Each of us has our own perception of what birds we consider rare and think of when someone says we saw a rare bird. Some would consider species with low world populations such as Whooping Crane as the only rare birds. Others think of vagrants such as the Nutting’s Flycatcher, Red-throated, or Pacific Loon in the Bill Williams River NWR first and consider those birds to be rare. Most of us, I suspect, think of both when we think of rare birds, though we may first think of the vagrants as that is what birders are most likely to see or find.

When you hear the term “rare bird” is your first thought of vagrants? This long staying Yellow-billed Loon frequented the Parker Strip CA/AZ here 15 Jun 2011. Copyright (c) 2013 David Vander Pluym

Before moving to Lake Havasu City I had my own perception of what species we would likely find in good numbers. After living here and birding regularly for over two years I have come to appreciate in many cases, I was wrong. Some species that I thought were noteworthy are actually common, and other species I thought I would have found have remained as elusive as ever. I now have a different perception of what is rare and what isn’t, but this is still my perception and is based off my largely Lake Havasu-centric viewpoint. The status of some species is also rapidly changing and may well change again.

For our purposes here the area covered is Lake Mohave south to the Mexico border and restricted to the general historic flood plain of the Colorado River (and the Bill Williams River NWR). Since living out here I have also become more involved in documenting and compiling the records of rarities out here including with ebird.org as well as the AZFO seasonal reports. This has helped to give me some insights as to what other people think are rare and worth reporting when they visit. Below I am going to discuss some of the species that seem to come up frequently. This is by no means a comprehensive list but just some birds that seem to cause confusion and how they relate elsewhere in the deserts of California and Arizona. This is also not meant to be a list of the most frequently misidentified birds in the LCRV (otherwise species like Orange-crowned Warbler would probably be on here among others), but rather a list of species which people seem to have misconceptions of their status, which can led to misidentifications. People might also want to check out my earlier blog entry about finding some of these species around Havasu. Click for information on review species (if it is on the review list for one state it will be equally rare on the other side of the river) for Arizona, California, and Nevada.

Mexican Duck: Though people realize that birds of diazi ancestry are showing up in the LCRV, the common perception is that there are no pure birds in the US therefore these birds have to be hybrids. This largely comes from  Hubbard 1977, whose work led to the taxa being lumped with Mallard, and this has been echoed in most recent works. Is this true though? Is there no such thing as a Mexican Duck in the United States? My own feeling is that Mexican Duck is a valid species and that pure birds do occur. Hopefully I should have more on this in the coming year (more work is needed) but for now check out this great article from Arizona Birds Online.

Scaup: The main issue is the rapidly changing status of these two species along the Colorado River. Greater is a sketch details species in Arizona, and away from the Colorado River in the SW this species is rare and worth documenting as it can be a tricky ID. In the LCRV, Greater Scaup has increased dramatically in recent years, particularly in the Bill Williams arm of Lake Havasu. People visiting the Bill Williams River NWR often report Lesser Scaup in winter because that is what they expect, but for this location this is no longer the case; Greater is the more common species here. A good sized flock of Greater also winters winters south of Havasu Landing (California side) on Lake Havasu, but elsewhere in the LCRV Greater Scaup are still uncommon and flocks of 20+ are rare.

33 Greater Scaup, part of a much larger flock. Numbers like this are a very recent occurrence. These were in the Bill Williams arm of Lake Havasu LAP, AZ here 5 Dec 2011, where Greater is know the expected wintering species. Copyright (c) 2013 David Vander Pluym

Barrow’s Goldeneye: A sketch detail species in Arizona and very rare away from the Colorado River in southern California. The opposite of Greater Scaup, this species has declined in the LCRV with the Bill Williams arm and recently Senator Wash Reservoir being the only places that regularly get this species. Elsewhere from Parker north, one or two individuals will typically be found, primarily in fall/early winter, often not sticking long.

