Author Archives: Sam Jones

About Sam Jones

I am an early-career ornithologist and conservation scientist and have been an avid birder and naturalist since childhood. I have been involved in a wide variety of work worldwide, particularly in expedition environments and field research throughout the new and old world tropics.

Offshore in the Pacific

South Seas ferries- The public pelagic

By Sam

The south Pacific- an unfathomably vast expanse of water peppered with myriads of sun-baked and hurricane-beaten islands- is relatively daunting territory for an independent travelling birder wishing to cover ground and experience the veritable smörgåsboard of spectacular natural history highlights on offer.
Although rife with terrestrial endemism, diversity is understandably very low on most islands and protracted periods spent in one location often lead to birding stagnation and sometimes insanity (in no given order).

Fortunately, however, as is the case with most island nations, regular (if not sometimes tenuously scheduled) boat services provide the main transport between islands. Although often creaky and a little uncomfortable, with an unevaluated capacity to deal with emergency situations at sea, these weathered bastions of the Pacific provide often unrivalled opportunities to spend cheap, quality time offshore in some of the least watched but most exciting pelagic locations in the world.

The unsung pelagic vessel?

The unsung pelagic?

At sea in Polynesia

A long winter on the island of Tutuila in the American Samoan archipelago, Polynesia, working on terrestrial birds offered scant opportunity to get offshore, but the chance to visit a field crew working on an island nearby finally offered some decent time travelling between islands. Buckets of chum no where to be seen, some of the finest bathymetry in the Pacific beckoned as we struck out to a stormy sunrise aboard as fine a craft for exploration as any- an old rusty ferry chuntering into the grey blue yonder..

The outbound journey, interspersed with heavy rainshowers, provided short spells of interest with numerous Tropical-type Shearwaters, revealing insights into the ongoing taxonomic conundrum of the Audobon’s/Little Shearwater Puffinus complex. These birds are likely to pertain to the dichrous central Pacific group of Tropical Shearwater.

Tropical Shearwater

Tropical Shearwater wheeling around against a dark and stormy sea at dawn

A handful of Wedge-tailed Shearwaters kept tubenose interest up, while a pod of Indo-pacific Bottlenose Dolphins joined in the fun. Sulids, in the shape of Red-footed and Brown Boobies provided plenty of close fly-bys as well as the vast feeding flocks of Black and Brown Noddies, with the odd Blue Noddie, White-tailed Tropicbird and Bridled Tern added to the mix.

Indo-pacific Bottlenose Dolphin pup

Indo-pacific Bottlenose Dolphin pup (note the Cookiecutter Shark wound)

Red-footed Booby

Red-footed Booby (white morph)

Wedge-tailed Shearwater

Wedge-tailed Shearwater- interestingly, all individuals observed and reported are dark morph birds in the immediate region

Although this outbound journey provided plenty of interest in commoner fare, the real target tubenoses remained elusive, as did a distant breaching cetacean (likely a Spinner Dolphin) or large pelagic fish sp.
Far less elusive, however, were more Hawksbill Turtles than you could shake a palm frond at, cruising around with tropical abandon in the balmy waters in the harbour of the island of Ofu.

Hawksbill Turtle

Hawksbill Turtle

Subsequently, a week spent in the beautiful Manu’a islands group allowed for a clean sweep of the terrestrial birds, including several endemic races (including the to-be-split and disjunct powelli race of Fiji Shrikebill). Good at-sea conditions heralded a much anticipated return crossing, the morning after we watched an unseasonal Humpback Whale puffing away offshore.

Seawatching Pacific style

Seawatching from shore Pacific style

IMG_1821

Striking out again, this time to brighter and less moody skies, albeit on a smaller vessel, a steady stream of Wedge-tailed Shearwaters throughout the crossing indicated birds were on the move. Greater luck was had when a pale-morph Herald Petrel appeared seemingly from nowhere on the port side and seared past at no more than 20ft away, fading into the horizon as quickly as it came.
Further interest was spiked shortly after, when a breaching Humpback provided wonderful, if not again too brief, views; perhaps the same individual as the previous evening. Finally, however, the main target tubenose materialised, the commonest of one the rarest genera of tubenoses, Pseudobulweria, in the shape of a Tahiti Petrel, giving exceptionally close views before banking away in our wake.

Tahiti Petrel

Excellent views (albeit without photos to match) of Tahiti Petrel with its trademark massive bill easily distinguishable.

Shortly after this initial encounter, a second petrel, almost certainly another Tahiti, was seen briefly carving away to our starboard side. This time, however, being on a smaller boat was not in our favour as the bird was rapidly lost behind the swell and never to be seen again. Two large and very brief dorsal fins relatively close inshore shared the same story, staying frustratingly elusive but perhaps pertaining to the inshore population of Rough-toothed Dolphins around the island of Tutuila.
Wedge-tailed Shearwaters continued to provide plenty of enjoyable viewing well into inshore waters, despite many hours of seawatching from shore not yielding a single tubenose.

Wedge-tailed Shearwater close inshore

Wedge-tailed Shearwater close inshore

All too quickly the return journey was over and we were back onshore amidst hordes of invasive Myna’s and the bustling, polluted harbour of Pago Pago. My mind, however, was still firmly offshore, wondering what else is really out there…

The opportunities and discoveries to be made offshore in vast regions of the Pacific are untapped and fully deserve more attention, with recent examples such as the putative discovery of New Caledonian Storm-petrel paying credence to this . Although the efforts for more adventurous travel and birding come with inherent elements of difficulty, the rewards often vastly outweigh the difficulties from both a travel and natural history perspective.

I encourage anyone wishing to seek adventurous and exciting birding; the outcomes of which could have genuinely useful outcomes for so many poorly understood pelagic seabirds; to consult your bathymetry, identify an interesting island chain and get offshore and explore the Pacific. What finer way to do so as well than allowing the rusty ferry to facilitate your journey.

Just imagine the possibilities!

 

The Ethiopian Bush-crow

African natural history’s best kept secret?

by Sam Jones

In line with Terry Townshends excellent piece some time ago on Jankowski’s Bunting (a very rare bird indeed), I thought it pertinent to carry on this theme, bringing some limelight onto undoubtedly one of the worlds most remarkable avian subjects and a bird I have had the pure privilege of a fascinating and compelling journey in conducting some of the first ecological study on during 2013; the Ethiopian Bush-crow Zavattariornis stresemanni.

Ethiopian Bush-crow Zavattariornis stresemanni head profile- sporting bright azure blue facial skin. Current taxonomic understanding places the species within the Corvidae with its closest relatively that of Magpies (Pica) and Asian Ground-jays (Podoces sp.). Further genetic study may re-classify this however

Ethiopian Bush-crow Zavattariornis stresemanni – sporting bright azure blue facial skin. Current understanding places the species within the Corvidae with its closest relatively that of Magpies (Pica sp.) and Asian Ground-jays (Podoces sp.).

“..enigmatic and baffling… one the most remarkable African discoveries of the 21st century”
Fry et al. (2000)

The Bush-crow was discovered (in the eyes of science at least) in 1937, when a specimen was collected during an expedition to southern Ethiopia led by Edoardo Zavattari from the Zoological Institute of the Royal Institute in Rome, leading to its formal description in 1938. Its genus name followed that of the finder, while the species name comes in honour of Erwin Stresemann, the influential german ornithologist. This name is often carried into its other widely used vernacular, Stresemann’s Bush-crow.
This relatively recent discovery is interesting, but undoubtedly the most intriguing aspect of its existence in this region is its bizarre range-restriction to one tiny area of nondescript rangeland and thornscrub in the arid Borana zone of southern Ethiopia. Adding complexity, these rangelands have been subject to anthropogenic influences by the pastoralist livelihoods of the native Borana for centuries, with vast expanses of seemingly identical habitat existing directly adjacent to its occupied range.
An early ornithologist studying the region, Constantine Walker Benson (1946), remarked-
‘The reason for this remarkably restricted distribution is not at all apparent to me. There seems to be nothing at all unique or distinctive about its environment.’ 

The rangelands the Bush-crow calls home have been subject to the traditional pastorlist practices of the Borana for centuries.

The rangelands the Bush-crow calls home have been subject to the pastorlist practices of the native Borana for centuries.

This bizarre range-restriction continued to perplex ornithologists while concern also grew over its population trends and pressures on habitat within the range. Until recently, however, the reasons underpinning its peculiar occupancy remained unsolved. This mystery was finally unearthed, when research by Donald et al. (2012) discovered its area of occupancy to be described, with remarkable precision, by a climatic envelope of some 6,000km2, harbouring a cooler, drier and more seasonal local climate than its surrounding areas. This compelling finding brought to light one of African ornithology’s best kept secrets and what is, on current knowledge, probably a unique case within the avian kingdom.

Looking South over the easterly edge of the Bush-crows range

Looking south over the easterly edge of the Bush-crows range, the limits of which are invisible to the eye.

To add complexity to the puzzle, the species appears unspecialised in its diet choice and (in relation to its reliance on human modified habitats) its broader habitat preferences, residing in good numbers around villages and heavily modified grazing land. Aspects of its behaviour and known ecology are also peculiar, complex social interactions, co-operative breeding and its enormous and conspicuous nests to name but a few. It is also widely recognised by the local people and fondly named the Kaka, a term synonymous with its common vocalisations

All this leads to the natural burning question therein, to further understand what is driving this range-restriction from the biological perspective of the bird and crucially for its conservation, what impacts these might have in the face of its long and short term threats. The Bush-crow is currently listed at ‘Endangered’ under the IUCN RedList although trends in its putative population decline remain unclear.

Post-fledging family party of Bush-crows

Post-fledging family party of Bush-crows

A body of observational evidence has indicated the likely sensitivity of the Ethiopian Bush-crow to high temperature and considering the critical recent discovery of the climatic limits that describe the bush-crows range restriction, this has been identified as one area of key ecological research to be addressed. This was precisely the aim for inquiry, to investigate the behavioural impacts of high temperatures on this most unique subject.

A number of birds were captured and colour-marked, creating several new datasets for the species. Interestingly, many adult birds tending nests were synchronously breeding and moulting. The likely product of careful energy allocations in relation to high temperatures and cooperative breeding strategies.

A number of birds were captured and colour-marked, creating several new datasets for the species. Interestingly, most adult birds tending nests were synchronously breeding and moulting, the likely product of careful energy allocations in relation to high temperatures and cooperative breeding strategies.

Early findings (although some needing further clarification) appear to support previously mooted ideas that it is a vulnerability of immature birds to high ambient temperatures that might be a key determinant in the range-restriction dynamics of the species. Furthermore, considering the seasonal polarity of dry/wet seasons within the climatic envelope and the co-operative breeding strategies of the species, it appears likely that the Bush-crow has developed a specific set of behavioural and ecological traits that allow for careful energy allocation in relation to high temperatures experienced during the post-breeding season, while tending temperature affected young.
Further research will aim to clarify these relationships and provide a greater body of baseline information for use in predicting the future impacts on the Bush-crow as a product of global warming.

