Biology subjects

Page, R. A.

Publications and source records attributed to Page, R. A..

8 recordsLinked to original sources

bioRxiv2025

If memory serves: Multisensory male display improves female memory during mate sampling

Across many taxa, males gather in leks to perform multisensory courtship displays for females. At a lek, changes in the sensory scene over the course of mate evaluation are inevitable. This dynamic nature makes a females ability to recall the location of individual signalers an important component of female mate choice. It is hypothesized that complex (especially multimodal) displays may improve a females ability to remember and thus discriminate amongst potential mates. To test this hypothesis, we presented female tungara frogs (Physalaemus (=Engystomops) pustulosus) with male calls (auditory) and robotic frogs (visual) that could later be obstructed from view via the lowering of blinds. Specifically, we asked if the visual component of a multimodal display improves the ability of a receiver to remember a signaler. While our initial experiment did not find memory instantiation in female frogs, subsequent experiments with a longer presentation time and a brief period of silence successfully instantiated memories in females. Moreover, females continued to demonstrate significant preferences for calls associated with the visual cue even after 25 s following the obstruction of the visual stimulus (robotic frog). Thus, we propose that the duration of presentation and/or the silent period impact memory capability. Silence is common in choruses, and our data suggest that complex, multisensory stimuli may have evolved to help females remember their preferred mate even with such fluctuations in signal production. LAY SUMMARYMultisensory signals function to stimulate one or more of a receivers senses, and in doing so, may make signalers more memorable to receivers. Multisensory signals are common in mating displays, including the advertisement of a male tungara frog: a call (acoustic) and a vocal sac inflation (visual). Here, we demonstrate that female tungara frogs were more likely to remember a multisensory male display over a unisensory display, but only after fluctuations in the signals intensity.

animal behavior and cognition↗

bioRxiv2025

Vocal convergence during formation of social relationships in vampire bats

In many group-living birds and mammals, the formation of affiliative relationships is hypothesized to cause vocal convergence (an increase in call similarity between individuals). However, testing this causal effect can be difficult, because it requires experimentally forming new relationships. Here, we demonstrate convergence in the contact calls of common vampire bats (Desmodus rotundus) that we introduced and experimentally housed together. To estimate and disentangle the roles of kinship, co-housing (familiarity), allogrooming, and food sharing in predicting call similarity, we first measured call similarity using 35 features of 693,494 contact calls from 95 bats, then fit a series of Bayesian generalized multi-membership models. We also measured changes in call similarity for a subset of individuals that were recorded before and after co-housing. We found that co-housing caused vocal convergence. Furthermore, food-sharing rates among familiar nonkin within the same co-housed group predicted contact call similarity. This finding suggests that the development of cooperative relationships causes further vocal convergence beyond the initial convergence caused by co-housing. Our findings have implications for the development of cooperative relationships and vocal learning.

animal behavior and cognition↗

bioRxiv2024

Food-associated calls in disc-winged bats

Animals that engage in social foraging can produce food-associated calls that elicit two main responses in receivers: the recruitment of other individuals to a foraging site, and an increase in feeding-related behaviors in conspecifics. Spixs disc-winged bat, Thyroptera tricolor, is a highly gregarious species that lives in stable social groups and relies on group call-and-response vocalizations to find ephemeral roosting sites. Because this bat also is known to feed on resources that are abundant but ephemeral - for example insect swarms - we hypothesized that it likewise emits vocalizations that serve to recruit conspecifics to a foraging site and elicit food consumption. We found that indeed, feeding bats emitted distinct vocalizations exclusively while consuming an abundant prey item, a call type that has not been previously described in the acoustic repertoire of any bat to date. We also observed that these "food calls" prompted responses typically associated with food-calling: they increased both feeding-related behaviors and social recruitment. Specifically, we observed that the onset of the consumption of novel prey items was strongly associated with the emission of food calls but not with other types of sounds. In addition, individuals approached a speaker broadcasting food calls, especially when food calls had not been broadcast before, while other types of sounds did not consistently prompt inspection. Taken together, these results suggest that T. tricolor coordinates foraging behavior through the emission of food-associated communication calls. SUMMARY STATEMENTThis study provides evidence of food-associated calling in Spixs disc-winged bats (Thyroptera tricolor), revealing its association with feeding contexts and its potential role in prompting social recruitment and feeding-related behaviors.

animal behavior and cognition↗

bioRxiv2022

Spatial learning overshadows learning novel odors and sounds in both a predatory and a frugivorous bat

AO_SCPLOWBSTRACTC_SCPLOWTo be efficient while foraging, animals should be selective about attending to and remembering the cues of food that best predict future meals. One hypothesis is that animals with different foraging strategies should vary in their reliance on spatial and feature cues. Animals that store food or feed on spatially stable food, like fruit or flowers, should be predisposed to learning a meals location, whereas predators that hunt mobile prey should instead be biased towards learning feature cues such as color or sound. Previous studies suggest that nectar- and fruit-feeding bats should rely relatively more on spatial cues, whereas predatory bats should rely more on feature cues, yet no experiment has compared these two foraging strategies under the same conditions. To test this hypothesis, we compared learning in the frugivorous bat, Artibeus jamaicensis, and the predatory bat, Lophostoma silvicolum, which hunts katydids using acoustic cues. We trained bats to find food paired with a unique odor, sound, and location. We then dissociated these cues to assess which cue each bat had learned. Rather than finding that the frugivore and predator are on opposite ends of a continuum in their relative reliance on spatial and feature cues, we found that both species learned spatial cues with no evidence that either learned the sounds or odors. We discuss interpretations of these results in the context of past work on use of spatial cues versus feature cues. Compared to feature cues, spatial cues may be fundamentally more rich, salient, or memorable. LO_SCPLOWAYC_SCPLOW SO_SCPLOWUMMARYC_SCPLOWWhen animals learn how to obtain food, they could attend to many possible cues--such as the associated smells, sights, sounds, or locations of the food. It has been hypothesized that natural selection has shaped animals to pay particular attention to the types of cues that are most useful for finding their typical food. In bats, this would predict that predatory species that hunt mobile, noisy insects by sound should be biased towards learning a food-associated sound, whereas bats that eat stationary and silent fruit should be biased towards learning a foods location. We gave predatory and fruit-eating bats the opportunity to simultaneously learn food-rewarded odors, sounds, or locations. Regardless of their diets, both species of bats learned locations rather than the odors or sounds associated with food. Spatial cues may be particularly rich or salient, and when they are reliable, animals may use them for learning over other cues regardless of their typical food.