Loons: Looking back at our old posts from when we used to visit the area, we would typically mention how many Common Loons we had on each trip. Now living out here we’ve come to realize just how numerous they are on Lake Havasu. 20+ in a day are not unexpected in migration, while 10-20 likely winter every year around the entire lake on average. It also seems at least one will stick around for the summer despite the heat.  Pacific Loon is another sketch details species and is known to be annual in late fall, primarily on Lake Havasu and Lake Mohave (and is very rare away from there). However it seems the perception is that this is an expected species in your average day, like Horned Grebe. This has not been the case since we have been here. There are yearly fluctuations with few in some years and as many as 10 individuals in other years. Though in a given late fall/early winter period, some will usually be found, it is always a treat to find one. Identification is not always straightforward as haze and distance can make a Common Loon look small billed and sharply bicolored on the neck. Red-throated Loon has been increasing though it is still a review species in Arizona with less than 25 records. In recent years it has been annual in the LCRV, primarily around Lake Havasu, but it should still always be documented thoroughly.

What might you think of this Common Loon with an abnormal bill, if seen in the distance? This is likely a returning bird to Lake Havasu CA/AZ here 20 Jan 2013. Copyright (c) 2013 David Vander Pluym

Horned Grebe: A sketch detail species, but regular in the LCRV. It is another species we used to report before we moved out here. Our idea of their status has changed and they seem as common in winter as Common Loon with likely 20+ wintering on Lake Havasu and some higher counts from fall migration. They also are regular on Lake Mohave and on Lake Mead. They also have been showing up earlier than previously thought. South of Lake Havasu they continue to be rare, and they are also rare around Topock Marsh on Havasu NWR. The species is rare in the rest of the desert southwest, but has been regular in small numbers in the rarely visited reservoirs outside of Phoenix.

Neotropic Cormorant: Coming from the Phoenix area one might expect to find this increasing species along the river, however it remains a rare bird and is a review species in California. Likely the same individual has been present in the Bill Williams arm of Lake Havasu since 2008, but elsewhere it is not expected and should be documented.

American Bittern: Lauren’s and my perception of this species along the river has changed, as moving out here we were expecting to find this species, but to date we have only seen them twice since Dec 2010. More reports come from the Yuma area where we don’t spend as much time as we would like. Given the secretive nature of this species there are likely more out there than are found, but it is certainly scarce.

Black Rail: It is well known that this species is found around Imperial and Laguna Dams outside of Yuma AZ, but the perception is that it only occurs along the river in this area. It is actually found locally north to the Havasu NWR with good numbers being found in the Bill Williams River NWR including upstream in the riparian where calling birds would surprise visitors last year looking for the Nutting’s Flycatcher.

Whimbrel: A sketch details species in Arizona but said to be regular and uncommon in the LCRV. Other reports have even stated that thousands may occur in spring around Blythe. In recent years, though the species has been annual, there have only been a few reports per migration season of small numbers. It is possible that a single pulse of a large flock could be missed, but in recent years it seems to be rarer than perceived to be.

Western Sandpiper: It seems that there is a perception that the species is expected in winter in the LCRV. This is not the case, with many reports likely pertaining to Dunlin or Least Sandpipers. There are several documented records for winter (with more from the Dome Valley just outside of our area), but it remains rare in winter.

Herring Gull: A rare species in most of Arizona (on the sketch details list) and in the desert SW away from the Salton Sea. Arizona birders are always excited to see this species, but it is regular in small numbers. South of Lake Havasu it is rare, but likely regular in migration. Around Lake Havasu it sometimes winters in small numbers, but is most regular in migration. Where the species is most regular and is not exceptional to see is around Bullhead City and Lake Mohave. Though counts are typically less than 10 (likely ~20 birds average in the area) it is rare not to find a couple around the Laughlin-Bullhead City bridge and at Katherine Landing in winter.

Note the thick bill, overall brown plumage, and pale inner primaries on this migrant 1st cycle Herring Gull. Here on 9 Nov 2011 at Pittsburgh Pt, Lake Havasu. Copyright (c) 2013 David Vander Pluym

Common and Forster’s Tern: Forster’s Tern may appear irregularly during any season. Migration is protracted so it is hard to know if a bird is summering or wintering in a given location. Common Tern is regular in fall migration (primarily Aug and Sept), but in recent years it has not occurred in large numbers and either species is equally expected at that season. Rarely do Common Terns occur earlier or into October in fall and there are a few records for spring.