Understanding and interpreting the puzzle of the Ethiopian Bush-crow is still in its earliest stages and future work will no doubt shed more light on this captivating and romantic evolutionary tale. In my eyes at least, there is also no finer setting for this story than in the beautiful Borana zone of southern Ethiopia, a region as fascinating and beautiful as its endemic birdlife.

“Whatever the reason this bird is confined to a bubble, alarm bells are now ringing loudly.  The storm of climate change threatens to swamp the bush-crow’s little climatic lifeboat – and once it’s gone, it’s gone for good.”
Prof. Nigel Collar-  BirdLife International

 

Call for observations

The Ethiopian Bush-crow still remains poorly understood biologically and much of its basic natural history is unknown.  A large number of observations alongside more systematic work were made during 2013 field campaigns that have added to our knowledge pool of the species. If any readers have birded the region and spent time watching Bush-crows, any field observations of note could well add to our existing understanding of the species. Currently, these notes are in preparation for publication and if you feel you may have something to add- please don’t hesitate to get in touch!
samuel.ei.jones<at>gmail.com

 

Post-script; White-tailed Swallow Hirundo megaensis

Another southern Ethiopian endemic, the White-tailed Swallow Hirundo megaensis, a species I have declined to mention thus far, also shares almost exactly the same range as the Ethiopian Bush-crow. Perplexingly, its sister taxa, the Ethiopian Swallow Hirundo aethiopica of which it is visibly similar, is widespread and common throughout east, west and central Africa. What the ecological drivers behind this range-restriction are, from the case of the Swallow, are entirely unknown and arguably even more baffling than the Bush-crow.

White-tailed Swallow Hirundo megaensis - Probably the first photograph of this species at the nest!

White-tailed Swallo Hirundo megaensisProbably the first photographic documentation of this species at the nest.

All photographs ©Sam Jones.

References

Benson, C.W.(1946) Notes on the birds of southern Abyssinia. Ibis. 88:180-205.

Donald, P. F., Gedeon, K., Collar, N. J., Spottiswoode, C. N., Wondafrash, M., & Buchanan, G. M. (2012). The restricted range of the Ethiopian Bush-crow Zavattariornis stresemanni is a consequence of high reliance on modified habitats within narrow climatic limits. Journal of Ornithology153(4):1031-1044.

Fry, C.H., Keith, S. & Urban, E.K.(2000) The birds of Africa, vol VI. Academic, London

Enfoque en: Trepatroncos Centroamericanos

After publishing Focus on: Central American Woodcreepers on Birding Frontiers in January, Honduran friend and colleague, Fabiola Rodriguez, mentioned that after sharing the piece with some friends in Central America, its dissemination was limited due to the language barrier. In response to this, it is with great pleasure that this has now been translated to Spanish, allowing for a greater readership in Latin America.
Special thanks must go to Fabiola Rodriguez for doing this!

¡Trepatroncos Maravillosos!

Por Sam

¡Agradecimiento especial a una buena amiga y colega Fabiola Rodríguez por traducir este artículo y permitir su lectura en países latinoamericanos!
Trepatroncos- un grupo diverso de moradores de los  árboles del bosque neotropical de carácter críptico y de tonos café que fácilmente pueden ser calificados como monótonos o no tan espectaculares por los aficionados a la observación de aves al ser comparados con el plumaje o estilo de vida de otras especialidades del neotrópico. Pienso que merecen un poco más de atención y quizá sean más intrigantes de lo que nos dejan ver al principio…

Tradicionalmente tratados como una familia aparte, Dendrocolaptidae, ahora forman parte de la extensa familia suboscina neotropical Furnariidae también llamados coloquialmente horneros (algo confuso para algunos ya que el hornero – “ovenbird” también es el nombre común de un chipe del nuevo mundo de zonas templadas). Como producto de la evolución convergente, muestran similitudes con la familia de trepadores, Certhiidae, cuya distribución básicamente es del viejo mundo. Al ser únicos al neotrópico y carecer de una contraparte en Asia y el bosque Afro-tropical, se convierten en un tema fascinante para estudiar por su traslape de nicho y su ecología de forrajeo en relación a la edad y estructura del bosque.

Trepatroncos corona-punteada Lepidocolaptes affinis- Una vista típica de esta especie del bosque nublado.

Trepatroncos corona-punteada Lepidocolaptes affinis– Una vista típica de esta especie del bosque nublado.

A pesar de ser generalmente de tonos cafés  y estriados, los trepatroncos son altamente variables en morfología y tamaño. Desde los más pequeños y delicados como el trepatroncos pico-cuña hasta los corpulentos trepatroncos colorado y gigante, los más grandes y corpulentos representantes del género Xiphocolaptes.  Se conoce que se alimentan principalmente de artrópodos arbóreos, pequeños vertebrados como lagartijas, ranas y regularmente de algunas especies de serpientes pequeñas. A esto se suman registros de depredación de nidos y alimentación especialista al visitar enjambres de hormigas.

Existen aproximadamente más de 50 especies que forman el gremio de trepatroncos en Centro y Suramérica. Este grupo, como la mayoría de las familias neotropicales diversas, se encuentran presentes en una variedad de hábitat, desde los bosques de altura de Polylepis sp. de la pendiente oeste andina hasta el bosque tropical de bajura de la cuenca amazónica. Predeciblemente, Suramérica cuenta con la mayor diversidad de especies de trepatroncos.

