More Gulls

[Dan P]

Taken on 2-26-2021 at Puddingstone Lake in San Dimas (Los Angeles County), CA.

Just curious, are there any other identifiable gull species in these shots besides California or Ring-Billed?

The eBird reports for this location over the past 2 weeks have reported many individuals specifically as California Gulls and many as Ring-Billed Gulls.  Then the large flocks of 100 to 200 have been reported either as "gull sp., Larinae sp." or as "Larus sp., Larus sp."  There was only one Western Gull reported during that period, and 2 (possibly 3) Herring Gulls -- with photos.

Thanks.

[Aidan B]

Nothing beside California's and Ringers from what I can see. 

[IKLland]

I see 3 westerns too

[Aidan B]

1 minute ago, IKLland said:

I see 3 westerns too

Where at? Western should be significantly larger than  the Ring-bills and California's.

[IKLland]

1 hour ago, Aidan B said:

Where at? Western should be significantly larger than  the Ring-bills and California's.

Last photo, look at bottom right. The juvy flying next to the one in the corner flying, has a gull right behind it, looks like a western to me. The rest are ringers and calis, so i agree with that now. 

[Aidan B]

6 minutes ago, IKLland said:

Last photo, look at bottom right. The juvy flying next to the one in the corner flying, has a gull right behind it, looks like a western to me. The rest are ringers and calis, so i agree with that now. 

I could possibly see that being Western, but it seems to small in comparison to the other gulls, and westerns don't seem that slender when I've seen them.

[AlexHenry]

Please don’t just take pictures of an entire flock of gulls and ask for IDs.

Take pictures of individuals.

[AlexHenry]

41 minutes ago, IKLland said:

Last photo, look at bottom right. The juvy 

There are no “juvy” gulls in these photos

[Dan P]

Alex, I'm not asking for IDs of individual birds in the flock.  I'm just asking if you see any species other than California Gulls or Ring-billed Gulls.   You can say, "No", or "a few Westerns" or "at least one Glaucous-winged" -- something like that.  I'm just wondering if all that can be seen and identified are California and Ring-billed.  Thanks.

[AlexHenry]

Just now, Dan P said:

Alex, I'm not asking for IDs of individual birds in the flock.  I'm just asking if you see any species other than California Gulls or Ring-billed Gulls.   You can say, "No", or "a few Westerns" or "at least one Glaucous-winged" -- something like that.  I'm just wondering if all that can be seen and identified are California and Ring-billed.  Thanks.

My advice is to not do this. Take pictures of individual gulls for us to ID. It is your job to look through the flocks for different birds that stand out. Then if you are not sure what they are, photograph them and we can help.

[Dan P]

Let me ask you this.  There was a large flock of gulls out in the middle of the lake.  From the photos I shot panning from one end to the other, I counted over 600 birds.  As I was counting them I didn't notice anything that looked like something other than a gull -- except for one cormorant.  About 10 minutes later a big portion of the flock started flying, and the 3 photos I posted are a few of the shots that I took.

I don't know how to report a large flock of gulls.  I've avoiding posting some of my checklists because I don't want to leave out gulls, but I don't want to mis-report them.  Everyone that has been reporting this flock at this location to eBird has been reporting them as one of these two:

gull sp., Larinae sp.
Larus sp., Larus sp.

Would one of these two be the correct way to report this flock?  Thanks.

[AlexHenry]

Either of those works. You say you counted over 600 birds. You can report 600 gull sp, or 600 larus sp. Either of those are accurate and acceptable.

Since MOST of the gulls we see in California are in the genus Larus, there is actually not much difference, except that “Larus sp” is slightly more specific. The only regular gulls you would see in this area that are not in the genus Larus are Bonaparte’s Gulls and Black-legged Kittiwakes, also Laughing and Franklin’s Gulls but those are rarer.

If you see a big flock off gulls and don’t identify any of them, you can call them “gull sp”.

If you see a big flock of gulls and don’t identify them to species, but there’s no “hooded gulls” such as Bonaparte’s Gull mixed in call them “Larus sp”.

 

Even better if you can identify some of them to species. You don’t even need to identify all of them. Let’s take your gull flock for example. There are 600 Larus gulls. You might look through part of the flock and see 60 California and 40 Ring-billed. Then you could report 60 California, 40 Ring-billed, and 500 Larus sp.

 

For really large gull flocks, something you could do is count part of the flock to estimate the ratio of species, then count or estimate the total number of gulls, then use the ratios to estimate total numbers of each species. Keep in mind that this relies on the assumption that you count a representative portion of the flock, i.e., the species are mixed together evenly. This method is probably best saved for when you have more experience and you have a better understanding of the local gull flock.

Ideally, you would go through the flock looking at each individual and identify and count each individual. However, this can get very difficult or even impossible with very large flocks, especially if there is regular movement/reshuffling within the flock, and especially on the West coast where there are many confusing hybrid taxa to contend with, and some individuals are simply ambiguous and best left unidentified (even true experts leave some individuals unidentified).

 

[Tony Leukering]

Nearly all Cals