Galapagos Flightless Cormorant. In the wake of the Beagle

One hundred and eighty-five years ago today His Majesty’s Ship Beagle weighed anchor in what is now known as Tagus Cove. She had arrived in the early evening of 30 September and Charles Darwin had spent the day ashore exploring the remarkable volcanic landscape of the island of Albemarle in the west of the Galapagos; there he also saw his first Land Iguanas.

Flightless Cormorant
Drying its short, sparse wing feathers

The waters and shoreline of Tagus Cove on the west coast of what Ecuador renamed Isabela was, when we were there in 2012 a good place to see Flightless Cormorants along with Galapagos Penguins, other birds and the ubiquitous Marine Iguana. Many tourists, even wildlife groups, do not see the cormorants because they live only on the northern half Isabela and the adjacent island of Fernandina (Narborough in Darwin’s day) to the west, and the shorter tours do not go to the landings where tourists are permitted on the west coast of Isabela.

The Flightless Cormorant is the largest cormorant and as can be seen from the photographs and video I made to show just this species, the wings are short with the feathers also reduced in size and number. It is very easy to see how flightlessness could have developed relatively recently; food inshore is abundant; there were no land predators until the arrival of feral dogs and cats; long feathery wings inhibit progress beneath the water. Under these circumstances, flight and the adaptations that go with flight would de disadvantageous. In Tagus Cove we were able to see two sea birds, one, a penguin, which became flightless over 50 million years ago, that uses its wings as flippers to ‘fly’ underwater, the other, a cormorant, which had a flying ancestor 2 million years ago, that uses its feet for propulsion.

For comparison, a Great Cormorant
(Phalacrocorax carbo)
João Manuel Lemos Lima on Wikimedia

It is not surprising that the Flightless Cormorant attracted the attention of comparative anatomists in the 19th and early 20th centuries, and now lends itself to genomic studies that try to determine the changes entailed by flightlessness, that, of course extend beyond the wing itself, in simple structural terms, to the size of the keel of the breastbone and the size of the muscles powering flight. Hans Gadow described the basic differences in 1902. In 1915 there followed a detailed description of the bones of the Flightless Cormorant in the Australian ornithological journal, Emu. It was written by an American surgeon and osteologist who appears to have been, even by the standards of the time, an odious character. Robert Wilson Shufeldt (1850-1934) achieved notoriety over his behaviour towards his second wife, the grand-daughter of John James Audubon. The whole story of how it all came to a judgement by the Supreme Court of the U.S.A. is described here. He also the author of books that promoted anti-black racial policies in that country. There is no doubt that in 2020’s parlance he would be ‘cancelled’.  However, he came to the conclusion that the Flightless Cormorant really was that, a cormorant sharing common ancestry with other living cormorants. He implied that the special genus erected for this one species, Nannopterum, was unnecessary. That conclusion, based on comparative morphology, was supported around a hundred years later by molecular phylogenetic analyses, such that our bird is usually now called Phalacrocorax harrisi. It shares a common ancestry with two extant species of the mainland americas, Double-crested Cormorant, P. auritus and the Neotropic Cormorant, P. brasilianus.

The Flightless Cormorant is found within 200 metres of the shore. Even the populations from Isabela and Fernandina, only 5 km apart at their nearest, are genetically distinct, so there is little mixing between populations, even along the shores of Isabela.

Like many of the animals of the Galapagos, Flightless Cormorants are fearless. None of us noticed for a while that one jumped onto the back of our inflatable panga and sat there ignoring the human passengers. The only reason I do not have a photograph is that it sat too near for the camera to focus. We can hardly be surprised that as recounted in my last post, Lord Moyne caught one and brought it back to London Zoo in 1932.

The population is said to fluctuate, like that of the Marine Iguana, with the El Niño-

Southern Oscillation. Once classified as ‘Endangered’, it is, with more recent estimates of population, classified by IUCN as ‘Vulnerable’. The survival of such a bird with a limited range in a specific and special habitat depends, of course, on avoiding an environmental catastrophe. If that catastrophe were to happen then we really would be in trouble.

