First Bugs of Spring!

We had our first day above 40 degrees since February 7, and our first day with above-average temps since February 11th. A midday hike at Van Patten Woods Forest Preserve produced one of these guys:

Diplocladius cultriger, 3/6/2012, Illinois Beach State Park

Well, maybe not this species -- today's wouldn't hold still long enough for a photo, and midges are difficult enough to ID with a good close look. On the other hand, the date's about right (this species appears to be an early riser, so to speak), so Diplocladius is probably as good a guess as any.

Most of the papers I can find on these guys are simple descriptive or taxonomic works (1) , but midges are so ubiquitous that they occasionally prove useful for more theoretical work. For instance, Broderson & Lindegaard used subfossil chironomids to examine the history of shallow lakes in the Netherlands. (2)

In an echo of my last post, Krosch & Cranston used chironomids to test the Gondwanan vicariance model of biogeography. (3) They were basically refining earlier work on dates of speciation and rates of evolution, and for the most part they confirmed that this group fits the vicariance model quite well. (Midges are very small and not very long-lived. They don't handle salt water well. Overall, it hardly seems surprising that they'd be poor candidates for long-distance dispersal events. Having said that, other truly surprising dispersals have been documented, so this wasn't a sure thing.) But they also found an oddity with regards to New Zealand. Speciation events seem to put the last colonization of New Zealand after its separation from Gondwana (favoring a dispersal scenario) but before the proposed "drowning" of the islands. If true, that would strongly suggest that the drowning wasn't complete, although the authors propose other possibilities as well.

Lofty thoughts, I think, over such a humble little critter.

(1) Saether, O. A. (1973). Four species of Bryophaenocladius Thien., with notes on other Orthocladiinae (Diptera: Chironomidae). The Canadian Entomologist, 105(01), 51-60.

(2) Brodersen, K. P., & Lindegaard, C. (1997). Significance of subfossile chironomid remains in classification of shallow lakes. In Shallow Lakes’ 95 (pp. 125-132). Springer Netherlands.

 

(3) Krosch, M., & Cranston, P. S. (2013). Not drowning,(hand) waving? Molecular phylogenetics, biogeography and evolutionary tempo of the ‘Gondwanan’midge Stictocladius Edwards (Diptera: Chironomidae). Molecular phylogenetics and evolution, 68(3), 595-603.

A Rare Sight on a Snowy Afternoon

This little beauty showed up in downstate Quincy, IL last week:

Ivory Gull (Pagophila eburnea),
Quincy, IL 1/5/2015

This is an adult Ivory Gull (Pagophila eburnea). It's an arctic bird, normally spending the winter on the ocean north of Alaska over to Labrador! Every once in a while, one wanders south to delight all the birders within reach. (Which includes a good bit of the continent, for a bird like this!)

I didn't put his picture up just to brag, of course. His arrival here is a very small data point in a rather large argument in the field of biogeography. Namely, is the distribution of living things largely the result of continental drift and evolution within those continents (vicariance) or the result of rare, random occurrences of long-distance travel, followed by evolutionary radiations within the new location (dispersal).

Here's some poster children for the vicariance argument:



Ostrich (Struthio camelus)
Brookfield Zoo, 1/10/2012

Double-wattled Cassowary (Casuarius casuarius),
Nashville Zoo, 3/29/13

Emu (Dromaius novaehollandiae),
Cheyenne Mt. Zoo, Colorado Springs,
12/27/2013
 

These 3 species are all ratites, or large, flightless birds with no keel on the breastbone. The Ostrich is, of course, from Africa, the Emu from Australia, and the Cassowary from Australia and New Guinea. (Well, these individuals are all from zoos here in the US, but you get the idea.) 2 more species, the Rheas, hail from South America. All of these continents were united into the supercontinent Gondwana, which started to split around 185 million years ago, after separating from Laurasia to the north. Many species seem to share the generally southern distribution that indicates that they likely radiated from a Gondwanan origin.




