What’s Next for Academic Ornithology?

Want to know how studying microorganisms relates to studying adaptive radiation, and evolution in selected traits like color and morphology in birds like this White-winged Crossbill?  Sexual selection is well studied in a host of bird species, but the genetics of sexual selection have yet to be worked out.  Gavin Leighton has brought us yet another great piece on where ornithology may be headed in the near future.  Read on and keep an open mind (White-winged Crossbill, Provincetown, MA, December 2012).

By Gavin M. Leighton

There’s no hiding it anymore: the major academic ornithological societies, e.g. The American Ornithological Union, The Wilson Ornithological Society, The Cooper Ornithological Society, and smaller raptor groups, are facing declining membership numbers and reduced revenues.  These groups are currently in the midst of talks about forming a singular society so as to pool resources and reduce inefficiencies due to overlapping functions.  Importantly, the decline in the groups also reflects a similar, though less drastic, proportion of research biologists performing research on natural populations.  While species such as the Darwin’s Finches continue to receive much press, the fields of evolutionary biology and behavioral ecology have diversified into new groups. 

This diversification is welcome; we can test overarching biological principles in more species and some of the new work is done on species that are amenable to controlled studies in labs.  Therefore, the appropriate response of academic ornithologists is not to resent the burgeoning work on species such as Dictyostelium discoideum; rather, academic ornithologists should turn their attention to the genetic and mutational techniques that have been developed in the microbial and agricultural worlds.  The DNA sequencing technology now available to researchers is staggering; we can sequence billions of base pairs of DNA in less than a few days.  Other groups of researchers have used this data to characterize soil meta-communities, identify mutations in agricultural crops, and delimit the mutations associated with coat color in some mouse species. 

ABI Prism 3100 Genetic Analyzer – we have the technology... (Photo from Wikipedia)

Not only are these techniques providing truck-loads of data, they are also being refined by the researchers performing the techniques.  The researchers have worked out most of the kinks associated with common next-generation sequencing technology thus delivering to ornithological researchers a massive opportunity that should not, and can not, be wasted.  The reasons that first attracted researchers to studying birds are the same reasons that should be used to create a mini-rebirth in academic ornithology. 

For instance, the biological community has gravitated towards studying sexual selection in birds because of the wealth of color traits and behavioral traits that are supposedly due to sexual selection.  As referenced before, Darwin’s finches are a classic example of species radiation (as an aside, Darwin didn’t even realize the finches were all finches until he had an ornithologist friend examine the specimens), and a considerable number of bird species are studied because of their cooperative breeding behaviors. 

Until recently, serious genetic studies could only be conducted on “model” species that were both reared in labs and also had their genome sequenced and published.  Now, a host of enzymatic digestion and sequencing allow researchers to discover large swaths of the genome at a time.  And in some cases, these DNA sequences can be mapped onto the genome of a closely related species; for example, individuals working on Darwin’s finches could map sequences onto the genome of the zebra finch.

What does all this mean? First, we can begin to understand the genetic architecture that underlies the variety of bird colors we see.  We would be able to compare tanagers and Northern Cardinals to see if selection produced red feather color along similar molecular pathways.  We will be able to delimit the genes that underlie behaviors like cooperative breeding, whereby some individuals give up the opportunity to breed elsewhere and instead help raise their siblings or half-sibs. 

Is red feather pigment selected for along the same or similar molecular pathways in all species?  Is bill morphology in Red Crossbill types selected for along similar pathways as bill morphologies in Darwin's finches?  (Red Crossbill, Provincetown, MA, December 2012)

Once we define these genes that are correlated with certain morphological or behavioral traits, it won’t be long before researchers can insert mutations or new forms of a gene into wild individuals using vectors such as viruses.  Field experimentation/validation is considered the holy grail of field biologists, and in the near future ornithologists will be able to perform the studies that conclusively show that certain genes are responsible for certain traits.  Once we understand which genes control which traits, we can follow those genes over time and track evolution in real time in animal species. 

