Breeding success = 1/5 = 20%

Basin D had 2 broods of 4 (May) and 3 (July) chicks.
2 chicks were successfully reared from the first brood, none from the third.
Breeding success = 2/7 = 28.6%

Basin E had 3 broods of 1 (May), 5 (June) and 5 (July) chicks.
1 chick was successfully reared from the first brood and 3 from the third.
Breeding success = 4/11 = 36%

Overall breeding success = 10/49 = 20.4%

Moorhen 2009 (Part 1)

The Moorhen (Gallinula chloropus) is described in the Atlas de las Aves Nidificantes en el Archipiélago Canario (Ed. J.A. Lorenzo) as having a small resident population on the island of La Palma, and reference is made to recent observations of individual birds, evidence of both successful and unsuccessful nesting, and the detection of chicks and juveniles still attached to their parents at various sites.


The following notes are based on the monitoring of 5 different irrigation basins in the municipality of Tazacorte; each one was inspected approximately 70 times during an eight month period, from early May 2009 to mid-December 2009.


Observations show that the species is well-established at specific locations on the island, and is a prolific breeder, with 2 - 3 broods per year.

Two images of the only surviving chick from a brood of 5 born in early May.

This bird eventually left the basin in late July.

A healthy-looking juvenile Moorhen

There was remarkable brood synchronisation in mid-July: the breeding pairs in all 5 basins had either a second or third brood on, or very close to, July 16th.

Cooperative care of chicks by siblings from previous broods was observed in three of the basins (B, D, E).

Although floating platforms of pond weeds were built by some birds, final nesting sites were always on dry land in undergrowth, on concrete steps or manmade structures, or else well-concealed in Rumex lunaria bushes, with the floating platforms being used merely for temporary refuge or as resting areas.

Building a floating platform from water weed

Heading for the nesting site on dry land

A commonly-employed escape strategy when danger threatens. The sequence of 3 images shows a juvenile re-emerging, after remaining motionless for several minutes with only its head above water.

Early December 2009

Osprey (Pandion haliaetus)

Photo: Isidro Brito

Coot (Fulica atra)


Greenshank (Tringa nebularia)



Pintail (Anas acuta) + Coot (Fulica atra)

Nothing new on the island so far this month, but on 05/12 Isidro Brito managed to observe and get excellent photographs of the juvenile Osprey (Pandion haliaetus) which has been around for several weeks. The bird perched twice to devour two small fish caught in a nearby irrigation tank.

The solitary female Pintail (Anas acuta), first detected on 28/11, has been rediscovered in a neighbouring basin, in the company of a large domestic duck.

The female Shoveler (Anas clypeata) can be found at the same location in Tazacorte, but the male Teal (Anas crecca) was no longer there on the evening of 09/12.

Otherwise, there are small numbers of Greenshank (Tringa nebularia), Green Sandpiper (Tringa ochropus), Common Sandpiper (Actitis hypoleucos), and 45 -50 Coots (Fulica atra) in the Martelas area, with a single Redshank (Tringa totanus) at the saltpans in Fuencaliente.

End of November

Osprey (Pandion haliaetus)

Female Pintail (Anas acuta)

Spotted Redshank (Tringa erythropus)

On 28/11 a solitary female Pintail (Anas acuta) appeared in a basin in Las Martelas presently occupied by 45 -50 Coots. This "rare and irregular winter visitor, recorded on all main islands except La Gomera", according to Birds of the Atlantic Islands (T. Clarke, Helm), had gone by the evening.

After temporarily "losing" the Spotted Redshank (Tringa erythropus), the bird was rediscovered at another irrigation basin together with the male Teal and female Shoveler shown in an earlier post (25-30/11).

Finally, on 30/11 I came across the juvenile Osprey (Pandion haliaetus), which has been on the island for a few weeks, being mobbed by gulls at the Dos Pinos reservoir. In the photo, the bird can be seen making off with the remains of a recently-caught fish.

