A really great walk around Cliffe with great birds including Green Woodpecker, Stonechat, a dozen (+) Goldfinch, a dozen Fieldfares, Blackbirds, 3 Chaffinch, Pochard, Pintail, Wigeon, Mallard, Shoveller, Teal, Shelduck, Coot, Moorhen, Greylag Geese, Little Grebe, Great Crested Grebe, Herring Gull, 2(+) Grey Heron, 2 Little Egret,
Stonechats are rounder, dumpier birds with shorter wings than the quite similar but migratory Whinchat,
Saxicola rubetra. The Stonechat that I saw,
Saxicola torquata hibernans, or perhaps more modernly,
Saxicola rubicola hibernans, was a beautiful male bird, with gorgeous colours in the sun. The face was very dark, just visibly darker in fact than the cap which was more a darker continuation of the brown streaky back. The throat was very dark, contrasting well with the half collar, which seemed narrower than the book pictures, but didn't seem to extend noticeably further back towards the rear of the neck, so being fairly typical of the normal western forms of this polytypic Eurasian (or bitypic European) species. The white wing-bar was there on the dark wing, but not noticeably wider or more obvious than predicted. The front warm pink was well-spread, again fairly characteristic of the western form. I didn't see the rump, but didn't mark it as very different from the back colours, definitely no obvious large white patch there! All I could see on the tail was the flicking, but it seemed dark to me, again as expected.
European [continental] Stonechats
S. torquata rubicola, or
S. rubicola rubicola are virtually indistinguishable from the British/Atlantic race
S. torquata hibernans or S. rubicola hibernans. The two subspecies are almost a cline with the intergrades at the boundary being indistinguishable, although the extreme British birds are particularly dark with reduced white patches, while the more Eastern birds of the European subspecies are very pale with obvious white patches, close to the Siberian type. Siberian-type or Eastern Stonechats,
Saxicola [torquata/maurus?] maurus/stejnegera are occasionally seen in the autumn on the coast of Kent, but are apparently rare. (N.B.
maurus is used here in preference to
maura as listed in BWP).
There have been quite a few reports of the British/Atlantic forms of Stonechats on the Kent coast this year, as in previous winters. The wintering numbers have increased somewhat in Kent since the 70's, sometimes inland along the Stour as well as around the coast, with occasional counts of 15 at favoured sites such as Cliffe being recorded, according to "Birds of Kent". However counts I see on the KOS website seem generally to be in the [smaller] single figures, typically at Cliffe, Elmley, Swale, Samphire Hoe and Dungeness, and the KBR 2012 suggests a county-wide over-wintering total in the mid-30's. A handful of pairs (averaging about 4) also nest in favoured habitats along the coast such as at Dover.
Kent records indicate that some degree of autumn migration of "
hibernans" Stonechats is usually obvious, but spring migration is rarely noticeable - perhaps the birds migrate back along a different flyway? Breeding is occasionally proved around the Kentish coast, in very small numbers. I get the impression that winter numbers are higher than summer numbers in this county.
The UK population probably declined after Victorian times due to habitat loss, but seems to fluctuate strongly. In 1961 Magee wrote a well researched report investigating the overall decline in populations over the century to that date. He showed how cold winters, particularly those involving long periods of snow or hard frost caused intermittent but great losses, particularly in inland areas, but populations generally recovered given milder conditions, recolonising coastal locations and then spreading inland. Ironic that the winter of 62/3 was to follow immediately after publication of this paper. The reliance on coastal areas for the survival of the core population is also suggested that in the more "Atlantic" conditions of Ireland, there is a greater tendency to regularly breed inland, so that territories are more evenly spread across the landmass as a whole. However Magee also showed an overall downward trend in numbers over the longer term, due to agricultural intensification, forestry planting and maturity, as well as [I imagine] human population growth and resulting disturbance. Populations recovered again after 62/3 and then rose significantly again between the 1990s and 2010, changing the species' status from amber to green, only for numbers to be halved between 2009 and 2010 from its peak, presumably by the harsh winter weather that winter. However although it is classified as a resident, surely there are more birds seen generally in the summer than in the winter? Might this imply some degree of migration? Perhaps Stonechats try to "spread the risk". Kent may be an exception, where Stonechats are easier to find in winter than in summer.
Food is of insects and other invertebrates throughout the year, with some seed and blackberries taken at times, and occasionally even small fish or lizards. The birds may often dart down from perches, often roughly a metre high, catching prey immediately or after a bit of hopping, but will also take insects in flight (note genetic link to flycatchers), off leaf-surfaces, off the surface of water, picked off surfaces while hovering, or picked up after a "hover-chase". May return to the same perch or a different one. adults seem to like caterpillars and shield-bugs!
