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The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, but detailed data from diverse taxa within a single ecosystem are rare. We collated first sighting and median activity within a high-elevation environment for plants, insects, birds, mammals and an amphibian across 45 years (1975–2020). We related 10 812 phenological events to climate data to determine the relative importance of climate effects on species’ phenologies. We demonstrate significant variation in climate-phenology linkage across taxa in a single ecosystem. Both current and prior climate predicted changes in phenology. Taxa responded to some cues similarly, such as snowmelt date and spring temperatures; other cues affected phenology differently. For example, prior summer precipitation had no effect on most plants, delayed first activity of some insects, but advanced activity of the amphibian, some mammals, and birds. Comparing phenological responses of taxa at a single location, we find that important cues often differ among taxa, suggesting that changes to climate may disrupt synchrony of timing among taxa.

Maternal characteristics, social dynamics, and environmental factors can all influence reproduction and survival and shape trade-offs that might arise between these components of fitness. Short-lived mammals like the golden-mantled ground squirrel (GMGS; Callospermophilus lateralis) tend to maximize effort toward current reproduction at the expense of survival but may be complicated by other aspects of the species' life history and environment. Here, we use 25years of data (1995-2020) collected from a population of GMGS at the Rocky Mountain Biological Research Laboratory in Gothic, Colorado, to test the effect of several maternal characteristics (e.g., age, experience, and timing of litter emergence), social context (e.g., litter sex ratio and kin density), and environmental context (e.g., date of bare ground and length of vegetative growing season) on survival of reproductive female GMGS using Cox proportional hazard models. Our results indicated that social dynamics (i.e., density) and environmental conditions (i.e., standardized first day of permanent snow cover and length of growing season) explained significant variation in annual maternal survival, while maternal characteristics did not. A higher density of related breeding females and the total number of females (both related and unrelated to the focal mother) were associated with an increase in the mortality hazard. A later standardized date of the first day of permanent snow cover and a shorter growing season both reduced the maternal mortality hazard. Together, our results suggest that factors extrinsic to the squirrels affect maternal survival and thus may also influence local population growth and dynamics in GMGS and other short-lived, territorial mammal species.

Weaving the future of the field of comparative psychology is dependent on the career advancement of early-career scientists. Despite concerted efforts to increase diversity in science, technology, engineering, and mathematics, scholars from marginalized groups are disproportionately underrepresented in the field-especially at advanced career stages. New approaches to sponsorship, mentoring, and community building are necessary to retain talent from marginalized communities and to create a culture and a system where all individuals can thrive. We describe the unique and supportive role of senior women scientists united through a professional society in initiating peer coaching circles to facilitate the success of a diverse cohort of early-career women scientists. We offer our experiences with the Weaving the Future of Animal Behavior program as a case study that illustrates the cascading impacts of professional societies investing in the success and career development of marginalized scholars. We focus on our peer coaching circle experience and share the products and outcomes after 2 years of meeting. Peer coaching transformed us from a group of loosely organized, anxious individuals into a collective of empowered agents of change with an enhanced sense of belonging. We end by presenting recommendations to institutions seeking to expand the landscape of opportunities to other marginalized scholars. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Modern genetic parentage methods reveal that alternative reproductive strategies are common in both males and females. Under ideal conditions, genetic methods accurately connect the parents to offspring produced by extra-pair matings or conspecific brood parasitism. However, some breeding systems and sampling scenarios present significant complications for accurate parentage assignment. We used simulated genetic pedigrees to assess the reliability of parentage assignment for a series of challenging sampling regimes that reflect realistic conditions for many brood-parasitic birds: absence of genetic samples from sires, absence of samples from brood parasites and female kin-structured populations. Using 18 microsatellite markers and empirical allele frequencies from two populations of a conspecific brood parasite, the wood duck (Aix sponsa), we simulated brood parasitism and determined maternity using two widely used programs, cervus and colony. Errors in assignment were generally modest for most sampling scenarios but differed by program: cervus suffered from false assignment of parasitic offspring, whereas colony sometimes failed to assign offspring to their known mothers. Notably, colony was able to accurately infer unsampled parents. Reducing the number of markers (nine loci rather than 18) caused the assignment error to slightly worsen with colony but balloon with cervus. One potential error with important biological implications was rare in all cases-few nesting females were incorrectly excluded as the mother of their own offspring, an error that could falsely indicate brood parasitism. We consider the implications of our findings for both a retrospective assessment of previous studies and suggestions for best practices for future studies.

Interspecific hybridization is recognized as an important process in the evolutionary dynamics of both speciation and the reversal of speciation. However, our understanding of the spatial and temporal patterns of hybridization that erode versus promote species boundaries is incomplete. The endangered, endemic koloa maoli (or Hawaiian duck, Anas wyvilliana) is thought to be threatened with genetic extinction through ongoing hybridization with an introduced congener, the feral mallard (A. platyrhynchos). We investigated spatial and temporal variation in hybrid prevalence in populations throughout the main Hawaiian Islands, using genomic data to characterize population structure of koloa, quantify the extent of hybridization, and compare hybrid proportions over time. To accomplish this, we genotyped 3,308 double-digest restriction-site-associated DNA (ddRAD) loci in 425 putative koloa, mallards, and hybrids from populations across the main Hawaiian Islands. We found that despite a population decline in the last century, koloa genetic diversity is high. There were few hybrids on the island of Kaua'i, home to the largest population of koloa. By contrast, we report that sampled populations outside of Kaua'i can now be characterized as hybrid swarms, in that all individuals sampled were of mixed koloa × mallard ancestry. Further, there is some evidence that these swarms are stable over time. These findings demonstrate spatial variation in the extent and consequences of interspecific hybridization, and highlight how islands or island-like systems with small population sizes may be especially prone to genetic extinction when met with a congener that is not reproductively isolated.

In hibernating squirrels, the amount of energy stored as fat may influence several important demographic traits, but is difficult to quantify in living animals. Thus, several non-destructive indices of body condition are used, including simple indices that use body mass and scaled indices that correct body mass for structural size. However, the accuracy of these indices for hibernating squirrels is poorly known. We used measurements of total body electrical conductivity (TOBEC) from adult female Golden-mantled Ground Squirrels (Callospermophilus lateralis) to characterize body composition (lean mass versusfat mass) and condition (fat stores) at multiple stages in the circannual cycle. Body mass explained a high proportion of the variation in fat mass during the emergence and pre-hibernation stages, but less during the reproduction stage. Contrary to expectation, correcting for structural size did not markedly improve the condition index. Our results suggest that body mass is a good estimate of body condition during the periods of emergence and pre-hibernation fattening, and therefore may be useful to predict important components of fitness such as reproductive success and overwinter survival.

An increasing number of empirical studies aim to quantify individual variation in demographic parameters because these patterns are key for evolutionary and ecological processes. Advanced approaches to estimate individual heterogeneity are now using a multivariate normal distribution with correlated individual random effects to account for the latent correlations among different demographic parameters occurring within individuals. Despite the frequent use of multivariate mixed models, we lack an assessment of their reliability when applied to Bernoulli variables. Using simulations, we estimated the reliability of multivariate mixed effect models for estimating correlated fixed individual heterogeneity in demographic parameters modelled with a Bernoulli distribution. We evaluated both bias and precision of the estimates across a range of scenarios that investigate the effects of life-history strategy, levels of individual heterogeneity and presence of temporal variation and state dependence. We also compared estimates across different sampling designs to assess the importance of study duration, number of individuals monitored and detection probability. In many simulated scenarios, the estimates for the correlated random effects were biased and imprecise, which highlight the challenge in estimating correlated random effects for Bernoulli variables. The amount of fixed among-individual heterogeneity was frequently overestimated, and the absolute value of the correlation between random effects was almost always underestimated. Simulations also showed contrasting performances of mixed models depending on the scenario considered. Generally, estimation bias decreases and precision increases with slower pace of life, large fixed individual heterogeneity and large sample size. We provide guidelines for the empirical investigation of individual heterogeneity using correlated random effects according to the life-history strategy of the species, as well as, the volume and structure of the data available to the researcher. Caution is warranted when interpreting results regarding correlated individual random effects in demographic parameters modelled with a Bernoulli distribution. Because bias varies with sampling design and life history, comparisons of individual heterogeneity among species is challenging. The issue addressed here is not specific to demography, making this warning relevant for all research areas, including behavioural and evolutionary studies.

Population monitoring is critical to effective conservation, but forest living taxa can be difficult to directly observe. This has been true of African forest elephants (Loxodonta cyclotis), for which we have limited information regarding population size and social behavior despite their threatened conservation status. In this study, we estimated demographic parameters using genetic capture-recapture of forest elephants in the southern Industrial Corridor of the Gamba Complex of Protected Areas in southwestern Gabon, which is considered a global stronghold for forest elephants. Additionally, we examined social networks, predicting that we would find matrilineal structure seen in both savanna and forest elephants. Given 95% confidence intervals, we estimate population size in the sampled area to be between 754 and 1,502 individuals and our best density estimate ranges from 0.47 to 0.80 elephants per km2. When extrapolated across the entire Industrial Corridor, this estimate suggests an elephant population size of 3,033 to 6,043 based on abundance or 1,684 to 2,832 based on density, approximately 40–80% smaller than previously suggested. Our social network analysis revealed approximately half of network components included females with different mitochondrial haplotypes suggesting a wider range of variation in forest elephant sociality than previously thought. This study emphasizes the threatened status of forest elephants and demonstrates the need to further refine baseline estimates of population size and knowledge on social behavior in this taxon, both of which will aid in determining how population dynamics in this keystone species may be changing through time in relation to increasing conservation threats.

Evolutionary theory predicts that parents should bias investment in offspring towards the sex that will yield the higher fitness returns, and one outcome may be biased offspring sex ratios. Bias in offspring sex ratios has been proposed to vary with specific social, maternal and environmental conditions that alter the fitness returns of each sex, but empirical evidence is conflicting both within and across taxa. We used 18 years of pedigree and demographic data to investigate variation in offspring sex ratios in a population of golden-mantled ground squirrels. Despite overall parity in offspring sex ratio, we found predictable changes in offspring sex ratio in response to female density at the population level: squirrels produced more daughters when female density was low and more sons when female density was high. At the individual level, females adjusted litter sex ratios similarly, but only in response to high densities of kin, and not in response to density of nonkin. This effect was reversed for older females (≥3 years) in dense kin neighbourhoods, which were more likely to produce daughters, perhaps because older females had the behavioural dominance necessary to recruit daughters at high densities. By contrast, litter sex ratios did not vary with maternal condition or food availability. Our results support the local resource competition theory of offspring sex allocation for this species. Knowledge of female relatedness revealed patterns of sex ratio adjustment that otherwise would have been obscured, highlighting the importance of interactions with kin in an asocial species.

The potential for extirpation of extremely small populations (ESPs) is high due to their vulnerability to demographic and environmental stochasticity and negative impacts of human activity. We argue that conservation actions that could aid ESPs are sometimes delayed because of a fear of failure. In human psychology, the fear of failure is composed of several distinct cognitive elements, including “uncertainty about the future” and “upsetting important others.” Uncertainty about the future is often driven by information obstacles in conservation: information is either not easily shared among practitioners or information is lacking. Whereas, fear of upsetting important others can be due to apprehension about angering constituents, peers, funders, and other stakeholders. We present several ways to address these fears in hopes of improving the conservation process. We describe methods for increased information sharing and improved decision-making in the face of uncertainty, and recommend a shift in focus to cooperative actions and improving methods for evaluating success. Our hope is that by tackling stumbling blocks due to the apprehension of failure, conservation and management organizations can take steps to move from fear to action.