Here's another example:

Rock Wallaby, (Petrogale concinna), Omaha Zoo, 12/30/2011

This is a Rock Wallaby (Petrogale concinna), from Australia. Everyone with a passing interest in mammals knows that Australia is the home of the marsupials. Turns out, though, that South America has quite a few of them as well, namely various species of Opossum. Several have moved north into Central America, and one (the Virgina Opposum, Didelphis virginiana) has colonized most of North America. We still see that southern distribution that indicates a Gondwanan background.

And then there's this guy:

Callimico, (Callimico goeldii),
Milwaukee County Zoo, 3/30/2007

This is a Callimico, or Goeldi's Monkey (Callimico goeldii). It's small, and like many relatives, it's found exclusively in South America. Given that Africa is the center of primate diversity, with additional species found throughout southern Asia, seems like a clear cut example of vicariance -- again we see the Gondwanan distribution. But.....

 

The earliest primate fossils anywhere date to less than 55 million years old, and the best molecular evidence for the split between the African monkeys and the S. American monkeys indicates an origin for the group at 40 million years ago. By that point, the south Atlantic had already opened, which means that those early monkeys would have had to take a long raft trip just to reach S. America! The total lack of earlier primate fossils in South America also supports this idea.

And this is where that Ivory Gull comes in. Opponents of dispersal ideas in biogeography make much of the fact that you can't possibly predict rare events in particular, which makes them very hard to test. How did that species get there? If we're allowed to postulate a one in a million raft journey, then we can explain anything, right?

The problem with that argument, of course, is that when you have billions or trillions of individual animals, plants, etc., composing millions of species, million to one events are going to be commonplace when we look at the Earth as a whole. I find it very hard to be critical of the dispersal ideas when we can demonstrate historical examples of just those sorts of events. This gull isn't likely to stick around and breed (for one thing, finding a mate would be very, very difficult), but with only three records in Illinois history (and only this one for Missouri) it's clearly a rare event.

While we can't predict where and when the next rare event will happen, we can make pretty good estimates on how many will occur in a given time frame, and those predictions can be tested. We can also look at mechanisms of dispersal, and how the biology of different groups should impact their likelihood of establishing themselves once they end up somewhere new, thus allowing for more predictions. For instance, birds that travel in flocks should be more likely to spread over long distances than species that travel alone, since loners aren't likely to find a mate in a new spot. So, finches on oceanic islands, yes. Woodpeckers, no. (That particular prediction holds up quite nicely, by the way.) We can also use birder's observations of rare vagrants to build up our estimates of rates of dispersal events, which can only help biogeographers add to our knowledge of the long history of life on this small blue planet.

This argument is developed more fully and much more clearly in The Monkey's Voyage by Alan de Queiroz.

Three Little Wasps

Here's a trio of neat little wasps:

Netelia sp, IBSP, Lake County, IL 11/1/14

This one's Netelia sp., in the family Ichneumonidae.

Gasteruption sp, Grant Woods FP,
Lake County, IL 7/9/14

This one's Gasteruption sp., in the family Gasteruptiidae.

Proctotrupes sp, IBSP, Lake County, IL 10/24/14

And this is Proctotrupes sp., in the family Proctotrupidae.

If you noticed that none of them are ID'd to species, well, that's what I get for looking at such unassuming little critters. They're very hard to identify beyond genus, usually requiring dissection at some point. This difficulty isn't, though, from a lack of effort on researcher's parts. If you search for papers on these three genera, you'll find plenty of taxonomic and descriptive work. What you won't find much of is theoretical work.

A couple of articles of some interest beyond the taxonomic one include Gokhman & Ãîõìàí's work on chromosomal evolution. (1) What they found, to my eyes, is that while it is possible to trace the evolution of karyotypes in this order (Hymenoptera, that is), evolution at this level is probably too fast for working out higher-level taxonomies. (The second name above is my computer's desperate attempt to render Cyrillic -- try searching for Gokhman on Google Scholar if you want to see it properly.)

Another, by Broad & Quicke, looked at echolocation in parasitoid wasps -- which all three of our critters here are. Apparently by tapping on old logs, tree trunks, etc., the wasps can find caterpillars, beetle grubs, and the like hanging out in the wood, and even estimate how deep they are (2) -- another example of a simply physical problem being solved repeatedly in different lineages.