 

Burga A, Wang W, Ben-David E, Wolf PC, Ramey, AM, Verdugo C., Lyons K, Parker PG, Kruglyak L. 2017. A genetic signature of the evolution of loss of flight in the Galapagos cormorant. Science 356 DOI: 10.1126/science.aal3345

Duffie CV, Glenn TC, Vargas FH, Parker PG. 2009. Genetic structure within and between island populations of the flightless cormorant (Phalacrocorax harrisi). Molecular Ecology 18, 2103-2111. https://doi.org/10.1111/j.1365-294X.2009.04179.x

Kennedy M, Valle CA, Spencer HG. 2009. The phylogenetic position of the Galápagos Cormorant. Molecular Phylogenetics and Evolution 53, 94-98. doi:10.1016/j.ympev.2009.06.002 

Shufeldt RW. 1915. Comparative Osteology of Harris’s Flightless Cormorant (Nannopterum harrisi). Emu 15, 86-114.

A Press Cutting from 1932: Burgess Barnett, Lord Moyne and Galapagos Marine Iguanas at London Zoo

 

This photograph I came across connects three topics I have written about before:

1. Dr Burgess Barnett shortly after taking over as Curator of Reptiles at London Zoo. I have found it difficult to find photographs of him and I will add this to the article on his life and works. The article here on Barnett, incidentally, is one of the most popular on this site.
2. Lord Moyne (Walter Edward Guinness, 1880-1944) back from an earlier expedition cruise than the one in 1934-35 in which he brought back Komodo dragons. That trip was well documented but the earlier one was not. Article can be found here.
3. Galapagos Marine Iguanas. Four collected by the Moyne Expedition being handed over to London Zoo. Article on Marine Iguanas in captivity here.

I have been unable to find find the name of the yacht Moyne used in 1932 since he seemed to have owned two at the time, both were converted passenger vehicles. My guess it was the MY Roussalka since she had tanks fitted during conversion to hold sufficient diesel fuel to cross the Pacific. Many of Moyne’s records were lost when the vessel sank after striking a rock in Killary Bay, Ireland, in 1933. That may account for the lack of information. All the passengers and crew, including Moyne, escaped.

Four Marine Iguanas were brought back by Moyne. A discussion on the ZooChat forum some time ago, notes that they were mentioned in the 1933 Zoo Guide with the statement that seaweed was brought up from Cornwall to feed them. One only was noted in 1934 and all mention had disappeared by 1935. So far I have found no description of how the Marine Iguanas were kept at the Zoo. Clearly, they did not do well, as was the case with many reptiles until the last thirty years or so.

Moyne also brought a Flightless Cormorant (Phalacrocorax or Nannopterum harrisi) and five Galapagos Doves (Zenaida galapagoensis). David Seth-Smith wrote of their arrival, the first in Britain in the case of the cormorant, in Avicultural Magazine. He provides no further information though on the expedition itself. We can though deduce that Moyne visited the west coast of Isabela (Albemarle) and/or Fernandina (Narborough) since that is the only place in the Galapagos the endemic Flightless Cormorant can be found.

Finally, a few observations in the photograph. I have not been able to identify the publication. It was obviously taken in the public area of the Reptile House—the barriers remain unchanged today. It would appear though that the fronts of some of cages were of wire mesh and not glass. The photograph has an odd appearance and only after looking at it for some time did I realise that Moyne’s hands and arms seem out of place. His right hand is grasping the lizard’s tail but the one shown apparently as the left hand seems to be coming out of thin air. Has there been some heavy retouching, or even the merging of two negatives?

Galapagos Iguana Hybrids: What about their Salt Glands?

Last week I gave a talk on salt glands to a local group. I remembered that I had not raised a question here that arises from the existence of some very odd animals on one island of the Galapagos.

