Dr. Lucinda P. Lawson, Ph.D. - Evolution, Ecology, and Conservation Biologist
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National Geographic expeditions to Tanzanian montane grasslands 2017-2019

Conservation of Mountain Apex Grasslands and associated ecotones: Biological surveys of overlooked but critical habitats of Udzungwa and Uluguru Mountains

Conservation, outreach, research, and teaching in the time of covid

11/6/2020

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2020 has been a challenging year for just about everyone. Education, research, and outreach have all be particularly effected and international projects more than most. Despite the challenges of not being able to physically travel to Africa while the pandemic is ongoing, this research team is still making amazing progress in describing new species, clarifying biodiversity loss, and creating new tools to facilitate conservation from afar.

In my own work, this year has had a larger focus on sengi evolution than any other year. While most of my research is related to amphibians, my broad Evolutionary background and experience in East African fauna has created a particularly rewarding collaboration in studying these enigmatic small mammals (also known as Elephant-shrews. Though, as they are neither elephant nor shrew, most mammalogists prefer the Bantu African name of sengi). I have two papers coming out in 2021 showing that we have more diversity than we thought, and more challenges than expected to ensure their continued conservation. Check out my "publications" tab to find references. Also, I'm having fun drawing sengis! Check out my cartoon above of Rhynchocyon petersi!

2020 and 2021 will also be big years for species descriptions, with two published in 2020 in collaboration with Simon Loader and his group at the British Natural History Museum and our Kenyan collaborators and a few more expected as direct results from these Udzungwa and Ukaguru studies. As we continue to clarify the biological diversity in Africa, it makes the conservation priorities clearer. In particular, we need to look outside of the tropical submontane forests to the under-valued diversity in grasslands and coastal areas.

Thinking of outreach, I am continuing to plan outreach projects in East Africa, particularly with the amazing women who run the villagelifeoutreachproject.org project which focuses on villages around Lake Victoria. I'm so excited to bring games, maps, and learning materials about the frogs around the lake to the schools that they work with.

And finally, I am so excited to be teaching a new Conservation Biology course this Spring where I can integrate so much content from this African work. Student interest in conservation and sustainability is growing at a record rate, and I'm so honored to get to spend time with these students and they prepare for their futures.

My best to you all, Lucinda

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Polymorphic Coloration Variation

9/25/2019

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PictureHyperolius viridiflavus ngorongorienis from Northern Tanzania. Lawson LP, HC Liedtke, M Menegon, SP Loader. 2018. Reproductive characteristics of two Hyperoliidae species (Afrixalus septentrionalis -Schiøtz 1974, and Hyperolius v. ngorongoriensis – Schiøtz 1975) from a miombo seasonal wetland in Northern Tanzania. Herpetology Notes 11:873-879.
      Many species of Hyperolius frogs have the curious trait of having polymorphic coloration. This means that individuals can be many different colors instead of a single color. As most species across vertebrates are fairly uniform in their coloration (either all males and all females are the same color, or all males are one color and all females are another color - sexual dichromatism), when you come across a species that is highly variable, the question that I usually think of is "Why?". What possible reasons would keep variation within a species?
     One idea is to confuse predators. This is common in species where predators can get a "search image" for a certain coloration, which they then use to more quickly find individuals of that color. Whatever color is "rare" then ends up surviving and reproducing better. Which then leads to the population to shift towards more of the "rare" color individuals, which then are no longer rare...
     Another possibility is that there may be fitness tradeoffs in the color morphs. In the common wall lizards native to Europe (Podarcis muralis), the yellow color morphs have more testosterone and have the associated traits of more aggression and more/smaller eggs than the red or white color morphs. They also have reduced immune responses that are also associated with higher testosterone (as seen in many species). These two life strategies, which I like to call "live fast and die young (yellow)" vs. "slow and steady wins the race (red and white)", are maintained in the species because different environmental years will favor different strategies. In a really great year with ideal weather and lots of food/resources, the yellow morphs can go to town reproducing a ton of offspring. In a poorer quality year, however, the red and white morphs will be more likely to have successful offspring because they will live longer and produce fewer eggs but with larger nutritional reserves in each egg so that each baby has a better chance of surviving in the harsh surroundings.
     We don't know if there are fitness tradeoffs for the color morphs within Hyperolius species, but this would be a great area of future research. Overall, our understanding of Hyperolius frogs is still in its infancy (we are still naming many new species each year), but there is a lot left to learn!

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Like Night and Day!

8/8/2019

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PictureAfrixalus uluguruensis at night (left) and day (right) showing starkly differing coloration.
Reed frogs are some of Africa’s most diverse groups of frogs and as their name suggests, usually hang out on reeds overhanging ponds and ditches. A peculiarity of this group of frogs is that many of them don’t lay their eggs in water (like most frogs), but instead attach them to said reeds. Once the tadpoles are ready to hatch, they just drop into the water below! The reason for this strategy is most likely to avoid aquatic egg predators, a big risk for frogs (but check out this cool video of snakes feeding on such leave-bound eggs in the famous red-eyed tree frog in Central America: https://www.youtube.com/watch?v=dNHC4OciQJw).

The two biggest groups (or ‘genera’) of reed frogs are Hyperolius and Afrixalus. The latter are sometimes referred to as the “spiny reed frogs” due to their rough, sandpaper-like skin and both are fairly wide-spread across the African subcontinent. Besides their spiny skin, Afrixalus has one more peculiarity up its sleeve… as day breaks and they search for places to rest (most frogs are nocturnal), they dramatically change their colour with some going completely white! Although most (if not all) frogs are able to change color to some extent (usually limited to different shades or intensities of the same colour), reed frogs like this Afrixalus uluguruensis are literally like night and day!

Although this oddity is fairly well known, and other species of frogs do it too, surprisingly little is known about the exact function of this colour change. Dramatically paler day time colourations are often seen in those species that also rest in fairly exposed places and so it might serve as some sort of UV protection or to keep cool and prevent dehydration during the sunniest parts of the day, but these hypotheses are yet to be formally tested.

-Christoph Liedtke

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The challenge of new species

8/1/2019

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PictureHyperolius cf. pusillus
     One of the most exciting parts of working in biologically diverse and understudied areas such at the Eastern Arc Mountains of Tanzania is finding new species! However, it can often be a very confusing process to decide if something is truly new. In reality, we often end up listing these as "cf. somethingsomething" which comes from the Latin word "conferre" meaning “compare to” or “confer.” For instance, this little guy is currently listed as Hyperolius cf. pusillus. While these frogs look something like H. pusillus, their call is different and they are found in the wrong habitat and in the wrong region of the country - thus we think they aren't really H. pusillus at all! Now begins the long hard work of describing a new species.
     The first step of describing a new species is figuring out what it ISN'T. Figuring out what it isn't requires us to compare this frog to other similar frogs to determine if we can rule them out. In modern herpetology, we employ a wide variety of techniques to characterize a species and sample a number of individuals in order to understand within-species variation in relation to between-species variation. We take morphological measurements of every aspect of these little frogs, we document coloration and variation (some species are hyper-variable even within a single clutch of eggs), we record calls, we sample DNA, and we document habitat type and distribution. Finally, we take all of this information into account and compare to all other similar species - noting ways in which they are similar and ways in which the differ.


PictureHyperolius howelli
Hyperolius frogs are a particularly difficult genus to work in because the ways in which they vary between species change a lot throughout their phylogenetic tree. In some groups of Hyperolius, many different species of frogs look incredibly similar and thus multiple lines of evidence are necessary to understand which are different species and which aren't (e.g., Hyperolius nasutus/acuticeps complex - preliminary clarification in Channing et al. 2013). See the picture on the left of H. howelli, a member of this complex named after one of the modern giants of East African Herpetology Dr. Kim Howell from the University of Dar es Salaam.

PictureVariation within Hyperolius substriatus.
Other species have incredible variation within single populations and throughout their ranges, such as Hyperolius substriatus found throughout mid-elevation forests in East Africa (right). Though challenging when doing biodiversity surveys, new species are incredibly exciting and incredibly valuable for conservation planning. When formulating a plan for conservation, if scientists can clarify that three species with small ranges exist instead of one broadly distributed species, for instance, then conservation biologists can create more targeted action plans for these vulnerable species.

-Lucinda Lawson

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Vanishing Grasslands in the Udzungwa Mountains forest and grassland mosaic

7/30/2019

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This is our first blog post, which will be followed by many more documenting the unique biological diversity of the montane grasslands of the Udzungwa Mountains in Tanzania.
Kassina senegalensis

-Lucinda Lawson

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    Authors

    Dr. Lucinda Lawson
    Dr. Simon Loader
    Dr. Michele Menegon
    Dr. Christoph Leidke
    John Lyakurwa, MS

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