Glucocorticoid and triiodothyronine concentrations do not correlate with behavior in vicuñas (Vicugna vicugna)

Catharine E. Pritchard, Rupert Palme, Tracy Langkilde

Research output: Contribution to journalReview article

Abstract

State-dependent foraging theory posits that animals should make foraging decisions based on energetic condition, where animals with fewer energetic reserves prioritize foraging over other behaviors, including antipredator behaviors. However, few studies have investigated these trade-offs at an individual level in wild, free-ranging animals. We investigated the relationships between internal condition and behavior in a wild mammal, the vicuña (Vicugna vicugna), which makes state-dependent decisions about the use of two habitats with different characteristics that contribute to their internal condition. Using non-invasively collected fecal samples, we measured glucocorticoid metabolites (GCMs) and thyroid hormones (THs) as indicators of combined stress (predation and nutritional), and just nutritional stress, respectively. We video recorded 20-minute behavioral observations and focused on behaviors which often demand a trade-off between energy acquisition and antipredator behaviors—vigilance and foraging. We found differences in expression of these behaviors between the two sites but found no relationships between physiological parameters (GCMs and THs) and behavior (vigilance and foraging) at either site. We suggest that state-dependent foraging may be difficult to observe in large mammals under baseline conditions and that GCMs and THs may be insensitive to small changes in stress stimuli at this scale, and where these wild animals have the entire suite of behavioral responses available to them.

Original languageEnglish (US)
Article number113299
JournalGeneral and Comparative Endocrinology
Volume286
DOIs
StatePublished - Jan 15 2020

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vicunas
New World Camelids
Triiodothyronine
triiodothyronine
glucocorticoids
Glucocorticoids
foraging
Thyroid Hormones
thyroid hormones
metabolites
Mammals
Wild Animals
mammals
animals
Ecosystem
wild animals
predation
energy
habitats

All Science Journal Classification (ASJC) codes

  • Animal Science and Zoology
  • Endocrinology

Cite this

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title = "Glucocorticoid and triiodothyronine concentrations do not correlate with behavior in vicu{\~n}as (Vicugna vicugna)",
abstract = "State-dependent foraging theory posits that animals should make foraging decisions based on energetic condition, where animals with fewer energetic reserves prioritize foraging over other behaviors, including antipredator behaviors. However, few studies have investigated these trade-offs at an individual level in wild, free-ranging animals. We investigated the relationships between internal condition and behavior in a wild mammal, the vicu{\~n}a (Vicugna vicugna), which makes state-dependent decisions about the use of two habitats with different characteristics that contribute to their internal condition. Using non-invasively collected fecal samples, we measured glucocorticoid metabolites (GCMs) and thyroid hormones (THs) as indicators of combined stress (predation and nutritional), and just nutritional stress, respectively. We video recorded 20-minute behavioral observations and focused on behaviors which often demand a trade-off between energy acquisition and antipredator behaviors—vigilance and foraging. We found differences in expression of these behaviors between the two sites but found no relationships between physiological parameters (GCMs and THs) and behavior (vigilance and foraging) at either site. We suggest that state-dependent foraging may be difficult to observe in large mammals under baseline conditions and that GCMs and THs may be insensitive to small changes in stress stimuli at this scale, and where these wild animals have the entire suite of behavioral responses available to them.",
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Glucocorticoid and triiodothyronine concentrations do not correlate with behavior in vicuñas (Vicugna vicugna). / Pritchard, Catharine E.; Palme, Rupert; Langkilde, Tracy.

In: General and Comparative Endocrinology, Vol. 286, 113299, 15.01.2020.

Research output: Contribution to journalReview article

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AU - Palme, Rupert

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