En general, se conoce poco sobre los trepatroncos. Muchas descripciones biológicas como reproducción y anidamiento, ecología alimenticia y muda son desconocidas para muchas especies y las dinámicas de bioacústica en trepatroncos como grupo son poco comprendidas. Similarmente, la taxonomía de los trepatroncos se encuentra  relativamente en su infancia, con algunas especies probablemente representadas en la actualidad por un número de especies. Por ejemplo el pequeño trepatroncos oliváceo, actualmente se considera monotípico y por ende, es la única especie en su género Sittasomus. Se encuentra representado por 20 subespecies (de acuerdo a la taxonomía de IOC) desde el norte de México hasta el noreste de Argentina. Se espera, sin embargo, que existan una cantidad de formas distintas en la misma especie. Estas subespecies se han “agrupado” en cinco radiaciones, con más estudio particularmente en análisis de vocalizaciones, esta es una investigación con prioridad.

Trepatroncos oliváceo Sittasomus griseicapillus-  Cola de un juvenil mostrando muda simétrica de rectrices donde R1 y R2 estan en crecimiento. Esta fotografía muestra el raquis largo de las rectrices en trepatroncos les sirve para balance.

Trepatroncos oliváceo Sittasomus griseicapillus– Cola de un juvenil mostrando muda simétrica de rectrices donde R1 y R2 estan en crecimiento. Esta fotografía muestra el raquis largo de las rectrices en trepatroncos les sirve para balance.

Durante trabajo de investigación en Honduras (Parque Nacional Cusuco) en el verano, tuve la oportunidad de apreciar de cerca y de manera personal lo que se volvió firmemente uno de mis grupos favoritos de aves desde mi primera visita al neotrópico. Ocho especies se encuentran fotografiadas a continuación para dar un vistazo a la diversidad y morfología de este grupo fascinante.

Trepatroncos Rojizo Dendrocincla homochroa

Trepatroncos Rojizo Dendrocincla homochroa

Los trepatroncos rojizos son asociados usualmente con las hormigas y puede ser dificil avistarlos lejos de los enjambres de las mismas. Se encuentra restringido a Centroamérica aparte de una o dos poblaciones segregadas en el norte de Suramérica. Esta es posiblemente la forma nominal homochroa.

Trepatroncos Oliváceo Sittasomus griseicapillus

Trepatroncos Oliváceo Sittasomus griseicapillus

Juvenil de Trepatroncos oliváceo- Bajo una muda pos-juvenil que se supone completa en la mayoría de los trepatroncos. P5 se observa en crecimiento con P6-9 aun de primera generación, así como las coberteras primarias correspondientes.

Juvenil de Trepatroncos oliváceo– Bajo una muda pos-juvenil que se supone completa en la mayoría de los trepatroncos. P5 se observa en crecimiento con P6-9 aun de primera generación, así como las coberteras primarias correspondientes.

Los trepatroncos oliváceos poseen un rango de distribución extenso en el neotrópico. Como se mencionó anteriormente, vocalmente son muy interesantes y esta distribución puede ser explorada en xeno-canto aquí. Este es de la forma sylvioides que compone parte del grupo centroamericano griseus (de los cinco mencionados anteriormente). Uno de los caracteres de este grupo es la banda blancuzca o crema como puede ser observada en la imagen arriba.

Trepatroncos Gigante Xiphocolaptes promeropirhynchus

Trepatroncos Gigante Xiphocolaptes promeropirhynchus

Trepatroncos gigante-. Este individuo era una hembra con un parche de incubación en recuperación, P1 también se encontraba en muda simétrica indicando que el ave comenzaba su rutinaria muda pos-reproductiva.

Trepatroncos gigante-. Este individuo era una hembra con un parche de incubación en recuperación, P1 también se encontraba en muda simétrica indicando que el ave comenzaba su rutinaria muda pos-reproductiva.

Este trepatroncos es uno de los más grandes con una distribución que abarca la mayor parte del neotrópico. Como el trepatroncos oliváceo, posee una taxonomía que se conoce de manera escasa con 24 sub especies conocidas (IOC). Se ha sugerido que es probable que existan tres radiaciones bajo esta especie. Este individuo es de la forma emigrans y parte del grupo mesoamericano. Son especímenes impresionantes en el campo, como lo muestra este video de uno devorando una polilla (Sphingidae).

Trepatroncos Pico-cuña Glyphorynchus spirurus

Trepatroncos Pico-cuña Glyphorynchus spirurus

El trepatroncos pico-cuña tiene una distribución amplia en el neotrópico y se encuentra representado en 14 sub especies. Este juvenil es de la raza centroamericana pectoralis. La variación acústica puede ser considerable, como puede ser explorado aquí.

Trepatroncos Barrado Norteño Dendrocolaptes sanctithomae

Trepatroncos Barrado Norteño Dendrocolaptes sanctithomae

Trepatroncos barrado norteño- Hembra con parche de incubación en recuperación también presentando una muda simétrica de P1 comenzando una muda pos-reproductiva. Foto- Jo Kingsbury

Trepatroncos barrado norteño– Hembra con parche de incubación en recuperación también presentando una muda simétrica de P1 comenzando una muda pos-reproductiva. Foto- Jo Kingsbury

Anteriormente subsumido bajo el trepatroncos amazónico barrado D. certhia, los trepatroncos barrados norteños tienen principalmente una distribución centroamericana con las aves de Honduras representando la forma nominal sanctithomae. Estos son otra especie conocida por seguir enjambres de hormigas. Los trepatroncos barrados norteños poseen vocalizaciones peculiares pero distintivas y pueden ser escuchadas aquí.

Trepatroncos manchado Xiphorhynchus erythropygius

Trepatroncos manchado- Juvenil con una visible comisura en pico. Foto- Iain Dickson

Trepatroncos manchado– Juvenil con una visible comisura en pico. Foto- Iain Dickson

Básicamente de distribución centroamericana el trepatroncos manchado es un residente de bosque montano, su trino descendiente es comúnmente escuchado al amanecer en los bosques de Cusuco. Las aves hondureñas son representadas por la subespecie parvus.

