Ancient vs Japanese Murrelet in Winter
Carlos Ross (3 Jan 2015)
Right now, there's discussion on the Advanced Bird ID group on Facebook regarding differentiation of Ancient Murrelet (Umisuzume) and Japanese Murrelet (Kanmuri-umisuzume) winter plumage, since there was talk of a potential Japanese Murrelet off California this winter, and there is the possibility of that species straying to the Eastern Pacific.
Here's the post from Alvaro Jaramillo:
"With the recent report of a Japanese-like Ancient Murrelet in California, I think a lot of us realized we do not know Ancient Murrelet very well. Today on the pelagic portion of the Moss Landing CA CBC we had a bunch of Ancients, one of which had a very strong post-ocular line. Not quite Japanese style, and no crest, but interesting as this is not a pattern one expects in mid-winter. Also note how narrow the black is below the white stripe, this area should be wide and black on Japanese."
Japanese Murrelet is just not a well known species on our side of the pond, so I think some advice and commentary from folks familiar with the bird would be extremely welcome.
***
Sean Minns
I'm not hugely knowledgeable, it's been a long time since I saw either species, and I have only seen Japanese Murrelet once or twice in winter. However, I'll try to summarise here some of the differences in non-breeding plumage.
On the water: Ancient Murrelet has black on neck, shoulder, forehead, cheeks and below the chin on throat. This contrasts with the lighter grey mantle, brighter stubby yellow bill and large white neck patch. Japanese Murrelet has dark grey-black rather than black on the hindneck, cheeks and shoulder. The dark grey-black on the head reaches just below the eye and cheeks, but not below the chin, with white extending onto the lores and chin. The white neck patch is smaller and less obvious than Ancient, whereas the white in front of the eye is very prominent.
See the following images on Oriental Bird Images for comparison:
Japanese Murrelet:
http://orientalbirdimages.org/search.php?p=12&Bird_ID=1009&Bird_Family_ID=&pagesize=1
Ancient Murrelet:
http://orientalbirdimages.org/search.php?Bird_ID=1003
There isn't much more to distinguish them when resting on the water in winter, but Japanese has a white spur in front of the wing, whereas Ancient has a darker grey-black area.
In flight: There also isn't much to distinguish them beyond the head pattern, but Japanese perhaps has whiter flanks and no dark spur in front of the wing, with the white on the front of the eye visible at distance and giving it a slightly more elongated appearance than Ancient, similar to Long-billed or Marbled Murrelet almost. Underwing pattern is not really much different, but possibly may appear whiter as there is less dark feathering on the flanks than with Ancient. Also, the bill on Japanese appears to me to be a little more elongated than Ancient, with a light blue colouration, compared to Ancient's almost bubble-gum pink colouration.
I think that Japanese attains breeding plumage at an earlier stage than Ancient, with birds in breeding condition by February, as compared to April with Ancient. Moreover, non-breeding birds or vagrants may not enter into full breeding plumage, so might cause confusion. There are some good images showing a transition-plumaged vagrant Japanese Murrelet from Hong Kong in April. Transitional birds might prove very difficult to ID unless excellent photos are obtained.
PS: I found photos here of the purported Japanese Murrelet in California: http://blog.aba.org/2014/11/open-mic-apparent-japanese-murrelet-in-california.html
The bird appears to already be attaining breeding plumage, and the head pattern, bill shape and colour certainly suggest Japanese. Given the quality of the observers I wouldn't be arguing with the ID.
***
Nick Lethaby
Well, you can’t make out much beyond the head plumes. The bill shape and color certainly looks suggestive but when you are dealing with poor distant photographs, things can get distorted. I have seen lots of times. Obviously the observers are really good (and very reliable), but Howell is apparently not certain, given that the bird wasn’t definitely seen in the field (at least not close enough to see anything in detail beyond what was seen in the photos). Japanese Murrelets in summer plumage often (but not always) look much darker above than Ancients due to more extensive black on the hind neck/base of the neck and (some birds only) blackish feathers in the wing coverts. That certainly doesn’t prove this wasn’t a Japanese at all, but it would have been nice if it showed that.
