Some early spring moths

As some early spring warmth has arrived, I have begun putting out the moth trap a few times a week in our small suburban garden. This is my first spring trapping after a moth trap arrived for Father’s Day last June (see here for the highlights of last summer’s mothing). As such, nearly everything I catch is new to me, which creates exciting and challenging identification puzzles. Moths have fabulous names. There are Small Quakers, Powered Quakers and Common Drab Moths, but mostly there seem to be a lot of Common Quakers, the default spring moth:

The appropriately named Early Grey always catches the eye:

A personal favourite is the Brindled Beauty…

… not least as it possesses fabulous antennae:

The Muslin Moth may not look that interesting from above:

But this is one magnificent beast. There is something quite noble about that face:

The small but colourful Red-green Carpet. The green colour also extends to it’s eyes: 

A surprise in the trap was this Dark-edged Bee-fly: 

These beasts predate wasp and bee pupae (see here for my experience of Dotted Bee-fly attempting the remarkable process of kicking it’s eggs into bee’s holes on the Oxfordshire downs).

That is one giant proboscis: 

Bring on the warm summer nights and an even greater selection of moths to enjoy.

No “wheet-wheet”? More on the Oxford Iberian Chiffchaff song

A recording of the Oxford Iberian Chiffchaff is now on Xeno-Canto [David Darrell-Lambert, XC411346. Accessible at www.xeno-canto.org/411346]:

 

Mick Cunningham made a comment, here, about the Oxford bird perhaps lacking the “wheeet-wheeet” part of the song typically heard by Iberian Chiffchaff. Now we have a recording and a sonogram from Xeno-Canto, I can hear and see what he means. Firstly, listen to an Iberian Chiffchaff recorded in Spain [Luis Gracia, XC409152. Accessible at www.xeno-canto.org/409152].

 

From having listened to a dozen recordings from Spain, to my ear there are three parts to a typical Iberian Chiffchaff song, always in this order:

  1. The “chiff-chaff” part.
  2. The “wheet-wheet” part.
  3. The rapid sequence of descending notes at the end.

We can see these on the sonogram of the bird recorded in Spain (labelled by me):

The Oxford bird’s sonogram looks like this (again, labelled by me):

To my ear, and from the sonogram, there is no “wheet-wheet” middle part to the song of the Oxford bird. Now, I am no expert on bird song, sonograms or Iberian Chiffchaffs. In fact I actively want this bird to be an Iberian Chifchaff for deeply held personal reasons: I have not seen one in Oxfordshire before. But I have not found a recording on Xeno-canto of Iberian Chiffchaff from Spain that does not have at least one “wheet-wheet” in the middle section. Admittedly, I have not listened to all the recordings, I have a family to keep happy and full time job. But somebody out there with more time and expertise must be able to help!

To my mind, this leaves four possible options:

  1. The Oxford bird is an Iberian Chiffchaff with a variant song that I have not come across in online recordings.
  2. The Oxford bird is an Iberian Chiffchaff with an atypical song (see also this video of the bird singing, again without the “wheet-wheet” part)
  3. The Oxford bird is not an Iberian Chiffchaff (what it is, is another matter – a hybrid, a collybita with a misspent youth in Spain, who knows?)
  4. I should spend more time on my day job.

You decide! Thanks again to Mick Cunningham for noticing this feature.

Oxford Iberian Chiffchaff: some thoughts on the song

The excitement of seeing Oxfordshire’s second Iberian Chiffchaff on Monday evening was tempered by two things: firstly, it was cold and windy, so the bird was rather secretive and the light was terrible; secondly, by the fact that whilst the bird was producing lots of classic Iberian Chiffchaff song, up to half of the song that we (Dave Lowe, Andy Last, Ian Reid and myself) heard that evening from this bird appeared to be similar to that of Common Chiffchaff. This raised the question in my mind of whether this bird could be a mixed singer?

