Friday, January 27, 2012

Mas mariposas de Chiloé (more butterflies of Chiloé)

As I only have a few days left here in Chile, I think I have found just about every species that the north end of this island can produce. I began this when I arrived and reported on it here back in November. In a summer of collecting, Concha-Bloomfield and Parra found 9 species here at the center (pdf here) - I found 16 from October to January. I also managed to photograph every species I encountered.

Butleria flavomaculata

My list (pdf) with photos and some notes (in spanish) is available for download here and on the downloads page of the blog.

A few more pictures:

Eroessa chilensis on Fuchsia magellanicus
Homoeonympha humilis, on Blechnum sp. 

Nelia nemyroides
Argopteron aureipennis, the most beautiful species here (in my opinion)
A. aureipennis, dorsal view

Tuesday, January 24, 2012

Another mystery

The last quiz I gave (here), was far too easy - everyone got it right (and quickly). The answer was Crabeater Seal (Lobodon carcinophagus), a southern ocean species that uses those crazy teeth to strain krill from the water. So a MUCH harder one this time. I was out along a trail here at Senda Darwin when I ran into an Austral Pygmy-owl with the remains of its breakfast.

You can see it is holding just one leg of a bird. The question is: what is the bird?

I'll give you a little bit of direction, as you probably don't all have The Birds of Chile sitting next to your computer: use eBird to find out what is in the area (or at Senda Darwin - it is listed as a "Hotspot"). That will narrow your search down a bit. Whomever gets this first (or at all) will have my undying respect.

Not the same owl. 

Sunday, January 22, 2012

New island breeders: Chilean Mockingbird

One of the most interesting thing about birdwatching, for me and most others, is finding important records, whether a rare stray, new breeder or simply abnormally large or abnormally small flocks. On Nov-28 of 2011, I found a pair of Chilean Mockingbirds at Caulin Bay, which was the second southernmost record that I could find - and south of their distribution in The Birds of Chile or Cornell's Neotropical Birds Online. The other record was from 1997 and reported to eBird, near the city of Quemchi - presumably a good find, as it merited addition many years later.

Total range of Chilean Mockingbird, per eBird - the most accurate resource. 

Southernmost region - North third of Chiloe on the bottom-left

Then on the morning of Jan 11th, I happened upon an adult at Senda Darwin, however, I was without a camera. Later that day I went to Caulin and came upon a family of four - two adults and two juveniles. Because the juveniles were following the parents around, it is pretty safe to assume that the breeding occurred  on Chiloe Island. Interestingly, this was not far (200m or so) from where I found the pair in November - presumably the same pair.

Fledgling, Caulin Bay, Jan 11, 2012

Overall, I don't know any population trends for the species, but it is worth noting that this breeding occurred. An ornithologist here said that she knew of one sighting two years ago, but that this was almost certainly the first documented breeding on the island.

Adult, from a LONG way away, Caulin Jan 11
Especially in underbirded areas, such as most of South America, any records you have are worth entering into eBird, thus that scientists and the interested public have access to them and they can be useful in documented range shifts, population fluctuations, habitat-use and migration timing/routes and more.

Images created via, 22-Jan-2012

Thursday, January 19, 2012

Bariloche, Argentina

In order to renew my Chilean visa, I made a quick trek over to Argentina with the alternative motive of checking out a swallow box site a bit outside the city of Bariloche. On the way in, I saw what perhaps is the most memorable natural phenomenon I have ever seen...

There was a pond here.
Looks like a snowstorm happened, doesn't it?

However, it was actually the eruption of the volcano Puyehue in October that caused this. Places along the route between Osorno, Chile and Bariloche, Argentina had around 6" of ash piled up. Along the sides of the road were piles where they used snowplows to move it off the road. Worse than the ash smothering all the undergrowth was that this is an evergreen forest, primarily of Nothofagus dombeyi.

I don't know if these trees are actually dead, or whether they just dropped their leaves, but I would think that 3 months later, were they alive they would be growing in new leaves (as they are evergreens). So perhaps thousands of hectares of forests died. I would love to go back in a few years and see the regrowth.