Osprey

Various images of Pandion haliaetus

The Osprey (Pandion haliaetus) breeds in small numbers on Tenerife, La Gomera and El Hierro, with only sporadic nesting elsewhere in the Canaries. On La Palma reproduction has not been confirmed, but the species is seen from time to time inland, and along sections of the coastline. The presence of old nests at certain points on the sea cliffs suggests that the species formerly bred on the island. (Atlas de las Aves Nidificantes, Ed. J.A.Lorenzo).

Inland, near Los Llanos and Tazacorte, the bird feeds on carp which have been introduced into some of the irrigation basins. From my enquiries, it would seem that some banana plantation workers have occasionally seen the bird fishing in their reservoirs, while others react with disbelief at the mere mention of the bird's name, "Fishing Eagle" in Spanish.

This year, I was lucky to spot an Osprey on 26/03, but unlucky not to have my camera prepared. It wasn't until 23/10 that I had another uncertain, distant sighting. Then Xabier Remirez reported and photgraphed an immature bird in Las Martelas on 24/10. On all three occasions, kestrels were mobbing the visiting raptor mercilessly.

Today, 23/11 I had a further encounter with the species and was able to get a few shots for the record. Close scrutiny of the photos above reveals that the individual was a juvenile, with traces of white on the back feathers and a finely cross-barred tail without the darker trailing band.

Late November 2009

Eurasian Teal (Anas crecca). Male

Shoveler (Anas clypeata). Female

Spotted Redshank (Tringa erythropus)

Tringa erythropus

Tringa erythropus

On the evening of 21/11 I had my second sighting of a Spotted Redshank (Tringa erythropus) on the island of La Palma.
A number of identifying features of this attractive wader can be clearly appreciated in the photos: the long bill with its subtly downwards tilting tip - the red being restricted to the lower mandible - and the species' obvious willingness to wade in relatively deep water. The irrigation basin where this scarce migrant was feeding is now being filled with water, so unfortunately this bird will be forced to move on.

22/11: The first ducks of the season! Usually arriving later than the waders, Eurasian Teal (Anas crecca) are fairly common in winter. Small flocks of mostly females and immature birds often spend short periods on the island, moving around in search of suitable basins to dabble in. The flashy male Teal and the female Shoveler (Anas clypeata) shown above were sharing an irrigation basin with two Coots.

In the same area, Tazacorte, there were also three Black-headed Gulls (Larus ridibundus), a fairly regular visitor in winter.

Spotted or Common Sandpiper?

The Spotted Sandpiper (Actitis macularia) is very similar in most plumages to the Common Sandpiper (Actitis hypoleucos). There have been several recent records of macularia on the Canaries, including one (17/10/1996) at the Fuencaliente saltpans, precisely where I saw the bird shown in the photos.

This solitary sandpiper has been at its present location for several weeks and has been confidently reported as Actitis macularia by at least one visiting birder. I still haven't seen the bird in flight or heard it call, two important aids to clinching identification, but the general shape, length of tail projection and absence of dark notches on edges of tertials would seem to tip the balance in favour of the Spotted, rather than the Common Sandpiper.

Any comments from birders with experience of the two species would be much appreciated.

Eurasian Spoonbill

Platalea leucorodia

The Eurasian Spoonbill (Platalea leucorodia) is described as "scarce on passage and in winter in the Canary Islands" in Birds of the Atlantic Islands (T. Clarke, Helm).

My own records of the species amount to 3-4 birds in mid-October 2008 at the Fuencaliente saltpans, and one bird in late November 2008 at the irrigation basins outside Los Llanos.

There have been several sightings so far this autumn on the islands of Lanzarote, Fuerteventura and Tenerife of up to 10 individuals (see http://avescanarias.blogspot.com/ for full details).

However, it wasn't until the evening of November 14 that I happened to be in the right place at the right time in order to see my first Spoonbill of 2009 on La Palma. The bird shown in the photograph flew straight over my head while I was checking the Moorhen population in an irrigation basin in the municipality of Tazacorte.

