Topics

Orange County Mergansers

Ryan Winkleman
 

Jeff's post mentioning recent eBird reports of Common Mergansers at Bolsa Chica without any documentation touches a sore spot with several people (not just us eBird reviewers) who monitor coastal bird reports in Orange County. This is an issue that we see every winter, where there are multiple reports of Common Mergansers along the coast, typically at Bolsa Chica, many times without any accompanying reports of Red-breasted Mergansers, and in greater than 9 times out of 10, without any photos or solid documentation. Nearly invariably when photos are taken, they are of misidentified Red-breasted Mergansers. With that in mind, I thought it would be helpful to distinguish preferred habitat types and basic field marks between these two merganser species (and I've included Hooded Merganser as a bonus!).  

Hooded Mergansers in winter are most often found on small creeks and small, shallow ponds, often but not exclusively in areas that have vegetation along the banks for cover. While they prefer inland freshwater areas, they can still occasionally be found in the coastal zone and/or in brackish waters, although it is rare and highly irregular for them to be found directly on the coast. The presence of a Hooded Merganser at Bolsa Chica this fall was truly notable for the location. Your best bet for finding Hooded Mergansers in Orange County is to look in protected freshwater creeks. Oso Creek at Forbes Road, Oso Creek upstream of Marguerite, Aliso Creek between Awma and Alicia, San Diego Creek downstream of I-405, and similar areas are where Hooded Mergansers can often reliably be found, as well as occasionally in suburban parks (Heritage Park in Irvine seems to be among the more reliable). Easily the cutest and most photogenic of the three North American merganser species, Hooded Mergansers are known for their gigantic crests that they raise up and down. Males have black and white heads (the crest is primarily white when raised) with brown flanks and a white breast with two black bars as well as bright yellow eyes. Females are generally brown with drabber yellow eyes.

Common Mergansers in winter are by and large a species of deep, large, freshwater bodies, including both rivers and lakes. It is uncommon for them to occur on small, shallow creeks and rare for them to be in salt or brackish water. Every once in a while I will receive correctly identified photos of Common Mergansers along the coast, such as a photo of 13 obvious Common Mergansers in flight taken on 5 Jan 2018 at Dana Point Harbor. They may irregularly be found on the larger lacustrine water bodies in the county, but your best bet for finding Common Mergansers in Orange County is by far along the "Upper" Santa Ana River in Anaheim, where they often congregate together in the Burris Basin area and in the river proper, particularly upstream of Tustin Avenue.  Common Mergansers have thicker-based bills than Red-breasted Mergansers. Males are generally characterized by dark green heads and bright white sides and breasts, while females have dark rusty-brown heads, gray sides, and a distinctive, well-demarcated white chin as well as a sharp cutoff from the brown head to the gray breast. Both sexes have dark eyes.

Red-breasted Mergansers in winter are a salt and brackish water species that is found almost invariably on the immediate coast in Orange County (e.g., the ocean, estuaries, lagoons, coastal riverine waters), occasionally extending inland a few miles where there are continuous brackish waters coming up from the ocean. The presence of a single bird on the "Upper" Santa Ana River this fall was very rare because of how far inland it is. Although they can be found anywhere along the coast, your best bet for finding Red-breasted Mergansers in Orange County is to go to the place where they are most frequently misidentified: Bolsa Chica! Red-breasted Mergansers have noticeably thinner-based bills than Common Mergansers. Males have green heads, a white collar on their necks, and generally a brown and black breast and gray sides. Females are very similar to female Common Mergansers but their heads are much duller brown and the border between their brown heads and gray breasts is more diffuse. Both sexes have shaggy crests (distinctive when visible) and red eyes.

While there is some overlap, as you can see the three North American species of merganser generally occupy distinct habitat types...but that doesn't mean that they are only ever found in those types. We encourage thorough documentation of any birds that are found outside of their typical range in the county.