In places, it was fine ash, and in places it was little pieces of pumice (~1cm) like this.
But it wasn't all doom and gloom (or the other side of the coin: a really interesting natural phenomenon). The swallow mission took me out into desert scrubland hills where I saw Black-chested Buzzard-eagles, Spectacled Tyrants, American Kestrels and some absolutely striking scenes.

La estanca el desafio, the golondrinas site with the best echo (it was awesome)!

Sunday, January 15, 2012

Darwin's Frog - la Ranita de Darwin

One of the most exciting animals of the temperate rainforests here is not much larger than a nickel. Rhinoderma darwinii, Darwin's Frog (la ranita de Darwin), inhabits old-growth forest floors, living in the leaf litter and wet mossy areas. There are two species in the genus though the other, R. rufum, may be extinct, as it has not been seen in over 30 years. What really makes these frogs interesting is their reproductive strategy: after the male finds a mate and guards the eggs, he takes the tadpoles into his mouth and they develop (for ~2 months) in the safety of his vocal sac. The tadpoles absorb nutritious secretions from the father in order to grow (more here).

Hiking through the forests here, I hear the species on a fairly regular basis (a loud tiiii tiiii tiiii). However, even when the frog is less than a meter from you, they are maddeningly hard to find - the brown or green color fits perfectly in with the brown or green leaf litter and mosses and the small size of the frog allows it to fit in little crevices, of which there are many.

A different individual, much whiter than the other
The species only inhabits patches of old-growth forest, which is disappearing on both private and public lands. However, unlike larger inhabitants, these guys don't need huge tracts of old-growth forest to survive, though perhaps in small patches inbreeding depression or a bad year could wipe out the population (speculation, of course).

Individual #2

Friday, January 13, 2012

Lens review: Sigma 150-500mm f/5-6.3 DG OS HSM

I’ll admit to being a little photo oriented, as you can probably notice from this site. However, it seems to me that some people suffer as naturalists because of this (the “let’s take a picture of this now, then identify and learn about it later” phenomena – I have been a victim of this before, certainly) – but I like photos to support findings and to replace specimens in taking records (imagine if all bird records needed to be substantiated with a specimen!). I usually do my birding without my camera at the ready – it usually resides in my backpack waiting for something good. But in December, my trusty lens, the Canon 100-400/4-5.6L, died unexpectedly and I was left without even the option of taking pictures of birds…

Chilean Swallow, Tachycineta meyeni, i.e. the reason I am here

A group of ornithologists from Cornell was coming down to Chiloe at the beginning of January and very kindly agreed to carry a lens down here for me. So the question was: which one to buy? The choices were: Canon 100-400/4-5.6L, 400/5.6L, or Sigma 150-500/5-6.3. The price for the Sigma was much lower than either of the Canons and it seemed to be garnering good reviews recently and I could not resist the 500mm range – I am not a professional, so the slight image quality reduction was not worth the nearly $800 price difference (to me) and I thought the slight reduction in speed would be OK.

Black-faced Ibis

So after two trips to Caulin bay and some walks around the Senda with it, here is my very unprofessional review:

The first thing I noticed was: it is heavy and large. Not so heavy that it is unusable, but heavy enough that continuous use probably would lead to strong forearms and biceps, i.e. a little bit heavier than the 100-400. The autofocus and image stabilizers are VERY QUIET – much more so than the Canon. Having had two months of only using a macro, on my camera it felt like I was aiming a telescope – I had trouble finding the birds at 500mm.

This picture exemplifies my problems with the lens, I had to bump up the ISO and produced a REALLY noisy
picture. I am not a post-processing guy, so I had to leave it, but what masquerades as a lack of sharpness here is
really just a mess of noise (and this is only shot at 400, I need a faster body, I think).
Black-necked Swans, Caulin Bay

The minimum aperture of 6.3 (at 500mm) lets in less light, thus forces a slower shutter speed than the 100-400, a disadvantage for birds and a real disadvantage with my quite old camera body (a 30D) which is not good at high ISO. But regardless, I have been satisfied with the image quality - though using a higher ISO, my photos have been noisy - and because it is slower, I have to bump the ISO up a level or two. It is reasonably sharp and improves as you move from 6.3 to 7.1 to 8 - the speed is more of an issue to me than the sharpness - it is fine for my purposes. 

Fire-eyed Diucan, Senda Darwin.

Physically, I like it better than the Canon. A nice feature of this lens is to zoom you turn a ring on the lens, not like the Canon which slides (or doesn’t, depending on how it feels) between focal lengths. That was my least favorite part of the Canon, the other that the lens caps and the hood would not stay on well – the Sigma seems to have no trouble in that respect, though when I bought the 100-400 it was well-used, and the Sigma is brand spanking new. Both lenses are built very solidly, which is nice, as should be expected in mid-range lenses and certainly a plus for field photography.

Sedge Wren, Caulin

For those that like to take pictures of butterflies and dragonflies while birding – this lens focuses to 2.2 meters – the 100-400 to 1.8m – but at 500mm, this is fairly comparable (though you get more shake and a lower aperture at 500 than 400, so perhaps it is much worse). I have gotten fair photos of dragonflies with it, though I have not played with this all that much yet.

All in all, I have only had the lens a week, but I am satisfied with it – whether I keep it or the 100-400 after repair remains to be seen, but it will be spending the remainder of Chile with me and heading out to Peru as well. 

South American Snipe, Caulin (near the bridge)

Tuesday, January 10, 2012

Frost Columns

This morning I took a walk through my family’s woods in central Ohio. One of the first things that I noticed was that in some places the ground had heaved up on pillars of ice. In some places, mossy patches had split apart to reveal many ice needles sticking up off of the soil about four or five centimeters. In others, moss or leaves rested on top of the frost columns.

'These ice needles, or frost columns, form when soil is damp and above freezing but the surface temperature drops below freezing. In Ohio, we have had a relatively warm winter, and lots of rain through November and December. The woods are very wet—I’ve been wearing rubber muck boots instead of hiking boots for fear of sinking. Last night the temperature got down to 24˚F. In these conditions, the liquid water in the ground is drawn to the surface through capillary action.

Basically, the drier soil above attracts water molecules, which defy gravity and rise through the ground. When the water particles reach the surface they freeze, adding to the bottom of a thin column of ice. They can twist, join together side-by-side, or strand very straight and alone. They seem to form especially well in areas without very many roots. I’ve never seen ice needles in a lawn, but often on trails in the woods under fallen leaves or thin patches of moss. They are easy to see in muddy areas. They can even push through very densely packed soil. I have seen frost columns heave up part of the dirt floor in our barn, which seems rock-solid when I’ve tried to dig parts of it up.

At any rate, ice needles are a beautiful phenomenon and make it well worth being outside in the cold even when there is no snow.

Monday, January 2, 2012

Bahamas: Feb, 2011

In February of 2011, I spent roughly three weeks on the island of Abaco, in the Bahamas. Having never before been to the Caribbean, everything was new. From the first time I was spoken to – in a language that was vaguely intelligible but clearly not the one I spoke – I knew this was going to be interesting. My job was to set up nest boxes for the endangered Bahama Swallow and to that end, I headed to the southern half of Abaco island, probably the best spot in the world for these swallows. Abaco is a really thin island, never more than a few miles wide, but well over 60 miles long. Most fortunately Abaco has not yet succumbed to the sprawling resorts and still has loads of “virgin” pine forests remaining – which are commonly said to be the only breeding sites for the swallow.