Chats and Wheatears

A Common Stonechat (Saxicola torquatus) discovered in an empty irrigation basin

On La Palma there are no resident species of chat or wheatear, the Canary Islands Stonechat (Saxicola dacotiae) being endemic to Fuerteventura, with sporadic records in recent years on the island of Lanzarote (Atlas de las Aves Nidificantes en el Archipiélago Canario, Ed. J. A. Lorenzo).

However, I have observed migratory Northern Wheatear (Oenanthe oenanthe) a number of times, a species described in Birds of the Atlantic Islands (T. Clarke, Helm) as a "regular passage migrant in the Canaries, with records from all main islands".

The three photos of a Common Stonechat (Saxicola torquatus) were taken recently on 10/11. The bird, a male moulting into winter plumage, was perching and foraging from low vegetation in an empty irrigation basin on the outskirts of Los Llanos. The Helm Guide refers to the species as a " scarce and irregular winter visitor, more common on eastern islands, and not recorded from either La Palma or El Hierro".

A "first" for La Palma?

Early November 2009

Common Snipe (Gallinago gallinago)

So far this month nothing unusual has been reported on the island. Small numbers of White Wagtails (Motacilla alba) can be seen in Las Martelas (see Observing Sites for birding areas), and the wintering Coot (Fulica atra) population has reached a total of 49 birds, all concentrated in a single irrigation basin. This figure compares favourably with winter 2008-2009, when less than 10 were present, but falls well short of typical numbers in previous years, such as the 109 birds in December 2004 (J.M.Castro, cited in "Atlas de las Aves Nidifcantes en el Archipiélago Canario 1997-2003", Ed. Juan Antonio Lorenzo). Although the possibility that some of these migrants may nest on the island cannot be discounted, conclusive evidence for successful breeding on La Palma has yet to be found.

There was a Redshank (Tringa totanus) at the salt-pans on 04/11, in addition to one Ringed Plover (Charadrius hiaticula), a Dunlin (Calidris alpina), and about 10 Turnstones (Arenaria interpres). Water levels are presently high, with very little sand exposed within the basins, and hence limited potential for waders.

I have spotted 2 Snipes in Las Martelas, plus two others in Tazacorte, photgraphed in a basin formerly occupied by a couple of Moorhens and their single chick.

Rare migrants in October 2009

Long-billed Dowitcher (Limnodromus scolopaceus)

Long-billed Dowitcher with Greenshank

(Limnodromus scolopaceus + Tringa nebularia)

Whiskered Terns (Chlidonias hybrida)

American Golden Plover

(Pluvialis dominica)

American Golden Plover

(Pluvialis dominica)

All photographs copyright R. Burton unless otherwise stated

Summary of sightings in October 2009

Whiskered Tern (Chlidonias hybrida)

October proved to be an exceptional month, with the presence of two national rarities on the island.

An American Golden Plover (Pluvialis dominica) was discovered in an empty irrigation basin, where it remained for several days (19-24/10).

In the evening of 26/10, a Long-billed Dowitcher (Limnodromus scolopaceus) was observed and photographed in poor light conditions. The bird was feeding in the shallow water and mud in the bottom of an almost empty basin. Unfortunately, this rare vagrant had flown on by the following morning.

A Spotted Crake (Porzana porzana) was present throughout the month, and a group of three juvenile Whiskered Terns (Chlidonias hybrida) spent about one week at another basin (13-22/10).

On 24/10, a juvenile Osprey (Pandion haliaetus) was observed and photgraphed by Xabier Remirez, who also saw the American Golden Plover in flight.

In the case of Pluvialis dominica and Limnodromus scolopaceus, the corresponding forms have been submitted to the Spanish Rarities Committee for homologation.

All photographs copyright R. Burton unless otherwise stated

Uncommon species observed in September 2009

Pectoral Sandpiper (Calidris melanotos)

Pectoral Sandpiper and Ruff

(Calidris melanotos + Philomachus pugnax)

Ruff (Philomachus pugnax)

Pectoral Sandpiper (Calidris melanotos)

Spotted Crake (Porzana porzana)

All photographs copyright R.Burton unless otherwise stated

Summary of September 2009

Ruff (Philomachus pugnax) at the saltpans

The second half of September saw the arrival of several uncommon passage migrants, including one rarity at national level.