animal behavior and cognition↗

bioRxiv2022

Long-term memory in frog-eating bats

Long-term memory has clear advantages but also has neurological and behavioral costs1-3. Given these opposing selection pressures, understanding how long memories last can shed light on how memory enhances or constrains animals abilities to exploit their niches. Although testing memory retention in wild animals is difficult, it is important because captive conditions do not reflect the complex cognitive demands of wild environments, and long-term captivity changes the brain4 (past studies on nonhuman long-term memory are reviewed in Table S1). Here, we trained wild-caught frog-eating bats (Trachops cirrhosus) to find prey by flying to a novel acoustic cue, released them back into the wild, and then re-captured some of them 1-4 years later. When re-tested, all eight experienced bats that previously learned the novel prey sounds flew to those sounds within seconds, whereas 17 naive bats tested with the same sounds showed weak responses. Experienced bats also showed behavior indicating generalization of memories between novel sounds and rewards over time. The frog-eating bats remarkably long memory for novel acoustic cues indicates that an ability to remember rarely encountered prey may be advantageous for this predator, and suggests hitherto unknown cognitive abilities in bats. O_TBL View this table: org.highwire.dtl.DTLVardef@15a8294org.highwire.dtl.DTLVardef@132eb3forg.highwire.dtl.DTLVardef@1f29583org.highwire.dtl.DTLVardef@135dff2org.highwire.dtl.DTLVardef@19cfa_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable S1:C_FLOATNO O_TABLECAPTIONStudies of animal memory durations documenting memories of months or years. Memory duration = the longest duration demonstrated in the study. Wild or captive = where animals spent the time of memory retention; some "captive" animals were originally wild caught. Context = the ecological context and memory task being tested. 2-AFC = Two-alternative forced choice. C_TABLECAPTION C_TBL

animal behavior and cognition↗

bioRxiv2020

Immune-challenged vampire bats produce fewer contact calls

Infections can affect how animals vocalize and, hence, interact with conspecifics. While this effect has been shown for mate-attraction calls, other vocalizations that facilitate social contact have received less attention. When isolated, vampire bats produce contact calls which attract highly associated groupmates. Here, we test the effect of an immune challenge on contact calling rates of individually isolated vampire bats. Sickness behavior did not appear to change call structure, but it decreased the number of contact calls produced. This effect could decrease contact with groupmates and augment other established mechanisms by which sickness reduces social encounters (e.g. mortality, lethargy, and social withdrawal or disinterest).

animal behavior and cognition↗

bioRxiv2019

Evidence for unfamiliar kin recognition in vampire bats

Kin discrimination allows organisms to preferentially cooperate with kin, reduce kin competition, and avoid inbreeding. In vertebrates, kin discrimination often occurs through prior association. There is less evidence for recognition of unfamiliar kin. Here, we present the first evidence of unfamiliar kin recognition in bats. We captured female vampire bats (Desmodus rotundus) from a single roost, allowed them to breed in captivity for 22 months, then released 17 wild-caught females and six captive-born daughters back into the same wild roost. We then used custom-built proximity sensors to track the free-ranging social encounters among the previously captive bats and 27 tagged control bats from the same roost. Using microsatellite-based relatedness estimates, we found that previously captive bats preferentially associated with related control bats, and that captive-born bats preferentially associated with unfamiliar kin among control bats. Closer analyses showed that these unfamiliar-kin-biased associations were not caused by mothers or other familiar close kin, because the kinship bias was evident even when those bats were not nearby. This striking evidence for unfamiliar kin recognition in vampire bats warrants further investigation and provides new hypotheses for how cooperative relationships might be driven synergistically by both social experience and phenotypic similarity.

animal behavior and cognition↗

bioRxiv2019

Thinking small: next-generation sensor networks close the size gap in vertebrate biologging

Recent advances in animal tracking technology have ushered in a new era in biologging. However, the considerable size of many sophisticated biologging devices restricts their application to larger animals, while old-fashioned techniques often still represent the state-of-the-art for studying small vertebrates. In industrial applications, low-power wireless sensor networks fulfill requirements similar to those needed to monitor animal behavior at high resolution and at low tag weight. We developed a wireless biologging network (WBN), which enables simultaneous direct proximity sensing, high-resolution tracking, and long-range remote data download at tag weights of one to two grams. Deployments to study wild bats created social networks and flight trajectories of unprecedented quality. Our developments highlight the vast capabilities of WBNs and their potential to close an important gap in biologging: fully automated tracking and proximity sensing of small animals, even in closed habitats, at high spatial and temporal resolution.

animal behavior and cognition↗