Bahama Swallow box, Abaco Neem farm

But no one told the swallows that, apparently. I found them breeding in two places: cell phone towers and roofs. This presented the paradox of the species: why are they restricted to two relatively undeveloped islands, yet utilizing human settlements almost exclusively? Personally, my thought is that House Sparrows abound in areas of high human development, but exist in low enough densities on these islands that the swallows still have some breeding sites available to them. House Sparrows (English Sparrows, Passer domesticus) we introduced to North America by some well-meaning, but tragically misguided Victorians about the turn of the century in New York and Boston. They wanted the New World to have the wonderful fauna of the old world and thus they brought a myriad of species from Europe (including, it is said because of its mention in a Shakespeare play, starlings).

Bahama Swallow, Abaco Neem Farm
I do not know whether the House Sparrows on the Bahamas were a separate introduction or part of the rapid expansion of House Sparrows after the initial release in the northeast, but they are certainly in great numbers there now. Additionally, I should note that besides some circumstantial evidence, I have nothing to back up my hypothesis that House Sparrows are outcompeting the Bahama Swallows. Many other hypotheses about the decline can be posited: perhaps they need pine forests to feed, not breed, or maybe they adapt well to small amounts of human disturbance, but not extensive development. But they are certainly competing on some level – a local guide took me to known nesting sites from previous years and in each one we found a sparrow nest, not a swallow.

Wilson's Plover, Abaco
But the island was not all doom and gloom – it was hard to dwell on the decline of a species when confronted with a comfortable hammock and beautiful blue water after work every day. And the birds and butterflies were simply fantastic: northern warblers migrate yearly to the Caribbean and mesh with local birds whose names I had to find in James Bond's bird guide. James Bond? The story goes that Ian Fleming often visited the Caribbean and birdwatched – remember that much of it was British holdings at the time – and when looking for title character's name, he found the author of the local bird guide possessed a fine-sounding British name and the rest is history. Whether apocryphal, I do not know, but the bird guide is still in use and allowed me to identify several bird that I would have been stymied by otherwise.

This bird does not show up in US bird guides: Black-faced Grassquit
Abaco also holds one of the last populations of the Cuban Parrot – a big beautiful bird with some odd habits. Not only does it not nest in trees, like any sane parrot would do, it also does not just nest on the ground – no, it nests in limestone crevasses, mostly in or near extensive cave networks. This puts it in jeopardy of being eaten by voracious predators: house cats and raccoons. Neither species is native to the island and both, despite their cute appearances are serious problems for island birds. Baby parrots in holes present an easy target for these predators and, especially as raccoons move southward on the island, the small population of parrots seems in jeopardy. I was lucky enough to see the parrots on a few occasions and hear them on many more occasions (almost all parrots are loud and obnoxious). 

Cuban Parrot, Abaco, in a flock of 8-10 or so
And I managed to find a pretty rare bird for the island: a Swainson's Warbler - one of the harder warblers to find in the US, as well.

Not a good picture - but a good bird! Swainson's Warbler
Western Spindalis, male. The females are completely nondescript tanagers.

A weatherbird - Magnificent Frigatebird - named for their tendency to come inshore before storms (or so they say).

Forest Destruction and Invasive Plants on Chiloe

The island of Chiloe holds some of the region's last, and greatest, temperate rainforests (bosques templado-lluviosos). However, little of their former range still exists as forest, much to the detriment of the whole host of wonderful endemic creatures (from the 5mm long scorpions to the 3,600 year old Alerce trees) that inhabit them.

I have known about old-growth forest destruction for years, but being a New Englander, I had never witnessed it firsthand (we cut all our forests hundreds of years ago!) and it seemed an abstract concept - like parachuting or actually catching fish while fishing. But I got the point awhile back. One of the other researchers here, Ariel, who studies mammals here (but is getting a PhD in biogeochemistry) was preparing a talk for a conference on Monitos, which he had researched for several years. One of his projects looked at habitat use in different forests, so he needed to take some pictures of his old study sites, which he had not visited in two years.

Argopteron aureipennis, a skipper that only lives in clearings in forests with Quila bamboo,
where the males dance for mates - flashing their iridescent gold wings. 

After some difficulty finding the desired site, we walked in about 15-20 yards into the seemingly intact forest and saw the damage – all large trees in one area had been cut and they seemed to be clearing the understory and brush from much of the rest. One small section of old forest was left as was the section between the road and the cuts.

After surveying the damage we returned and talked to others at the center about it. Apparently it followed the typical logging routine here: cut forest away from the road, allowing the area near the road to stand. Of course, in a few years, that too will either die or be cut – a section of forest 200m x 20 m is not going to survive. And then the invasives will move in at the expense of the native plants.

Ariel surveys the once old-growth forest

One of the sharpest memories of my first few field days in Argentina was simply that I knew a good number of the plants. I am not a botanist but I have a pretty good knowledge of the common New England plants. And here they were: in Argentina. And then in Peru. And then in the Bahamas. Even Tierra del Fuego had some old friends: hawkweeds and dandelions popping out of the sidewalk, daisies in the fields – not to mention the muskrats, beavers, trout and salmon that have completely demolished almost all of the wetland ecosystems in the area.

Here in Chile though, it seems worse. On Chiloe, acres upon acres of Scotch broom turn the countryside yellow, a common forest type is Eucalyptus, you can get as mired in patches of blackberry  as at home and a maple species (I think it is Norway) is taking over roadsides. In Santiago it was hardly better: tree-of-heaven (Alanthius) sprouting in any barren place with the standard set of weedy exotics around it.

Eucalyptus grove, Argentina

South America has had a short history of interchange of flora with North America/Europe/Asia, geologically speaking, of course. Instead, much of the flora (and fauna) is similar to that of Australia and Africa, as they were once connected in the supercontinent of Gondwana after the breakup of Pangea. Nothofagus, the dominant tree genus in Tierra del Fuego, and common here on Chiloe shows this Gondwanan distribution well, it occurs in South America, Australia and New Zealand. The common ferns here, in the genus Blechnum, are also found in New Zealand. Marsupials radiated in Australia and South America – now in both they are threatened by human activity – development of the fragile habitats they inhabit and our introductions: dogs, cats, rats, plants and more. Were it not for these introductions, the logged areas of Chiloe would grow back into the standard Chiloe forest (eventually), instead, it turns into a monoculture of Eucalyptus or a scrub of Scotch broom.

However, let's not carry this pessimism too far. I am firmly of the belief that over time, many invasives get assimilated into the community. Of course, we do not know the consequences at the time of older invasions, in New England, for example: plantain, dandelion, daisy, and many others, including some that we probably just associate with our region. Will autumn olive, purple loosestrife, Japanese beetles and gypsy moths integrate into the communities which they invade or remain hugely damaging species forever?

This dung beetle - I think Homocopris torulosus - has increased substantially with development and introductions
of cattle/sheep/horses and the massive increase in dung that comes with them. 

Some evidence points to the former. The famous story is the Brown-tailed Moth, which is probably better known for its horrible sting than anything else (the caterpillar sends people to the hospital with regularity!). But it was a huge problem species in New England during the first half of the 20th century – its range extended into every state and was a pest of many tree/shrub species. Then, rather suddenly, it declined – and now is found on a few islands in Maine and at the very tip of Cape Cod. Why? One paper claims that an introduced parasitic fly probably played a big role and the authors did a very clever experiment to support this by transferring caterpillars to plots within the former range, which resulted in higher mortality than found in the remnant range. Other invasives have expanded and then contracted as well: the Skylark and Mynha in the Pacific northwest, hops in the northeast, Argentine ants in several places. And others, such as English plantain, have become hosts for native species (in that case, the Baltimore Checkerspot).

Here in Chiloe, I found one native butterfly, Butleria elwesi, ovipositing on a European grass, suggesting that here – where the history with such species is shorter than in New England (Darwin remarked on the lack of cleared land when he passed through Chiloe) – adaptation to these exotic species is occurring, too. In 200 more years, will Eucalyptus trees peek through the canopies of Nothofagus forests? 

B. elwesi, showing the distinctive underwing pattern.
Egg of B. elwesi, on I think, Dactylis sp