Tuesday, September 12, 2017

Post #116 - Info sought on grebe nesting failure!

This is a different sort of post as I am really looking for reader input on a bird health/conservation issue that I have recently found curious and disturbing. I am going to speak very generally about large a nesting population of Clark's and Western Grebes somewhere in Northern California. I am doing it this way since I don't want to outright publicize the location, but I am certain that many of you will know the spot to which I am referring. If you do, please just keep it under your hat, thanks. So, with that caveat out of the way, I want to field opinions as to what seems to be a complete nesting failure of a population of several hundred if not several thousand grebes. 

Grebes EVERYWHERE, but no chicks to be found anywhere?!?!?

I first visited this particular location on July 5th of this year, and I was completely blown away by the number of birds I observed. I saw only 1 chick on that visit, but countless other birds were sitting on eggs at that time. I figured I had arrived just on the front end of what was surely going to be an huge hatch-out of grebe chicks in coming weeks. Consulting the Cornell Lab page on Western Grebe, it stated that the incubation period for the species is 24 days. I figured that if I returned in a few weeks, more of the eggs would have hatched by then. You can understand my surprise when I returned on July 24th - 19 days later - and found zero recently hatched chicks. If all of the eggs that I observed on the July 5th were just-then laid, sure, it would make sense that none of them had reached the required 24 days of incubation to hatch. But that seems really unlikely, particular once you read on.

Western Grebe on nest - Aechmophorus occidentalis
Canon 400mm f/4 IS DO II + 1.4x III on EOS 1D Mark IV
1/2000 at f/5.6, ISO 400, handheld

Fast forward to my third visit, on August 13. I thought for sure there would be all sorts of chicks by then, but, again, I found loads of birds sitting on eggs and no chicks (well, one, photo below). At that point I realized that something had to be very seriously wrong as the entire population hatched effectively zero young from what were certainly thousands of individual eggs from hundreds of individual pairs. To complete the timeline, a friend of mine visited the area this past weekend, on September 9, and said that all the nests had been totally abandoned. What the heck is going on?!?!!??

Western Grebe with chick - Aechmophorus occidentalis
Canon 400mm f/4 IS DO II + 1.4x III on EOS 1D Mark IV
1/1600 at f/8, ISO 400, handheld

What was really strange is that the adults looked generally healthy to my eye. Notably, I did not see a single adult bird catch or consume a fish in any of my three visits. That lead me to wonder if a food shortage could have affected the nesting success of the entire population (though that would more likely affect chicks than unhatched eggs)? I also wondered if the unusually heavy rains that Northern California experienced this winter might have contributed. Perhaps increased runoff deposited more of a certain toxin in the water? Altered the sediment composition? Changed the osmolarity, etc? I really have no idea what cold explain the apparent nesting failure, so I'm really grasping for any possible explanation.

So, I am looking to generate some discussion about this topic. I'd love to have what comments people make as official blog comments below. That way they are part of the post and others can read follow whatever discussion we can together generate. So with that, I want to hear what people think is going on with these birds......

Tuesday, September 5, 2017

Post #115 - Arizona birding! Plus Desert Photography at Elephant Head Pond!

What the heck happened to summer?!?!? It seems as though we've jumped right into fall! With that in mind, I want to quickly rewind to the first week of August, a week that I spent birding and photographing in Southeastern Arizona. Beyond what is fast becoming an annual pilgrimage to that birding Mecca (see Post #72 and Post #73 from last year), this year's trip was additionally motivated by 3 long-staying rarities that I wanted to add to my ABA list: Common Crane in Mormon Lake, Rose-throated Becard on the Santa Cruz in Tumacacori, and Tufted Flycatcher in the Huachucas. I found all three of those birds plus Five-striped Sparrow in California Gulch, so it was a great trip on the birding front, one that pushed my ABA list to 721! Both the crane and sparrow were so far away so as to not be worth photographing, but I did get record shots of the other two.

Rose-throated Becard                           Tufted Flycatcher

As for photography, I spent a wonderful morning at Elephant Head Pond in Amado adjacent to the the Santa Ritas Mountains (Madera Canyon). For those not familiar with this spot, it is desert photography at its finest. Seed and suet are put out every day, and many species  (Gambel's Quail, White-winged Dove, Curve-billed Thrasher, Hooded Oriole, Northern Cardinal, Gilded Flicker, Lucy's Warbler, Pyrrhuloxia, etc) cycle through the property to graze on the handouts each day. There are several blinds, and photographers are free to configure a wide array of perches however they like. The place has recently changed ownership and is now run by world-renowned wildlife photographer Dano Grayson. Dano is a really great guy and has some of the most amazing photography stories I've ever heard, so be sure to engage him if you make it to his place. If you're interested in shooting at the Pond at Elephant Head, you can get in touch with Dano at dano@danograyson.com. Tell him I sent you! I should also mention that Dano has a second set of blinds higher up in Madera Canyon that gets a completely different set of birds (Hepatic Tanager, Black-headed Grosbeak, Acorn Woodpecker, Mexican Jay, etc) than the pond. It's totally possible to spend one day down low and another up high.

With that I'll throw up a few of the shots I collected during my single morning at the pond. The flicker is the bird I most wanted this year. He was lured - only briefly - to this perch by a bit of suet packed into the back of the cholla skeleton. The idea in all of these shots is to get the bird to land on perch that has been positioned to be both fully lit and sufficiently far from the backing foliage that the background is rendered smooth and creamy. For best results, the perch should be at least twice as far from anything in the background than it is from the photographer.

***click on images for higher resolution views, 
particularly those landscape/horizontal oriented***

Gilded Flicker - Colaptes chrysoides
Canon 400mm f/4 IS DO II + 1.4x III on EOS 1D Mark IV
1/3200 at f/5.6, ISO 800

White-winged Dove - Zenaida asiatica
Canon 100-400mm f/4.5-5.6 on EOS 7D2
1/3200 at f/5.6, ISO 800

Pyrrhuloxia - Cardinalis sinuatus
Canon 400mm f/4 IS DO II + 1.4x III on EOS 1D Mark IV
1/3200 at f/5.6, ISO 800

Do notice that the above two shots both utilize the same perch, albeit at different proportions in the final image. That's always a dead give-a-way for set-up shots. The idea is to make set-ups shots look as natural as possible, and that's really hard to do if the same perch is used repeatedly. Varying perches will alway give the most interesting results. It's also a lot of fun to try to get exactly the bird you want on exactly the perch you want (see also these examples from last year).

These 2 cardinal shots were actually my favorites of those that I collected this year. Believe it or not, they were my first nice shots of this species. They were very common where I lived in Boston (2011-2013), but I was always focused on photographing shorebirds or generally rarer species. I kept assuming that I'd catch up with cardinal at some point but never did - until now!


Northern Cardinal - Cardinalis cardinalis
Canon 400mm f/4 IS DO II on EOS 7D2
1/3200 at f/5.6, ISO 800

Northern Cardinal - Cardinalis cardinalis
Canon 400mm f/4 IS DO II on EOS 7D2
1/3200 at f/5.6, ISO 800

I'll leave you with one technical tip. It is really important when shooting in bright desert sun to be mindful that you don't blow away the whites or completely saturate the colors of bright birds like the cardinal. If you overexpose, you'll lose all that lovely feather detail and be left with birds that look like nondescript blobs.

So, that's it for this installment. I'm sure migration and my upcoming pelagic trips will yield some interesting content in the next few weeks. Beyond that, I head to Taiwan in October and Ecuador in December, so please stayed tuned for recaps of those trips as the year winds down. Cheers!