28 December 2011

Night-birding at REGUA

It was the ghostly sight of 2 Barn Owls on a family holiday to the Isle of Wight when I was 9 years old that ignited my interest in birds, and ever since then owls and other nocturnal families have held a special fascination for me. So when I first visited REGUA in Brazil's Atlantic Forest back in 2006, I soon found myself birding the trails around the wetland at night. Over the last five years, Adilei (one of REGUA's sharp-eyed bird guides) and I have spent many hours birding around the reserve at night, and we've found reliable sites for several sought-after nocturnal species.

For many birders visiting REGUA, Giant Snipe is near the top of the list of target birds. REGUA is one of the best sites for these large, mainly nocturnal waders, with birds often showing down to just a few metres! A few years ago Giant Snipe could be seen at the REGUA wetland, but with the grassy areas here now replanted, birds are easier to find in pasture just outside the reserve. Giant Snipe are most vocal, and are therefore easier to find, between July and December, when they display by calling overhead (they are very difficult outside of this period). Joining a guided excursion from the lodge to one of several known feeding grounds at dusk or dawn is essential, where Barn Owl and Spot-tailed Nightjar are also possible.

Giant Snipe Gallinago undulata, REGUA wetland, November 2008. REGUA is one
of the best sites for these large nocturnal waders, however, they are almost
impossible to locate if they are not calling.

The Wetland Trail provides the easiest night-birding at REGUA. Beginning just a few minutes walk from the lodge, the trail is easy, not too long (2.8 km), and (since November 2011) well marked with yellow posts every 50 m. The main targets here are Tawny-browed Owl, Striped Owl, Tropical Screech-Owl, Common Potoo and Scissor-tailed Nightjar. Allow at least two hours to walk the whole trail.

Tawny-browed Owl is usually found in the larger trees by the Conservation Centre but sometimes perch up in the cecropias around the volunteer accommodation at the very start of the trail (as well as in the lodge garden). Also try the forest edge around post 1400. Common Potoo can be found anywhere along the trail, but especially between posts 900 and 1750 - scan the tops of any bare trees, and from post 1450 to 1740 can sometimes be good for Striped Owl. Scissor-tailed Nightjar prefer the less wooded areas - from post 1600 onwards, scan the hillsides with a torch to pick birds up in flight and eye-shine of perched birds, and at post 1900 carefully scan the ground to the right, where birds can often be found. Barn Owl are sometimes seen hunting over the more open areas (although as the replanted trees mature they are becoming less frequent, and the fields just outside the reserve main entrance are a much more reliable spot nowadays), and occasionally also Short-tailed Nighthawk and Spot-tailed Nightjar. Tropical Screech-Owl and Pauraque can be found anywhere along the trail.

Striped Owl Asio clamator, REGUA wetland, November 2008. Imagine a
Long-eared/Short-eared Owl hybrid!

Male Scissor-tailed Nightjar Hydropsalis torquata, REGUA wetland, July 2010.
Although the reforestation at the wetland is now become quite mature, this
species can still be found around the remaining scrubby hillsides.

Tropical Screech-Owl Megascops choliba, Forest Trail, adjacent to the REGUA
wetland, July 2011. This species prefers forest edge habitats and can be seen
anywhere around the wetland.

It is worth keeping your eyes peeled for a variety of mammals around the wetland at night. You should encounter plenty of Capybara, and at dusk Fishing Bats appear in good numbers over the larger bodies of open water. Common Grey Four-eyed Opossum and South-eastern Common Opossum are often seen, and if you're lucky you might glimpse a Nine-banded Armadillo or Paca crossing the trail. On a cautionary note, tracks of Puma and Ocelot (and other smaller cat species) are now being found very frequently on the Wetland Trail, and in 2011 some birding groups even heard Puma growling on the trail at night! Therefore, potentially you could encounter a Puma at night which might be dangerous, and therefore walking this trail at night in a group, preferably with a guide, is strongly recommended.

The 1.3 km Onofre Cunha Trail, located 3 km from the lodge, passes through a fragment of lowland humid evergreen forest. Over the last two years this trail has proven to be excellent for night-birding and in particular for allowing easy access to forest interior species such as Long-tailed Potoo, Black-capped Screech-Owl and Mottled Owl. Tawny-browed Owl, Common Potoo and Ferruginous Pigmy-Owl are frequently encountered, and an area of rough pasture at the end of the trail is worth trying for Giant Snipe, but the real prize here is Black-banded Owl, with a pair of birds in residence.