Iberian Chiffchaff, unlike Common Chiffchaff, has different advertising and conflict songs:

“In the context of spring vagrancy, Iberian Chiffchaff has two major song types: an advertising song used by males trying to attract a mate and a conflict song used primarily during antagonistic interactions with other males. The same is true of Common Chiffchaff, although in that species the advertising and conflict songs are virtually identical. The conflict song of Iberian is very similar to that of Common but the advertising song is more variable and contains song elements not used by Common Chiffchaff“. (Collinson and Melling 2008)

I trawled through Xeno Canto to try to find some examples of both the conflict and advertising songs of Iberian Chiffchaff.

Iberian Chiffchaff advertising song from Iberia. [Luis Gracia, XC409152. Accessible at www.xeno-canto.org/409152] This is the well known song of Iberian Chiffchaff:

 

Possible Iberian Chiffchaff conflict song from Iberia. [Paulo Alves, XC304478. Accessible at www.xeno-canto.org/304478]. Similar, but not identical to, the song of Common Chiffchaff:

 

Common Chiffchaff, from the UK. [Frank Lambert, XC324041. Accessible at www.xeno-canto.org/324041]. Advertising and conflict songs are identical in Common Chiffchaff:

 

Collinson and Melling state that “the definition of a ‘mixed singer’ is reserved for those birds that use song elements characteristic of both Iberian and Common Chiffchaff within a single advertising song“. This was not something that we heard on Monday evening. The Iberian Chiffchaff was either in full “Iberian mode” or reverted to a song similar to Common Chiffchaff. Bearing in mind the above, this was probably Iberian Chiffchaff conflict song. Once again, an instructive experience with a great bird, though it would be interesting to see someone address this issue properly with sonograms taken from recordings of this bird.

Grimsbury Reservoir Black-necked Grebe

This is turning into a good spring for Black-necked Grebe in Oxfordshire. The latest to be found was a summer plumaged bird on the small Grimsbury Reservoir in Banbury. I popped in at lunchtime today…

Just a few meters offshore, in full summer plumage… wow!

These were the sort of views of Black-necked Grebe that I had only previously dreamt about. Look at those eyes!

Those golden ear tufts!

Occasionally the bird would tilt it’s head to scrutinise birds flying over:

Good to bump into Ewan and Moth there too. There are more details about Black-necked Grebe records in Oxfordshire in this post here.

Black-necked Grebe records in Oxfordshire 2000-2013

This is an article that I wrote for the Oxon Birding website, as part of the March 2018 bird news update:

Black-necked Grebe is a scarce passage and winter visitor to Oxfordshire but has been recorded in every month of the year and in every year during this period, except for 2008, when there were no records in the county. Scanning a reservoir or gravel pit in spring and finding a summer-plumaged Black-necked Grebe may be the highlight of spring migration for birders in a land-locked county such as Oxfordshire. This article looks at the pattern of occurrence for Black-necked Grebe in the 14 years from 2000 to 2013 inclusive.

As many observers can submit records for each individual bird present, using the total number of records per year on the OOS database does not provide an accurate reflection of the actual number of birds present. The table below was calculated by examining the OOS reports from 2000-2013 and determining the likely number of birds present in each month, rather than the total of submitted observer records. A conservative approach to numbers was taken if birds were reported from nearby locations on consecutive dates, so the real numbers of birds involved may well be higher than this estimate. Figure 1 shows, for example, that there has been a total of 5 Black-necked Grebes recorded in the month January in the years 2000-2013:

 

Spring records:

There is a clear spike in records beginning in March and increasing in April. These records are of wintering birds returning to their breeding grounds in northern and central England. Black-necked Grebes were recorded in the month of March in three years and in the month of April in six years during the fourteen-year period between 2000 and 2013. There were cumulative totals of 9 birds recorded in March and 18 in April (see figure 1). Birds recorded in early March, such as the birds pictured below at Dix Pit on 7th March 2018, are in predominantly winter plumage. By the end of April most Black-necked Grebes will be in full breeding plumage.

However, the totals for March and April are inflated by two significant flocks of Black-necked Grebes: 5 birds together at Dix Pit on 6th March 2002 and 7 summer plumaged birds together at Farmoor Reservoir on 27th April 2012. Some of these birds remained for a number of days and gave fabulous views, even performing courtship displays on occasions:

 

Breeding season records:

There is only one May record (of two birds on 24th May 2013 at Farmoor) and a single record from June: a bird in full breeding plumage seen at Standlake on 4th June 2000. This is the only June record of Black-necked Grebe in Oxfordshire (OOS Annual Report, 2000) and at time of year when breeding birds are usually on territory, hence the paucity of Oxfordshire records in early summer. This bird could have been a very early failed breeder, but perhaps is more likely to have been a breeding bird dispersing in search of potential nesting habitat. This species is noted for “widespread aerial reconnaissance” (CBWP).

Post-breeding records: 

The gradual increase in records from July through to September correlates with the arrival of failed breeders and post-breeding dispersal. Failed breeders may leave breeding ponds as early as July, whilst post-breeding dispersal typically occurs from mid-August (Migration Atlas, BTO). This accounts for the gradual rise in Oxfordshire records in the autumn period. In eight of the fourteen years analysed Black-necked Grebes were recorded in September, making this the most productive month overall for records in Oxfordshire, even though the overall number of birds found in September, sixteen, is eclipsed by the total found in April, eighteen.

Winter records: 

In the western palearctic Black-necked Grebes winter within the breeding range, with movements to the coast when inland water-bodies freeze. CBWP states that most birds are on their wintering grounds by November and that the UK wintering population may receive birds from continental Europe that shelter in the estuaries and inland water bodies of south-east England. Winter records in Oxfordshire increase from October to December (see figure 1) and could conceivably be from both Black-necked Grebes that breed in the UK or from birds that have migrated to southern England from breeding grounds in continental Europe.

A global footnote:

The movements described above are trivial compared to the migration of Black-necked Grebe in other parts of its global range. Hundreds of thousands of Black-necked Grebes are thought to winter in the south Caspian Sea off the coast of Iran, with tens of thousands on Turkish lakes in winter (BTO, Migration Atlas).

In North America nearly 1.5 million Eared Grebes (the name by which Black-necked Grebes are known in the west) migrate to Lake Mono in California where the adults undergo a complete moult and the juvenile birds a partial moult. The birds at Lake Mono more than double their weight on their autumn staging grounds, their chest muscles shrink as their bodies favour rapid fat deposition. Eared Grebes are rendered flightless during this period and are flightless for up to 9 or 10 months of the year, the longest flightless periods for any species bird capable of flight in the world (Cornell 2017). Eventually the brine shrimp population, on which the vast numbers of grebes feed, collapses.  The grebes, by now having completed their moult,  migrate to the coast at night. The nocturnal movements of so many birds can leave them prone to severe weather-related incidents, such as this report of some 4,000 Eared Grebes that landed in a Walmart car park in a storm in Utah in December 2011. In Europe both diurnal and nocturnal migration of Black-necked Grebe has been recorded, in contrast to the purely nocturnal migration of Eared Grebe in North America (Migration Atlas, BTO).

References:

“Bird Atlas 2007-2011”, BTO, 2013.

“The Birds of the Western Palearctic”, concise edition (CWBP); Snow & Perrins; OUP 1998.

“The Migration Atlas”, BTO, 2002.

The Cornell Lab of Ornithology; “Eared Grebe” website; 2017;  [https://www.allaboutbirds.org/guide/Eared_Grebe/overview]

Weblinks to news items on the mass downing of thousands of Eared Grebes in Utah in 2011:

https://www.ksl.com/?sid=18498424

https://www.cbsnews.com/news/more-than-4000-birds-crash-land-in-parking-lot/

Black-necked Grebes, Dix Pit

On 6th March 2002 I found a flock of 5 Black-necked Grebes a Dix Pit, one of my first noteworthy self-found birds in the county. A photo of that flock, by George Reszeter, was published in Birdwatching magazine. Despite the caption on the photo, I don’t think it is too unusual it is to see small groups of these grebes, as recently a party of 5 have spent the last couple of months at Sonning Eye  gravel pits.

