Singing starlings

Starlings sing all year round. True that in spring they spend more time atop vantage points near their nest, throat feathers fluffed, wings fluttering, emphasising their phrases. Even in December though, they find time to sing. They include calls from other birds, often copied to perfection: pied wagtails, sparrows, swift are some that have misled me when I realised it was a starling singing. I was tidying up the photos of the year when I found this photo from May, which captures the enthusiasm of a starling singing.

Two nest hole snatchers

Some birds make nests from scratch, building them from twigs, branches, spider's webs, lichens or mud. Others need a hole to nest on, and they will use natural holes or those drilled by other birds. This post is about two such 'nest snatchers' I've watched recently. In the last few days, I've noticed starlings moving a lot of back and forth between an Ash and the grass lawns in my local park. Yesterday, they were actually using last year's Great Spotted Woodpecker's nest. Woodpeckers have a reputation for feeding on the chicks of hole nesting birds, but they also might be providing them with the nest hole in the first place.

A photo from last year (24th June), with a chick almost ready to fledge calling to its parent (on the right branch) 

Yesterday, a Starling getting in the hole

 The other nest snatching event happened just in front of my house. There's been an owl box in the Lime tree in front of the house for over 15 years. It was well used, the hooting and gurgling noises of the Tawny Owls from the nest very obvious in the night. A few years ago the bottom of the nest fell off, and the sky was visible from the ground. On Valentine's day the next year the owls called from the nest, probably inspecting it, but it was deemed useless and we stayed owl-less for a few years. This year, Stock Doves showed a lot of interest in the owl house (top shot taken 9th April). They stuffed the box with branches, and miraculously, the branches stayed, the box had been repaired!

The repaired nest, branches sticking out at the bottom.

 The booming call of the Stock Doves greeted me in the mornings as I left for work. Until one night we heard a Tawny Own hooting. The owl was actually sitting atop the nest, calling, then flew off low over the roofs. The owls have been calling regularly since, and I guess they have taken possession of the owl box and evicted the Stock Doves.
 

 Tawny Owl watching us from the nest box (20th April).

The starlings jump

Today there was a clamour of 'charr!' calls from adults and fledgling starlings in my street. Several families of starlings accompanied from their noisy offspring fed on the verges. The young ones watched their parents and appear to move in slow motion compared to their frantic parents foraging on the grass and then feeding their young. Occasionally passers by would idadvertently scare the birds and the families would become separated. The young called from trees and roofs until they got together with their parents again. A fledgling spent some time on a tree, probing - in that unique starling style - with its bill open, on leaves and branches around it.

busy parent with head down and watchful young.

Calling

Probing, tasting, leaves 

Calling!

Young starlings have a heron-like look to them

Investigating

more calling!

its a big bad world out there

Offspring recognition in Starlings

The first Starling fledglings joined their parents in the lawn of the park this morning, running behind their parents begging for food, with a cacophony of calls. Starlings are highly social birds, they like to feed together, so the chances are that the still dependent young will join unrelated young while still expecting to be fed by their parents. Furthermore, starlings in an area have synchronised egg laying so that many young will fledge on the same day. While the young are inside the nest, parents do not need to particularly recognise their offspring individually - they are likely to be their young. However, how can they make sure they recognise their offspring from others in the flock, so that they feed their own young after they fledge?
  Every year, a week or so before the fledglings leave the nest, adults start using a harsh call 'charr, charr!' (above, listen here) and the by then loud voices of the young can be heard replying from inside the nest. Why, I wondered, do they do this?
 Linda van Elsacker, Rianne Pinxten and Rudolf Frans Verheyen carried out experiments in nest box starling colonies in Antwerp (Belgium), either swapping broods of different ages for a day (Exchange experiment), or offering a choice between their chicks and alien chicks in nearby nests (Choice experiment), or swapping the nest by an empty one and relocating their nest containing young at a certain distance (Search experiment) at different chick ages.
In their choice experiments, carried out when young were 5, 11 and 16 days old, they showed that parents accepted and fed strange chicks until they were 16 days old, as shown by the weight gain of the chicks. In contrast, most parents were able to recognise their chicks when they reached 19 days, ignoring the strange ones completely, and this behaviour was found in all parents when chicks were 20 days old. So by this age adults were able to recognise their chicks.
In the search experiments they showed that the ability of parents to locate their offspring improves quickly and by the time chicks reach fledging age (20-22 days old) 97% of parents searched for and relocated the moved nest containing their young within an hour of the nest having been moved.
 The constant calling by parents and offspring in the days before fledgling might be a way of reinforcing this recognition. So, by the time the offspring are ready to fledge, and then mingle with other chicks, parents are able to recognise their offspring, presumably by their calls.

More information

Frans Verheyen, R., Van Elsacker, L., & Pinxten, R. (1988). Timing of Offspring Recognition in Adult Starlings. Behaviour, 107 (1), 122-130 DOI: 10.1163/156853988X00232

Chaiken, Marthaleah (1992) Individual recognition of nestling distress screams by European starlings (Sturnus vulgaris). Behaviour : 139-150.

Young starling looking for food this morning

...and chasing its parent begging.

Autumn songs

Despite the days becoming shorter and darker, a few birds are still singing. Robins, both males and females claim their winter territories with their heartfelt, melancholic song, Wrens can be prompted to go on their outburst of song all year round, often by other bird calls and Starlings, donning their brightly spotty winter plumage call enthusiastically from chimneys and aerials.

Woodpigeon eating elderberries

The elders are now fully laden with a plentiful berry harvest. Early this morning, a group of nervous starlings came up and down to one, feeding on the berries. A relaxed woodpigeon stretched and fed as well. The light wasn't perfect, and the birds a bit far, but I like that the berry bunches are still pretty much intact. Elder provides berries from mid August to early November. In their monograph on Birds and Berries, Barbara and David Snow recorded 16 species of seed dispersers and 6 of seed predators feeding on elder berries, the largest diversity of species for any other fruit. Numerically, Starlings were the most common, followed by Blackbirds, but other thrushes, migrating warblers, robins, corvids and even moorhens were recorded feeding on berries. Woodpigeons, after Blue Tits, were the main seed predators, although woodpigeons can also be seed dispersers of this fruit.

Fledglings galore

The resident birds seem to have synchronised their breeding to such extent that I saw/heard seven different species of fledglings or chicks in my way to work. A Blackbird (#1) fledgling gave a try to hunt for itself, its parents out of sight. It was hilarious to watch it picking up a dried berry and dropping it and listening for worms.

A lovely fluffy Robin (#2) fledgling by the university parking lot, still very naive, let me get quite close (top photo), a pair of Greenfinches landed next to it and had me confused for a while!

Then a pair of noisy rook (#3) youngsters by the university woodland area demanded to be fed, I could only get a poor shot.

The family of Wrens (#4) I pictured a couple of posts ago were still around, the young giving their calls from a bed of nettles and docks opposite the Wilberforce building.

In my way back from work, a lovely family of Long Tailed Tits (#5) 'see-see-seeing', but the young ones shun me and only gave me their tails to photograph.

In my kids school, the Blue Tit (#6) eggs have finally hatched and I watched the live footage, with one of the parents sitting on very hungry and bare chicks

Near home, the Starling (#7) adults and youngsters in the nest have starting calling to each other with their 'churrr' calls which mean that they are almost ready to leave their nests.