(1) Gokhman, V. E., & Ãîõìàí, Â. Å. (2011). Morphotypes of chromosome sets and pathways of karyotype evolution of parasitic Hymenoptera Ìîðôîëîãè÷ åñêèå òèïû õðîìîñîìíûõ íàáîðîâ è íàïðàâëåíèÿ ýâîëþöèè êàðèîòèïà ïàðàçèòè÷ åñêèõ ïåðåïîí÷ àòîêðûëûõ (Hymenoptera).

 

(2) Broad, G. R., & Quicke, D. L. (2000). The adaptive significance of host location by vibrational sounding in parasitoid wasps. Proceedings of the Royal Society of London. Series B: Biological Sciences, 267(1460), 2403-2409.

A Proper Mink Coat

This little guy seemed remarkably unconcerned about my presence this afternoon:

This is an American Mink (Neovison vison), a rather large member of the weasel family. He was hunting the rocks along the side of N. Pt. Marina, hoping to find some mice for dinner.

This is the same species that mink coats are made of, and these days they are intensively farmed for their fur. Here in the US and in Canada, this is a cause for concern, since domesticated mink are genetically distinct from wild ones by now. When they escape, some are able to survive, and can dilute the gene pools of wild mink in the area. (1)

In Europe, this is even more of a concern -- in addition to farm escapes, wild mink have been released in a number of countries as a source of fur. As they are semiaquatic predators, it isn't surprising that they've been implicated in declines of muskrats, at least in Poland. (2) (Muskrats are a favored food in their native range as well.) These days, mink control programs are common throughout Europe, (3)  but they are hampered by continuing escapes of domesticated mink. (4)

There does appear to be some hope in this regard, though. Some island populations have actually been eradicated, in part through careful consideration of how the mink respond to trapping pressure. (5) Modelling efforts suggest that eradication may even be possible in some mainland populations. (3)

Of course, my little model is a native mink, and there's no pressure at all to get rid of him. Which means he's still free to consider me a curiosity:

(1) Kidd, A. G., Bowman, J., Lesbarreres, D., & SCHULTE‐HOSTEDDE, A. I. (2009). Hybridization between escaped domestic and wild American mink (Neovison vison). Molecular Ecology, 18(6), 1175-1186.

 

(2) Brzeziński, M., Romanowski, J., Żmihorski, M., & Karpowicz, K. (2010). Muskrat (Ondatra zibethicus) decline after the expansion of American mink (Neovison vison) in Poland. European journal of wildlife research, 56(3), 341-348.

 

(3) Zabala, J., Zuberogoitia, I., & González-Oreja, J. A. (2010). Estimating costs and outcomes of invasive American mink (Neovison vison) management in continental areas: a framework for evidence based control and eradication. Biological invasions, 12(9), 2999-3012.

 

(4) Zalewski, A., Michalska-Parda, A., Bartoszewicz, M., Kozakiewicz, M., & Brzeziński, M. (2010). Multiple introductions determine the genetic structure of an invasive species population: American mink< i> Neovison vison</i> in Poland. Biological Conservation, 143(6), 1355-1363.

 

(5) Bodey, T. W., Bearhop, S., Roy, S. S., Newton, J., & McDonald, R. A. (2010). Behavioural responses of invasive American mink Neovison vison to an eradication campaign, revealed by stable isotope analysis. Journal of applied ecology, 47(1), 114-120.

 

(6) Zalewski, A., Michalska‐Parda, A., Ratkiewicz, M., Kozakiewicz, M., Bartoszewicz, M., & Brzeziński, M. (2011). High mitochondrial DNA diversity of an introduced alien carnivore: comparison of feral and ranch American mink Neovison vison in Poland. Diversity and Distributions, 17(4), 757-768.

 

 

Aquatic Beauties

 Here's a little beauty:

This is a Fragrant Water Lily, Nymphaea odorata. It's one of  approximately 36 species in the genus, itself one of 7 or 8 genera in the family Nymphaeaceae. According to the Flora of North America website, this is one of 9 species of Nymphaea that occur in North America.