***
Sean Minns
I should just clarify that I agree with the comments suggesting Ancient, as it seems prolonged observation has confirmed it as an Ancient Murrelet. There is, I imagine and as discussed, a lot of variation in plumage, with 1st and 2nd winter birds as well as adults being at varying stages of moult between October and February/March.
It is uncanny though how in one image you could be fooled into thinking the bill shape and colour, as well as rear of the head pattern, are similar to that of a Japanese Murrelet. Given the relatively small and declining world population and fairly restricted range, I'd guess an extralimital vagrant is unlikely, though they have got as far as Hong Kong.
...
As you say though, Nick, the photos sadly don't show the kind of detail of such things as the hindneck, wing coverts, etc. I'm not sure the photo is at the best angle to show just how much black there is on the hindneck, and better photos/views would establish how extensive the black on the throat or breast is and the extent and shape of the white above the eye. In non-breeding plumage you might possibly expect slightly less obvious black in the hindneck in Japanese Murrelet than in breeding plumage.
There isn't much information on moult strategy for either species in The Auk monograph.
It seems from my limited reading that Ancient Murrelet on the E Pacific side moult into breeding plumage quicker than they do on the W Pacific side and so could, after the non-breeding moult ends in October, already be in full breeding plumage by December.
The moult strategy of Japanese Murrelet is, from what I have read, even more poorly known, but they will moult into breeding plumage by January and could conceivably have started that pre-breeding moult by the end of October, as they breed slightly earlier than Ancient Murrelet in the W Pacific/Japan Sea.
***
Nick Lethaby
A few years ago, I looked at specimens of Japanese Murrelets at the Yamashina Institute. I found several birds from the end of May/early June that were already showing some white flecking in the black on the throat, which I presumed to be the start of the molt into basic plumage. Given their early breeding season, I would expect them to get into basic plumage by July/August.
***
Sean Minns
That would suggest that they could be in full breeding plumage even earlier than January and certainly start moult by October and be very close in some cases by the end of November.
***
Nick Lethaby
I think I have seen photos of “winter-plumaged” birds in January or so. However, the problem is understanding whether birds seen that late may be first-year birds, who would likely not attain adult breeding plumage until their second year.
***
Nial Moores, Birds Korea
Perhaps the discussion on timing of moult in these two species is even more complicated than is being suggested? Especially, Ancient Murrelet has a huge breeding range, from at least the Yellow Sea all the way to British Columbia.
Both Ancient and Japanese Crested Murrelet breed in Korea (even in the same colonies at a couple of sites), with five or so confirmed breeding sites and several hundred pairs of the latter species. Most birders here (including myself), however, get to see many more Ancients than Japanese Cresteds: there are (very) occasionally day-counts of up to 10,000 or so Ancients between November and February, especially along the east coast. I think five is my day high-count of Japanese Crested here.
Either way, I have now seen both species in non-(adult?) breeding plumage in early January and even into February; and both species in more or less breeding plumage in late January. I have also seen Ancients assuming breeding plumage in Korean waters in December (but I think none yet in November). In Korea, at least some young Ancients are hatched in April and some Japanese Crested are hatched as early as May. At least in April and May too, there can still be pockets of Ancients around—many in non-breeding plumage, that might either be local breeders, local non-breeders, or could even potentially be birds that have yet to migrate up to more northern breeding colonies. We see almost no Ancients post-breeding (have seen only one in total between mid-June and late October) and I have only once seen what I took to be a family of Cresteds in mid-June. Really awful image is at:
http://www.birdskorea.org/Gallery/Species/BK-GA-Synthliboramphus-wumizusume.shtml ).
At least in Korean waters, only a very few Ancients develop white headbands that appear to match the width and length of the Point Reyes bird. It is also interesting that the bird in question looks smaller than the accompanying Ancients. For what it is worth, the few times I have seen them together, the Japanese Cresteds invariably looked both smaller and flimsier than Ancient.
Carlos Ross (3 Jan 2015)
Right now, there's discussion on the Advanced Bird ID group on Facebook regarding differentiation of Ancient Murrelet (Umisuzume) and Japanese Murrelet (Kanmuri-umisuzume) winter plumage, since there was talk of a potential Japanese Murrelet off California this winter, and there is the possibility of that species straying to the Eastern Pacific.
Here's the post from Alvaro Jaramillo:
"With the recent report of a Japanese-like Ancient Murrelet in California, I think a lot of us realized we do not know Ancient Murrelet very well. Today on the pelagic portion of the Moss Landing CA CBC we had a bunch of Ancients, one of which had a very strong post-ocular line. Not quite Japanese style, and no crest, but interesting as this is not a pattern one expects in mid-winter. Also note how narrow the black is below the white stripe, this area should be wide and black on Japanese."
Japanese Murrelet is just not a well known species on our side of the pond, so I think some advice and commentary from folks familiar with the bird would be extremely welcome.
***
Sean Minns
I'm not hugely knowledgeable, it's been a long time since I saw either species, and I have only seen Japanese Murrelet once or twice in winter. However, I'll try to summarise here some of the differences in non-breeding plumage.
On the water: Ancient Murrelet has black on neck, shoulder, forehead, cheeks and below the chin on throat. This contrasts with the lighter grey mantle, brighter stubby yellow bill and large white neck patch. Japanese Murrelet has dark grey-black rather than black on the hindneck, cheeks and shoulder. The dark grey-black on the head reaches just below the eye and cheeks, but not below the chin, with white extending onto the lores and chin. The white neck patch is smaller and less obvious than Ancient, whereas the white in front of the eye is very prominent.
See the following images on Oriental Bird Images for comparison:
Japanese Murrelet:
http://orientalbirdimages.org/search.php?p=12&Bird_ID=1009&Bird_Family_ID=&pagesize=1
Ancient Murrelet:
http://orientalbirdimages.org/search.php?Bird_ID=1003
There isn't much more to distinguish them when resting on the water in winter, but Japanese has a white spur in front of the wing, whereas Ancient has a darker grey-black area.
In flight: There also isn't much to distinguish them beyond the head pattern, but Japanese perhaps has whiter flanks and no dark spur in front of the wing, with the white on the front of the eye visible at distance and giving it a slightly more elongated appearance than Ancient, similar to Long-billed or Marbled Murrelet almost. Underwing pattern is not really much different, but possibly may appear whiter as there is less dark feathering on the flanks than with Ancient. Also, the bill on Japanese appears to me to be a little more elongated than Ancient, with a light blue colouration, compared to Ancient's almost bubble-gum pink colouration.
I think that Japanese attains breeding plumage at an earlier stage than Ancient, with birds in breeding condition by February, as compared to April with Ancient. Moreover, non-breeding birds or vagrants may not enter into full breeding plumage, so might cause confusion. There are some good images showing a transition-plumaged vagrant Japanese Murrelet from Hong Kong in April. Transitional birds might prove very difficult to ID unless excellent photos are obtained.
PS: I found photos here of the purported Japanese Murrelet in California: http://blog.aba.org/2014/11/open-mic-apparent-japanese-murrelet-in-california.html
The bird appears to already be attaining breeding plumage, and the head pattern, bill shape and colour certainly suggest Japanese. Given the quality of the observers I wouldn't be arguing with the ID.
***
Nick Lethaby
Well, you can’t make out much beyond the head plumes. The bill shape and color certainly looks suggestive but when you are dealing with poor distant photographs, things can get distorted. I have seen lots of times. Obviously the observers are really good (and very reliable), but Howell is apparently not certain, given that the bird wasn’t definitely seen in the field (at least not close enough to see anything in detail beyond what was seen in the photos). Japanese Murrelets in summer plumage often (but not always) look much darker above than Ancients due to more extensive black on the hind neck/base of the neck and (some birds only) blackish feathers in the wing coverts. That certainly doesn’t prove this wasn’t a Japanese at all, but it would have been nice if it showed that.
