Green Backed Rufous Hummingbirds

25 07 2020

Rufous Hummingbird – Luke Tiller

Rufous vs Allen’s Hummingbird is an age old ID conundrum here in Southern California. While Allen’s Hummingbird are resident year round in Los Angeles, Rufous are just passing migrants whose breeding range barely dips into the very far north of the state. Though they have been seen outside the following window, migrant Rufous are mainly an ID issue for local birders between the first week of February and the end of May and the last week of June through the third week of September. Beyond those times it’s probably relatively safe to assume you are looking at an Allen’s Hummingbird unless you have direct evidence to the contrary.

I think it’s safe to say that if you asked most local birders they’d know that it’s very difficult to identify Rufous and Allen’s Hummingbirds in the field unless you are looking at adult male birds. The common theory goes that most female and juvenile birds are best left unidentified to species during the aforementioned window, but that if you are looking at adult males the orange backed birds are probably Rufous and the green backed ones probably Allen’s.


Allen’s Hummingbird – Luke Tiller

Though of course I’ve known that around ten percent of adult male Rufous Hummingbirds can be green backed I think I’ve somewhat lazily presumed that one in ten is a low enough percentage that you’re probably fairly safe assuming any green backed adult male Rufous/Allen’s here in Altadena is an Allen’s even during this migration period.

This spring however (2020) was an excellent one for finding Rufous Hummingbirds at one’s feeders. I think cool temps and rain in February and March had stunted blooms and left birds more dependent on feeder set-ups. For some reason our yard has never been that popular with adult male Allen’s Hummingbirds, so when I suddenly started seeing a fair few green backed adult male Rufous/Allen’s coming to the feeders I started getting curious about their true identities.


Feeder Hummingbirds – Luke Tiller

The only way to truly separate these two species are by looking at individual tail feathers. This is essentially impossible to do without a camera as you need spread views of their tails. I therefore set myself the task of photographing a few of these green backed birds in order to uncover their identities.

Though the outer two tail feathers (retrices four and five) on adult male Rufous Hummingbirds are wider than adult male Allen’s Hummingbirds, the most obvious identifier is retrix two (the tail feather to the right or left of the two central tail feathers) which has a distinct notch on its inner edge, creating a distinctly shaped feather different to the smoothly tapered retrix two (R2) of an Allen’s Hummingbird.


Allen’s vs Rufous Hummingbird Tail Pattern – Luke Tiller

To my surprise when I started taking spread tail photos of these green backed birds I discovered that many of them were in fact Rufous Hummingbirds. In fact at my feeders I had more green backed Rufous Hummingbirds than I had actual Allen’s Hummingbirds.

To illustrate the point, here are the tail patterns of these two green backed birds in the photo above. First the right hand bird that’s perched in the shot. Following that is a blow up of the above feeder photo. Again showing the distinct tail notch of an adult male Rufous Hummingbird. This bird is even more extensively green backed than the one on the right.


Rufous Hummingbird with notched R2 – Luke Tiller

After taking these two photographs I’m now convinced that I need to be much more careful about how I enter data into eBird, even when it comes to identifying the supposedly more easily identifiable adult male Rufous/Allen’s Hummingbirds. Every year there are Rufous Hummingbirds that show up outside the typical window, but I think Kimball Garrett’s challenge of photographing an adult male Rufous in midwinter has yet to find a claimant for that prize.

Young male and female birds of all ages are even harder to identify. If you want to do some research into identifying Rufous and Allen’s Hummingbirds, check out Sheri Williamson’s excellent blog post (here). I highly recommend her hummingbird field guide too (here).


Blow up of above photo. Note notched R2 of Rufous Hummingbird – Luke Tiller

Birding for locals – Los Angeles – July

21 07 2020

Long-billed Curlew – Luke Tiller

Family Focus – Shorebirds.

July sees the start of the peak of much of shorebird migration with adult birds arriving first and the juveniles a few weeks after. Unlike spring migration, where we are generally waiting for later in the season for rarities, some of LA County’s rarest shorebirds have been found very early in shorebird migration including both county Red-necked Stints (July 16 and 23) and one of our two county Little Stints (July 23).

As we get later into the month we will start to see juvenile shorebirds returning south too. This is a great time to work on aging shorebirds, which is often a key part of identifying many species successfully.

Unfortunately, due to a lack of open water there aren’t really a huge number of places to view shorebirds in the local area. By far and away the best spot is the LA River at Willow Street in Long Beach (eBird hotspot here)  I always park on the east side of the river on De Forest Ave. Google gives the address there as 2600 (here). I also never leave anything in my car here after having seen a car broken into here before.

There are lots of other places that might be worth exploring though including the Rio Hondo South of Garvey (though word is that water levels this year might be too high for shorebirds) and the LA River in Glendale near the Bette Davis Picnic Area.

There are even fewer spots in LA County to look for shorebirds this year due to the closure of Piute Ponds to the public. One spot on the desert side that might be worth checking is Amargosa Creek Flood Basin (eBird Hotspot here). You might also find some shorebirds on the sod fields on East Ave 50 too, though personally I’ve only really had luck there a handful of times.

LA Beaches are surprisingly under watched at this time of year and are well worth checking out for shorebirds as well as terns and nearshore seabirds. There is always the chance of turning up a rarity too (see Vagrant Hunting section below).


Anna’s Hummingbird – Luke Tiller

Family Focus – Hummingbirds

Shorebirds aren’t the only birds on the move in July, Rufous Hummingbirds are undertaking their incredible migration from breeding sites as far north as Alaska to wintering sites in Oaxaca, southern Mexico – a journey of up to 4000 miles. Hummingbird watching is the perfect socially distanced birding as it is possible to attract them to your own balcony or yard with feeders and plantings. Plantings in local parks and open spaces also promise great hummingbird watching possibilities too.

It’s a great time to study hummingbirds as there are lots of young and female birds to work through the identity of. Photographing tricky individuals can be a good part of the learning process and some species are almost certainly best left unidentified without good photos: like Rufous and Allen’s Hummingbirds. See this useful page on the ID challenge (here). I wrote a blog post about my observations trying to ID Rufous and Allen’s Hummingbirds this spring on my blog (here).

Across state lines in Arizona the monsoon season is about to enter full swing. This is a wonderful time of year for birding in Arizona as migrant hummingbirds and wanderers head to Arizona to take advantage of the blooms in their “second spring”. If you haven’t visited Arizona before in late summer, I’d definitely add this to your list of future must do local trips. Though much less common there is some pattern of vagrancy of hummingbirds here in California at this time of year too, so maybe you’ll hit the jackpot and discover a Mexican Violetear, Violet-crowned Hummingbird or Blue-throated Mountain-Gem (Previously Blue-throated Hummingbird) at your feeders!


Red Crossbill – Luke Tiller

Mountains: Beat the Heat

As the San Gabriel Valley heats up, it is the perfect time to head to the mountains to escape the heat and see some cool high elevation species. As a rule, the higher the elevation the more interesting the species tend to get.

There is plenty of species to be found here that are easiest (or only) found during these summer months: Black-chinned Sparrows, Hermit Warblers, Green-tailed Towhees and Flammulated Owls among others. Plus there’s Cassin’s Finches, Clark’s Nutcrackers and other exciting montane goodies. This year (2020) seems to have been a particularly good one for Red Crossbills (according to Lance Benner) so a timely visit would seem appropriate for those hoping to seek them out.

I’ve particularly enjoyed exploring a few lesser known spots in the San Gabriels this year up Route 39 and along Upper Big Tujunga Canyon Road. The eastern end of the mountains is almost always under birded and worth an explore (as Naresh’s Red-eyed Vireo from earlier in the year highlighted). My top tip for birding the mountains is to remember to bring your own bird seed for visits to Grassy Hollow and Chilao. Though these spots are excellent for any number of species, the filling of the feeders is sporadic. I have even known people bring their own hummingbird feeders to hang up while they explore these spots.