The entire family is often referred to as water-lilies, of course, since they are entirely aquatic. They grow rooted to the bottom of ponds and slow rivers, with leaves submerged, emergent, or floating on the surface. The flowers are raised above the surface to some degree, as seen here:

In addition to their beauty, and their ecological importance in warm wetland areas, water lilies are of interest to botanists because of their taxonomic position. They are generally thought of as the second most basal group of angiosperms, branching off from the other flowering plants just after Amborella did so. A recent paper, however, argues that Amborella is the sister group of a Nymphaeaceae - Hydatellaceae clade. (Hydatellaceae is a small family of minute aquatic plants.) This means that the water lilies are direct descendants of that first branch off the flowering plants, basal to all of the other angiosperms.

Water lilies and Hydatellaceae are aquatic plants, but Amborella is a land plant, as are most of the angiosperms. So: were the original angiosperms aquatic, with Amborella climbing onto land, or were they terrestrial, with the water lilies aquatic preference evolving after that next split?

In a similar vein, Amborella has vascular tissue that is missing certain elements normally found in angiosperms (one reason why they've been considered a basal group). But if they're in a clade with two or three other families that do have that tissue, did they somehow lose those elements? Or is this an interesting case of convergent evolution between the Nymphaeaceae and the rest of the angiosperms?

The Evolutionary Root of Flowering Plants. Vadim V. Goremykin, Svetlana V. Nikiforova, Patrick J. Biggs, Bojian Zhong, Peter Delange, William Martin, Stefan Woetzel, Robin A. Atherton, Patricia A. Mclenachan, and Peter J. Lockhart. Syst Biol (2013) 62 (1): 50-61 first published online July 31, 2012 doi:10.1093/sysbio/sys070

Salt-water Musicians?

Here's a critter from deep in the archives (if not so deep in the sea).

This is a Brown Guitarfish (Rhinobatos schlegelii), from the Denver Aquarium. While he looks like a cross between a stingray and a shark, he's actually considered to be in the family Rhinobatidae, in the Order Rajiformes. (That is, he's a ray, but closer to the skates than the stingrays.) He's found in the western Pacific, from Korea to Australia. 1 There are 50 species of these guys, found throughout the warmer oceans of the world. 2  Mostly they hang out in shallow coastal waters, eating snails, clams, and other bottom-dwellers.

I haven't had much luck finding studies that focused on this one, although Fishbase does state that it's a fine eating species, but other species, such as the Common Guitarfish (R. rhinobatos) from the Eastern Atlantic and Mediterannean, and the Shovelnose Guitarfish (R. productus) from the west coast of the US and Mexico, are quite well-studied, from distributions to reproductive biology 3,4,5,6 to genetic variation. 7

That last study found something quite interesting to my mind -- unrecognized genetic differentiation between fish from the west coast of Baja California and those from the Gulf of California just to the east. The authors didn't go so far as to claim the two forms were separate species, but they did point out that this sort of variation should be a concern when we're contemplating conservation or management measures. This species isn't endangered, but several others are, including the Common Guitarfish. (Brown and Shovelnose are listed as data-deficient by the IUCN).8

While the Brown and Shovelnose aren't considered endangered, they are both heavily fished, so all of this study, including the ongoing taxonomic work, are very important, if we want to keep them around.


1) http://www.fishbase.org/summary/Rhinobatos-schlegelii.html

2) http://en.wikipedia.org/wiki/Guitarfish

3) Enajjar, S., Bradai, M. N., & Bouain, A. (2008). New data on the reproductive biology of the common guitarfish of the Gulf of Gabes (southern Tunisia, central Mediterranean). Journal of the Marine Biological Association of the UK, 88(05), 1063-1068.

4) Ismen, A., Yıgın, C., & Ismen, P. (2007). Age, growth, reproductive biology and feed of the common guitarfish (< i> Rhinobatos rhinobatos</i> Linnaeus, 1758) in İskenderun Bay, the eastern Mediterranean Sea. Fisheries Research, 84(2), 263-269.

 

5) Abdel-Aziz, S. H., Khalil, A. N., & Abdel-Maguid, S. A. (1993). Reproductive cycle of the common guitarfish, Rhinobatos rhinobatos (Linnaeus, 1758), in Alexandria waters, Mediterranean Sea. Marine and Freshwater Research, 44(3), 507-517.