Small doves: Small doves are rare north of Parker Dam so for us living here, the perception is that they are a rare species. However once you move south of Parker Dam you start picking up Inca Doves (though they seem to be declining) and one you reach the Parker area you can find Common Ground-Doves. By the time you reach Blythe both species can be locally common. The drop in numbers in recent years of Inca Doves appears to be part of a larger decline in Arizona and California. The species use to be regular in the Needles and Bullhead City areas. Ruddy Ground-Dove, though rare, has recently been found regularly in fall in the Wellton and Tacna area just outside of the LCRV.

These 5 Inca Doves (part of a group of 9) at Rotary Park, Lake Havasu City on 13 Feb 2013 are currently the only known flock in the LCRV north of Parker Dam. This species in recent years has declined across much of its range in California and Arizona. Copyright (c) 2013 David Vander Pluym

Yellow-billed Cuckoo: An increasing species that has really taken to some of the restoration sites along the river, especially around Blythe. They are also regular in the Bill Williams River NWR, but away from these areas the species is very rare. Hopefully the recent increase will continue of this rare species.

Common Nighthawk: Rarely reported, but on occasion reports surface. Though the species breeds north of us it is very rare as a migrant anywhere in the desert southwest and there are only a couple of documented records for the LCRV. As the ID is tricky, full documentation is always needed.

Broad-tailed and Calliope Hummingbird: Hummingbirds are often a tricky identification challenge. Both of these species are montane and migrate at higher elevations across most of the interior southwest. Broad-tailed is very rare at low elevations with only a couple records for the LCRV and reports need to be documented. Calliope are more regular, but only in spring when they are a rare migrant.

Gilded Flicker: Given their range and historical status it is not surprising that the perception is that the Gilded Flicker is to be expected in the LCRV. However. this species has declined at the western edge of its range, and is a rare visitor in the LCRV away from the east end of the Bill Williams River NWR, where birders seldom go. Reports surface from people who only had a brief look and don’t realize that Red-shafted Northern Flicker is the expected taxa, and Yellow-shafted Northern Flickers are about as likely as a Gilded Flicker anywhere in the LCRV in fall and winter.

Gilded Flickers have undergone severe declines in the LCRV and are nowvery rare, even in the eastern part of the Bill Williams River NWR where few pairs remain. This individual was a great find on an AZFO field trip to the north end of Lake Havasu 26 Oct 2012 Copyright (c) 2013 David Vander Pluym

Empidonax flycatchers: Still one of the hardest identification challenges in North America, much work has been done to improve our ability to identify silent birds, but they can still be incredibly tricky and it can be better to leave them unidentified than to try and force a name on an individual. Because field guides illustrate some of the known field marks, birders often feel they should be able to identify every individual, ignoring the pitfalls and cautions in the text. People have a handle on Willow and Pacific-slope Flycatcher (spring and fall migration nearly overlap), though Willow Flycatcher is nearly extirpated as a breeder from the LCRV and thus a Willow Flycatcher you are seeing is unlikely to be a Southwest Willow Flycatcher. Given the range of the debated taxon Cordilleran Flycatcher, it wouldn’t be surprising for there to be records of it for the LCRV, but currently there are no well-documented records and it is generally rare throughout the lowlands of the southwest. Hammond’s are fairly common spring migrants, but are rare in fall. Gray Flycatcher is uncommon as a migrant and is also the only regular Empid in winter in the LCRV; no other species is annual (except possibly Pacific-slope). Dusky Flycatcher is a very rare migrant and winter visitor with few documented records. It is always a good bird in the LCRV, similar to its status in the Salton Sink, and is rarer here than elsewhere in the Mojave and eastern Sonoran Deserts.

Plumbeous and Cassin’s Vireo: As Plumbeous Vireo is regular across much of Arizona, many Arizonans expect to see it in the LCRV, whereas it is rare across California, so many Californians think of it as a rare species. The Birds of the LCRV (written in 1991 before the split) also lists the status of both taxa as being about the same in all seasons. This doesn’t appear to be true, with Plumbeous outnumbering Cassin’s in recent years in the fall and winter. On the other hand, Cassin’s is more common in the spring, and true spring migrant Plumbeous (as opposed to lingering wintering birds) are likely not regular.