Everybody knows there are the Marine Iguanas (Amblyrhynchus cristatus) and Land Iguanas (Conolophus sp.) on the Galapagos Islands. Evidence indicates they had a common ancestor about 4.5 million years ago. Watchers of television wildlife programmes cannot fail to have noticed the entirely different lifestyles. Land iguana eat plants and do not venture into the sea. By contrast, Marine Iguanas eat seaweed often foraged at considerable depths.

Over the past forty years it became evident that on one very small island, Plaza Sur, just off the east coast of Santa Cruz (Indefatigable) there were hybrids present between Marine and Land Iguanas (Conolophus subcristatus). These hybrids are sterile as one might expect. There is good evidence that their fathers are male Marine Iguanas, their mothers Land Iguanas. It seems that the breeding seasons of the two species can overlap there. The habitats are very not very far apart either, the thin vegetation where the Land Iguanas bask and feed being only a matter of yards from the rocks on which the Marines bask.

We took video and still photographs of one of these hybrids on Plaza Sur in January 1012. It was lying with Land Iguanas. Local guides say they are not very active and typically have a ‘spaced out’ look like the one below:

Hybrid Marine x Land Iguana, Plaza Sur, 12 January 2012

For comparison: Galapagos Land Iguana, Plaza Sur, 12 January 2012

Also for comparison: Galapagos Marine Iguana, Plaza Sur, 12 January 2012

Nesting burrows of Land Iguanas. Plaza Sur, 12 January 2012

Vegetation on Plaza Sur, 12 January 2012. The marine iguana-like claws of the hybrid iguanas are said to be advantageous in reaching the fruits of the prickly pear. The land iguanas have to wait for them to drop

The question I have had since then is what do the salt glands of these hybrids do? Marine Iguanas have very active salt glands which operate to remove the sodium chloride ingested during feeding. In addition, the concentration of potassium is about ten times higher than in birds which could reflect the high potassium concentration in the plants of their diet. Marine iguanas on land can be seen snorting secretion from the salt glands out of their nostrils, a phenomenon observed by Charles Darwin who did not appreciate its significance to their survival.

Other, species of iguanid lizard have salt glands that can secrete both sodium and potassium. There is evidence that the ratio can be changed by varying the diet. Lizards on a high sodium diet or given a salt load produced a secretion with a more sodium than potassium. As far as I am aware, the Land Iguanas of the Galapagos have not been studied in this respect.

The hybrids seem to live and eat like their Land mothers although I see there are anecdotal reports of their being seen eating seaweed but not entering the water to do so.

So do the hybrid iguanas on Plaza Sur have functional salt glands? How does their size compare with the Marine and the Land? If the salt gland is functional, what are the stimuli for secretion, and does the ratio of sodium:potassium change to reflect changes in the dietary intake?

Possibilities of studying the hybrids to answer these questions are low but the insights into which genes are involved in salt-gland structure and function would be fascinating outcome of this ‘natural experiment’ but biological dead end.

I  used this drawing from Bill Dunson's paper in our book on salt glands

On making a living as a naturalist and on Galapagos tortoises in the 19th Century

Archives of Natural History, the journal of the Society for the History of Natural History, always contains articles that inform and entertain. The latest issue does not disappoint.

The question of how people with an abiding interest in animals and wildlife generally found jobs that satisfied that interest when there was no career path to follow or any form of established employment in the offing has always interested me. In the late 19th and  20th centuries there were very few graduates and very few graduate jobs. Some worked up their interest and started small zoos; others worked as collectors of dead or alive specimens to satisfy the craze for natural history that gripped Victorian Britain, or as animal dealers sometimes added on to a pet shop, while others worked in publishing.

In the first paper in the latest issue Susannah Gibson has written The careering naturalists: creating career paths in natural history, 1790-1830. She describes the life of Edward Donovan (1768-1848) who carved a niche for himself as a ‘writer, artist, engraver, collector, curator and popularizer of natural history’. Donovan wrote and illustrated volumes of works on mainly British insects, birds, shells and plants. He also founded a museum in London to display his collections. He was highly successful, other than with his museum which lost money but seems eventually to have been diddled out of his earnings by the bookseller (then, as in Samuel Pepys’s time, in St Paul’s Churchyard) he had collaborated with throughout. The sums involved were, for the day, enormous at £60,000-£70,000. The only way he could attempt to get his money was through the Court of Chancery, an enormously expensive process. He tried to raise the money from his subscribers but he failed and he died with the matter unresolved.