It is worth spending at least a couple of hours walking slowly along the trail listening for calls (use recordings/playback very sparingly as the birds soon get wise to them (plus using recordings/playback as little as possible is to be encouraged to reduce any adverse effect on the birds) and keeping an eye out for birds perched up quietly beside the trail. I’ve often picked up Black-banded Owls just by scanning with a torch or even finding them perched up in trees over the trail, and once a Mottled Owl flew in and landed just a few metres from me (without any encouragement from recordings) while I was looking for a calling Long-tailed Potoo! In my experience, the last few hours of dark before dawn are best, and birds are seemingly more vocal on clear moonlit nights.

Black-banded Owl Strix huhula, Onofre Cunha Trail, December 2011.
Birds in the Atlantic Forest are a unique subspecies S. albomarginata.
(Photo by Nicholas Locke)

Tawny-browed Owl Pulsatrix koeniswaldiana, Onofre Cunha Trail, May 2010.
This species is endemic to the Atlantic Forest where it replaces the widespread
Spectacled Owl Pulsatrix perspicillata. There are good numbers at REGUA.

For the Onofre Cunha Trail, hiring one of REGUA's bird guides is strongly recommended. Transport is required to reach the trail head from the lodge (although I guess you could walk at a push), and the entrance to the trail is very difficult to find. It is usually Adilei who will accompany you and he knows the best spots for all the birds.

We've only scratched the surface as far as birding at night at REGUA is concerned. The reserve is huge and most of the forest interior remains unexplored at night. The Near-threatened Rusty-barred Owl is probably present at higher elevations, the mysterious Ocellated Poorwill is possible in the forest interior and surely Great Horned Owl is waiting to be found in the more open habitats? Even relatively well-explored areas continue to yield surprises. In July, RJ state's third Stygian Owl was found at the wetland, and there have been several records of Nacunda Nighthawk from just outside the reserve.

Black-capped or Variable Screech-Owl Megascops atricapilla, Waterfall Trail,
November 2008. This Atlantic Forest endemic is only found in forest interiors.

Acknowledgments

Many thanks to Nicholas Locke for permission to use his photo of Black-banded Owl.

19 December 2011

Brazilian moorhens - a laughing matter

When I first visited Brazil over five years ago, I soon became aware of how different the long 'cackling' calls of the local race of Common Moorhen Gallinula chloropus galeata are compared to the familiar short calls of nominate G. c. chloropus back in the UK. A closer look at these birds also revealed that they look a little different too, being slightly bigger with a larger red shield with a broad square top edge, giving the head profile a peak at the front of the crown. With the recent taxonomic scrutiny of moorhens focusing on the variation between Old World and New World forms, much has been written about the morphological differences between the North American race G. c. cachinnans and Old World chloropus, that might allow a transatlantic vagrant to be identified. Adult cachinnans, in addition to the features above, tend to show a different bill pattern with less extensive yellow on the lower mandible and a more clearly defined red/yellow border, a duller red iris and richer reddish-brown upperparts, particularly on the upper mantle where there is a more clearly demarcated contrast with the dark grey neck (see here and here). Immature birds are much more similar and possibly indistinguishable in the field?

In July, the AOU (but so far not the BOU) decided to split all New World forms from Old World chloropus as Common Gallinule (in favour of the name Laughing Moorhen suggested by The Sound Approach). However, it is galeata, the most widespread form across South America, that has been designated the nominate race rather than cachinnans. I'd like to know what features distinguish these two races? As far as I can tell they are vocally inseparable (compare the calls of galeata and cachinnans here and chloropus here), but I've observed that galeata does appear to be much greyer on the upperparts than both Old World chloropus and North American cachinnans, with brown tones restricted to the lower mantle, rump, greater coverts and flight feathers (compare below), and perhaps they are also a little darker overall. Are there other differences?

Former race G. c. galeata, now split by the AOU as Common Gallinule Gallinula
galeata
, REGUA, Brazil, November 2011. Note the large, square-topped shield, the
well defined lower mandible pattern and the dark eye. galeata seem to have much
greyer upperparts than both North American cachinnans and Old World chloropus.