--
Ryan Winkleman
Rancho Santa Margarita

Martin Fee
 

Hi Ryan,

Many thanks for that explanation. I feel one of the biggest challenges is that eBird does not always flag a given bird as being rare for a given location, therefore not all of us "citizen scientists" are aware that reviewers would like additional documentation, and/or just to be extra cautious that perhaps we have misidentified the bird. Many of us are still novices, don't know the typical ranges for all birds in the county, and we rely on eBird to guide us.  Also, not all birders are photographers, so the best we can do is describe the bird. And again, it's not always transparent what birds warrant photographs or additional documentation; Common Mergansers are the expected mergansers in the Upper Santa Ana River after all.

I believe the "root cause" issue is a lack of granularity in eBird's software. I think it has been mentioned previously that there are only two or three filters for all of Orange County. Given the amount of data we have for our area, I would think the software could do better than that (e.g. flagging a Common Merganser as a rarity along the coast). With an enhanced application, eBird reviewers would not have to spend so much of their valuable time cleaning up and correcting the data. As part of my job I am involved in software development on the healthcare side, and I see a lot of analogies in what eBird is trying to do with theirs.

Anyway, just some suggested feedback to give to the "powers that be" at eBird, to make this work better for all of us. Thanks for all you do!

Martin Fee
North Tustin


-----Original Message-----
From: Ryan Winkleman <rswinkleman@...>
To: Orangecountybirding <OrangeCountyBirding@groups.io>
Sent: Mon, Jan 6, 2020 11:58 pm
Subject: [OrangeCountyBirding] Orange County Mergansers

Jeff's post mentioning recent eBird reports of Common Mergansers at Bolsa Chica without any documentation touches a sore spot with several people (not just us eBird reviewers) who monitor coastal bird reports in Orange County. This is an issue that we see every winter, where there are multiple reports of Common Mergansers along the coast, typically at Bolsa Chica, many times without any accompanying reports of Red-breasted Mergansers, and in greater than 9 times out of 10, without any photos or solid documentation. Nearly invariably when photos are taken, they are of misidentified Red-breasted Mergansers. With that in mind, I thought it would be helpful to distinguish preferred habitat types and basic field marks between these two merganser species (and I've included Hooded Merganser as a bonus!).  

Hooded Mergansers in winter are most often found on small creeks and small, shallow ponds, often but not exclusively in areas that have vegetation along the banks for cover. While they prefer inland freshwater areas, they can still occasionally be found in the coastal zone and/or in brackish waters, although it is rare and highly irregular for them to be found directly on the coast. The presence of a Hooded Merganser at Bolsa Chica this fall was truly notable for the location. Your best bet for finding Hooded Mergansers in Orange County is to look in protected freshwater creeks. Oso Creek at Forbes Road, Oso Creek upstream of Marguerite, Aliso Creek between Awma and Alicia, San Diego Creek downstream of I-405, and similar areas are where Hooded Mergansers can often reliably be found, as well as occasionally in suburban parks (Heritage Park in Irvine seems to be among the more reliable). Easily the cutest and most photogenic of the three North American merganser species, Hooded Mergansers are known for their gigantic crests that they raise up and down. Males have black and white heads (the crest is primarily white when raised) with brown flanks and a white breast with two black bars as well as bright yellow eyes. Females are generally brown with drabber yellow eyes.

Common Mergansers in winter are by and large a species of deep, large, freshwater bodies, including both rivers and lakes. It is uncommon for them to occur on small, shallow creeks and rare for them to be in salt or brackish water. Every once in a while I will receive correctly identified photos of Common Mergansers along the coast, such as a photo of 13 obvious Common Mergansers in flight taken on 5 Jan 2018 at Dana Point Harbor. They may irregularly be found on the larger lacustrine water bodies in the county, but your best bet for finding Common Mergansers in Orange County is by far along the "Upper" Santa Ana River in Anaheim, where they often congregate together in the Burris Basin area and in the river proper, particularly upstream of Tustin Avenue.  Common Mergansers have thicker-based bills than Red-breasted Mergansers. Males are generally characterized by dark green heads and bright white sides and breasts, while females have dark rusty-brown heads, gray sides, and a distinctive, well-demarcated white chin as well as a sharp cutoff from the brown head to the gray breast. Both sexes have dark eyes.