Gibson contrasts Donovan’s career with that of George Shaw (1751-1813) who had degrees from Oxford and Edinburgh. He got a job at the Natural History Museum so could write books while being paid by the museum. By contrast, Alexander Macleay (1767-1848) became a civil servant in the Transport Office and pursued his interests as an amateur; he made an extensive collection, became Secretary of the Linnean Society, and then, when appointed Colonial Secretary in New South Wales became an important figure in Australian natural history. Money was a great problem to Macleay as well as to Donovan. They and other naturalists spent a lot of money buying specimens for their collections. In the end many collections, including those of Donovan and Macleay had to be sold in whole or in part to stave off bankruptcy. The sale of Donovan’s was by auction of close on 8000 lots over 65 days.

The second paper by Storrs Olson, The early scientific history of the Galapagos tortoises, deals with just that, up to and including the voyage of HMS Beagle in 1835. Olson takes to task those authors who have repeated the myth that the differences between the tortoises from different island contributed to Darwin’s thinking that led to the Origin of Species. He concludes (after naming the culprits in references):

Contrary to the mythology still being perpetuated today, Galapagos tortoises played almost no role in the development of Darwin’s evolutionary thinking. It would be nearly eight decades after the voyage of the Beagle before appreciation of the full extent of diversity of tortoises in the Galapagos would be revealed following the expedition of the California Academy of Sciences in 1905-1906.

Giant tortoises from the Cerro Azul population at the captive breeding centre
on Isabela (Albemarle). This form is now being treated as a separare species,
Chelonoidis vicina. 20 January 2013

Gibson S. 2017. The careering naturalists: creating career paths in natural history, 1790–1830. Archives of Natural History 44, 195-214 https://doi.org/10.3366/anh.2017.0444

Olson SL. 2017. The early scientific history of Galapagos tortoises. Archives of Natural History 44, 241-258 https://doi.org/10.3366/anh.2017.0447

Galapagos Marine Iguana: Genes and Islands

The Galapagos never cease to fascinate. New discoveries are being made all the time on the animals that live there and how they have evolved. 

Marine Iguana. Santa Fé
(Barrington) 

I watched Marine Iguanas (Amblyrhynchus cristatus) for hours when we there in 2012: lekking behaviour, males fighting, mating, salt glands in action, feeding on algae, and just sitting around on rocks in large numbers.

Marine Iguanas vary in appearance between the islands and those with an obsession for artificial pigeonholes have created subspecies accordingly. I shall ignore those dated divisions and concentrate on a recent paper* in which mitochondrial and nuclear DNA sequences have been used to investigate the population genetic structure.

This paper has highlighted the tendency towards the splitting into different species—speciation—and the hybridization between lineages that tends to wipe out that tendency. While the split between the Galapagos Land Iguanas and the Marine Iguana was calculated to have occurred 4.5 million years ago, division into genetic lineages in the Marine Iguana was found to be very recent—within the last 50,000 years.

As well as differences between islands, different lineages were even found on one island: San Cristobal or Chatham as it was known in Darwin’s day, and to some of us still is. It is presumed that volcanic events, with their huge lava fields divided the populations at some stage; there was a major eruption 1800-3000 years ago which reduced the population and produced a severe bottleneck in both lineages. What is surprising is that migration and hybridization between these two populations, termed LO (for Lobería in the south-west of the island) and PP (for Punta Pitt in the north-east) was uncommon despite there being only 12 km of coastline between them. However, evidence was obtained for hybridization of both LO and PP lineages with animals from other islands rather than the adjacent population. Indeed, migrants were found from Santa Cruz (Indefatigable) and Espaniola (Hood) during the collection of samples. Therefore, introgression of genes from other populations acts to oppose the isolation that would tend towards speciation.

