scholarly journals Linking locomotor performance to morphological shifts in urban lizards

2018 ◽  
Vol 285 (1880) ◽  
pp. 20180229 ◽  
Author(s):  
Kristin M. Winchell ◽  
Inbar Maayan ◽  
Jason R. Fredette ◽  
Liam J. Revell

Urban habitats are drastically modified from their natural state, creating unique challenges and selection pressures for organisms that reside in them. We compared locomotor performance of Anolis lizards from urban and forest habitats on tracks differing in angle and substrate, and found that using artificial substrates came at a cost: lizards ran substantially slower and frequently lost traction on man-made surfaces compared to bark. We found that various morphological traits were positively correlated with sprint speed and that these same traits were significantly larger in urban compared to forest lizards. We found that urban lizards ran faster on both man-made and natural surfaces, suggesting similar mechanisms improve locomotor performance on both classes of substrate. Thus, lizards in urban areas may be under selection to run faster on all flat surfaces, while forest lizards face competing demands of running, jumping and clinging to narrow perches. Novel locomotor challenges posed by urban habitats likely have fitness consequences for lizards that cannot effectively use man-made surfaces, providing a mechanistic basis for observed phenotypic shifts in urban populations of this species.

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.


Sociobiology ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 5861
Author(s):  
Ana Isabel Sobreiro ◽  
Lucas Lopes da Silveira Peres ◽  
Jessica Amaral Henrique ◽  
Rosilda Mara Mussury ◽  
Valter Vieira Alves-Junior

Forest habitats are important sources of food and nesting resources for pollinators, primarily in urban areas and landscapes with intense agricultural activity. The forest fragmentation and environmental changes occurring in these green refuges are known to impose survival challenges to pollinating bees, leading to species loss. However, it is not well known how the species of bees that visit flowers are distributed in forest micro-environments. To fill this gap, we sampled flower visiting bees in a continuous forest matrix with micro-environments of two forest types (mature and regenerating forest). We examined how the local environmental changes and climatic conditions affect the composition and uniformity of bee communities in the different micro-environments. Our results indicated that both abundance and richness were similar between forest types studied here, however climatic conditions and plant flowering patterns affect the composition of bees. Thus, our results demonstrated that the continuous micro-environments can favor floral visits and the reintegration of bee communities, and still, that this strategy can be used to minimize the impacts of environmental changes at local scales.


1985 ◽  
Vol 63 (2) ◽  
pp. 263-266 ◽  
Author(s):  
J. F. Geggie ◽  
M. B. Fenton

We compared the foraging activity of populations of Eptesicus fuscus in rural and urban settings in eastern Ontario and western Quebec by monitoring their echolocation calls and by radio tracking individuals during the summer of 1980. Foraging was detected in all of the rural and urban habitats we monitored. There were no significant differences in the levels of foraging activity over different urban habitats, but the overall foraging rates were significantly higher in the rural than in the urban areas. Foraging in rural areas was significantly higher in residential zones and over water and was less common in parkland and farmland. Bats in rural areas foraged among aggregations of insects at lights, a pattern of behaviour not seen among urban bats. Differences in foraging rates and the fact that rural bats spent significantly less time away from their roosts suggest that prey density was lower in the urban setting. Although urban habitats appear to provide E. fuscus with a wealth of roosting sites, food supplies are lower there.


Author(s):  
Roohi Rawat ◽  
A. R. Siddiqui

Clean and safe drinking water is important for the overall health and wellbeing; therefore, access to safe potable drinking water is one of the basic amenities of humankind, especially in urban areas with high consumption pattern of the large population inhabiting these spaces. Among the various sources of water, groundwater is considered to be the safest source of drinking water. However, due to rapid industrialization and population growth, the groundwater resources are getting polluted with harmful contaminants. These contaminants can be chemical or microbiological and cause various health problems. According to the World Health Organization (WHO), about 80 percent of all diseases in the world are directly or indirectly related to the contamination of water. Water in its natural state is colorless, odorless, and free from pathogens with pH in the range of 6.5–8.5. This water is termed as “potable water.” In the present study, the researchers have made an attempt to assess the physiochemical characteristics of drinking water quality in Allahabad and the effect of these contaminants on the health of the consumers. A comparison of the parameter standards as per the Bureau of Indian Standards (BIS) (ISI, Indian standard specification for drinking water (IS10500). New Delhi: ISI, 1983 ) and the WHO (Guidelines for drinking water quality (Vol. 1). Geneva: WHO, 1984 ) have also been made to understand the national and global benchmarks. With the help of the standards of various parameters given by these organizations, the assessment of water quality of samples from various locations in Allahabad has been done.


2021 ◽  
Author(s):  
Alexander Joseph Blumenfeld ◽  
Pierre Andre Eyer ◽  
Anjel M Helms ◽  
Grzegorz Buczkowski ◽  
Edward L Vargo

Biological invasions are becoming more prevalent due to the rise of global trade and expansion of urban areas. Ants are among the most prolific invaders, with many exhibiting a multi-queen colony structure, dispersal through budding and a lack of inter-nest aggression. Although these characteristics are generally associated with the invasions of exotic ants, they may also facilitate the spread of native ants into novel habitats (e.g., urban areas). Native to North American forests, the odorous house ant Tapinoma sessile has become abundant in urban environments throughout the United States. Forest-dwelling colonies typically have a small workforce, inhabit a single nest, and are headed by a single queen, whereas urban colonies tend to be several orders of magnitude larger, inhabit multiple nests and are headed by multiple queens. Here, we explore and compare the population genetic and breeding structure of T. sessile within and between urban and natural environments in several localities across its distribution range. We found the social structure of a colony to be a plastic trait in both habitats, although extreme polygyny (i.e., nests with multiple queens) was confined to urban habitats. Additionally, polydomous colonies (i.e., nests lacking genetic differentiation and behavioral antagonism) were only present in urban habitats, suggesting T. sessile can only achieve unicoloniality within urbanized areas. Finally, we identified strong differentiation between urban and natural populations in each locality and continent-wide, indicating cities may restrict gene flow and exert intense selection pressure. Overall, our study highlights urbanization's influence in charting the evolutionary course for species.


1979 ◽  
Vol 57 (12) ◽  
pp. 2358-2368 ◽  
Author(s):  
Richard K. Lancaster ◽  
William E. Rees

We examine relationships between bird communities and habitat structure along a gradient of urban habitats in Vancouver, B.C. Bird species diversity, evenness of species abundances, and numbers of species increase with foliage height diversity and total vegetation as they do in "natural" habitats. Few ecological niches for birds are enhanced by man-made features of the urban environment. Bird species diversity is actually inversely related to the apparent increase in habitat diversity contributed by elements of the built environment. While limited to a few niches, food provided by man has a major effect on density and distribution of birds in urban areas. Therefore, despite declining natural productivity and species diversity, total bird density does not decline across the Vancouver urban gradient. Overall, available habitat and food in highly urbanized environments strongly favour the few cavity-nesting, ground-feeding graminivorous or omnivorous bird species that have already come to dominate.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1062
Author(s):  
Charel Reuland ◽  
Leigh W. Simmons ◽  
Stefan Lüpold ◽  
John L. Fitzpatrick

In polyandrous species, males face reproductive competition both before and after mating. Sexual selection thus shapes the evolution of both pre- and postcopulatory traits, creating competing demands on resource allocation to different reproductive episodes. Traits subject to strong selection exhibit accelerated rates of phenotypic divergence, and examining evolutionary rates may inform us about the relative importance and potential fitness consequences of investing in traits under either pre- or postcopulatory sexual selection. Here, we used a comparative approach to assess evolutionary rates of key competitive traits in two artiodactyl families, bovids (family Bovidae) and cervids (family Cervidae), where male–male competition can occur before and after mating. We quantified and compared evolutionary rates of male weaponry (horns and antlers), body size/mass, testes mass, and sperm morphometrics. We found that weapons evolve faster than sperm dimensions. In contrast, testes and body mass evolve at similar rates. These results suggest strong, but differential, selection on both pre- and postcopulatory traits in bovids and cervids. Furthermore, we documented distinct evolutionary rates among different sperm components, with sperm head and midpiece evolving faster than the flagellum. Finally, we demonstrate that, despite considerable differences in weapon development between bovids and cervids, the overall evolutionary patterns between these families were broadly consistent.


2016 ◽  
Vol 24 (2) ◽  
Author(s):  
А. A. Zimaroyeva ◽  
A. V. Matsyura ◽  
K. Jankowski