Trepatroncos Corona-Punteada Lepidocolaptes affinis

Trepatroncos corona punteada- La delgada raya malar se aprecia ligeramente en esta foto, uno de los rasgos característicos que lo distingue del similar trepatroncos corona-rayada.

Trepatroncos corona punteada– La delgada raya malar se aprecia ligeramente en esta foto, uno de los rasgos característicos que lo distingue del similar trepatroncos corona-rayada.

Otro especialista típico de los bosques nublados centroamericanos, el trepatroncos corona punteada es uno de los más frecuentes encontrados en Parque Nacional Cusuco y en Honduras se encuentra representado por la raza nominada affinis. A altitudes menores se ve reemplazado por el congénere trepatroncos cabeza rayada. L. souleyetii.

Trepatroncos Sepia Dendrocincla anabatina

Trepatroncos sepia- Adulto y juvenil con variación en color de ojo interesante. Foto- Lynn Schofield

Trepatroncos sepia– Adulto y juvenil con variación en color de ojo interesante. Foto- Lynn Schofield

El trepatroncos sepia aun es un enigma en Cusuco, con los primeros registros de esta área protegida proviniendo de la temporada 2012 de trabajo de campo. Aun cuando monitoreos se hayan llevado a cabo en años anteriores, esto no es del todo sorprendente debido a la baja tasa de detección de algunos trepatroncos en bosque denso.  Es un congénere del trepatroncos rojizo en Dendrocincla y también es conocido por sus hábitos de seguir enjambres de hormigas así como seguir tropas de monos ardilla que se alimentan de insectos voladores.
En Honduras se encuentran una vez más representados por la raza nominal anabatina.

¿Se encuentra pajareando en el neotrópico pronto o ya ha visitado esta zona? Ha visto algo que puede elucidar más sobre la vida críptica de algún trepatroncos. Con información básica aun desconocida como biología reproductiva, las observaciones casuales de campo pueden ser de mucha significancia para ciertas especies. Si Usted ha visto pero no observado a los trepatroncos en el pasado, le animo para que profundice. ¡Nunca se sabe lo que se puede encontrar!

Focus on: Central American Woodcreepers

Wonderful Woodcreepers!

By Sam

Woodcreepers- a diverse group of cryptic, brown, tree-dwelling denizens of Neotropical forest can easily get branded as dull or unspectacular by many visiting birders when compared to the plumage or lifestyle of some other Neotropical specialities.
I think they deserve a bit more focus however, and perhaps are a little more intriguing than first meets the eye…

Traditionally treated as a separate family, Dendrocolaptidae, they now make up part of the vast suboscine Neotropical family of Furnariidae, or vernacularly, the Ovenbirds (confusingly, the Ovenbird itself is actually a New World warbler). As a product of convergent evolution, they display obvious similarities to the (primarily) Old World family of Treecreepers, Certhiidae. As well as being taxonomically unique to the Neotropics, they also lack an obvious counterpart in Asian and Afro-tropical forest, making them a fascinating subject for the study of niche overlap and feeding ecology in relation to age and structure of the forest.

Spot-crowned Woodcreeper Lepidocolaptes affinis - A typical view of a typical cloud-forest species.

Spot-crowned Woodcreeper Lepidocolaptes affinis – A typical view of a typical cloud-forest species.

Despite being generally brown and streaked, woodcreepers are highly variable in morphology and size, from some of the smaller and delicate species such as Wedge-billed Woodcreeper, to the brutish Great Rufous and Strong-billed Woodcreepers, the largest and most bullish representatives of Xiphocolaptes.
Although they are primarily known to feed on arboreal arthropods, small vertebrate prey in the shape of lizards, frogs and small snakes have been recorded regularly in some larger species, as well as nest predation and specialist feeding at ant swarms.

There are some 50+ species that make up the woodcreeper guild through Central and South America. They, like most diverse neotropical families, are present in an array of habitat, from the high altitude Polylepis forests of the Andean west slope to lowland rainforest of the Amazon basin. Predictably, South America has the greatest diversity of Woodcreeper species.

Woodcreepers, overall, are rather poorly known. Many basic biological descriptions such as breeding/nesting biology, feeding ecology and moult are lacking in many species and the bioacoustic dynamics in woodcreepers as a whole are very poorly understood. Similarly, taxonomy of woodcreepers is in its relative infancy, with some species likely to actually be represented by a number of species.
For example- the tiny Olivaceous Woodcreeper, currently considered monotypic and thus the only species in its genus Sittasomus is represented by some 20 subspecies (as per IOC taxonomy) from northern Mexico to north-eastern Argentina. It is expected, however, that there are a number of distinct forms within the species, based on morphological and vocal differences. These subspecies have been ‘grouped’ into five radiations, with further study, particularly on vocal analysis, a research priority.

Olivaceous Woodcreeper- Tail spread of a juvenile undertaking symmetric tail moult with replaced R1 and growing R2

Olivaceous Woodcreeper Sittasomus griseicapillus – Tail spread of a juvenile undertaking symmetric tail moult with replaced R1 and growing R2. This photograph displays the long shafts on Woodcreeper rectrices used for balance.

During fieldwork in Honduras (Cusuco National Park) in the summer, I had the chance to get up close and personal with what firmly became one of my favourite avian groups since my first visit to the Neotropics.
Eight species are photographed below that give an insight into the diversity and morphology of this fascinating species group.


Ruddy Woodcreeper
Dendrocincla homochroa

Ruddy Woodcreeper; Cusuco national park (Guanales), Honduras

Ruddy Woodcreepers are usually associated with Ants and can be tough to see away from swarms. It is restricted to Central America apart from one or two disjunct populations in northern South America.
This is presumably the nominate form homochroa.


Olivaceous Woodcreeper
Sittasomus griseicapillus

Olivaceous Woodcreeper (juv), Cusuco NP

juvenile wing undertaking pos-juvenile moult which is thought to be complete in most Woodcreepers

Juvenile Olivaceous Woodcreeper- undertaking post-juvenile moult which is thought to be complete in most Woodcreepers. P5 can be seen growing with P6-9 still first generation, as well as the corresponding primary coverts.

Olivaceous Woodcreepers have a huge range throughout the Neotropics. As mentioned earlier, vocally they are very interesting and this range can be explored on the excellent ‘new look’ xeno-canto here.
This is from the form sylvioides which makes up part of the predominantly Central American griseus group (of the five mentioned earlier). One of the characterising features of this group is the whitish or buff wing-band, as can be seen above.

Strong-billed Woodcreeper Xiphocolaptes promeropirhynchus

Woodcreeper (Guanales) Cusuco NP 3

Strong-billed Woodcreeper- this individual was a female with a recovering brood  patch. Interestingly, P6 was also symetrically moulting , indicating a routine post-breeding moult.

Strong-billed Woodcreeper– this individual was a female with a recovering brood patch. Interestingly, P1 was also symetrically moulting , indicating the bird was starting its routine post-breeding moult.

The powerful Strong-billed Woodcreeper is one of the largest woodcreepers with a range through much of the Neotropics. It, like Olivaceous Woodcreeper, has a poorly understood taxonomy with 24 recognised sub-species (as per IOC). It has been suggested that there are likely to be three distinct radiations under Strong-billed Woodcreeper. This individual is of the form emigrans and part of the Mesoamerican group.
They are impressive beasts in the field, as this video of one devouring a Sphingidae moth shows!


Wedge-billed Woodcreeper
 
Glyphorynchus spirurus

Wedge-billed Woodcreeper, Santo Thomas, Cusuco NP

Wedge-billed Woodcreepers have a widespread distribution across the Neotropics and are represented by 14 sub-species. This juvenile is of the the Central American race pectoralis.
Acoustic variation can be considerable, as can be explored here.

Northern Barred Woodcreeper Dendrocolaptes sanctithomae

Northern Barred Woodcreeper Cusuco NP (Guanales)

Northern Barred Woodcreeper- A female with a recovering brood patch symetrically moulting P1

Northern Barred Woodcreeper– Female with recovering brood patch also symetrically moulting P1 (just visible) beginning its post-breeding moult. Photo- Joe Kingsbury

Formerly subsumed under Amazonian Barred Woodcreeper D.certhia, Northern Barred Woodcreepers have a primarily Central American distribution with Honduran birds representing the nominate form sanctithomae. They are another species known to follow ant swarms.
Northern Barred Woodcreepers have peculiar, but very distinctive vocalisations, as can be heard here.

Spotted Woodcreeper Xiphorhynchus erythropygius

Spotted Woodcreeper- juvenile with a very visible commisure. Photo- Iain Dickson

Spotted Woodcreeper- juvenile with a very visible commisure. Photo- Iain Dickson

Primarily Central American, Spotted Woodcreeper is a typical montane forest resident, its descending trills are a common sound at dawn around the forests of Cusuco. Honduran birds are represented by ssp. parvus.


Spot-crowned Woodcreeper
Lepidocolaptes affinis

Spot-crowned Woodcreeper- the thin, black malar strip is jus visible in this photo, one of the distinguishing features from the similar Streak-headed Woodcreeper

Spot-crowned Woodcreeper– the thin, black malar strip is just visible in this photo, one of the distinguishing features from the similar Streak-headed Woodcreeper.

Another typical Central American cloud-forest specialist, Spot-crowned Woodcreepers are the most frequently encountered woodcreeper in Cusuco NP and in Honduras are represented by the nominate race affinis. At lower altitudes it is replaced by the congeneric Streak-headed Woodcreeper L.souleyetii.

Tawny-winged Woodcreeper Dendrocincla anabatina

Tawny-winged Woodcreeper- ad and juv eye colour etc...

Tawny-winged Woodcreeper– adult and juvenile with interesting eye colour variation. Photo- Lynn Schofield

Tawny-winged Woodcreeper remains as something of an enigma in Cusuco, with the first documented records for the park coming during fieldwork in Summer 2012. Although work has taken place here for several years, this is not so surprising given how low detection rates of some woodcreeper species are in thick forest habitat. It is a congener of Ruddy Woodcreeper in Dendrocincla and is also known to feed at ant swarms and even follow troops of Squirrel Monkeys, feeding on fleeing insects. Honduran birds are again represented by the nominate race, anabatina.

Are you birding in the Neotropics soon or have been recently? Seen anything that might shed a bit more light on the cryptic life of a Woodcreeper sp.?
With paucities in basic knowledge such as breeding biology, casual field data can be of significance for a number of species.
If you might have overlooked Woodcreepers a bit in the past, I encourage you to look a little deeper, you never know what you might find out!

Some assorted further reading;

Brooke, M. D. L. (1983). Ecological segregation of woodcreepers (Dendrocolaptidae) in the state of Rio de Janeiro, BrasilIbis125(4), 562-567.
Irestedt, M., Fjeldså, J., Dalén, L., & Ericson, P. (2009). Convergent evolution, habitat shifts and variable diversification rates in the ovenbird-woodcreeper family (Furnariidae). BMC evolutionary biology9(1), 268. [open access]
Irestedt, M., Fjeldså, J., & Ericson, P. G. (2006). Evolution of the ovenbird‐woodcreeper assemblage (Aves: Furnariidae)‐major shifts in nest architecture and adaptive radiation. Journal of Avian Biology37(3), 260-272. [open access]
Kupriyanov, V. M. S., Daza, J. D., Bauer, A. M., Gaban-Lima, R., Rocha-Brito, G. R., & Höfling, E. (2012). Six species of Amazonian Woodcreepers (Aves: Dendrocolaptidae) preying upon lizards and frogsJournal of Natural History,46(47-48), 2985-2997.
Patten, Michael A. (2011). Olivaceous Woodcreeper (Sittasomus griseicapillus), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=359106

IOC Dendrocolaptinae:Woodcreeper radiations

Expedition research; ornithological frontiers

Back into the heart of Borneo..

by Sam Jones

Borneo hardly needs an introduction to many birders or naturalists with its enigmatic Bornean Orangutans and hoards of easily accessible endemic birds. Phylogenetically speaking, endemism has run riot across all taxa on the island and Borneo still harbours some of the worlds least studied and most sought after avian treats such as Bornean Peacock-Pheasant, Bulwer’s Pheasant, Bornean Ground-cuckoo, Black Oriole, Bornean Bristlehead, Everett’s Thrush, Dulit Frogmouth, Black-browed Babbler and four endemic Pittas amongst a host of others.

Whitehead’s Trogon– Kinabalu national park, Sabah- a sought after endemic.

It is likely, however, that the majority of prior knowledge or experience is based on the Malaysian state of Sabah- ‘the land below the wind’, where eco-tourism is a thriving trade and the states natural wonders are easily accessible. Sabah only represents one small corner of this huge island however, so what about the rest…

Mountain Litter Frog Leptobrachium montanum, Kinabalu national park, Sabah- a montane Borneo endemic

For the last year or so I have had an involvement with the Heart of Borneo Project  working on a number of pioneering research and conservation initiatives in the Murung Raya province of Central Kalimantan, Indonesian Borneo.

It takes several days of travel by river, passing rapids on old logging roads and taking gradually smaller boats to eventually work your way up the mighty Barito and then its tributaries into the centre of this magical island. It is here that the largest area of primary rainforest standing in Southeast Asia still survives. The only place in the region where tropical forest can be conserved, protected and researched at a grand scale.  Spanning three national borders (Malaysia, Brunei and Indonesia) this is coined as ‘the Heart of Borneo’.
Darwin describes Borneo as ‘one great wild untidy hothouse made by nature for herself’, probably an apt description of this beautiful, unique and threatened place.
Kalimantan makes up nearly three-quarters of the island and it is here that many areas remain, scientifically at least, unexplored, often lacking even the most basic inventory data. Primary forest here is ancient, some of the oldest in the world, and is deeply engrained in the ethnological history of this mysterious land.

Forest as far as the eye can see- from an old logging road in Central Kalimantan, Indonesia

It is one such area that I am soon leaving for, a short expedition to summit a peak known as Gunung Bondang in Murung Raya regency, Central Kalimantan, researching and documenting along the way. The peak is geographically isolated from similar habitat, an island covered in a variety of altitudinal forest types, all virgin and undisturbed. It is regarded as a sacred natural feature by the local community and has not been hunted on or logged with only a handful of small groups climbing to its summit. A ceremony is also undertaken by the local community prior to setting out to appease the spirits of the mountain. The peak rises up from its surrounding lowland forest to a height of 1347metres, its closest similar altitudinal habitat 80km away in the Muller mountain range that traverses from the NE to the SW across the island.

Perhaps most excitingly, however, it has never been zoologically surveyed; a proverbial blank canvas of scientific and ornithological potential.

I’ll be loaded up with mist-nets, recording equipment, camera gear, books to give to locals, camera traps and most importantly binoculars round my neck and a notebook in my pocket with the realisation that everything is a discovery and significant in its own right.
I don’t know what is up there, but i’ll be doing my very best to find out, with the spirit of exploration on the natural history and ornithological frontier burning as bright as ever.

Gunung Bondang– Murung Raya, Central Kalimantan

Resplendent Quetzals…

The jewel in the cloud-forests of central America..

By Sam

I never tired of waking up to the peculiar sound of comfortably one of the most striking and beautiful creatures I have ever seen. Many times in the pre-dawn gloom in the forests of Cusuco National ParkI was brought back to memories as a child, staring at pictures in my ‘Rand Mcnally Atlas of World Wildlife’. It was certainly the completion of a boyhood dream finally connecting with this fabled creature.

Resplendent Quetzal Cusuco National park, Honduras
These birds represent the nominate ssp mocinno which are slightly larger than costaricensis of Costa Rica and western Panama

Resplendent Quetzals are firmly and deservedly at the top of the worlds must-see birds list and special for so many reasons. Culturally revered throughout the Mesoamericas, the ‘god of the air’ was reputedly never killed, only trapped so that the ‘tail’ streamers could be plucked to be worn by nobility and royalty within Mesoamerican society, a use that was protected by law and penalty of death if this etherial bird was harmed.

In several Mesoamerican languages the word quetzal is synonymous in meaning for sacred or precious. It also shares an association of divinity with the Mesoamerican god Quetzacoatl which in ancient Nahuatl means plumed serpent. It is of course, not the the tail at all that grows to such extraordinary lengths, but the uppertail-coverts, the greater coverts also growing to extended lengths creating a ‘shawl’ effect across the upper wing.

Skutch (1944) describes in descriptive prose (of the male);

‘…a word picture that I wrote in my journal on April 28, 1938, when I had the living birds daily before me: “The male is a supremely lovely bird; the most beautiful, all things considered, that I have ever seen. He owes his beauty to the intensity and arresting contrast of his coloration, the resplendent sheen and glitter of his plumage, the elegance of his ornamentation, the symmetry of his form, and the noble dignity of his carriage.’

