Research

Keywords: Aves, behavioural ecology, birdsong, coloration, conservation, communication, competition, interspecific aggression, outreach, misidentification, remote sensing, salamanders, visual perception

Animal Communication

A complete understanding of the evolution of sexual dimorphism requires a thorough understanding of the adaptive significance of elaborate multimodal signals and the mechanisms that facilitate their expression in both sexes. However, our understanding of signal evolution in female animals lags far behind that of males. My PhD research addresses this knowledge gap by exploring multimodal signaling function as well as the endocrinological basis for signal expression in the white-shouldered (Malurus alboscapulatus) of Papua New Guinea. Additionally, to explore how these traits are conserved across differing biological levels (e.g, between sexes, populations, and species), I explore how androgen sensitivity influences flexible ornament expression in male red-backed fairywrens (Malurus melanocephalus) of Australia.

In Papua New Guinea, white-shouldered fairywrens are unique among fairywrens; females have three distinct plumage phenotypes across the island, ranging from brown (highly sexually dichromatic), to pied, to fully ornamented (nearly monochromatic with males). In the field, my aim is to understand how divergent patterns of female coloration is adaptive and the underlying proximate mechanisms that may have facilitated that evolutionary shift. As part of this project, I focus on their behavioural ecology, circulating androgens (testosterone), and androgen-receptor densities in peripheral tissues.

Wren Map
Left: dichromatic populations of white-shouldered fairwrens of western province (brown circle). Right: nearly monochromatic population in Milne Bay Province (black circle).

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Unlike white-shouldered fairywrens, red-back fairywren males, but not females, vary in degree of that they are ornamented; this variation is flexible among younger males, with some males retaining drab brown, female-like plumage while others develop ornamented (black and red) plumage to breed in. The acquisition of this plumage state is associated with age, such that testosterone is necessary and sufficient in younger, but not older males to acquire their nuptial, black and red ornamentation. My research will explore the role that sensitivity to testosterone plays in facilitating ornamentation across varies age classes.

cropped-2017-rbfw-duo-3.jpg
Red-backed fairywren female (left) and ornamented male (right). Males of this species cycle annually between brown and black/red plumage during the non-breeding and breeding season respectively. 

Interspecific Aggression

Why do animals fight? The most common (and well-documented) explanation is that animals are competing for shared ecological resources. But what about when animals are not interspecific competitors?

The focus of my Masters research was to document why golden-winged and chestnut-sided warblers of the southern Appalachian Mountains engaged in agonism. This research was pertinent to my research interest because it combined my research interests of coloration and behavioural ecology with conservation, as golden-winged warblers are a species of significant conservation concern.

I used a combination of reflectance spectrometry coupled with models of avian vision to determine that coloration variation between birds should be distinguishable. However, in the field, I tested for fitness consequences of sympatry and found there were negative affects of chestnut-sided warblers on golden-winged warblers. Finally, I used wooded models to test for misidentification and found that warblers engage in interspecific aggression due to mistaken identity rather than competition.

But what are the mechanisms to reduce interspecific aggression? I am looking to start a project investigating agonistic character displacement between warblers across a geographic gradient. If interested (and if you have the means to conduct research on this project as well), please contact me.

Relevant citations:
Jones, JA, AC Tisdale, MH Bakermans, JL Larkin, CG Smalling, and L Siefferman. 2017. Multiple plumage ornaments as signals of intrasexual communication in golden-winged warblers. Ethology, 123: 145-156.
Jones, JA, AC Tisdale, JL Tucker, MH Bakermans, JL Larkin, CG Smalling, and L Siefferman. 2016. A case of mistaken identity: Understanding the stimulus of agonism between two wood warblers. Animal Behaviour, 114: 81-91.
Jones, JA and L Siefferman. 2014. Agonistic behaviors between chestnut-sided (Setophaga pensylvanica) and golden-winged warblers (Vermivora chrysoptera) are unlikely a result of plumage misidentification. Wilson Journal of Ornithology, 126(4):708-716.

Interspecific Competition

How do species that share ecological resources coexist? I am interested in competition broadly, as I believe it plays a large role in ecosystem structure.

My undergraduate research focused on Eastern Bluebird and Tree Swallow competition. I used historical occupation data for bluebirds and remote sensing to characterise habitat quality. I found there is a tradeoff between physical habitat quality (determined by resources) and social habitat quality (determined in interspecific competition), where bluebirds who settle with high abundances of tree swallows suffered fitness consequences if they also did not preferentially select higher quality habitat. When tree swallows are not present, there is no influence of habitat quality on reproductive success.

Relevant citation: 
Albers, AN, JA Jones, and L Siefferman. 2017. Behavioral differences among eastern bluebird populations may be a consequence of tree swallow presence: A pilot study. Frontiers in Ecology and Evolution, 5:116
Jones, JA, MR Harris, and L Siefferman. 2014. Physical habitat quality and interspecific competition interact to influence territory settlement and reproductive success in a cavity nesting bird. Frontiers in Ecology and Evolution, 2:71.

Additional Research Interests

It is important to note that birds are not my only research interests, but they are the core of my biological career thus far.  I study birds in general because every major ecological theory can be applied to Aves. However, I am interested in applying all of the above topics (in particular, the evolution and function of coloration) to any taxonomic group (e.g., salamanders).

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