***
Sean Minns
I should just clarify that I agree with the comments suggesting Ancient, as it seems prolonged observation has confirmed it as an Ancient Murrelet. There is, I imagine and as discussed, a lot of variation in plumage, with 1st and 2nd winter birds as well as adults being at varying stages of moult between October and February/March.
It is uncanny though how in one image you could be fooled into thinking the bill shape and colour, as well as rear of the head pattern, are similar to that of a Japanese Murrelet. Given the relatively small and declining world population and fairly restricted range, I'd guess an extralimital vagrant is unlikely, though they have got as far as Hong Kong.
...
As you say though, Nick, the photos sadly don't show the kind of detail of such things as the hindneck, wing coverts, etc. I'm not sure the photo is at the best angle to show just how much black there is on the hindneck, and better photos/views would establish how extensive the black on the throat or breast is and the extent and shape of the white above the eye. In non-breeding plumage you might possibly expect slightly less obvious black in the hindneck in Japanese Murrelet than in breeding plumage.
There isn't much information on moult strategy for either species in The Auk monograph.
It seems from my limited reading that Ancient Murrelet on the E Pacific side moult into breeding plumage quicker than they do on the W Pacific side and so could, after the non-breeding moult ends in October, already be in full breeding plumage by December.
The moult strategy of Japanese Murrelet is, from what I have read, even more poorly known, but they will moult into breeding plumage by January and could conceivably have started that pre-breeding moult by the end of October, as they breed slightly earlier than Ancient Murrelet in the W Pacific/Japan Sea.
***
Nick Lethaby
A few years ago, I looked at specimens of Japanese Murrelets at the Yamashina Institute. I found several birds from the end of May/early June that were already showing some white flecking in the black on the throat, which I presumed to be the start of the molt into basic plumage. Given their early breeding season, I would expect them to get into basic plumage by July/August.
***
Sean Minns
That would suggest that they could be in full breeding plumage even earlier than January and certainly start moult by October and be very close in some cases by the end of November.
***
Nick Lethaby
I think I have seen photos of “winter-plumaged” birds in January or so. However, the problem is understanding whether birds seen that late may be first-year birds, who would likely not attain adult breeding plumage until their second year.
***
Nial Moores, Birds Korea
Perhaps the discussion on timing of moult in these two species is even more complicated than is being suggested? Especially, Ancient Murrelet has a huge breeding range, from at least the Yellow Sea all the way to British Columbia.
Both Ancient and Japanese Crested Murrelet breed in Korea (even in the same colonies at a couple of sites), with five or so confirmed breeding sites and several hundred pairs of the latter species. Most birders here (including myself), however, get to see many more Ancients than Japanese Cresteds: there are (very) occasionally day-counts of up to 10,000 or so Ancients between November and February, especially along the east coast. I think five is my day high-count of Japanese Crested here.
Either way, I have now seen both species in non-(adult?) breeding plumage in early January and even into February; and both species in more or less breeding plumage in late January. I have also seen Ancients assuming breeding plumage in Korean waters in December (but I think none yet in November). In Korea, at least some young Ancients are hatched in April and some Japanese Crested are hatched as early as May. At least in April and May too, there can still be pockets of Ancients around—many in non-breeding plumage, that might either be local breeders, local non-breeders, or could even potentially be birds that have yet to migrate up to more northern breeding colonies. We see almost no Ancients post-breeding (have seen only one in total between mid-June and late October) and I have only once seen what I took to be a family of Cresteds in mid-June. Really awful image is at:
http://www.birdskorea.org/Gallery/Species/BK-GA-Synthliboramphus-wumizusume.shtml ).
At least in Korean waters, only a very few Ancients develop white headbands that appear to match the width and length of the Point Reyes bird. It is also interesting that the bird in question looks smaller than the accompanying Ancients. For what it is worth, the few times I have seen them together, the Japanese Cresteds invariably looked both smaller and flimsier than Ancient.