This Plumebous Vireo, here on 31 Oct 2012, attempted to winter at Rotary Park, Lake Havasu City. Wintering birds have clouded the status of this species in spring in the the LCRV. Copyright (c) 2013 David Vander Pluym

Western Scrub-Jay, Bushtit, Nuthatches, Brown Creeper, Golden-crowned Kinglet, Cassin’s Kingbird and other highland species: A broad category of birds, they seem to share some common themes. It is interesting that there seems to be a divide, with some people thinking that these species are regular wanderers to the LCRV (as they are to nearby high desert areas) while another group has the perception that all are very rare finds. Most of these species are also irruptive which complicates the true picture, but it seems that some of these are locally rare but regular in fall and winter. Species such as Western Scrub-Jay, Brown Creeper, and Golden-crowned Kinglet are likely annual in the valley, particularly in the Bill Williams River NWR. However other species such as Steller’s Jay or White-breasted Nuthatch are incredibly rare with only a few well documented records for the LCRV.

Thrashers: Sage Thrasher is a regular migrant in late winter and early spring, but is rare in the fall and as a wintering species. The only regular Toxostoma thrasher in the LCRV is the Crissal Thrasher. This species has endured the destruction of much of its native habitat and is still fairly common throughout the valley. Curve-billed Thrasher is a common species across most of Arizona (including where most birders are/visit), so it is often assumed to occur in the LCRV. However, though it gets just east of the valley (i.e. east side of the Black and Mohave Mountains), it is a very rare species west of its range including within the valley. The species is especially fond of dense cholla and if typically found near it. Most documented reports are from the California side where it is a review species. All reports from the LCRV should be well documented. Bendire’s and LeConte’s Thrashers both breed in the desert surrounding the valley (LeConte’s primarily on the California side) but both species are rare in the valley proper with Bendire’s a casual visitor to areas away from desert habitat. There are more records of Bendire’s Thrasher for the LCRV than for Curve-billed Thrasher.

Many people are surprised to learn that Curve-billed Thrasher is actually a very rare species in the LCRV. The only individual(s) Lauren Harter and I have seen in the LCRV has been known bird(s) present at Black Meadow Landing, California. Here on 3 Feb 2011. Copyright (c) 2013 David Vander Pluym

Canyon Towhee: This species gets reported from time to time. Almost always it is of a briefly seen bird by someone who expected the species to be present. They are regular just east of the LCRV, including desert hills and washes just outside of the Bill Williams River NWR. However there are no documented records for the LCRV (or California) and given its sedentary nature it is unlikely to occur.

Indigo Bunting: This species often surprises people with how it is locally uncommon in the LCRV. The restoration sites around Blythe, Cibola and Havasu NWR have small populations of them and it is not surprising to find territorial males away from these areas.

We often use our perception to help short cut our way in making an ID. X species is expected while Y is rare so we don’t double check or question ourselves on the ID. This is usually a very useful tool in bird identification, but it is important to have a good understanding of status before making assumptions. I highly recommend finding a copy of Birds of the Lower Colorado River Valley Rosenberg et al 1991 ($20+ on Amazon for used copies) as it gives the most complete idea of status and distribution for birds in the LCRV. It is interesting that many of the landbirds share a similar status to the Salton Sea area which makes The Birds of the Salton Sea, Patten et al, 2003 worth having as well.

The LCRV is part of the Sonoran desert adjacent to the Mojave and the status of most birds is the same across these regions. However the LCRV is a unique ecosystem and, though the status of many species is the same as nearby areas, this is not true across the board. Some species status are also changing and will continue to change, along with our perceptions along with them. When changing regions it is also a good idea to double check your perceptions!

-DVP

Literature cited

Hubbard, J. P. 1977. The biological and taxonomic status of the Mexican Duck. N.M. Dept. Game and Fish Bull. 16: 1-56.

Patten, M. A., et al. 2003. Birds of the Salton Sea: Status, Biogeography, and Ecology. Unviersity of Caliornia Press, Berkeley, Ca.

Rosenberg, K.V., et al. 1991. Birds of the lower Colorado River Valley. The University of Arizona Press, Tuscon, Az.