Multiple paternity is common in vertebrates that produce several offspring in the same reproductive bout, but the rate often varies among and within populations. Three primary explanations for this variation have been advanced: null models based on encounter rate of mates, socioecological models dependent on the ability of males to monopolize females, and age- or condition-dependent models of female choice. We used 18 years of genetic and demographic data to examine the mating system and patterns of multiple paternity in a free-living population of golden-mantled ground squirrels (Callospermophilus lateralis). The mating system was polygynandrous, but opportunity for sexual selection was lower for females than for males. Annual reproductive success of males was low for yearlings and new immigrants and increased with breeding tenure in the population. Multiple paternity was evident in 62% of litters. In accordance with the socioecological model of male monopolization, rates of multiple paternity decreased with female spatial clustering, unless male–male competition, as indicated by male density, was also high. From Bateman gradients, we found no direct fitness benefit of multiple paternity for females. Though not statistically significant, multiple paternity appeared to decrease with maternal age and peri-oestrous mass, in possible support of the female choice model. Together, our results suggest that variation in the rate of multiple paternity in golden-mantled ground squirrels was determined by density and the active strategies of males and females. Since the advent of molecular parentage assignment several decades ago, we have known that females of many species produce offspring with different fathers. Several theories have been developed for why females produce multiply-sired clutches or litters, but rarely are we able to identify the environmental, social, or individual conditions under which they do so. In this study, we genotyped offspring produced in one population of ground squirrels over 18 years, and found that the frequency of multiple paternity varied considerably from year to year, that density of female kin interacted with male density to influence multiple paternity, and that older and heavier females tended to be less likely to produce multiply-sired litters. These results demonstrate how dynamic population and individual characteristics of breeding males and females contribute to mating system variation in the same population over time.

Reproduction is thought to be costly for female mammals due to high energetic costs associated with pregnancy and lactation. Such costs of reproduction can be particularly high for younger females, who are less experienced and smaller than fully grown adults, and can manifest themselves within (intra-individual or intra-generational trade-offs) or between (inter-generational trade-offs) generations. Using lifetime survival and reproductive histories of 416 female golden-mantled ground squirrels (Callospermophilus lateralis) in Colorado, USA, we tested for the evidence of intra- and inter-generational trade-offs between age of first reproduction and fitness and its components. Females who waited to begin reproduction lived longer but they did not experience a greater number of lifetime reproductive events, did not produce larger litters, nor did they have higher lifetime reproductive success than those females who attained reproductive maturity earlier. However, delaying age of first reproduction substantially reduced individual fitness, quantified as the dominant eigenvalue of the population projection matrix, suggesting that fitness benefits of earlier maturity exceeded associated costs. Females born to mothers who delayed age of first reproduction had a higher probability of surviving to reproduce at least once during their lifetimes. Thus, in our study system, daughters pay for their mothers’ reproductive decisions, suggesting that some costs of reproduction can transcend a generation. Studies testing for costs of reproduction on survival or reproductive output within a short timeframe or those focusing within a generation may fail to detect inter-generational trade-offs.

IT HAS BECOME COMMONPLACE to remark that humans are now the dominant environmental force on the Earth. The indications are strong and diverse. They range from paleontologists reaching a consensus that humans contributed to megafaunal extinctions on at least two continents, North America and Australia;1 recognition that formerly intact marine ecosystems have changed enormously;2 suggestions that climate has changed sufficiently that no ecosystem is immune from alterations in species composition;3 remarks that pollution is widespread even in Antarctica;4 and arguments that human predation on mammals is pernicious and the principal driver of changes in phenotypic traits of exploited species in many areas.5 Some scientists use geographic data to show that human activities affect almost every terrestrial system (e.g., the human footprint6). Indeed, the current epoch is now being referred to as “the Anthropocene,”7 which has led geologists to formally debate stratigraphic evidence for this new phenomenon and to argue over not if but when it began.8 With the catchword Anthropocene in ascendancy, one might easily come away with the impression that nowhere on Earth is natural, in one of the word’s specific meanings of ecosystems being untouched by humans,9 and indeed it is common to hear the phrase “humans have altered everything.”