Kat Shaw

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Kat with an amphibious vehicle, Alaska field season '08

Katherine A. Shaw, Doctoral Student

B.A./M.A. (2005) Clark University, Department of Biology

Doctoral Student (2005 - Present) University of Connecticut, Ecology & Evolutionary Biology


Contact Info:

Department of Ecology and Evolutionary Biology

75 North Eagleville Rd, U-43

Storrs, CT 06269

_______________________________________________

Office: TLS 363

Voice: (860) 486-4638

Fax: (860) 486-6364

Email: katherine.shaw@uconn.edu

Advisor: Carl Schlichting

Fall 2008 Courses:

Teacher Assistant: Biology 1107 - Principles of Biology 1
Co-Instructor: EEB 3894 - Current Topics in Ecology and Evolution

Interests:

Evolution of mating systems and phenotypically plastic traits; The evolution and maintenance of conditional reproductive tactics; Causes and consequences of geographic variation in behavior and the implications of ancestral behavioral plasticity; behavioral ecology, fish biology and Gasterosteid behavior.

Research:

Study Species

Anadromous threespine stickleback study population at Francis Peninsula Lagoon, British Columbia

There are a number of stickleback species (Family: Gasterosteidae), many named for their number of dorsal spines (threespine, fourspine, ninespine, fifteenspine!). I've spent the last few years working with threespine stickleback (Gasterosteus aculeatus L.) in British Columbia and Alaska, specifically studying population differences in reproductive behavior. Marine populations of threespines invaded freshwater environments during the last glacial recession between 15,000 and 10,000 years ago. Depending on the type of aquatic habitat invaded, populations have come to differ in morphology and behavior. This is especially interesting because, not only does it tell us much about how environment affects morphology and behavior but, since the ancestral (marine) populations have changed little in the last 20,000 years, we can determine the directionality of behavior and morphological changes in the more derived, freshwater populations.

What is especially interesting about these fish is that they have a very active social life. Male threespines build nests on the substrate and exhibit a nuptial coloration to attract females and signal territoriality to other males. When males spot a gravid female, they often perform a courtship dance and if the female is interested, she will enter the nest and leave a clutch of eggs for the male to fertilize. The male may do this dance until he collects clutches from several females. He then provides all parental care for the eggs, fanning oxygen over the eggs with his fins as they develop. Males in some populations are very territorial and actively defend their nests and fry from intruders.

Previous Research

Conspicuousness of courtship depends on potential threats to the nest in some population. If large foraging groups of stickleback are present in a population they may cannibalize young in nests that they encounter. Males in cannibalistic populations often utilize a less conspicuous courtship display and perform behaviors (diversionary displays) to distract groups away from a territory containing a nest and young. Comparisons of courtship intensity in populations with varying levels of cannibalism have shown that some populations are more plastic in their behavioral response than others. Males from populations in which some degree of cannibalism is present show an increase in courtship intensity when observed under laboratory conditions (where the threat of cannibalism is absent) as compared to observations under field conditions (where individuals experience foraging groups). This reaction norm is related to population type in that the population experiencing the greatest frequency of foraging groups show the smallest increase in conspicuous courtship under laboratory conditions. Males from a population in which no large foraging groups form show consistently high courtship intensity under both field and lab conditions. Preliminary results involving lab-reared individuals from the low cannibalism and high cannibalism populations mirror the results of wild-caught fish suggesting an underlying genetic component to the difference in courtship intensity (see Shaw et al. 2007). Further studies on the effects of cannibalism on behavior under laboratory conditions are being carried out by students at Clark University. This will help determine the extent to which behavioral variation is exhibited upon exposure to foraging groups under standardized conditions.


Current Research

Sneaker male near shore at Big Lake, Alaska
Drab male threespine stickleback (Gasterosteus aculeatus L.) performing sneaking behaviors during a laboratory assay trial

My current interests are focused on alternative male mating tactics -- behaviors males use to obtain matings instead of (or in addition to) nesting and courtship behavior. Drab colored male threespines have been observed to sneak along the substrate, hiding behind objects and in vegetation, in an attempt to rush into nests of courting males in order to fertilize eggs that are not their own. There are several factors proposed to elicit sneaking in individual males but of greater interest is the fact that there are some populations in the Pacific Northwest where sneaking occurs at high frequencies (Alaska) and other populations where sneaking has never been observed (British Columbia). Freshwater populations in this region are all derived from marine ancestors so it is plausible that ancestral plasticity in this behavior has influenced geographic variation in the propensity to sneak. There may be certain characteristics (genetic and/or environmental) specific to populations in which sneaking is absent. My current work involves:

  1. Regional investigations of the conditional factors suggested to covary with sneaking behavior (sex ratio; inter-nest distances, visibility, etc.) Are any of these factors correlated with an in situ propensity to sneak both within and between regions (Alaska vs British Columbia)?
  2. Intra- and Interspecific comparisons of sneaker color variation and investigation of the adaptive significance of sneaking patterning. Is there low variability in sneaker coloration across populations? Are sneaking males utilizing crypsis or female mimicry?
  3. Laboratory-based comparisons of sneaking propensity with lab-reared individuals from sneaking and non-sneaking populations. Is there a genetic component underlying variation in sneaking propensity?

Utilizing population and regional comparisons will allow me to understand:(1) the extent of genetic variation underlying the sneaking phenotype, (2) factors that elicit sneaking, and (3) the role of the ancestral state in influencing the regional pattern of sneaking behavior.

Future Research Prospects

Drab male observed moving along tank bottom in response to a courting pair during a taped behavioral lab assay

I hope to gain insight into both the external and internal factors that foster or limit the evolution of alternative mating tactics. Once the interplay between ancestral plasticity and the environmental contexts eliciting sneaking are understood, my long term goals are to evaluate hormonal correlates of sneaking behavior, and, ideally, transcriptional profiles of the brains of sneaking and non-sneaking males to understand the genetic and physiological underpinnings of sneaking behavior. Such research should be attainable given the availability of the genome sequence and genomic tools developed for this model system.

Publications:

Foster, S.A., K.A. Shaw, K.L. Robert, J. A. Baker. 2008. Benthic, limnetic and oceanic threespine stickleback: Profiles of reproductive behavior. Behaviour 145 (4): 485 - 508.

Shaw, K.A., M.L. Scotti, S.A. Foster. 2007. Ancestral plasticity and the evolutionary diversification of courtship behaviour in threespine sticklebacks. Animal Behaviour 73: 415 – 422. PDF


Ornamental lawn G. aculeatus on the Sunshine Coast of BC