Black-necked Grebes appear annually in Oxfordshire, often in small numbers in early spring, as they move to their breeding grounds on pools in northern England. I thought of the flock that I found in 2002 as I headed out to Dix Pit this morning, 16 years and one day later. It was a nice moment then, when scanning from one end of the pit, I picked out 2 Black-necked Grebes on the far side. I worked my way around the gravel pit to get closer, the light was better and the birds showed nicely. These birds were more in winter plumage than summer. Their heads and necks are taking on the black of their breeding plumage, but they had not yet grown their fabulous golden ear tufts. Nevertheless, seeing the red eye is always a treat:

Having found a single, very distant, Black-necked Grebe on Monday at Henley Road gravel pits, it was good to get much better views of these beautiful grebes:

Henley Road GPs and Sonning Eye

A productive couple of hours on the southern border of Oxfordshire. The redhead Smew was not only on the same pit as when I lasted visited on 7th February, but was pulled out of the water on exactly the same branch, above.

The Smew was here:

The other side of the peninsular produced a distant Black-necked Grebe.  It was mobile and fishing constantly:

I wondered if this bird may have been part of the flock of 5 Black-necked Grebes that had spent the last couple of months on nearby Sonning Eye gravel pits, so I popped over to have a look.

As well as all the usual suspects, such as Great Crested Grebe, above…

Sonning held 3 Goosander (above),  a Little Egret, a singing Cetti’s Warbler, a flock of 30 Siskin and 18 Goldeneye. I could find no sign of the Black-necked Grebes in the small bay past the sailing club, perhaps they have moved on?

The male Goldeneye were displaying, bobbing their heads up and down, whilst their evocative calls sounded out over the lake, something like this:

Florence Park, Oxford

An hour in the snow with the children. “Daddy, there is a big white bird in the stream, come and look!”:

The cold weather has forced birds into the park and the need to feed has made them approachable.

It is always a treat when Redwings allow a good look:

Willow & Marsh Tits, Banbury

Personally I have never found distinguishing Marsh and Willow Tits particularly easy. The scolding “taah, taah, taah” call of Willow Tit was always a good basis, but that wasn’t helpful in birds which did not call. In silent birds the pale wing panel and more bull-necked appearance of Willow Tits seemed the best features, though these seemed more obvious in birds that I saw in Europe than in British Willow Tit candidates. Then in 2009 British Birds published updated criteria for separating these two similar species. The size of the bib and the glossy cap of Marsh Tit were demoted as less reliable features. The most reliable criteria seemed to be song, call, an unmarked upper mandible in Willow Tit and a strong contrast between the white cheeks and the pale brown neck sides in Marsh Tit:

This morning Dave Lowe and I paid a visit to the wood just north of Grimsbury Reservoir in Banbury, pretty much the only reliable site in the county for seeing Willow Tit. It was a cold, sunny morning but we worked our way through the riverside trees finding Goldfinches, Siskins, a single Lesser Redpoll and Blue, Great, Coal and Long-tailed Tits. After about 15 minutes I picked out an all dark-headed Tit in trees on the far bank of the River Cherwell:

Fortunately, it and another similar bird, did the decent thing and flew across to our side of the river where we enjoyed good views of this pair of birds feeding in the wood. On three occasions we heard the “taah, taah, taah” call and at no time the loud “pitchoo” of Marsh Tit. Both birds had a pale wing panel, formed by pale creamy edges to the tertials and secondaries, though these were more obvious in one bird than the other. This was the bird with the brighter pale wing panel:

Meeting the other criteria for Willow Tit on the other bird required some work! In bright sun some images seemed to show that there were pale markings on the bill (but could this be reflected sunlight?): 

But it was the contrast between the white ear coverts and the pale brown neck sides, of which there is little in Willow Tit, but much contrast in Marsh Tit, that I struggled with the most. Both the pictures above and below do show a clear contrast between the white ear coverts and the buff neck sides on this bird, a better feature for Marsh Tit:

Compare the buff colour of the neck area behind the ear coverts on the two images above with the clean white colour on the bird with the brighter wing panel, below:

I posted some of the above pictures on the Oxon Birding website as Willow Tits at Grimsbury Reservoir and Richard Broughton came to the rescue:

“Hi Tom, definitely Marsh and a Willow in those pics – maybe the nightmare scenario of a mixed pair! Pics 1, 4 & 5 are Marsh, the others are Willow. Cheek pattern (white/grey) and pale bill mark are definitely there in the Marsh (see especially pic 5 where the bill is in shade, and the white mark shows nicely). Clear dark bill on the willow in pic 3, and undertail also shows the graduated tail tip (at least 3 feather tips visible in steps, sometimes shown by adult marsh, but generally a good pointer for willow). Pic 2 also shows willow tit pattern on greater coverts – dark centres and contrasting pale margin (new feature: http://nora.nerc.ac.uk/id/eprint/517411). Had another report of mixed pair up north last year – the Marsh Tit was even ringed as a Willow by mistake (out of usual range), and seemed paired with a Willow. Oddly, it seemed to be mimicking willow calls when associating with Willows, and only gave a pitchoo call in response to playback. There a record in the literature of a mixed pair attending a nest, so they might be able to hybridise (never been proven genetically). Cheers, Richard”.

If both species are present, then extra caution is required when looking out for Willow Tit at this site in Oxfordshire! All in all a thoroughly enjoyable and instructive morning.

Hawmageddon!

The unprecedented numbers of Hawfinch in southern England are now well documented, but this week I came across reports of a huge Hawfinch flock near Box Hill in Surrey, totalling at least 250 birds.  These birds were found by Steve Gale who also got Peter Alfrey in on the act. Peter’s account of coming across this mega-flock of hundreds of Hawfinch is well worth a read and is here. Realising that this may be a once in a lifetime experience to see a huge Hawfinch flock in the UK I visited Ashurst Rough Wood, just east of Box Hill Country Park, this morning. There are a number of wooded hills in the area, with stands of Juniper among the deciduous trees.

As I made my way up to the local high point of Juniper Top I could hear Hawfinch calling in the woods, I had brief glimpses of 2 flying birds and found another pair perched up in bare branches. Most of the birds were lower down, feeding and flying between Ashurst Rough Wood and Bramblehall Wood. This valley was bursting with Hawfinch activity! I spent 90 minutes here and there was hardly a moment when I was not watching or listening to Hawfinches. Birds would fly between the two woods, sometimes as individuals…

.. but often in small flocks:

Occasionally larger flocks of birds, one nearly 50 birds strong, would swirl around the tree tops, or fly across the valley:

One such flock passed right overhead and the birds settled in the treetops, high up on the slope behind me. The woods were then filled with the calls of vocal Hawfinches, both the hard “ptik” call and the softer “zih” call. The sound of calling Hawfinches drowned out all other birdsong, was I really in England?! Scanning through the treetops also revealed flocks of Hawfinches perched up in bare branches before they dropped down to feed:

I estimated that I saw around 150 Hawfinch in total, based on counts as the small flocks gradually made their way south down the valley. However, with so many flocks swirling around the true number could easily be significantly higher. The views of the birds were usually in the medium distance and always in flight or perched, I saw no birds on the ground. However, this was a fabulous birding experience, 90 minutes of continuous Hawfinch activity, at times I felt surrounded Hawfinches, both in sight and in sound. Just incredible!

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