Saturday 18 July 2015

Some common British birds' nests

Song Thrush's nests are easily recognized by the hard mud lining, typically placed in a hedge or thick shrub. Although this one was up against the wall of our house, we couldn't prevent predation of the young chicks - either by Magpie or Jay. We didn't catch the culprit red-beaked.  

Similar in size to a Song Thrush nest, the Blackbird lines its nest with grasses. Both species lay four or five eggs, and in a good year raise two broods. By mid-July the males stop singing until next March, depriving us all of what must be my favourite birdsong. 

The tiny Wren punches above its weight: both in the volume of its song and the size of its nest. The mossy nest is always domed, with a small side-entrance, typically in low bushes or ivy against trees or walls. This one, which successfully fledged a family in June, was in ivy and clematis, against the wall of the old garden privy, now our tool-shed. Male Wrens build several nests each spring, and let the female choose which to use. The other nests are often used as roosts. They are also double-brooded, and usually lay five or six eggs.  

The Dunnock is one of our commonest but most understated garden residents. Their mossy nests are placed in low bushes, brambles or hedges; and the four or five pale blue eggs are incubated only by the female. Their shy retiring character belies an unexpected sex life: analysis of eggs in a nest reveals that many females have two or more partners.  Cuckoos sometimes victimize Dunnocks, but these days (as Cuckoos have drastically declined), Meadow Pipits and Reed Warblers are more usual hosts.  

Until recently, the Blackcap (one of our most tuneful warblers) was strictly a summer visitor, wintering in Africa; but now many stay in the UK, surviving our milder winters on ivy-berries, insects and (increasingly) bird-tables. The flimsy nest is usually placed in low bushes or brambles, and again four or five is the usual clutch size. The male is illustrated here: females and young have a chestnut cap.  

Blue Tits take readily to bird boxes, and can be attracted to most gardens. One pair successfully nested this year in our garden in the top of a roll of roofing felt. The nest itself contains moss, animal hair, and often wool and feathers. Adults will readily come to a basket of hair or wool put out in early spring to provide easy nest material. The female lays about ten eggs, and the huge outlay of energy in fledging such a large brood ensures that pairs only nest once in a year. 

Typically building on a ledge or rafter in a barn, the Swallow devotes its entire summer to raising two or three broods. The nest is a mixture of grass and mud. Occasionally they build an unsupported nest against a wall, like a House Martin's, but with an open top. The clutch is of four or five white eggs, with reddish-brown freckles. Unlike the Blackcap, Swallows always migrate across the Sahara each autumn, and many winter as far south as South Africa. 

The Chaffinch's cheery song starts in February and heralds another breeding season. The beautifully constructed nest is usually well hidden in a hedge, bush or tree. It is carefully woven of moss and grasses, lined with hair and decorated on the outside with cobwebs and lichens. Four to six eggs are laid, and usually only incubated by the female. The male is illustrated here - females and young have more sober plumage.

 The Goldfinch also builds a neat, compact nest: usually in a tree or tall bush, and often in a fruit tree. Their twittering song - at its best rich and canary-like - is one of the joys of our garden, heard in any month. We attract them here with a year-round offering of niger seed, supplemented by sunflower hearts from October to April. From July the adults bring their plain-faced young to the feeders, but the gold wing-bar is characteristic from the moment they fledge.

Not obvious from these photos, a Greenfinch nest is usually much more untidy than a Goldfinch's. They always choose a bush, tree or creeper on a wall, usually between 4 and 15 feet up. Grass and moss are the main materials used, sometimes on a base of small twigs, (though not as much as a Bullfinch's). Hair and feathers are used as lining. Four to six whitish eggs are laid, with some reddish speckles. As with most birds in this post, incubation is about two weeks, as is the fledging time (i.e. the time from hatching to leaving the nest). 

 A pair of Bullfinches often nest in one of our hedges: when feeding young the pair usually arrive and depart together. The rather untidy, twig-based nest contains five greenish-blue eggs. Only the male is brightly coloured; in most species as dimorphic as this, only the female attends to nesting duties. Two broods are normal. (My thanks to Richard Fitter's classic Pocket Guide to Nests and Eggs, first published 1954, for many of the facts and figures. R.A.Richardson's wonderful illustrations were an important part of my childhood). 

The Linnet has declined rapidly in Britain; but loose colonies are still common especially in gorse bushes. In June a large flock feeding on local rapeseed surprised me - typical winter behaviour occurring in the breeding season. The nests in this collection belong to Montgomeryshire Wildlife Trust; many were donated by Paul Roughley. All were collected after the nesting season. My thanks to the Trust and to Paul. When displaying them at our recent village show, I was asked if I had made all the nests!

Wednesday 6 May 2015

Costa Rica

Following on from last year's successful tour, I co-led another Ornitholidays group to Costa Rica in March. We stay in five main centres, at various altitudes and on both Pacific and Caribbean slopes. In the mossy, cool forests of the highlands we found a pair of Resplendent Quetzals excavating a nest-hole. This is the male, but the female took turns too throwing out beakfuls of rotten wood. This is such a special bird that the Guatemalans have adopted it as their currency. However, they don't seem to value it much: one US dollar buys you (at today's rate) 7.74 quetzals! As the four corners of the photo suggest, I took this through the telescope. 

In tropical heat on the Pacific coast, our local guide Herman led us to a roosting pair of Black-and-white Owls at their day-time roost. They are strictly nocturnal, flying after dark to feed on large insects, small rodents and bats. This is another digiscoped image.

Back in the highlands, Herman took this portrait of a Long-tailed Silky-flycatcher, a member of a small American bird-family more closely related to waxwings than to flycatchers. They feed more on berries than insects, and build a beautiful nest of mosses and lichens that is very well camouflaged with the branches that support it. It is the size of a thrush, but with long tail and pointed crest, quite a different shape. This species is one of over 100 that are endemic to Costa Rica and West Panama, though only three or four of these, including two hummingbirds, are strict Costa Rica endemics. 

Here the highland forests are much better preserved than in other Central American countries. Costa Rica, which has no army and so no military expenditure, directs an unusual proportion of its income towards the environment.   

The tanager family is huge and usually colourful. This is the male Passerini's Tanager, a common bird of open country on the Caribbean slope. The female is less brilliant, being olive on the back and orange-buff below. The male's plumage is a velvety-black, making a vivid contrast with the neon-bright scarlet rump. 

Though primarily a birding tour, we are always happy to watch other wildlife - like this Northern Tamandua. Sometimes known as Lesser Anteater, they feed on ants, termites and bees. Their long, sharp claws are designed to rip open termite nests. This one moved fast in the canopy, on a hunting mission. They are both diurnal and nocturnal, but on hot days they curl up in a ball in the canopy and sleep. I failed to capture any in-focus shots, but luckily Mark was more successful. 

This strange portrait of a Black Iguana or Ctenosaur is from Carara National Park, on the Pacific coast. These large lizards are great burrowers and climbers, often noisily clambering about on roofs (and sometimes falling off). They frequent fields and savannas more than forest, and are mostly vegetarian. However, birds' eggs and young are also on its menu.  

As for invertebrates, some Costa Rica species are huge. This is Rothschild's Silkmoth, which was attracted to a lamp and white sheet at a lodge on the Caribbean slope. Many thanks to Herman and Mark for the two photos; the others are mine. 

Tuesday 7 April 2015


At the end of February Clare and I managed to get a holiday! A few days on the Pacific coast of Mexico was perfect. Busman's holiday or what? We still went birding most mornings along a quiet road inland from the beach hotel. Here we found a Black-throated Magpie Jay - or rather several. This is one of the many endemics of the region. 

Also endemic is the Yellow-winged Cacique - very common along this coast. Normally looking well groomed, this one was just having a bad feather day. The feeder at the Puerto Vallarta Botanical Garden was the location here.

 In the same spot, but much more shy and retiring, was this San Blas Jay, which never stopped to feed in the open. Instead, it quickly made off with a beakful and hid. Around San Blas (a town to the north), the jay has become scarce, but there was a family group in our hotel grounds.

This is the quiet dirt road where we would stroll as the sun rose. Only once did we see these White-nosed Coatis - but there were 34 of them, all in single file. And, in a hurry. Most mornings we never saw a vehicle. 

We called it Bunting Road, since we saw four species of bunting along it, mostly feeding on grass seeds. This is the male Blue Bunting - the others were migrant Painted and Varied, and the lovely endemic Orange-breasted. 

Above the grassy verges were a number of gumbo-limbo trees, in fruit. The caciques and this Elegant Trogon would come to feed here - sometimes with the yellow-bellied Citreoline Trogon too. The tree (Bursera simaruba) is also called 'tourist tree' as its sunburnt bark is always peeling!

This female Pale-billed Woodpecker lived in the hotel grounds, with its mate. Once we saw them with a pair of very similar Lineated Woodpeckers. Between the four of them they soon made a mess of a rotting tree like this one.

This Yellow-crowned Night Heron is trying to subdue a small octopus that it found in a rock pool along the beach. At the moment Clare pressed the shutter, its head is totally upside-down, with the neck twisted through 180 degrees. It soon swallowed the unfortunate mollusc. Along the beach we found a number of shorebirds, Heerman's Gulls, Royal Terns, Brown Pelicans and Magnificent Frigatebirds. 

Banderas Bay is famous as a breeding ground for Humpback Whales. This population migrates up to Alaska in April. There were usually a few mother-and-calf pairs in view in the distance - from just outside our room. Many thanks to Clare for taking the photos and being a great holiday companion! 

Friday 9 January 2015

Antarctica part 3 - Marine Mammals

Humpback Whales are recovering well from the devastation of the whaling years (from 1904 to 1965). The population that visits the Antarctic Peninsula for six months a year comes south to feed up on the abundant krill. During the southern winter, the whales swim north to warm waters off Brazil and South Africa to breed, where they eat little or nothing. This pair were so busy feeding that they took little notice of our zodiacs. The animal on the right has its head above water: the mouth is clearly visible (and many on the image to enlarge). I find watching Humpbacks even more of a thrill than watching penguins!

The Antarctic Minke Whale is much smaller than the Humpback, and usually much shier, but occasionally an inquisitive individual will cause a surprise by nosing up to a zodiac. They also migrate to warmer waters to breed. The Japanese still take over 400 Minkes from Antarctic waters annually for 'scientific' purposes. An interesting theory that I recently heard suggests that if Greenpeace and the IWC (International Whaling Commission) were to stop condemning Japan, then Japan would be likely to announce that their 'scientific' programme is complete and to back off of their own accord.  

We had various encounters with Orcas or Killer Whales during the two months I spent on board this season. My niece Sarah took this photo when a pod spent time close to the ship. A closer look between the fins of the adults reveals the head of a young calf! Different groups of Orcas have specialized diets: we believe that this is one of the resident Gerlache Strait pods that feeds on seals. Sometimes they ram icebergs with all their weight to try to dislodge sleeping seals. Another population specializes in hunting penguins; while a third targets Minke Whales, tiring them out by preventing them from surfacing to breathe. 

On the beaches of South Georgia, the main battles of the Elephant Seal beachmasters takes place in October. I took this photo in November, when the largest 12-year-olds were already back at sea after their exhausting month of defending harems, fighting and mating. Nevertheless, these young males were huge and fearsome beasts, and a few were still finding females to mate with. Here the beach was so crowded with seals that the King Penguins had to weave their way between them to reach their colony. 

These Elephant Seal pups were about ten weeks old when we spent an hour with them as we stood in the shallows, helping passengers onto zodiacs. They were constantly on the move, nuzzling each other, the zodiacs, and our boots. Their mothers wean them at three weeks, but they don't know that! So here they stay, each one patiently waiting for her return, until hunger finally forces them to swim out to sea and learn how to dive and catch fish and squid. An adult's average dive is for 20 minutes, to a depth of about 500 m. Males reach a weight of 3.7 metric tons. 

The Leopard Seal is a predator that all our passengers hope to see. Armed with a mouthful of razor-sharp teeth, they specialize in catching penguins in the water, but their diet includes squid, krill, fish and young Crabeater Seals too. The combination of long neck and large head makes even a distant Leopard easy to identify on an ice floe - if it's facing sideways!

Weddell Seals are best identified by mottled pelage, large rotund body and small head. While most Antarctic mammals and birds depend on krill for their food, Weddells feed mainly on fish, diving to great depths and often feeding under ice. At Deception Island in November we came across a Weddell Seal feeding an albino pup: pure white, with pink flippers. Unfortunately it is likely to have a short life at sea, as it certain to be conspicuous to predators. It may also have problems with weak eyesight.  

Finally, the region's most abundant mammal: the Crabeater Seal. We often see these seals hauled out on ice-floes, usually looking slender, elongated, and plain buff in colour. Misnamed by early sealers, Crabbies feed only on krill. They feed mostly at night, when they are vulnerable to attacks by Orcas and Leopard Seals. Making estimates of their population has proved difficult: totals from 10 to 75 million have been proposed. My usual thanks go to those who have provided photos to share. 

Thursday 8 January 2015

Antarctica - part 2

My last blog was all penguins. Now for three albatrosses. What a contrast - the non-fliers and the constant-fliers! This adult Southern Royal Albatross is taking a break from nesting this year, since it's half a world away from its nesting grounds on Campbell Island, off New Zealand. My staff colleague Bruce took this portrait in the Drake Passage, south of Tierra del Fuego. These great albatrosses (with wingspan of up to 3.5 m) are such masters of air currents that they hardly need to flap their wings, and spend the non-breeding years constantly circumnavigating the globe at latitudes of about 50 degrees South. Their breeding population is estimated at 8,500 pairs.  

The Wandering Albatross is a very close relative of the Royal. Here we see a fully grown juvenile begging for food from a parent - on its nest on Prion Island, off South Georgia. It takes a pair of Wanderers a whole year to complete a nesting cycle - three months of egg and nine months of chick in nest. So when half-grown this chick will have endured a harsh winter of snowfalls and gales. Once it fledges, it must learn to fly and catch squid by itself - its parents have finished their work, and now take a year off to roam the southern ocean.

 Also in the same family, but far smaller and darker, is the elegant Light-mantled Sooty Albatross, another emblem of the South Georgia region. Breeding sites echo to the sound of their mournful cries, as pairs pass alongside the cliffs in synchronized flight. The large head, white eye-ring, and pointed tail are characteristic. Unlike their larger relatives, sooties can raise a chick each year. 

Petrels are close relatives of albatrosses; and there's not much size difference between a sooty albatross and this Southern Giant Petrel. This is one of the white morph that occurs in small numbers among the more common grey-coloured giant petrels. Here seen on nesting grounds in the South Shetlands, giant petrels nest in loose colonies and are easily disturbed while breeding. I took this photo with my Nikon Coolpix through the telescope. 

Cape Petrels are often firm favourites with passengers in the Drake Passage, as they follow ships in friendly gangs, riding the air currents for hours and often passing conveniently at deck height. They are also known as Pintado, the Spanish name for 'painted,' since the white back seems to be splashed with black paint. The scientific name Daption is an anagram of Pintado, and has no latin root. 

Finally, we were happy to see that Antarctic Shags had hatched their chicks well before Christmas. These beautiful cormorants nest in small colonies, and can raise three chicks in a good year. The nests are used each summer for decades, perhaps centuries, and comprise fresh seaweed bound with guano. While krill is the preferred food of most Antarctic birds, shags supplement this with small fish. Many thanks to One Ocean staff and passengers for the use of their images. Next time, some Antarctic mammals.....  

Wednesday 7 January 2015

Penguins! The Essence of Antarctica!

I am recently back from two months on board ship with One Ocean Expeditions, with four groups of passengers. All four voyages visited the Antarctic Peninsula; the first two also visited Falklands and South Georgia. One of the most special experiences is the King Penguin colony at Salisbury Plain, South Georgia, which has an estimated 60,000 breeding pairs. Here most of the downy chicks (9 months old) are cooling off by flattening themselves on the cold ground, since they soon feel the heat when the sun shines. (Click on the image to enlarge.) 

The Rockhopper Penguins on Westpoint Island in the Falklands choose to nest among Black-browed Albatrosses. When a predator flies over, such as skua, caracara or Turkey Vulture, the long-necked albatrosses help to keep it at a distance. In November the albatrosses were incubating a single egg, while the Rockhoppers had two.

Macaroni Penguins are the world's most abundant penguin, but it's easy to miss them in South Georgia as most of their colonies are on the inaccessible southern side. On our first voyage, we were lucky enough to watch them from zodiacs at a small colony on the east side of Elephant Island, though it was hard to keep bins and cameras steady in the swell. Macaronis lay two eggs, though it is rare for the first one to hatch. 

Down on the Antarctic Peninsula, we had a great day for visiting the Adelie Penguins. This group were heading away from their nests, towards a stretch of shore clear of icebergs. As with all penguins, males and females share the nesting duties and regularly take turns with incubating and feeding young. The decline of Adelies on the Antarctic Peninsula is linked to a reduction in winter sea-ice. Krill, their staple food, feeds on algae under the sea-ice. In the Ross Sea, the vast Adelie colonies are stable as they are much further south, where the ice levels remain unchanged.  

This Chinstrap Penguin is busy bringing another stone to the nest, essential for keeping the nest-base well drained. Eggs laid on snow, ice or mud fail to hatch. In a good year, both eggs hatch and two chicks may fledge. Hatching occurs around Christmas, with the youngsters taking their first dip two months later. At this time Leopard Seals are likely to be patrolling the shallows, looking out for first-time swimmers. 

Finally, a photo from Christmas Eve. This Gentoo Penguin had just hatched both chicks on a good stone-based nest. The chicks will be fed at regular intervals by regurgitation. In February they are nearly fully grown, very mobile and inquisitive, frequently walking up to visitors and pecking at rubber boots, cameras and gloves. In my next post, I will feature some of the region's flying birds.