Madeleine M. Ostwald

• Arizona State University

Climate is a fundamental driver of macroecological patterns in functional trait variation. However, many of the traits that have outsized effects on thermal performance are complex, multi‐dimensional, and challenging to quantify at scale. To overcome this challenge, we leveraged techniques in deep learning and computer vision to quantify hair cover...

Body size is a salient functional trait in bees, with implications for reproductive fitness, pollination ecology, and responses to environmental change. Methods for quantifying bee body size commonly rely on indirect estimates and vary widely across studies, particularly in studies of the large carpenter bees (Xylocopa Latreille) (Apidae: Xylocopin...

Functional traits offer an informative framework for understanding ecosystem functioning and responses to global change. Trait data are abundant in the literature, yet many communities of practice lack data standards for trait measurement and data sharing, hindering data reuse that could reveal large‐scale patterns in functional and evolutionary ec...

Climatic factors are known to shape the expression of social behaviours. Likewise, variation in social behaviour can dictate climate responses. Understanding interactions between climate and sociality is crucial for forecasting vulnerability and resilience to climate change across animal taxa. These interactions are particularly relevant for taxa l...

Climatic stressors are important drivers in the evolution of social behavior. Social animals tend to thrive in harsh and unpredictable environments, yet the precise benefits driving these patterns are often unclear. Here, we explore water conservation in forced associations of a solitary bee (Melissodes tepidus timberlakei Cockerell, 1926) to test...

Sex pheromones are species-specific chemical signals that facilitate the location, identification, and selection of mating partners. These pheromones can vary between individuals, and act as signals of mate quality. Here, we investigate the variation of male pheromones in the mesosomal glands of the large carpenter bee Xylocopa sonorina, within a N...

Sex pheromones are species-specific chemical signals that facilitate the location, identification, and selection of mating partners. These pheromones can vary between individuals, and act as signals of mate quality. Here, we investigate the variation of male pheromones in the mesosomal glands of the large carpenter bee Xylocopa sonorina, within a N...

As small-bodied terrestrial organisms, insects face severe desiccation risks in arid environments, and these risks are increasing under climate change. Here, we investigate the physiological, chemical, and behavioral mechanisms by which harvester ants, one of the most abundant arid-adapted insect groups, cope with desiccating environmental conditio...

Chemical communication plays a critical role in the organization of insect societies. Although the identity and function of chemical signals in eusocial species have been well-characterized, there is still relatively little understood about the role that chemical communication plays in insects with the simplest forms of social organization. General...

The evolution of long-range pheromonal communication is often facilitated by morphological adaptations in glandular structures. Male carpenter bees (Xylocopa) in four subgenera possess hypertrophied sex pheromone glands responsible for their long-distance mate attraction. The valley carpenter bee (Xylocopa sonorina) is known for its “dispersed lek”...

Environmental challenges are major drivers of the evolution of group living. In particular, harsh seasonal conditions can promote temporary or facultative social behaviour in primarily solitary animals. We asked how winter conditions might favour group living in a desert population of a facultatively social carpenter bee, Xylocopa sonorina Smith, t...

Investigations of thermally adaptive behavioral phenotypes are critical for both understanding climate as a selective force and for predicting global species distributions under climate change conditions. Cooperative nest founding is a common strategy in harsh environments for many species, and can enhance growth and competitive advantage, but whet...

Despite the prominence of kin selection as a framework for understanding the evolution of sociality, many animal groups are comprised of unrelated individuals. These non-kin systems provide valuable models that can illuminate drivers of social evolution beyond indirect fitness benefits. Within the Hymenoptera, whose highly related eusocial groups h...

Kin selection theory has dominated our understanding of the evolution of group living. However, many animal groups form among non-relatives, which gain no indirect fitness benefits from cooperating with nestmates. In this study, we characterized the relatedness and inter-nest migration behavior of the facultatively social carpenter bee, Xylocopa so...

Social groups form when the costs of breeding independently exceed fitness costs imposed by group living. The costs of independent breeding can often be energetic, especially for animals performing expensive behaviours, such as nest construction. To test the hypothesis that nesting costs can drive sociality by disincentivizing independent nest foun...

The fitness consequences of cooperation can vary across an organism’s lifespan. For non-kin groups, especially, social advantages must balance intrinsic costs of cooperating with non-relatives. In this study, we asked how challenging life history stages can promote stable, long-term alliances among unrelated ant queens. We reared single- and multi-...

Collective defense is one of the most ubiquitous behaviors performed by social groups. Because of its importance, complex societies may engage a set of defensive specialists, with physical and/or neurological attributes tuned for defense against specific invaders. These strategies must be balanced, however, with the need to flexibly respond to diff...

The advantages of group living are partially offset by the cognitive challenges associated with maintaining social boundaries. These challenges can give rise to recognition mechanisms that adaptively integrate information across multiple sensory modalities. The valley carpenter bee, Xylocopa varipuncta, nests in dead wood in large aggregations of u...

Task allocation is a central challenge of collective behavior in a variety of group-living species, and this is particularly the case for the allocation of social insect workers for group defense. In social insects, both benefits and considerable costs are associated with the production of specialized soldiers. We asked whether colonies mitigate co...

Social insect colonies are high-value foraging targets for insectivores, prompting the evolution of complex colony defensive adaptations as well as specialized foraging tactics in social insect predators. Predatory ants that forage on other social insects employ a diverse range of behaviors targeted at specific prey species. Here, we describe a sol...

Sociometry is the description and analysis of the physical and numerical attributes of social insect colonies over their lifetimes. Sociometric data, such as worker number and nest size are essential for understanding how colonies develop but are rarely collected. Even Apis mellifera, the most intensively studied social insect, has never received a...

This study investigated how a honey bee colony develops and quenches its collective thirst when it experiences hyperthermia of its broodnest. We found that a colony must strongly boost its water intake because evaporative cooling is critical to relieving broodnest hyperthermia, and that it must rapidly boost its water intake because a colony mainta...

Organisms face the challenge of optimally allocating limited resources among investments that promote survival, growth or reproduction. In species whose members build complex nests, this resource allocation problem also applies to the building and use of the nest structure, a critical part of an individual's extended phenotype. Honeybee colonies fa...

Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that...