Marine iguana population clusters and phylogenetic relationships. (a) Map of the Galápagos archipelago with major islands colour-coded according to their marine iguana population cluster assignment inferred from structure analysis of 614 individuals genotyped for 12 microsatellite loci (vertical panel in (b)). (b) Species tree cloudogram based on an analysis of 6257 RADSeq-derived SNPs in 33 marine iguanas from across the archipelago, including both San Cristóbal lineages. The graph shows the posterior distribution of consensus trees. Asterisks mark nodes with posterior probability = 1.0 (all other nodes less than 0.9). Specimens were grouped according to population assignment based on structure analysis. From MacLeod et al. 2015

Genetic and morphological differentiation of LO and PP lineages on San Cristóbal Island. LO-SRL and PP-SRPC refer to the original Lobería and Punta Pitt localities, photos show adult LO and PP males. (a) Assignment of 454 individuals based on 18 microsatellite loci, after exclusion of inter-island hybrids and migrants. Abbreviations show sampling locations and 1993 marks specimens sampled in that year. (b) Haplotype network of control region sequences (mtDNA) for LO and PP specimens. (c) Map of sampling localities; arrows indicate migrants/hybrids from Santa Cruz (green), Española (orange) and Lobería (blue); dagger symbols denote locations of within-island hybrids between PP and LO; triangles denote locations of inter-island hybrids. Population SRECA contains Española migrants/hybrids only. Shaded areas mark lava groups 4–6 aged less than 0.1 Ma [40]. (c) Mean, standard deviation and range of morphological variables differing between LO and PP. ***p < 0.001, **p < 0.01, *p < 0.05; sample sizes above each plot, details and abbreviations in Results and electronic supplementary material. From MacLeod et al. 2015

There are differences in size between lineages, PP for example, being smaller than LO, but I will leave consideration of the significance of that and to what happens during El Niño oscillations, when food in the form of algae is short and the populations of Marine Iguana crash, to another time.

We only visited the south of Cristobal, so saw just those of the LO lineage. The question then, of course, is: which ones did Darwin see when he collected on Chatham (named, like Punta Pitt, after William Pitt the Elder, 1st Earl of Chatham, 1708-1778)? LO, certainly, in the south where there are groups of iguanas around Cerro Brujo, for example, but it is likely that he also saw PP, since some of his landing and collection points were well to the north and within the PP lineage’s range^†.

The photographs shows Marine Iguanas from some of the islands we visited:

Española (Hood)

South Plaza

Isabella (Albemarle)

Fernandina (Narborough)

The extent of the lava fields can be seen in this photograph taken on Isabella between from near Darwin Volcano to the south east:

A close-up of the lava on Santiago (James):

…and these are three videos, all taken on a wonderful morning on Fernandina (Narborough):

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*MacLeod A, Rodríguez A, Vences M, Orazco-terWengel P, García C, Reillmich F, Gentile G, Caccone A, Quezada G, Steinfartz S. Hybridization masks speciation in the evolutionary history of the Galapagos marine iguana. Proceedings of the Royal Society. B 282, 20150425.

†Estes G, Grant KT, Grant PR. 2000. Darwin in Galapagos: his footsteps through the archipelago. Notes and Records of the Royal Society of London 54, 343-368.

Galapagos: Does the Charles Darwin Foundation have a future?

There may be more between the lines to the story that has hit the newspapers these past few weeks on the threatened closure of the Charles Darwin Foundation in the Galapagos. It was obvious when we visited as tourists in 2012 that the premises in Puerto Ayora were in a poor physical state. The tortoise breeding facilities were not so impressive as those on other islands and we felt that visitors were tolerated rather than welcomed.

The proximate cause of the financial collapse is reported as being the closure by the local authorities of the gift shop that was opened by the Foundation to secure an element of reliable income. The local souvenir shops that line the road to the Foundation’s premises apparently objected to the opening of what they saw as a rival business. The fact that the local shops would lose virtually all of their trade if the Foundation closed down seems not to have entered the minds of their proprietors. The road lined by souvenir shops only leads to the Foundation.