Red-breasted Mergansers in winter are a salt and brackish water species that is found almost invariably on the immediate coast in Orange County (e.g., the ocean, estuaries, lagoons, coastal riverine waters), occasionally extending inland a few miles where there are continuous brackish waters coming up from the ocean. The presence of a single bird on the "Upper" Santa Ana River this fall was very rare because of how far inland it is. Although they can be found anywhere along the coast, your best bet for finding Red-breasted Mergansers in Orange County is to go to the place where they are most frequently misidentified: Bolsa Chica! Red-breasted Mergansers have noticeably thinner-based bills than Common Mergansers. Males have green heads, a white collar on their necks, and generally a brown and black breast and gray sides. Females are very similar to female Common Mergansers but their heads are much duller brown and the border between their brown heads and gray breasts is more diffuse. Both sexes have shaggy crests (distinctive when visible) and red eyes.

While there is some overlap, as you can see the three North American species of merganser generally occupy distinct habitat types...but that doesn't mean that they are only ever found in those types. We encourage thorough documentation of any birds that are found outside of their typical range in the county.

--
Ryan Winkleman
Rancho Santa Margarita

Ryan Winkleman
 

Martin,

You are correct, there are three filter areas for Orange County: Mountains, Central, and Coastal. An additional filter would be a lot of work to set up and maintain. Most counties in the U.S. only have one single filter, and if I remember correctly from our reviewer listserv, I think that some areas only have one filter for the entire state. This does result in some less than ideal filter settings, such as Bewick's Wrens, Rufous-crowned Sparrows, and Wrentits not being flagged in the northern coastal area because they are common in South County. These are manageable, however, and three filters are fine for OC.

Common Mergansers were previously allowed on the Coastal filter without requiring documentation due to the distance inland that it extends. However, upon reviewing the last 10 years of eBird data it was decided yesterday to drop this species off the filter (meaning from now on Common Mergansers will be flagged along the coast). The number of actually adequately documented and/or correctly photographed birds in the coastal zone didn't outweigh the value of having documentation at all times in this area, and hopefully it will lead to fewer erroneous reports of this species and a more accurate dataset.

Regarding the status & distribution, your best resource remains Hamilton & Willick's Birds of Orange County: Status & Distribution, which the Audubon House sells in Irvine. The species maps in eBird are generally good but the eBird database requires constant upkeep and maintenance, obviously, to watch for questionable records. We do what we can to periodically sweep for species that have very specific habitat requirements but we also rely on volunteers to send us questionable reports as well (shout-outs especially to Terry Hill and Brian Daniels). To a lesser extent, your eBird app can sometimes give you clues as to whether a species is expected or not by the presence of half-circles or full-dark circles next to a species name. These are very coarse estimates of species rarity based on local eBird reports but they can sometimes help to indicate when a species is unexpected (though not always reliable). A certain degree of knowledge of S&D comes from just being out birding, and as Jon Dunn once told me, outside of learning actual identification, the best thing you can do to aid in your birding is to learn status & distribution (which I agree with!).




On Tue, Jan 7, 2020, 8:50 AM Martin Fee <mfee@...> wrote:
Hi Ryan,

Many thanks for that explanation. I feel one of the biggest challenges is that eBird does not always flag a given bird as being rare for a given location, therefore not all of us "citizen scientists" are aware that reviewers would like additional documentation, and/or just to be extra cautious that perhaps we have misidentified the bird. Many of us are still novices, don't know the typical ranges for all birds in the county, and we rely on eBird to guide us.  Also, not all birders are photographers, so the best we can do is describe the bird. And again, it's not always transparent what birds warrant photographs or additional documentation; Common Mergansers are the expected mergansers in the Upper Santa Ana River after all.

I believe the "root cause" issue is a lack of granularity in eBird's software. I think it has been mentioned previously that there are only two or three filters for all of Orange County. Given the amount of data we have for our area, I would think the software could do better than that (e.g. flagging a Common Merganser as a rarity along the coast). With an enhanced application, eBird reviewers would not have to spend so much of their valuable time cleaning up and correcting the data. As part of my job I am involved in software development on the healthcare side, and I see a lot of analogies in what eBird is trying to do with theirs.

Anyway, just some suggested feedback to give to the "powers that be" at eBird, to make this work better for all of us. Thanks for all you do!

Martin Fee
North Tustin


-----Original Message-----
From: Ryan Winkleman <rswinkleman@...>
To: Orangecountybirding <OrangeCountyBirding@groups.io>
Sent: Mon, Jan 6, 2020 11:58 pm
Subject: [OrangeCountyBirding] Orange County Mergansers

Jeff's post mentioning recent eBird reports of Common Mergansers at Bolsa Chica without any documentation touches a sore spot with several people (not just us eBird reviewers) who monitor coastal bird reports in Orange County. This is an issue that we see every winter, where there are multiple reports of Common Mergansers along the coast, typically at Bolsa Chica, many times without any accompanying reports of Red-breasted Mergansers, and in greater than 9 times out of 10, without any photos or solid documentation. Nearly invariably when photos are taken, they are of misidentified Red-breasted Mergansers. With that in mind, I thought it would be helpful to distinguish preferred habitat types and basic field marks between these two merganser species (and I've included Hooded Merganser as a bonus!).  

Hooded Mergansers in winter are most often found on small creeks and small, shallow ponds, often but not exclusively in areas that have vegetation along the banks for cover. While they prefer inland freshwater areas, they can still occasionally be found in the coastal zone and/or in brackish waters, although it is rare and highly irregular for them to be found directly on the coast. The presence of a Hooded Merganser at Bolsa Chica this fall was truly notable for the location. Your best bet for finding Hooded Mergansers in Orange County is to look in protected freshwater creeks. Oso Creek at Forbes Road, Oso Creek upstream of Marguerite, Aliso Creek between Awma and Alicia, San Diego Creek downstream of I-405, and similar areas are where Hooded Mergansers can often reliably be found, as well as occasionally in suburban parks (Heritage Park in Irvine seems to be among the more reliable). Easily the cutest and most photogenic of the three North American merganser species, Hooded Mergansers are known for their gigantic crests that they raise up and down. Males have black and white heads (the crest is primarily white when raised) with brown flanks and a white breast with two black bars as well as bright yellow eyes. Females are generally brown with drabber yellow eyes.

Common Mergansers in winter are by and large a species of deep, large, freshwater bodies, including both rivers and lakes. It is uncommon for them to occur on small, shallow creeks and rare for them to be in salt or brackish water. Every once in a while I will receive correctly identified photos of Common Mergansers along the coast, such as a photo of 13 obvious Common Mergansers in flight taken on 5 Jan 2018 at Dana Point Harbor. They may irregularly be found on the larger lacustrine water bodies in the county, but your best bet for finding Common Mergansers in Orange County is by far along the "Upper" Santa Ana River in Anaheim, where they often congregate together in the Burris Basin area and in the river proper, particularly upstream of Tustin Avenue.  Common Mergansers have thicker-based bills than Red-breasted Mergansers. Males are generally characterized by dark green heads and bright white sides and breasts, while females have dark rusty-brown heads, gray sides, and a distinctive, well-demarcated white chin as well as a sharp cutoff from the brown head to the gray breast. Both sexes have dark eyes.

Red-breasted Mergansers in winter are a salt and brackish water species that is found almost invariably on the immediate coast in Orange County (e.g., the ocean, estuaries, lagoons, coastal riverine waters), occasionally extending inland a few miles where there are continuous brackish waters coming up from the ocean. The presence of a single bird on the "Upper" Santa Ana River this fall was very rare because of how far inland it is. Although they can be found anywhere along the coast, your best bet for finding Red-breasted Mergansers in Orange County is to go to the place where they are most frequently misidentified: Bolsa Chica! Red-breasted Mergansers have noticeably thinner-based bills than Common Mergansers. Males have green heads, a white collar on their necks, and generally a brown and black breast and gray sides. Females are very similar to female Common Mergansers but their heads are much duller brown and the border between their brown heads and gray breasts is more diffuse. Both sexes have shaggy crests (distinctive when visible) and red eyes.

While there is some overlap, as you can see the three North American species of merganser generally occupy distinct habitat types...but that doesn't mean that they are only ever found in those types. We encourage thorough documentation of any birds that are found outside of their typical range in the county.

--
Ryan Winkleman
Rancho Santa Margarita

--
Ryan Winkleman
Rancho Santa Margarita

Bruce Aird
 

Jon Dunn is a VERY wise birder (and a really good guy too!). Then again, I hear that pretty often from Jeff Bray too!

Cheers!
Bruce Aird
Lake Forest, CA

On Tue, Jan 7, 2020 at 12:04 PM Ryan Winkleman <rswinkleman@...> wrote:
Martin,

You are correct, there are three filter areas for Orange County: Mountains, Central, and Coastal. An additional filter would be a lot of work to set up and maintain. Most counties in the U.S. only have one single filter, and if I remember correctly from our reviewer listserv, I think that some areas only have one filter for the entire state. This does result in some less than ideal filter settings, such as Bewick's Wrens, Rufous-crowned Sparrows, and Wrentits not being flagged in the northern coastal area because they are common in South County. These are manageable, however, and three filters are fine for OC.

Common Mergansers were previously allowed on the Coastal filter without requiring documentation due to the distance inland that it extends. However, upon reviewing the last 10 years of eBird data it was decided yesterday to drop this species off the filter (meaning from now on Common Mergansers will be flagged along the coast). The number of actually adequately documented and/or correctly photographed birds in the coastal zone didn't outweigh the value of having documentation at all times in this area, and hopefully it will lead to fewer erroneous reports of this species and a more accurate dataset.

Regarding the status & distribution, your best resource remains Hamilton & Willick's Birds of Orange County: Status & Distribution, which the Audubon House sells in Irvine. The species maps in eBird are generally good but the eBird database requires constant upkeep and maintenance, obviously, to watch for questionable records. We do what we can to periodically sweep for species that have very specific habitat requirements but we also rely on volunteers to send us questionable reports as well (shout-outs especially to Terry Hill and Brian Daniels). To a lesser extent, your eBird app can sometimes give you clues as to whether a species is expected or not by the presence of half-circles or full-dark circles next to a species name. These are very coarse estimates of species rarity based on local eBird reports but they can sometimes help to indicate when a species is unexpected (though not always reliable). A certain degree of knowledge of S&D comes from just being out birding, and as Jon Dunn once told me, outside of learning actual identification, the best thing you can do to aid in your birding is to learn status & distribution (which I agree with!).




On Tue, Jan 7, 2020, 8:50 AM Martin Fee <mfee@...> wrote:
Hi Ryan,

Many thanks for that explanation. I feel one of the biggest challenges is that eBird does not always flag a given bird as being rare for a given location, therefore not all of us "citizen scientists" are aware that reviewers would like additional documentation, and/or just to be extra cautious that perhaps we have misidentified the bird. Many of us are still novices, don't know the typical ranges for all birds in the county, and we rely on eBird to guide us.  Also, not all birders are photographers, so the best we can do is describe the bird. And again, it's not always transparent what birds warrant photographs or additional documentation; Common Mergansers are the expected mergansers in the Upper Santa Ana River after all.

I believe the "root cause" issue is a lack of granularity in eBird's software. I think it has been mentioned previously that there are only two or three filters for all of Orange County. Given the amount of data we have for our area, I would think the software could do better than that (e.g. flagging a Common Merganser as a rarity along the coast). With an enhanced application, eBird reviewers would not have to spend so much of their valuable time cleaning up and correcting the data. As part of my job I am involved in software development on the healthcare side, and I see a lot of analogies in what eBird is trying to do with theirs.

Anyway, just some suggested feedback to give to the "powers that be" at eBird, to make this work better for all of us. Thanks for all you do!