Quetzalcoatl– the ‘plumed serpent’ on part of the Codex Telleriano held at the Bibliothèque nationale de France in Paris

Quetzals are still deeply engrained in the ethnography of Central America and no more so than in Guatemala where it is the national emblem and even has the currency named after it, an example of the national value it holds, at least culturally. In bitter irony, the Quetzal in Guatemala has not fared well in recent times due to widespread degradation of its habitat primarily for coffee plantations.

Skutch (1944) again writes;

‘Later, when I came to travel in Guatemala, I found its image very much in evidence, in the medallion displayed on the walls of most of the public edifices and in the center of the blue and white banner. I even carried quetzales in my pocket and disbursed them at sundry hotels and shops; for Guatemala has named her monetary unit for her national bird, as many of the neighboring republics have named theirs for famous men. The second city of the land bears the name of this bird-Quezaltenango, the place of Quetzals- but today one searches in vain for these trogons on the wind-swept plains and through the low oak woods in the vicinity of this metropolis of the West.’
and;
‘In selecting the Quetzal as their national emblem, the Guatemalans made a more than usually felicitous choice, a creature at once native of the land itself, ornate as a design, and refreshingly different from the belligerent birds, beasts, and mythological fire-breathers that adorn the coats of arms of so many other nations. And the Quetzal, no less than the soaring eagle and the rampant lion, has its appropriate legend, to illustrate its nobility of spirit and reflect that of the people it represents.’

They are renowned for being highly stressed in captivity, suffering high mortality. Folklore dictates that the Quetzal will die of a broken heart if deprived of its freedom, a trait that gave its status as a symbol of liberty.

Resplendent Quetzal with short tail-streamers, likely a product of the heavy damage often sustained during breeding/incubating or routine post-breeding moult (Bowes and Allen, 1969; Skutch, 1944) Cusuco National park, Honduras

Quetzals are classified as ‘Near-threatened’ under the IUCN redlist (BirdLife International, 2012). Predictably, its primary threat lies in habitat destruction from illegal logging and clearing for agriculture. Cusuco National park is no exception to this rule and the land use change and habitat degradation has been evident over the last few years despite its protected status.In core areas, however, Quetzals remain not uncommon, although heard more than seen, and live in good numbers in secondary growth.
There may be light at the end of the tunnel, however, with the hard work of a dedicated team of individuals that have been involved in long term research in the park recently instigating and forcing greater action from the government to protect against illegal logging, hunting and clearing. A continued dialogue with local communities is, as ever, crucial to long-term success.

As anyone who has scoured the worlds tropical forests for Trogons will know, they are easily overlooked, perching for long periods of time before sallying to feed or moving silently through the mid and upper-storey layers of the forest. Quetzals particularly can sometimes be seen perched for long periods, ‘surveying’ the scene, turning their head slowly seemingly in curiosity or forethought. Bowes and Allen (1969) also describe the birds as sometimes orientating themselves so that the red on its underbelly would not be seen by intruders.

A Resplendent Quetzal slowly surveys its surroundings. Cusuco National park, Honduras

Perhaps this silent dignitary, a symbol of liberty and freedom surveying its habitat thoughtfully, carefully planning its next move, provides us with an example of how we as humans should conduct our habits in relation to our environment.

The Quetzal still looks on- a bastion of Central American natural and cultural heritage, in a changing and threatened land.

 

References and further reading;

BirdLife International (2012) Pharomachrus mocinno. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. <www.iucnredlist.org>. Downloaded on 27 August 2012.
Bowes, A.L. and Allen, D.G.  (1969)  Biology and conservation of the quetzal.  Biological Conservation 1(4): 297-306.
Collar, N.J., Long, A..J., Gil, P.B. and Rojo, J. (2007) Birds and People; Bonds in a timeless journey., CEMEX-Agrupacion Sierra Madre-BirdLife International, Mexico City, Mexico
Powell, G. V. N and Bjork, R. D. (1994) Implications of altitudinal migration for conservation strategies to protect tropical biodiversity: a case study of the Resplendent Quetzal Pharomacrus mocinno at Monteverde, Costa Rica. Bird Conservation International. 4:161-174
Skutch, A. F. (1944) Life history of the quetzal.  Condor. 46: 213-235

Curious Hummingbird Behavior

Washing on the wing…

by Sam

 

Hummingbirds are surely one of the world’s most fascinating, compelling and addictive avian groups, offering something to every level of birder or ornithologist. One of the new world’s most marvelous natural specialities!

Stripe-tailed Hummingbird near Santa Elena, Costa Rica by Dirk van der Made

Although they are of course ubiquitous across the neotropics, views are usually brief and observing an individual for any prolonged period of time is often difficult! I have recently been engaged in fieldwork in Honduras. During a survey at one of our lower sub-sites (ca 600masl) I had the opportunity to watch a female Stripe-tailed Hummingbird washing ‘on the wing’ in a pool of a mountain stream. Reminiscent of a Dragonfly ovipositing, dunking two or three times before flying to a perch to preen and then repeating the process.

Taking the plunge! Stripe-tailed Hummingbird dunking into the pool

…then zipping back to the perch to preen.

and again!

I’ve seen hummingbirds washing from wet leaves or drips before, but not in standing water whilst still on the wing. I’ve heard from others of similar observations of this washing behaviour but particularly in Costa Rica where apparently there is a regular site to observe large numbers of hummers doing this.

Presumably this behaviour is relatively common, just infrequently observed… It would be interesting and intriguing to hear of your similar observations!