Crypsis in a polymorphic mammal along an urbanization gradient DOI Creative Commons
J. Proctor,

A. M. Bryan,

Bradley J. Cosentino

и другие.

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Дек. 12, 2024

Abstract Urbanization transforms landscapes and alters visual environments for polymorphic species that rely on cryptic coloration survival, potentially generating urban-rural clines in pigmentation. Such are evident eastern gray squirrel (Sciurus carolinensis) populations, which a melanic morph is currently more prevalent cities but was historically rural woodlands prior to urbanization. We compared the degree of crypsis between two primary color morphs squirrels – among suite habitats predominate along an urbanization gradient test whether altered environment may contribute maintenance cline prevalence. Crypsis quantified using online game with human observers image pixel classification measure detectability taxidermic mounts each against their backgrounds replicate sites within habitat. The conspicuous than all habitat types across seasons, as evidenced by greater detection probabilities lower background matching. Coat likely mediates predators, resulting selection conspicuous, woodlands. Conversely, via road mortality favor urban areas if vehicular collisions melanics easily avoided due conspicuity. conclude differential continuum gradients play important role maintaining coat color.

Язык: Английский

Road mortality contributes to the evolution of an urban-rural cline in squirrel coat color DOI Creative Commons
Adam F. Parlin, Bradley J. Cosentino, Richard M. Lehtinen

и другие.

Research Square (Research Square), Год журнала: 2025, Номер unknown

Опубликована: Фев. 11, 2025

Abstract Cities impose unique selection pressures on wildlife and generate clines in phenotypic traits along urban-rural gradients. Roads, as a ubiquitous feature of human dominated landscapes, are significant source direct mortality for wildlife, but their role selective force producing trait variation is not known. This study tested the hypothesis that roads influence natural coat color eastern gray squirrel (Sciurus carolinensis), species which vehicular collisions mortality. has two distinct colors: morph common all areas, melanic more prevalent urban areas than rural ones. We conducted standardized road cruise surveys to compare proportion each among road-killed living squirrels an urbanization gradient Syracuse, New York, USA. also examined prevalence off surfaces range-wide compilation > 100,000 photographs S. carolinensis. The melanism Syracuse was negatively related distance from city center, whereas there no cline squirrels. underrepresented by up 30% gradient. found image database. Our highlights important cause can contribute maintenance clines.

Язык: Английский

Процитировано

1
Crypsis in a polymorphic mammal along an urbanization gradient DOI
J. Proctor,

A. M. Bryan,

Bradley J. Cosentino

и другие.

Urban Ecosystems, Год журнала: 2025, Номер 28(2)

Опубликована: Март 21, 2025

Язык: Английский

Процитировано

1
Rural selection drives the evolution of an urban–rural cline in coat color in gray squirrels DOI Creative Commons
Bradley J. Cosentino, John P. Vanek, James P. Gibbs

и другие.

Ecology and Evolution, Год журнала: 2023, Номер 13(10)

Опубликована: Окт. 1, 2023

Phenotypic differences between urban and rural populations are well-documented, but the evolutionary processes driving trait variation along urbanization gradients often unclear. We combined spatial data on abundance, variation, measurements of fitness to understand cline structure test for natural selection heritable coat color morphs (melanic, gray) eastern gray squirrels (

Язык: Английский

Процитировано

9
Does differential predation of Littorina saxatilis colour morphs contribute to the maintenance of a colour cline? Insights from a field tethering experiment DOI Creative Commons
Juan Gefaell, Ramón Vigo, Emilio Rolán-Álvarez

и другие.

Journal of Molluscan Studies, Год журнала: 2025, Номер 91(1)

Опубликована: Фев. 26, 2025

ABSTRACT Colour clines constitute an interesting topic of study for evolutionary ecologists as they allow the testing different hypotheses on adaptive value colour variation. One possible explanation selective advantage colouration is crypsis. In Littorina saxatilis from Rías Baixas (northwest Iberian Peninsula), a temporally stable and spatially recurrent cline has been described. This extends wave-sheltered localities to most wave-exposed areas, latter bearing monomorphic populations lineated morph. As ecological communities, therefore background colours, change gradually along wave-exposure continuum, plausible this selection crypsis, by which less cryptic morphs are weeded out populations, presumably crabs. would be especially intense at cline. present study, we describe tethering experiment representative site (Cabo Silleiro) aimed hypothesis, in addition series complementary analyses Cabo Silleiro nearby polymorphic (Aguncheiro), snails used were collected. The analysis Aguncheiro revealed slight differences distribution shell scars (reflecting past crab attacks) across morphs, without clear support crypsis hypothesis. experiment, predation rates crabs recorded three transplanted Aguncheiro, with resident morph Silleiro. results suggestive, but not conclusive. more conspicuous was likely predated only one two sessions when classifying both chips substantive breaks attempts. While limited power, do provide valuable data designing future experiments motivation continued investigation variation organism.

Язык: Английский

Процитировано

0
Road Mortality Contributes to the Evolution of an Urban–Rural Cline in Squirrel Coat Color DOI Creative Commons
Adam F. Parlin, Bradley J. Cosentino, Richard M. Lehtinen

и другие.

