Assessing seasonal demographic covariation to understand environmental‐change impacts on a hibernating mammal

Natural populations are exposed to seasonal variation in environmental factors that simultaneously affect several demographic rates (survival, development and reproduction). The resulting covariation in these rates determines population dynamics, but accounting for its numerous biotic and abiotic drivers is a significant challenge. Here, we use a factor‐analytic approach to capture partially unobserved drivers of seasonal population dynamics. We use 40 years of individual‐based demography from yellow‐bellied marmots (Marmota flaviventer ) to fit and project population models that account for seasonal demographic covariation using a latent variable. We show that this latent variable, by producing positive covariation among winter demographic rates, depicts a measure of environmental quality. Simultaneously, negative responses of winter survival and reproductive‐status change to declining environmental quality result in a higher risk of population quasi‐extinction, regardless of summer demography where recruitment takes place. We demonstrate how complex environmental processes can be summarized to understand population persistence in seasonal environments

Evaluating potential effects of solar power facilities on wildlife from an animal behavior perspective

Solar power is a renewable energy source with great potential to help meetincreasing global energy demands and reduce our reliance on fossil fuels.However, research is scarce on how solar facilities affect wildlife. With inputfrom professionals in ecology, conservation, and energy, we conducted aresearch-prioritization process and identified key questions needed to betterunderstand impacts of solar facilities on wildlife. We focused on animalbehavior, which can be used to identify population responses before mortal-ity or other fitness consequences are documented. Behavioral studies canalso offer approaches to understand the mechanisms leading to negativeinteractions (e.g., collision, singeing, avoidance) and provide insight into mit-igating effects. Here, we review how behavioral responses to solar facilities, including perception, movement, habitat use, and interspecific interactionsare priority research areas. Addressing these themes will lead to a morecomprehensive understanding of the effects of solar power on wildlife andguide future mitigatio

Feeling vulnerable? Indirect risk cues differently influence how two marsupials respond to novel dingo urine

In Tasmania, introduced predators are becoming more common. How Tasmanian prey respond to novel predator cues is of particular interest for their survival and management. Prey response to predator scents may depend on whether predator and prey share an evolutionary history and may be influenced by indirect risk cues such as perceived shelter or safety in the environment. To simultaneously explore the effects of indirect and direct risk cues (predator scent) on free-living Tasmanian pademelons (Thylogale billardierii) and brush tail possums (Trichosurus vulpecula), we placed dingo (Canis lupus dingo) urine scents inside and outside a 25 -m2 selective feeding enclosure to mimic a heterogeneous risk landscape. Despite the lack of a historical relationship between dingoes and Tasmanian fauna, pademelons and possums demonstrated flight and vigilance when confronted with the novel scent outside the enclosure. According to our index of deterrence, number of successful entries/approaches, both species were deterred. However, responses inside the safe enclosure differed according to species. For instance, pademelons made more approaches/entries into the enclosure and fled more following approaches to scent marks both inside and outside the enclosure. In comparison, possums only exhibited similar responses outside the enclosure, and there was no effect of stimulus inside the safe compound. Our findings suggest that small animals may be pre-adapted to avoid some predators they have not previously been in contact with, and that brush tail possums are more likely to respond to predation cues when exposed and vulnerable. Ultimately, the cumulative effects of direct and indirect risk cues may either increase or reduce a repellent response

Is sociality associated with high longevity in North American birds?

Sociality, as a life-history trait, should be associated with high longevity because complex sociality is characterized by reproductive suppression, delayed breeding, increased care and survival, and some of these traits select for high longevity. We studied the relationship between cooperative parental care (a proxy of complex sociality) and relative maximum lifespan in 257 North American bird species. After controlling for variation in maximum lifespan explained by body mass, sampling effort, latitude, mortality rate, migration distance and age at first reproduction, we found no significant effect of cooperative care on longevity in analyses of species-specific data or phylogenetically independent standardized linear contrasts. Thus, sociality itself is not associated with high longevity. Rather, longevity is correlated with increased body size, survival rate and age of first reproduction

An in situ vertebrate bioassay helps identify potential matrices for a predator-based synthetic management tool

To assist management and conservation needs, researchers have called for active kairomones to be elucidated and synthesized directly from animal exudates. However, the existing literature does not provide guidance on how to initiate this complex process. To our knowledge, composite synthetic predator scents that incorporate multiple compounds to accurately mimic the natural signal have not been produced. One approach to improve the accuracy of synthetics is to identify and recombine all major infochemicals within a benign solvent. Therefore, we tested 2 natural, pre-existing matrices for their potential as vehicles for delivery of a predator scent, dingo (Canis lupus dingo) urine, which causes a startle reaction among western gray kangaroos (Macropus fuliginosus), and avoidance by European foxes (Vulpes vulpes). We compared 2 putative backbone matrices -aged (3-yr old) dingo urine from a previously active lot, and 10% methanol -to a distilled water control. We used a novel fence-crossing assay to observe kangaroo interactions with both solvents and a negative control. Our assay allowed us to control for high feeding motivation by testing compounds away from the food source. We determined that neither free-ranging kangaroos nor European red foxes were adversely affected by either treatment matrix. Foxes were, however, attracted to the aged dingo urine, and were often observed scent-rolling in the inactive substance. Our results suggest that dilute methanol could be a possible matrix for predator-scent applications for kangaroos, while aged scents may act as an attractant for nontarget species, particularly canids

Harnessing natural selection to tackle the problem of prey naivete

Many populations are threatened or endangered because of excessive predation resulting from individuals’ inability to recognize, avoid, or escape alien predators. Such prey na€ıvete is often attributed to the absence of prior experience and co-evolution between native prey and introduced predators. Many reintroduction programs focus on reducing predation rate by excluding introduced predators, a focus which ignores, and indeed exacerbates, the problem of prey na€ıvete. We argue for a new paradigm in reintroduction biology that expands the focus from predator control to kick-starting learning and evolutionary processes between alien predators and reintroduced prey. By exposing reintroduced prey to carefully controlled levels of alien predators, in situ predation could enhance reintroduction success by facilitating acquisition of learned antipredator responses and through natural selection for appropriate antipredator traits. This in situ predator exposure should be viewed as a long-term process but is likely to be the most efficient and expedient way to improve prey responses and assist in broadscale recovery of threatened species.Katherine E. Moseby, Daniel T. Blumstein, Mike Letni

Kin recognition in a macropod marsupial

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Do film soundtracks contain nonlinear analogues to influence emotion?

A variety of vertebrates produce nonlinear vocalizations when they are under duress. By their very nature, vocalizations containing nonlinearities may sound harsh and are somewhat unpredictable; observations that are consistent with them being particularly evocative to those hearing them. We tested the hypothesis that humans capitalize on this seemingly widespread vertebrate response by creating nonlinear analogues in film soundtracks to evoke particular emotions. We used lists of highly regarded films to generate a set of highly ranked action/adventure, dramatic, horror and war films. We then scored the presence of a variety of nonlinear analogues in these film soundtracks. Dramatic films suppressed noise of all types, contained more abrupt frequency transitions and musical sidebands, and fewer noisy screams than expected. Horror films suppressed abrupt frequency transitions and musical sidebands, but had more non-musical sidebands, and noisy screams than expected. Adventure films had more male screams than expected. Together, our results suggest that film-makers manipulate sounds to create nonlinear analogues in order to manipulate our emotional responses