Common Moorhen Gallinula chloropus, London Wetland Centre, UK, December
2011. Note the smaller, narrower shield with a rounded top, slightly more extensive
yellow on the lower mandible with a slightly less demarcated pattern, brighter red
iris and browner upperparts (click to enlarge). North American cachinnans is
apparently even browner above.

At REGUA, galeata also exhibit some differences in behaviour compared to the Old World Common Moorhen. Here the birds seem to be more social, forming large flocks throughout the year, often containing 40 or so individuals that feed and rest together. They also appear to be more aquatic in their feeding habits, preferring to forage in open and often quite deep water, picking plant material from the surface, and feed much less frequently on land than Common Moorhen do in the UK, where bird seem to prefer to graze on grass. Has anyone noticed a similar feeding behaviour in cachinnans, or in any other race? For some excellent footage by Ron Jackson showing the behaviour, calls and features of galeata at REGUA, click here.

A typical feeding group of Common Gallinule Gallinula galeata, REGUA, July
2011. Based on observations at REGUA, Brazilian birds are seemingly much
less terrestrial in their feeding habits than their Old World counterparts?

Common Moorhen Gallinula chloropus London Wetland Centre, UK, December
2011. Birds in the UK seem to prefer grazing on land.

So is the situation as straightforward as separating New World from Old World moorhens? Looking at photos, meridionalis from sub-Saharan Africa and St. Helena in the mid South Atlantic (here), orientalis of south-east Asia (here), and pyrrhorrhoa from Madagascar and surrounding islands (here), all look very similar to galeata to me, with perhaps a very slightly more rounded top to the shield. Have these been allied to Common Moorhen or Common Gallinule, and are they also different species?

18 December 2011

Winter at the London Wetland Centre

A quiet afternoon with cold north-westerlies produced 2 drake Pintail, 5 Shelduck, 56 Wigeon, 5 Pochard, 30 Gadwall, 1 Water Rail, 17+ Common Snipe, 15+ Lapwing, 2-3 Stonechat, 15+ Lesser Redpoll, 14+ Siskin and 5 Redwing. Good numbers of Great Tit and Blue Tit were seen, but 4 Long-tailed Tit, 3 Robin, a few Blackbird were the only other passerines of note. Many of the smaller pools are partially frozen and although there were plenty of Teal around there seemed to be less wildfowl than usual, with just small numbers of Northern Shoveler and Tufted Duck. There was also a pair of Mandarin on the Main Lake, which I guess could be from the collection?

11 December 2011

Staines Bore

A couple of hours at Staines Moor produced almost bugger all, with 1 Water Pipit (terrible photo below) associating with a lone Meadow Pipit and a Pied Wagtail along the Colne, 17+ Fieldfare, 15 Linnet and a Reed Bunting being about it. Also, 80+ Linnet were kicking about on adjacent Stanwell Moor.

10 December 2011

Papercourt Short-eared Owls

A brief visit to Thursley Common today found no sign of the Great Grey Shrike, or much else for that matter, with only 10 Lesser Redpoll, 2 Stonechat and a few Meadow Pipits seen. Mid afternoon I found myself back at Papercourt water meadows for some more owl action (I can't believe how many people were out to watch them! Around 50 or so!). At least 4 Short-eared Owls put on a fantastic display, hunting over the rough grass, being mobbed by 2 Kestrels and Carrion Crows, and occasionally even fighting and calling right overhead! This time I managed a few rubbish photos. 1 Barn Owl, 1 Stonechat and a Roe Deer were also seen.






There's been a large influx of Short-eared Owls into the UK this autumn, see here.

2 December 2011

Two of my favourite birds together in Surrey

Surrey is not the best place in the world for birds (what an understatement!), and it's not often you get the opportunity to see two of your favourite birds in the world, in Surrey, at the same place, and on the same day. Therefore I couldn't resist a quick visit to Papercourt water meadows this afternoon to give it a shot. Just a few minutes after arrival I caught sight of the unmistakable deep wing beats of a Short-eared Owl in the distance, and after a few minutes I realised there were actually 3 birds hunting over the rough grass. They showed fairly well but unfortunately stayed a little distant and I didn't manage a single half decent photo! One down, one to go, but I didn't have to wait too long before a Barn Owl appeared quartering the fields. Simply amazing birds! I never tire of watching Short-eareds or Barn Owls! Also seen were c.100 Siskin, c.50 Fieldfare and a single Redwing. I must make a return visit to try and get a few snaps!