There was a Ruff (Philomachus pugnax) at the salt pans on 23/09, and another bird in an irrigation basin from 23-26/09, accompanied by a Spotted Crake (Porzana porzana) 24-30/09, and a Pectoral Sandpiper (Calidris melanotos) 23-26/09. Another Pectoral Sandpiper was discovered at the salt pans on 29/09.

A Dotterel (Charadrius morinellus) was seen and photographed by Daniel Martín, at an altitude of approximately 1,800m, halfway along the Cumbre Vieja ridge in the southern half of the island.

Calidris melanotos is a rarity at national level, and the corresponding form has been submitted to the Spanish Rarities Committee for homologation.

All photos copyright R.Burton unless otherwise stated.

Observing sites

The key locations for finding migratory birds on the island are:

1 The salt-pans at Fuencaliente, on the island's southermost tip
2 Fresh-water irrigation basins on the outskirts of Los Llanos and Tazacorte
3 Disused gravel-pits on the coast alongside the airport
4.Laguna de Barlovento reservoir (there are a couple of independent posts for this location; enter the words Laguna de Barlovento in the search engine)

A brief description of sites 1-3 follows, with a short list of species to be expected:

1. Fuencaliente salt-pans

A group of shallow, man-made pools where sea-salt is still produced in the traditional way. Access is at present unrestricted, but visitors are advised to remain on the track which runs round the outside of the complex. Water levels are artificially regulated and hence the amount of exposed sand inside the pools varies. Regular visiting waders include Dunlin, Sanderling, Curlew Sandpiper, Ringed Plover and Common Sandpiper in small numbers, more numerous Turnstones, and, less frequently, Knot, Little Stint, Ruff, Redshank etc. Rare sightings in recent years have included Flamingo, Shelduck, Spoonbill, Pectoral Sandpiper, Lesser Yellowlegs, and Buff-breasted Sandpiper...
An easy-to-reach, scenic location on the southern tip of the island.

2 Irrigation ponds around Los Llanos/Tazacorte

Dozens of fresh-water storage tanks located south of Los Llanos de Aridane, in an area loosely referred to in the literature, and also in this blog,  as "Las Martelas". To access this laberynth, take the main road from Los Llanos to Puerto Naos, and after passing the new ring-road at a roundabout (visible immediately right of the LP-2 label above), take the next turning on the right (at the LP-124 label). Best to park at the main pond, and explore nearby side roads and tracks on foot.

Further south, between Montaña la Laguna and Montaña Todoque, in the Tazacorte municipality, are several other ponds of interest. (The 1:25 000 Mapa Topográfico Nacional de España, sheet 1085-1 shows all ponds, or, of course, Google Earth).

Many of the tanks are abandoned, and the water-level in those still in use varies considerably. Full or partially-full basins attract Grey Heron, Little Egret, Coots, Moorhens (small resident population) and Teal, with the occasional Tufted Duck, Shoveler, Spoonbill, Squacco Heron or Black-necked Grebe in recent years. Common Sandpiper, Green Sandpiper, and Greenshank are also regularly seen in small numbers. In empty ponds containing a layer of mud or sand, and perhaps a shallow puddle of rainwater, the occasional Red-throated Pipit, Water Pipit, Pectoral Sandpiper, Spotted Crake or American Golden Plover might turn up, along with the regular Snipe.

Nearctic vagrants are often found during spring/autumn migratory periods.

The main pond in Las Martelas

Typical example of an abandoned pond, with accumulated rainwater

3. Disused gravel pits:

At present, not exactly an idyllic location due to construction work at airport, but worth checking for Grey Plover, Ringed Plover, Turnstones, Whimbrel ... and perhaps the occasional surprise. The former gravel pits are on the coast alongside the airport, immediately north of the wind generators.

The above notes are intended as a brief guideline only. Contact me at grajaland@gmail.com for further details. For information on past records, species status/rarities, or for submitting personal sightings: jalorenzo@seo.org