Martin Fee
North Tustin


-----Original Message-----
From: Ryan Winkleman <rswinkleman@...>
To: Orangecountybirding <OrangeCountyBirding@groups.io>
Sent: Mon, Jan 6, 2020 11:58 pm
Subject: [OrangeCountyBirding] Orange County Mergansers

Jeff's post mentioning recent eBird reports of Common Mergansers at Bolsa Chica without any documentation touches a sore spot with several people (not just us eBird reviewers) who monitor coastal bird reports in Orange County. This is an issue that we see every winter, where there are multiple reports of Common Mergansers along the coast, typically at Bolsa Chica, many times without any accompanying reports of Red-breasted Mergansers, and in greater than 9 times out of 10, without any photos or solid documentation. Nearly invariably when photos are taken, they are of misidentified Red-breasted Mergansers. With that in mind, I thought it would be helpful to distinguish preferred habitat types and basic field marks between these two merganser species (and I've included Hooded Merganser as a bonus!).  

Hooded Mergansers in winter are most often found on small creeks and small, shallow ponds, often but not exclusively in areas that have vegetation along the banks for cover. While they prefer inland freshwater areas, they can still occasionally be found in the coastal zone and/or in brackish waters, although it is rare and highly irregular for them to be found directly on the coast. The presence of a Hooded Merganser at Bolsa Chica this fall was truly notable for the location. Your best bet for finding Hooded Mergansers in Orange County is to look in protected freshwater creeks. Oso Creek at Forbes Road, Oso Creek upstream of Marguerite, Aliso Creek between Awma and Alicia, San Diego Creek downstream of I-405, and similar areas are where Hooded Mergansers can often reliably be found, as well as occasionally in suburban parks (Heritage Park in Irvine seems to be among the more reliable). Easily the cutest and most photogenic of the three North American merganser species, Hooded Mergansers are known for their gigantic crests that they raise up and down. Males have black and white heads (the crest is primarily white when raised) with brown flanks and a white breast with two black bars as well as bright yellow eyes. Females are generally brown with drabber yellow eyes.

Common Mergansers in winter are by and large a species of deep, large, freshwater bodies, including both rivers and lakes. It is uncommon for them to occur on small, shallow creeks and rare for them to be in salt or brackish water. Every once in a while I will receive correctly identified photos of Common Mergansers along the coast, such as a photo of 13 obvious Common Mergansers in flight taken on 5 Jan 2018 at Dana Point Harbor. They may irregularly be found on the larger lacustrine water bodies in the county, but your best bet for finding Common Mergansers in Orange County is by far along the "Upper" Santa Ana River in Anaheim, where they often congregate together in the Burris Basin area and in the river proper, particularly upstream of Tustin Avenue.  Common Mergansers have thicker-based bills than Red-breasted Mergansers. Males are generally characterized by dark green heads and bright white sides and breasts, while females have dark rusty-brown heads, gray sides, and a distinctive, well-demarcated white chin as well as a sharp cutoff from the brown head to the gray breast. Both sexes have dark eyes.

Red-breasted Mergansers in winter are a salt and brackish water species that is found almost invariably on the immediate coast in Orange County (e.g., the ocean, estuaries, lagoons, coastal riverine waters), occasionally extending inland a few miles where there are continuous brackish waters coming up from the ocean. The presence of a single bird on the "Upper" Santa Ana River this fall was very rare because of how far inland it is. Although they can be found anywhere along the coast, your best bet for finding Red-breasted Mergansers in Orange County is to go to the place where they are most frequently misidentified: Bolsa Chica! Red-breasted Mergansers have noticeably thinner-based bills than Common Mergansers. Males have green heads, a white collar on their necks, and generally a brown and black breast and gray sides. Females are very similar to female Common Mergansers but their heads are much duller brown and the border between their brown heads and gray breasts is more diffuse. Both sexes have shaggy crests (distinctive when visible) and red eyes.

While there is some overlap, as you can see the three North American species of merganser generally occupy distinct habitat types...but that doesn't mean that they are only ever found in those types. We encourage thorough documentation of any birds that are found outside of their typical range in the county.

--
Ryan Winkleman
Rancho Santa Margarita

--
Ryan Winkleman
Rancho Santa Margarita