This road in Puerto Ayora leads to the Charles Darwin Foundation

There have been many reports over the years of clashes between local inhabitants and immigrants from the mainland on the one side and the conservation agencies on the other. Where the Ecuadorian government and its agencies lie in all this is not clear. The Foundation itself, in terms of activities, has the scientifically unglamorous but important role in trying to eliminate invasive species and in trying to prevent the extinction of the Mangrove Finch, for example. Having looked at the accounts for 2012 (the latest available) it is evident that grants from charities are insufficient to do very much, let alone improve or even save the physical infrastructure.

In terms of the organisation of science and conservation it is also clear that the one essential is core funding and even if a deal is stitched together to keep the Foundation going, only substantial core funding will attract charitable project funding from North America, Europe and Japan. On that note I see that the Foundation has made an urgent appeal:

Running an independent scientific research station in a remote place like Galapagos, now costs upward of $3 million annually.  50% of our annual budget comes from successful funding proposals, supported by international donors. However, indirect costs such as preserving our world famous collections and running our research station account for 50% of our annual budget. The increasing difficulty in funding for ongoing indirect costs, could bring CDF to breaking point very soon.

The only point I would disagree on is the amount; $3 million dollars is not enough. My guess is that $6 million per annum is needed, with $3 million as core funding.

So who should provide the infrastructure for conservation and research in the Galapagos. Well, I am afraid to say that it should be the government of Ecuador. The tourist industry in the Galapagos is vast and a small percentage of that tourist income would put conservation on a firm footing. The government already controls, in a probably necessarily authoritarian manner, access to defined sites and one has to ask the question of how important the government sees the work of the Charles Darwin Foundation. Sadly, I suspect, the government sees the Galapagos mainly as a tourist destination with animal attractions. That is how the Galapagos are marketed in the USA by travel agents and one only has to walk along the road in Puerto Ayora to realise that a lot of tourists arrive expecting simply a beach and water sports resort. The marine iguanas that disport themselves along the edges of the road come as a revelation to many and as a shock to some. Puerto Ayora is a great place for people watching and overhearing.

All those involved in supporting the Foundation are agreed that it would be a tragedy if the organisation were to founder and for its role to disappear.

Finally, a press release of 25 November states:

The General Assembly saw strong participation and support from a large number of Government entities: Galapagos National Park Directorate, Ministry of Environment, Technical Secretariat for International Cooperation (SETECI), Ministry for Foreign Relations, Provincial Government of Galapagos, Ministry of Agriculture. 

At the meeting, it was agreed that the CDF is to form a work group with several governmental entities working towards 2016, which is the year that the current contract between CDF and the Government needs to be reviewed. This committee will then start a dialogue to strengthen the longer-term cooperation between the CDF and the government, and to strategically secure the operation of the research station. 

The Foundation has been identified by the Government as essential for Ecuador. There is a need and a desire to further strengthen the collaboration between the CDF and the Government, e.g. with regards to proposing major initiatives to international funding sources; and linking Ecuadorian research initiatives. 

The Director of the Park made the following statement: “We need the Foundation. We need the link to the scientific community that provides us with first class scientific advice. We thank you for that.” 

The Board of the CDF is in permanent dialogue with the Municipality of Santa Cruz to find a mutually beneficial solution for the souvenir store of the CDRS. 

The General Assembly reconfirmed that the Charles Darwin Research Station has to remain open and in operation. The focus of the Board, the Executive Director and the entire team is to find a solution for the short-term financial difficulties. Today's General Assembly did not bring an immediate solution to these problems, but progress was made towards carrying out successful fundraising activities in the very foreseeable future.

The world is holding its breath and hoping that unlike its famous inhabitant, Lonesome George, the Charles Darwin Foundation not only survives but thrives.

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Conservation of the Land Iguana was one of the early success stories of the Foundation: