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284 results on '"Dantzer, Ben"'

7. Behavioral variation among Fox Squirrel (Sciurus niger) populations in urban environments.

Author

Devitz, Amy-Charlotte and Dantzer, Ben

Subjects
*URBAN animals, *URBAN density, *CITIES & towns, *CITY dwellers, *ANIMAL experimentation, *ANIMAL populations
Abstract

Urbanization presents a myriad of challenges to wildlife, yet some individuals or species persist and even thrive in urban environments. Specific behavioral traits that have been proposed to enable animals to cope with challenges and frequently observed in urban wildlife populations across many taxonomic groups include changes in docility, activity, boldness, sociability, and aggression. We conducted a series of standardized behavioral assays to test the hypothesis that urbanization favors these traits in fox squirrels (Sciurus niger), a species that is widespread in urban areas. Based upon previous studies, we predicted that squirrels would exhibit higher levels of boldness, activity, and aggression and lower docility in urban areas with higher human density compared to their counterparts in areas with lower human density areas. We instead found a trend of higher sociability—but not aggression—in squirrels at higher human density sites over lower human density sites, and no differences in docility, boldness, or activity. Our results indicate that the behavior of fox squirrels does not vary dramatically on a fine scale of human density, apart from a trend in heightened sociability in higher human density urban environments. [ABSTRACT FROM AUTHOR]

Published
2024
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17. A future food boom rescues the negative effects of early-life adversity on adult lifespan in a small mammal.

Author

Petrullo, Lauren, Delaney, David, Boutin, Stan, Lane, Jeffrey E., McAdam, Andrew G., and Dantzer, Ben

Subjects
ADULTS, PHENOTYPES, LONGEVITY, DIETARY supplements, CALORIE
Abstract

Early-life adversity, even when transient, can have lasting effects on individual phenotypes and reduce lifespan across species. If these effects can be mitigated by a high-quality later-life environment, then differences in future resources may explain variable resilience to early-life adversity. Using data from over 1000 wild North American red squirrels, we tested the hypothesis that the costs of early-life adversity for adult lifespan could be offset by later-life food abundance. We identified six adversities that reduced juvenile survival in the first year of life, though only one—birth date—had continued independent effects on adult lifespan. We then built a weighted early-life adversity (wELA) index integrating the sum of adversities and their effect sizes. Greater weighted early-life adversity predicted shorter adult lifespans in males and females, but a naturally occurring food boom in the second year of life ameliorated this effect. Experimental food supplementation did not replicate this pattern, despite increasing lifespan, indicating that the buffering effect of a future food boom may hinge on more than an increase in available calories. Our results suggest a non-deterministic role of early-life conditions for later-life phenotype, highlighting the importance of evaluating the consequences of early-life adversity in the context of an animal's entire life course. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Reproductive state alters vocal characteristics of female North American red squirrels (Tamiasciurus hudsonicus).

Author

Hare, Alexander J, McAdam, Andrew G, Dantzer, Ben, Lane, Jeffrey E, Boutin, Stan, and Newman, Amy E M

Subjects
TAMIASCIURUS, ESTRUS, FEMALES, COINCIDENCE, PARTURITION, BIOACOUSTICS
Abstract

Female advertisement of reproductive state and receptivity has the potential to play a large role in the mating systems of many taxa, but investigations of this phenomenon are underrepresented in the literature. North American red squirrels (Tamiasciurus hudsonicus) are highly territorial and engage in scramble competition mating, with males converging from spatially disparate territories to engage in mating chases. Given the narrow estrus window exhibited in this species, the ubiquitous use of vocalizations to advertise territory ownership, and the high synchronicity of males arriving from distant territories, we hypothesized that female vocalizations contain cues relating to their estrous state. To test this hypothesis, we examined the spectral and temporal properties of female territorial rattle vocalizations collected from females of known reproductive condition over 3 years. While we found no distinct changes associated with estrus specifically, we did identify significant changes in the spectral characteristics of rattles relating to both female body mass and reproductive state relative to parturition. To the best of our knowledge, this is the first evidence of changes in vocal characteristics associated with late pregnancy in a nonhuman mammal. [ABSTRACT FROM AUTHOR]

Published
2024
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32. Consistent spatial patterns in microbial taxa of red squirrel gut microbiomes.

Author

Halhed, Alicia, Petrullo, Lauren, Boutin, Stan, Dantzer, Ben, McAdam, Andrew, Wu, Martin, and Cottenie, Karl

Subjects
TAMIASCIURUS, GUT microbiome, BIOMES, DATA replication, MICROBIAL communities
Abstract

Gut microbiomes are diverse ecosystems whose drivers of variation remain largely unknown, especially in time and space. We analysed a dataset with over 900 red squirrel (Tamiasciurus hudsonicus) gut microbiome samples to identify the drivers of gut microbiome composition in this territorial rodent. The large‐scale spatiotemporal replication in the data analysed was an essential component of understanding the assembly of these microbial communities. We identified that the spatial location of the sampled squirrels in their local environment is a key contributor to gut microbial community composition. The non‐core gut microbiome (present in less than 75% of gut microbiome samples) had highly localised spatial patterns throughout different seasons and different study areas in the host squirrel population. The core gut microbiome, on the other hand, showed some spatial patterns, though fewer than in the non‐core gut microbiome. Environmental transmission of microbiota is the likely contributor to the spatiotemporal distribution observed in the North American red squirrel gut microbiome. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Closing the Mentorship Gap through Youth-Initiated Mentoring

Author

Dantzer, Ben

Subjects
ComputingMilieux_THECOMPUTINGPROFESSION, GeneralLiterature_MISCELLANEOUS
Abstract

Ben Dantzer, a UBC 3MT Finalist, shares their Youth- Initiated Mentoring model with the goal of helping close the mentorship gap in Canada. This mentoring model presents a process for empowering Canadian youth to identify and connect with adults they already know in their community, and to work with them to invite these individuals to more formally mentor them. Ben Dantzer is completing their PhD in Human Development, Learning, and Culture under the supervision of Dr. Nancy Perry.

Published
2022
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