Olfactory attractants and parity affect prenatal androgens and territoriality of coyote breeding pairs

Abstract

Hormones are fundamental mediators of personality traits intimately linked with reproductive success. Hence, alterations to endocrine factors may dramatically affect individual behavior that has subsequent fitness consequences. Yet it is unclear how hormonal or behavioral traits change with environmental stressors or over multiple reproductive opportunities, particularly for biparental fauna. To simulate an environmental stressor, we exposed captive coyote (Canis latrans) pairs to novel coyote odor attractants (i.e. commercial scent lures) mid-gestation to influence territorial behaviors, fecal glucocorticoid (FGMs) and fecal androgen metabolites (FAMs). In addition, we observed coyote pairs as first-time and experienced breeders to assess the influence of parity on our measures. Treatment pairs received the odors four times over a 20-day period, while control pairs received water. Odor-treated pairs scent-marked (e.g. urinated, ground scratched) and investigated odors more frequently than control pairs, and had higher FAMs when odors were provided. Pairs had higher FAMs as first-time versus experienced breeders, indicating that parity also affected androgen production during gestation. Moreover, repeatability in scent-marking behaviors corresponded with FGMs and FAMs, implying that coyote territoriality during gestation is underpinned by individually-specific hormone profiles. Our results suggest coyote androgens during gestation are sensitive to conspecific olfactory stimuli and prior breeding experience. Consequently, fluctuations in social or other environmental stimuli as well as increasing parity may acutely affect coyote traits essential to reproductive success.

Parental habituation to human disturbance over time reduces fear of humans in coyote offspring

“…We provide evidence to suggest that second‐litter pups had lower testosterone at 5 weeks of age (Figure , Table ), supporting our a priori prediction that offspring testosterone levels would match decreased prepartum testosterone of experienced parents found in our previous study (Schell et al, ). However, that trend was reversed over time, as second‐litter pups demonstrated higher cortisol and testosterone concentrations at 15 weeks of age compared to their first‐litter siblings (Figure , Table ).…”

“…Our initial study did not have an outgroup odor; however, previous studies indicate that coyote behavioral responses toward other chemical attractants are characteristically similar to the behavioral responses we observed in our previous work (Kimball, Johnston, Mason, Zemlicka, & Blom, ; Kimball, Mason, Blom, Johnston, & Zemlicka, ; Schell et al, ; Shivik, Wilson, & Gilbert‐Norton, ). We did not find a statistical effect of our odor manipulation on subsequent parenting behavior (Schell et al, ) or prolonged hormonal effects (Schell et al, ). Nevertheless, we also included parental odor treatment (i.e., “odor”) as a fixed effect in our statistical analyses.…”

“…Third, we predicted that developmental testosterone, but not cortisol, would be lower in second versus first‐litter siblings. Previously, we demonstrated that parents had reduced gestational testosterone (but not cortisol) as experienced versus naïve parents (Schell, Young, Lonsdorf, Mateo, & Santymire, ). Hence, our third prediction assumes that parent‐offspring endocrine responses will positively covary as found in previous work (Meylan, Miles, & Clobert, ; Sheriff et al, ).…”

“…Briefly, experimental groups (2011: n = 4; 2013: n = 4) received the odor cues four times over a 20‐day period, whereas control pairs (2011: n = 4; 2013: n = 4) received water as a delivery control (Schell et al, ). Our initial study did not have an outgroup odor; however, previous studies indicate that coyote behavioral responses toward other chemical attractants are characteristically similar to the behavioral responses we observed in our previous work (Kimball, Johnston, Mason, Zemlicka, & Blom, ; Kimball, Mason, Blom, Johnston, & Zemlicka, ; Schell et al, ; Shivik, Wilson, & Gilbert‐Norton, ). We did not find a statistical effect of our odor manipulation on subsequent parenting behavior (Schell et al, ) or prolonged hormonal effects (Schell et al, ).…”

“…We included litter year (i.e., first vs. second litter), pup developmental age, litter size, and sex as fixed effects in our model. In addition, male-female pairs in this study were previously exposed to olfactory attractants to simulate high-density conspecific environments meant to increase glucocorticoid concentrations prepartum (Schell et al, 2016), comparable with prior studies of vertebrate maternal effects (Dantzer et al, 2013;Schweitzer, Schwabl, Baran, & Adkins-Regan, 2014). Briefly, experimental groups (2011: n = 4; 2013: n = 4) received the odor cues four times over a 20-day period, whereas control pairs (2011: n = 4; 2013: n = 4) received water as a delivery control (Schell et al, 2016).…”