 

6) Sandoval-Castillo, J., Rocha-Olivares, A., Villavicencio-Garayzar, C., & Balart, E. (2004). Cryptic isolation of Gulf of California shovelnose guitarfish evidenced by mitochondrial DNA. Marine Biology, 145(5), 983-988.

 

7) Márquez-Farías, J. F. (2007). Reproductive biology of shovelnose guitarfish Rhinobatos productus from the eastern Gulf of California México. Marine biology, 151(4), 1445-1454.

8) The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 16 October 2014.

(Nearly) Lost Wanderers

Early October, and soon we'll be seeing the last of these guys winging their way past the watch:

This is a Peregrine Falcon (Falco peregrinus). The name literally means wanderer, and it's appropriate. They live on every continent except Antarctica, and routinely show up in Hawaii.

There was a time, however, when this would have been an exceptional sight here in Illinois:

Starting after World War II, the US started using DDT to control mosquitoes and other insects. We used a lot of it, much of it for agricultural purposes. We didn't realize, though, that it bioaccumulates, (in other words, the higher trophic level you feed on, the more you absorb) especially in aquatic systems. Neither did we recognize that in larger doses it has serious impacts on calcium metabolism in birds.

Peregrines feed largely on ducks and shorebirds. (Well, today a lot of them feed on pigeons, but that's a rather new development.) That puts them squarely in a high trophic level, at the top of an aquatic system. So it's no surprise that they got doses more than high enough to disrupt calcium uptake. This is especially important for birds, since their eggshells are primarily made up of calcium. In the case of Peregrines, in the eastern US, eggs became so fragile that the females couldn't successfully incubate them. And by the early 1970's, Peregrines were no longer found east of the Mississippi.

After DDT was banned in the US in 1972, several of the most heavily impacted birds began to rebound. (Osprey, Bald Eagles, Brown Pelicans). But there weren't any Peregrines left to start a recovery. Into this gap stepped the folks at the Peregrine Fund. They raised a bunch of money, began to acquire Peregrines from elsewhere, and then learned how to successfully reintroduce them. As a result, they were removed from the US Endangered Species List in 1999.

But where did they come from? Therein lies an interesting debate on the nature of subspecies and the authenticity of our natural history.

The eastern anatum was gone -- there were a few pairs breeding in easternmost Canada that appeared to have been anatum, and that was it. Out west, they were still hanging on in scattered locations. So, what to do? Try to catch a few of the Canadian birds (which might have unfortunate effects on the one wild population left), or bring some western birds east?

Or you could try what the Peregrine Fund actually did -- bring in birds from all over the world, and rely on natural selection to sort out a new subspecies that would be well-suited to this new environment. (And a new environment it is -- many of the original nesting areas have become unsuitable, whereas many of today's birds nest in high-rise buildings in various cities.) These new birds are currently termed "mutts" by many raptor enthusiasts. I've been told that "nothing about Peregrine's nesting in Chicago is natural", to which I reply "What about Chicago IS natural?"

Admittedly, this is a long-term strategy. It will be decades, probably even centuries, before we can expect a population that is homogeneous enough to give it a subspecies designation all its own. But then again, that's how natural selection works.
One of the things that interests me about this is the insistence that the Canadian birds were still anatum, so they should have been used. Yes, they looked like birds from New York or Illinois, (or Florida, even), but does that mean that they would be genetically well-adapted to this area? That's an open question -- for most species, we don't have any idea how closely the genetics follow appearances across populations, and even if we did, we don't know which genes are important in adapting to local conditions. (Or even how closely those genes correlate with environmental variation.)

I do find the debate interesting, but fortunately for my own peace of mind, I find myself in agreement with the Peregrine Fund. This is a neat long-term experiment in applied evolutionary biology, and if we're still willing to do the work in the decades to come it could prove invaluable in helping us learn how species can adapt to the changes we like to make in our environment.

No matter how you feel about the current situation, though, it's neat to know that this shot could be across the sunrise of a new population, and not the sunset of a species: