Steffi Lazerte

Steffi Lazerte
steffilazerte.ca

MSc, PhD

About

24
Publications
7,831
Reads
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230
Citations
Introduction
Steffi Lazerte currently works as an independent biological consultant and R programer in Brandon, Manitoba. She focuses on research on animal behaviour, particularly in urban systems, as well as on the development of tools (R packages/scripts) to help with data management and analysis.
Additional affiliations
July 2018 - present
Brandon University
Position
  • Professor (Associate)
May 2017 - present
steffilazerte.ca
Position
  • Consultant
Description
  • As an independent biological consultant and R programer I provide services in R programming, R instruction, data management/cleaning, and data analysis. I also develop free and open-source R packages (http://github.com/steffilazerte/)
May 2016 - April 2017
Thompson Rivers University
Position
  • PostDoc Position
Description
  • Further development of the feedr package, including the an R shiny app for a user-friendly online portal (animalnexus.ca)
Education
September 2010 - April 2015
University of Northern British Columbia
Field of study
  • Avian Communication
September 2007 - August 2010
McGill University
Field of study
  • Animal Behaviour
September 2003 - May 2007
University of Toronto
Field of study
  • Animal Behaviour

Publications

Publications (24)
Article
Hypotheses on regional song variation (“dialects”) assume that dialects remain stable within regions, are distinct between regions, and persist within populations over extensive periods [1, 2, 3]. Theories to explain dialects focus on mechanisms that promote persistence of regional song variants despite gene flow between regions [4, 5, 6], such as...
Article
Urbanization results in novel ecosystems with unique challenges. These may lead to problems during song learning or development and could result in the singing of atypical songs. During studies of Mountain Chickadees (Poecile gambeli) and urbanization in British Columbia, Canada, we observed males singing atypical songs along an urbanization gradie...
Article
Variation in resource availability can lead to phenotypic plasticity in the traits comprising the worldwide leaf economics spectrum (LES), potentially impairing plant function and complicating the use of tabulated values for LES traits in ecological studies. We compared 14 Carex (Cyperaceae) species in a factorial experiment (unshaded/shaded × suff...
Article
Anthropogenic noise can mask avian vocalizations, and several urban‐dwelling species adjust frequency or amplitude of vocalizations in ways that appear to compensate for increased noise levels. Playback studies have investigated whether receivers differentiate between signals produced by rural and urban males, but it is difficult to determine wheth...
Article
Full-text available
Gaps in forest habitat are well documented to negatively impact the movements of forest songbirds. Much past research on avian gap-crossing decisions has utilized playback experiments. However, playbacks are limited by short observation times and often cannot be used to reveal differences in behaviors among individuals. Here, we present a novel app...
Article
Vocal output during the dawn chorus is often an honest indicator of male quality, where males with greater access to food and in better condition produce more vocalizations. We compare the vocal output among male mountain chickadees living along an urbanization gradient to assess how urbanization affects male signalling. Chickadees forage in the ca...
Article
Full-text available
Radio frequency identification (RFID) provides a simple and inexpensive approach for examining the movements of tagged animals, which can provide information on species behavior and ecology, such as habitat/resource use and social interactions. In addition, tracking animal movements is appealing to naturalists, citizen scientists, and the general p...
Article
Full-text available
Urbanization creates new habitats with novel benefits and challenges not found in natural systems. How a species fares in urban habitats is largely dependent on its life history, yet predicting the response of individual species to urbanization remains a challenge. While some species thrive in urban areas, others do poorly or are not present at all...
Article
Full-text available
Low-frequency urban noise can interfere with avian communication through masking. Some species are able to shift the frequency of their vocalizations upwards in noisy conditions, which may reduce the effects of masking. However, results from playback studies investigating whether or not such vocal changes improve audibility in noisy conditions are...
Article
Full-text available
Vocal plasticity may allow birds to reduce masking effects of noise pollution arising from urbanization. Mountain chickadees (Poecile gambeli) use both songs and calls during the dawn chorus, which vary in masking susceptibility. Thus, increasing song or call frequency, or switching between vocalization types are all potential mechanisms to reduce...
Article
Measuring activity of small mammals in the field is challenging because they are often out of view. We used a novel method, based on temperatures of collar radio transmitters, to quantify the proportion of time eastern chipmunks (Tamias striatus (L., 1758)) spent active, curled up resting, and torpid during the summer and fall of 2 years in souther...
Article
Urban noise can interfere with avian communication through masking, but birds can reduce this interference by altering their vocalizations. Although several experimental studies indicate that birds can rapidly change their vocalizations in response to sudden increases in ambient noise, none have investigated whether this is a learned response that...
Article
Landscape features influence individual dispersal and as a result can affect both gene flow and genetic variation within and between populations. The landscape of British Columbia, Canada, is already highly heterogeneous because of natural ecological and geological transitions, but disturbance from human-mediated processes has further fragmented co...
Article
Full-text available
When habitats overlap and species compete for resources, negative interactions frequently occur. Character displacement in the form of behavioural, social or morphological divergences between closely related species can act to reduce negative interactions and often arise in regions of geographic overlap. Mountain chickadees Poecile gambeli have an...
Article
Urbanization creates communication challenges for many species. Birds in particular rely on vocal communication for reproduction and territory defence, but in noisy or acoustically altered environments signals may be compromised. Both ambient noise and habitat openness affect signal transfer, but it is not clear how these two variables interact in...
Article
Signals of closely related species tend to be more distinct when occurring in sympatry than in allopatry. Such differences allow species-specific identification and presumably reduce interspecific mating. Among chickadees, dawn chorus behaviour affects female mate choice. Within our sympatric study population of black-capped chickadees, Poecile atr...
Article
We present a protocol for using temperature records from external thermosensitive radiotransmitters recorded by data-logging receivers to identify bouts of rest and activity in mammals that sleep in a curled-up posture. We illustrate the protocol using eastern chipmunks (Tamias striatus) sampled in the Ruiter Valley Land Trust near Mansonville, Que...
Thesis
Thermosensitive radio telemetry has the potential to document rest, and hence activity, in mammals that have a curled-up resting posture, but this promising technique has never before been applied to detailed studies of burrow-dwelling animals. I developed a method to use data from thermosensitive radio transmitters to estimate diel and seasonal pa...

Questions

Question (1)
Question
I'm trying to use binomial mixed models in R to model daily chipmunk activity (proportion of observation points active out of total observation points) in relation to time of day (day/night), season and year (all fixed effects), while controlling for the individual (random effects). Each day for each individual is a data point, containing the total number of 15 minutes intervals the individual was observed active (active) or resting (rest). e.g. Day = "2007-06-23", ID = "B024", timeofday = "day", year = 2007, season = 1, active = 10, rest = 45
If you're familiar with R, the model I'm running is set up as follows:
lmer(cbind(active,rest) ~ year * season * timeofday + (1|ID), family=binomial), data=x)
Generally, I would like to know if anyone has any insight as to whether I am violating the assumptions of a binomial regression with my data.
Assumptions:
1. There is only one outcome for each trial – No problem, here each trial is a 15min interval where the chipmunk is either active or resting
2. Each trial has the same probability of success – It is possible that some parts of the day the probability of activity is higher than rest (i.e. morning and evening vs. midday)
3. Each trial is mutually exclusive – Possibly my biggest problem. Because chipmunks tend to be active for blocks of time, whether it's active at point 2, will be related to whether it was active at point 1. However, within each day, point 1 is most likely independent from point 30.
So if anyone has any comments on a) Whether this is complete mismatch of model and data, b) If not, whether I'm violation these assumptions, c) If I am violation these assumptions, is the model very sensitive to these types of violations, and d) any suggestions for alternative models or approaches.
I'd also welcome suggestions of any reading material you think might help me solve my problem.

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Projects

Projects (3)
Project
To develop R packages which facilitate science. These packages generally involve collecting, summarizing, transforming, and visualizing different types of data to facilitate analysis, particularly in the field of Biology and Natural Sciences in general.
Project
To develop the feedr R package and it's companion website http://animalnexus.ca into a suite of tools for easy loading, transforming and visualizing RFID data.