“Least” Bell’s Vireo – Luke Tiller

Last Call for Summer Birds

As we start to head into August more and more breeding birds will be leaving Los Angeles, so that means that time is running out if you were hoping to see anything from Bell’s Vireos to Black Swifts this year. This eBird spreadsheet should help you work out when birds are more or less easily found in Los Angles County. Check out the link (here).

If you want to work out what’s around when you are out in the field I highly recommend Birdseye Birding App. It’s been useful to me on numerous occasions both professionally and when out enjoying a day’s birding. It essentially allows you to simply research what birds have been seen locally and has a number of filters to help refine your search criteria. Link to the App (here).


Grasshopper Sparrow – Luke Tiller

Local (Patch) Birding

As we head into late July, we will start to see many more species heading south for the winter. This means that all your local parks start to hold possibilities for interesting birds. A quick visit to my local park yesterday (July 29th) saw me tally a few birds that were on the move already including Western Tanager, Warbling Vireo and Lark Sparrow. When I moved to Pasadena I quickly identified (mainly thanks to my dog Possum) Vina Vieja Park as my favored local patch. It has been good to me over the past few years with over 150 species tallied there, including such rarities as Grasshopper Sparrow, Eastern Phoebe, Broad-winged Hawk and Black-and-White Warbler. On April 20, 2020 I logged 70 species around this park in just a single morning, which I think highlights the excellent possibilities local parks offer for great birding (checklist here). In next month’s issue I’ll give some suggestions and thoughts on picking and making the most of your own local patch.


Scissor-tailed Flycatcher – Luke Tiller

Vagrant Hunting

Many birders enjoy the challenge of looking for and finding rare birds. These rare species often exhibit some pattern of vagrancy so there are better times of year to be looking out for them than others. As well as the aforementioned shorebirds here’s some other things to keep your eyes open for:

Odd Ducks! Though summer isn’t usually prime time for duck watching there have been a number of rare ducks show up in southern California in this time including such rarities as Tufted Duck, Harlequin Duck and Fulvous Whistling Duck.

Shoreline Seabirds: Magnificent Frigatebird sightings in LA are most common in July and August and there have been sightings of all five booby species during both months though oddly the one Blue-footed is from the rather unlikely location of Hansen Dam! Incredibly a couple of weeks after publishing this a Magnificent Frigatebird was spotted in Pasadena at Hahamongna!!!!! (ebird checklist here).

Early Easterners: Some Eastern species that seem to show up here in the west fairly early in migration include Scissor-tailed Flycatchers, Eastern Kingbirds (as if to underline this one appeared just as I was writing this on July 15 2020 at Sepulveda Basin) and Indigo Buntings are often to be found among the hordes of Lazuli Buntings that can start to be found at places where there are weedy seed heads to be found in the LA Basin.

Just to highlight that you never know what you are going to see if you’re birding, I was lucky enough to have a Zone-tailed Hawk fly over my yard on July 28th 2020. It was definitely the same bird that was in Monrovia earlier in the year, but at this point it had been missing for two and a half months (ebird checklist here)!


Pectoral Sandpiper – Luke Tiller

Typical Seasonal PAS Field Trips.

Typically this is a fairly quiet time for PAS field trips but some of our standard trips include one to Wrightwood to check out E. Blue Ridge Rd (which starts at Inspiration Point here) and sometimes heads to Grassy Hollow and Jackson Lake too. The road out to Guffy Campground can be pretty rough so high clearance is advised. The first three miles of the road are most productive in my experience.

Though the COVID19 pandemic is certainly crimping my birding travels I am thankful that it’s a hobby that can still be enjoyed during these difficult times. I’m also grateful for the opportunity it’s giving me to explore more of the wonderful flora and fauna of Los Angeles County. I hope this series of essays will help spur you to find new places to explore.