The spatial distribution and abundance of Corvidae species in Zhytomyr region was studied in terms of the urban-rural gradient. We selected Rook (Corvus frugilegus L.), Eurasian Jackdaw (C. monedula L.), Hooded Crow (C. cornix L.), Common Raven (C. corax L.), Eurasian Magpie (Pica pica L.) and Eurasian Jay (Garrulus glandarius L.) for our observations during 2009–2012. Some 38 survey routes totaling more than 8000 km were surveyed in 21 settlements in Zhytomyr region. Among them 13 routes were in Zhytomyr city. The average density of Rooks was 55.9 birds/km2. We found a strong correlation between Rook density and rural-urban gradient and observed that the numbers of wintering Rooks in cities significantly increased due to the influx from villages. The peak number of Rooks in villages was registered in the breeding and post-breeding seasons while in the cities it was high in winter and during the spring migration. The average density of Eurasian Magpies in the study area was 8.7 birds/km2 and we registered weak correlation with the urban-rural gradient. Their maximum density in urban habitats was in the winter period whereas the highest density in rural habitats was fixed in the summer months. The density of Magpies varied insignificantly within a narrow range during the three years of research, which suggests the species has successfully adjusted to the transformed landscapes. Average density of Hooded Crows in towns was 6.6 birds/km2. The linear relationship between the urban-rural gradient and the density of this species was rather weak. In the breeding period, the birds’ density was considerably higher in urban habitats. We also registered that the average density of Hooded Crows changed insignificantly but gradually increased during the study period. The average density of Eurasian Jackdaws was 9.7 birds/km2 and had high annual dynamics. It also changed significantly during the three years of research. The average density of Eurasian Jays was 2.4 birds/km2 and varied significantly in different settlements, although the fluctuation range was small (0.1–9.3 birds/km2). We registered an expansion in the breeding distribution of Eurasian Jays in recent years i.e. the birds began to nest in old urban neighborhoods and small central parks of large cities. However, the number of birds naturally decreased along the gradient of landscape transformation. The impact of urban-rural gradient on Eurasian Jay density was significant but the correlation was weak and negative. The density of this species was highest in small villages (4.9 birds/km2) and the lowest in medium-sized cities (1.5 birds/km2). The seasonal density of Jays varied significantly and the greatest value was registered in the post-breeding period. In urban areas the birds’ density was much higher in winter compared to the nesting period, and in villages we observed the reverse situation. The number of Eurasian Jays remained almost stable in all the settlements during the study period indicating the stability of the local populations. The average density of the Common Raven was 1.3 birds/km2 and the highest density was registered in small villages (2.2 birds/km2), the lowest – in the townships (small urban type settlements) (0.6 birds/km2). The urban-rural gradient significantly affected the spatial distribution of Common Ravens, but we cannot claim an increase or decrease in their numbers along the gradient of urbanization, since the value of this indicator also depended on habitat conditions in each specific settlement. The spatial distribution of Common Ravens varied seasonally and the highest density was typical in winter due to food migrations towards human settlements.


Author(s):  
Sharlene L. Gomes ◽  
Leon M. Hermans

Abstract. Urbanization creates challenges for water management in an evolving socio-economic context. This is particularly relevant in transitioning peri-urban areas like Khulna, Bangladesh where competing demands have put pressure on local groundwater resources. Users are unable to sufficiently meet their needs through existing institutions. These institutions provide the rules for service provision and act as guidelines for actors to resolve their water related issues. However, the evolving peri-urban context can produce fragmented institutional arrangements. For example in Khulna, water supply is based on urban and rural boundaries that has created water access issues for peri-urban communities. This has motivated local actors to manage their groundwater needs in various ways. General institutional theories are well developed in literature, yet little is known about institutions in transitioning peri-urban areas. Institutions that fail to adapt to changing dynamics run the risk of becoming obsolete or counter-productive, hence the need for investigating institutional change mechanisms in this context. This paper examines peri-urban case studies from Khulna using the Institutional Analysis and Development framework to demonstrate how institutions have contributed to spatial differences in groundwater access with local actors investing in formal and informal institutional change as a means of accessing groundwater.


Author(s):  
Agnieszka Nikel ◽  
Magdalena Szczepaniak

The paper lists 135 taxa and 12 main plant communities found in the Dolina Potoku Olszanickiego – Łąki Olszanickie ecological use area during field research done in 2018–2019. For each taxon, information about the occupied habitat, synanthropic status, number of localities and frequency of occurrence are given. Phytosociological groups of species were distinguished and analysed. In the ecological use area, Conium maculatum, an endangered species (VU) of the Małopolska Upland, was recorded. The occurrence of rush meadow Scirpetum sylvatici (typical and degradated patches), meadow thistle Cirsietum rivularis (various degradative forms) and rush vegetation Caricetum rostratae was found. The main threats to ecological use is degradation of communities and natural succession as a result of cessation of extensive use of meadows (mowing, grazing) and the expansion of the invasive species Solidago gigantea and S. canadensis, which occupy a significant part of the non-forest habitats. Information about needed protection measures is also given. The paper highlights the need for biodiversity protection in urban areas, for their sustainable development and the quality of life of their inhabitants.


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