Evolutionary Applications, Год журнала: 2025, Номер 18(5)

Опубликована: Май 1, 2025

ABSTRACT Cities impose unique selection pressures on wildlife and generate clines in phenotypic traits along urban–rural gradients. Roads are a widespread feature of human‐dominated landscapes known to cause direct mortality; however, whether they act as selective force influencing trait variation gradients remains unclear. This study tested the hypothesis that roads influence natural coat color eastern gray squirrel ( Sciurus carolinensis ), species with two distinct colors: morph is common all areas melanic more prevalent urban than rural ones. Vehicular collisions significant mortality squirrels, visually conspicuous easily detected avoided by drivers morph. Standardized road cruise surveys an urbanization gradient Syracuse, New York, USA, revealed prevalence melanism among living squirrels Syracuse was negatively related distance from city center, whereas there no cline road‐killed individuals, underrepresented up 30% gradient. An examination each off surfaces range‐wide compilation > 100,000 photographs S. also indicated imaged. Our highlights vehicular important source traits, suggesting potential role shaping patterns evolution contributing maintenance clines.

Язык: Английский

Процитировано

0
Ecological and evolutionary impacts of urbanization: applying a causal modeling framework DOI Creative Commons
Jesse B. Borden, James P. Gibbs, John P. Vanek

и другие.

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Сен. 7, 2024

Abstract Urbanization, as the fastest growing land use type, shapes biodiversity through a suite of abiotic and biotic changes driven by profound alteration environmental conditions in built environments. Understanding mechanisms behind patterns urban areas requires disentangling direct indirect pathways which urbanization impacts ecological evolutionary dynamics. We show how structural causal modeling framework can be used to provide insight into processes generating contexts building equation models disentangle affects abundance coat color variation eastern gray squirrels ( Sciurus carolinensis ). Integrating camera traps point count surveys across 49 sites, we observed pronounced urban-rural gradients squirrel variation. Human population density affected morphs mediating resource availability, predator activity, habitat amount, fragmentation. But markedly different drove landscape. Our findings reveal explicit multiple change deepen our mechanistic understanding alters patterns.

Язык: Английский

Процитировано

1
How does urbanization affect natural selection? DOI Creative Commons
Anne Charmantier, Tracy T. Burkhard, Laura Gervais

и другие.

Functional Ecology, Год журнала: 2024, Номер 38(12), С. 2522 - 2536

Опубликована: Сен. 29, 2024

Abstract Urbanization is one of the most significant contributors to Anthropocene, and urban evolutionary ecology has become an important field research. While it commonly assumed that cities impose new stronger selection, contradictory assertion selection may be relaxed in also frequently mentioned, overall, our understanding effects urbanization on natural incomplete. In this review, we first conduct a literature search find evidence for patterns phenotypic traits including morphology, physiology, behaviour life history, non‐urban populations animals plants. This reveals coefficients context are scarce ( n = 8 studies providing gradients/differentials include total 200 coefficients) lack standardized methods hinders quantitative comparisons across (e.g. with meta‐analysis). These studies, however, provide interesting insight agents shaping improve mechanistic processes at different spatial scales. We then perform second review genomic assessing intensity cities, genome non‐human populations. returns 383 articles, only 34 these truly investigate footprints associated urbanization, study provides genetic coefficients. Here again, highly heterogeneous approaches, yet some strong adaptation. neither nor were able quantitatively assess versus habitats. Thus, propose roadmap how future should metrics facilitate mega‐ or meta‐analyses explore generalized selection. Read free Plain Language Summary article Journal blog.

Язык: Английский

Процитировано

1
Distracted foragers: competitors impair foraging efficiency, accuracy and speed for eastern grey squirrels DOI Creative Commons
Julie A. Teichroeb,

H. Ghorbani,

Kian Fallah

и другие.

Animal Behaviour, Год журнала: 2024, Номер 215, С. 241 - 250

Опубликована: Июль 14, 2024

Social foraging can be beneficial, but it also disrupt optimal strategies. Animals possess limited capacity for attention allocation and distractions may impact their rates of food acquisition. Attention to conspecific competitors prevent kleptoparasitism likely affects intake in multiple ways. We used two field experiments assess the nearby on urban eastern grey squirrel, Sciurus carolinensis, a forest setting University Toronto Scarborough campus. tube apparatus first experiment examine efficiency tipping container second speed (handling time) accuracy. Competing squirrels within 1 m or having just been involved chasing aggressive physical contact with led decreases efficiency, Competitors 5 focal did not measures. Over course experiments, adapted solving apparatuses presence competitor(s) improved accuracy speed. Vigilance were greater that had nearby; thus, seemed caused by need allocate conspecifics. These show social impairs acquisition individual squirrels.

Язык: Английский

Процитировано

0
Crypsis in a polymorphic mammal along an urbanization gradient DOI Creative Commons
J. Proctor,

A. M. Bryan,

Bradley J. Cosentino

и другие.

Research Square (Research Square), Год журнала: 2024, Номер unknown

Опубликована: Дек. 12, 2024

Abstract Urbanization transforms landscapes and alters visual environments for polymorphic species that rely on cryptic coloration survival, potentially generating urban-rural clines in pigmentation. Such are evident eastern gray squirrel (Sciurus carolinensis) populations, which a melanic morph is currently more prevalent cities but was historically rural woodlands prior to urbanization. We compared the degree of crypsis between two primary color morphs squirrels – among suite habitats predominate along an urbanization gradient test whether altered environment may contribute maintenance cline prevalence. Crypsis quantified using online game with human observers image pixel classification measure detectability taxidermic mounts each against their backgrounds replicate sites within habitat. The conspicuous than all habitat types across seasons, as evidenced by greater detection probabilities lower background matching. Coat likely mediates predators, resulting selection conspicuous, woodlands. Conversely, via road mortality favor urban areas if vehicular collisions melanics easily avoided due conspicuity. conclude differential continuum gradients play important role maintaining coat color.

Язык: Английский

Процитировано

0