From BTO records, Stonechats can breed from a year old onwards, with the record for longevity being a bird nearly five years old. They can produce several broods a year, from April onwards, with 5 - 6 eggs per batch. The eggs take about a fortnight to hatch and the young take about another fortnight to fledge. Stonechats are generally monogamous and both parents do take care of the chicks, feeding and protecting.
It is generally held that Stonechats are generally found to be more coastal and lowland, 9 out of 10 Stonechat nests being below 125 m asl, while Whinchats are rather more upland in distribution. According to the Welsh Chat Survey of 2012 - 2013, both Stonechat and Whinchat were associated with extensively managed, non-intensive, unimproved, habitats, and not with linear features such as hedges. Both Stonechats and Whinchats forage from prominent features and were associated with scrub or bracken but Stonechats were also associated with coarser herbaceous cover and Whinchats with semi-natural grassland and damp areas. Whinchats, which are migratory, have had a population collapse over the years - and natural while not too heavily grazed grassland is increasingly rare. Stonechats did seem to be doing quite well, until the terrible losses over the winter of 2009 - 2010 mentioned earlier.
The calls are interesting, particularly of the parents. Breeding Stonechats (
Saxicola torquata) made mixed sequences of two calls when a human intruder entered territories. ‘whits’ are modulated notes with a small frequency range, and in laboratory tests caused nestlings to stop begging. ‘chacks’ cover a wide range of frequencies, and in the field were combined with flights made so as to distract an intruder from the nest. On average male and female call-rates were similar, but varied greatly according to the intruder's distance from the nest, and at different stages of the nesting cycle. Rates increased rapidly after hatching, and this correlated most closely with the cumulative total of parents' visits to feed nestlings. This suggests that the level of defence may be adjusted to the value of the offspring to their parents. Call-rates declined about one week after fledging. A smaller peak by some pairs at the start of incubation was apparently related to probable poor condition after a previous breeding attempt, and after laying large clutches. Rates of 'whits' were higher at nests with larger broods, up to an asymptote, but rates of 'chacks' were independent of brood size. Birds suffering nest-predation showed lower call-rates before the event than equivalent successful birds, suggesting that the calls do reduce the risk of predation. Parental investment in nest defence by Stonechats (Saxicola torquata). Animal Behaviour, Volume 28, Issue 2, May 1980, Pages 604-619 P.W. Greig-Smith.
The birds tend to be seen as either singles, or more commonly as pairs, in the winter, not generally as groups. The pairs may not be the breeding pairs for the next summer, subject to change particularly when migrant birds arrive in the spring. Males tend to be more noticed as singles than the females. Pairs which do not disperse after breeding
may defend the same [albeit often larger in the UK, maybe smaller in Spain] territories over the winter.
Breeding territories vary between 0.5 and 4 ha in size. Males may sing and display from higher than normal perches. The white wing coverts tend to be displayed, while the male stands erect, with the head held up, and there are also intermittent singing display flights at 10 - 25 m. lasting for up to 15 s, slow and jerky, with shallow wing-beats and perhaps brief hovering. The bird may rise and fall while hovering. The tail and legs are held down and the white on the neck, wing coverts and rump is very obvious. There may be a lot of tail flicking when a male lands after a display flight. Males may fly back and forward over the female, hover over her, chase her violently, fan his tail or bow to her. The last two are part of the male pre-copulation display, with the female reciprocating by crouching and shivering, with quiet calls. Displays and singing of paired males may continue over the breeding season. Unpaired males may sing frequently near to females for the first half of the season, but then tend to depart.
Nests of grass and lining are placed at bases of bushes, in different positions for successive broods. Year to year fidelity of territories apparently low, perhaps due to mortality. Generally monogamous, although mates may be interchanged between seasons [on spring stopovers for migratory birds??], or even between individual broods. In Jersey, existing pairs broke down over a short period as the migrant birds arrived. In the breeding season other species of small birds may congregate around the individual watchful Stonechats.
The female along broods the eggs for about a fortnight, with the male visiting her with food. After the eggs hatch, the female continues to brood the blind fairly helpless nestlings for about five days until their eyes open, both parents feeding the young. In large broods the nestlings compete for the rear of the nest where they can lie on top of the ones at the front, to get priority for food. The young then may move to hiding places about 5 m. away from the nest for a few days and then start to follow parents, finally fledging after about 12 - 13 days after hatching. Broods follow in quick succession, 2 broods for migrants, perhaps 3 for residents. The high potential productivity of the early season starts perhaps explains the terrible risks the birds take by overwintering, and the occasional and irregular but ultimately inevitable very heavy winter losses.
Once juveniles fledge, they may leave voluntarily or at the insistence of the male parent when the next brood hatches, and then may may move around the parental and neighbouring breeding territories in groups of 4 - 5. They chase and supplant each other, about 2 m. or more apart.
A cracking male bird, for sure! I wonder if there was a female there as well, that I just didn't spot?