In total, the depth and breadth of our understanding of the natural world will grow exponentially.  The only necessary step is for ornithologists to catch-up with the technology that is coming online.  Regrettably, many ornithologists are only familiar with the new techniques, but hesitant to dive into the new world of next-generation sequencing.  This is disconcerting as the potential data that could be collected and analyzed on bird species would firmly entrench ornithology as a relevant and exciting field of biology.  Indeed, there is no reason why the bird traits that have drawn both researchers and the public to birds in the past, can’t be studied and understood using the new technology we have now.  Importantly, if academic ornithologists do take advantage of the opportunities presented by new sequencing technology, then we could reverse declining membership in bird societies and potentially engender a new renaissance in birding.

Gavin is a PhD candiate at the University of Miami studying cooperative behavior in Sociable Weavers.  To learn more about Gavin, see our Guest Writers page.

We at BoomCha are excited and hopeful to hear from you.  Please comment on this post with your thoughts, concerns, and opinions on Gavin's piece.

Socializing with Socaible Weavers

Adult sociable weaver.  Sex can't be identified in the field and we have to use genetics to identify the sex of the weavers.[Photo by Gavin Leighton]

Avian biology and behavior have contributed much to our understanding of social behaviors.  The natural world is rife with prosocial behaviors, despite the tendency for natural selection to promote selfish individuals. An especially intriguing case of cooperative behavior is displayed by Sociable Weavers (Philetairus socius).  These small birds (~30g) live in semi-arid savannah in southwestern Africa; but what sets these small passerines apart is that they live in colonies that build and maintain perennial, communal nests (See below). Interestingly, several other species of birds such as Pygmy Falcons, Rosy-faced Lovebirds, and Scaly-feathered Finches have been known to roost in the empty chambers of Sociable Weaver nests. 

Sociable weaver colony.  At the colony we trapped 108 birds. [Photo by Gavin Leighton]

The communal nest also presents an opportunity to understand the evolution of cooperative behaviors that maintain communal goods.  Theoretically, Sociable Weavers that exploit the nest-building behavior of other weavers should be selectively favored, therefore increasing selfishness.  In contrast, such selfishness is avoided, and I am interested in delimiting the evolutionary mechanisms that maintain cooperative nest construction in Sociable Weavers.

These are two rosy-faced lovebirds, one of the species of parrots in Namibia.  Common in the Khomas region, they are known to hang around sociable weaver nests and in some cases even roost in the chambers of a sociable weaver nest. [Photo by Gavin Leighton]

One possible mechanism that may maintain cooperative nest construction is kin selection.  Kin selection supports cooperative behaviors by allowing cooperative individuals to spread their genes by helping relatives reproduce, who share genes with the actor due to common ancestry.  To delineate the relatedness of Sociable Weaver colonies, I recently visited Namibia to collect blood samples from Sociable Weavers.  The weavers are trapped en masse in the morning and it often requires multiple individuals to quickly remove all the birds.  I removed blood from the trapped individuals and will be performing genetic analyses to see if the nests are composed of extended family groups. 

To complete the work, I was helped by multiple individuals from the local city.  Most of the individuals that helped with the projects were Namibian ornithologists in the region, and most of these individuals are birders by passion and have a career in a field other than avian biology.  This is probably the most salient difference between birders in the US and Namibia.  In the US, most bird banding is conducted at designated banding stations, whereas in Namibia banding is performed by a dedicated group of individuals who band on the weekends and in back yards.

Ostrich.  The red on the lower shins is indicative that this individual is in breeding condition. [Photo by Gavin Leighton]

Such banding is critical to the success of Namibian ornithology, as there are no dedicated banding stations or dedicated ornithologists at the universities.  Due to the lack of research in the country, much of the bird life in the region is still shrouded in mystery.  As an example, Ludwig’s bustard is endemic to the region, but only one individual has ever been banded, and its behavior and breeding tendencies are almost completely unknown.  The landscape is entirely wide open, and the density of birds reflects the pristine habitat; in one day we found a nest of Secretary Birds 200 meters away from a nest of Lappet-faced Vultures.  Namibia also offers diverse habitats for birds and birders; from coastal regions to two deserts, birds of all types inhabit the land of Namibia.   

Yellow Canary. [Photo by Gavin Leighton]

Purple-cheeked waxbill.  Common in the region. [Photo by Gavin Leighton]

Scaly-feathered finch.  Like Rosy-faced lovebirds, Scale-feathered finches are known to join sociable weaver feeding flocks and are also reported to roost in the chambers of sociable weaver nests. [Photo by Gavin Leighton]

 

By Gavin Leighton