Citizen science programs are becoming increasingly popular among naturalists but remain heavily b... more Citizen science programs are becoming increasingly popular among naturalists but remain heavily biased taxonomically and geographically. However, with the explosive popularity of social media and the near-ubiquitous availability of smartphones, many post wildlife photographs on social media. Here, we illustrate the potential of harvesting these data to enhance our biodiversity understanding using Bangladesh, a tropical biodiverse country, as a case study. We compared biodiversity records extracted from Facebook with those from the Global Biodiversity Information Facility (GBIF), collating geospatial records for 1013 unique species, including 970 species from Facebook and 712 species from GBIF. Although most observation records were biased toward major cities, the Facebook records were more evenly spatially distributed. About 86% of the Threatened species records were from Facebook, whereas the GBIF records were almost entirely Of Least Concern species. To reduce the global biodivers...
The global rise of pharmaceutical contaminants in the aquatic environment poses a serious threat ... more The global rise of pharmaceutical contaminants in the aquatic environment poses a serious threat to ecological and evolutionary processes. Studies have traditionally focused on the collateral (average) effects of psychoactive pollutants on ecologically relevant behaviors of wildlife, often neglecting effects among and within individuals, and whether they differ between males and females. We tested whether psychoactive pollutants have sex-specific effects on behavioral individuality and plasticity in guppies (Poecilia reticulata), a freshwater species that inhabits contaminated waterways in the wild. Fish were exposed to fluoxetine (Prozac) for 2 years across multiple generations before their activity and stress-related behavior were repeatedly assayed. Using a Bayesian statistical approach that partitions the effects among and within individuals, we found that males—but not females—in fluoxetine-exposed populations differed less from each other in their behavior (lower behavioral in...
Scientific awards can shape scientific careers, helping secure jobs and grants. Awards also have ... more Scientific awards can shape scientific careers, helping secure jobs and grants. Awards also have a potential to reinforce the “Matthew Effect” and the quest for “novelty” in science when eligibility and assessment criteria give preference to nominees with traditional careers and to “excellent” research. As such, recognition awards for early and mid-career researchers can contribute to the lack of intersectional diversity at the senior levels and in elite networks of scientists. To assess the status quo and historical trends, we evaluated “best researcher” awards and “best paper” early and mid-career awards from broad-scope international journals and societies in ecology and evolution. Specifically, we collated information on eligibility rules and assessment criteria and quantified historical gender biases in the lists of past winners. Our results reveal that, overall, few awards foster equitable access and assessment. Although many awards now explicitly allow extensions of the eligi...
Citizen science programmes are becoming increasingly sophisticated and popular among those with a... more Citizen science programmes are becoming increasingly sophisticated and popular among those with an interest in natural history, but remain the domain of a relatively small portion of the public and heavily biased toward certain areas. Although systematic recording of biodiversity data has been practiced for centuries in the Global North, many tropical nations are still vastly under-surveyed. Yet with the explosive popularity of social media, and the near-ubiquitous availability of smartphone cameras, millions of people are posting photographs on social media daily. Here, we illustrate the potential of harvesting these data to enhance our biodiversity understanding using Bangladesh, a megadiverse South Asian nation, as a case study. We compared biodiversity records extracted from Facebook with those from the Global Biodiversity Information Facility (GBIF) collating geospatial records for 1,013 unique species, including 970 species from Facebook (representing 25% of observation record...
Old age in males is commonly associated with negative effects on reproduction and offspring trait... more Old age in males is commonly associated with negative effects on reproduction and offspring traits. Even so, how a male's age affects reproductive traits under sexual selection is poorly understood. In Chapter 1 I note that a problem in quantifying male age effect is that age and mating history are highly confounded: older males usually have more mating experience. This begs the question: to what extent does mating history rather than male age explain variation in traits under sexual selection? The answer requires an experimental approach. In this thesis, I disentangle the effects of male age and mating history to test for their independent and interactive effects on reproduction in eastern mosquitofish (Gambusia holbrooki). Chapter 2 investigates the effect of paternal lifetime mating history on offspring traits. I found that the daughters, but not the sons, of 'no-mating' treatment males matured significantly sooner, and at a significantly smaller size, than those of &...
As cities continue to grow it is increasingly important to understand the long-term responses of ... more As cities continue to grow it is increasingly important to understand the long-term responses of wildlife to urban environments. There have been increased efforts to determine whether urbanization imposes chronic stress on wild animals, but empirical evidence is mixed. Here, we conduct a meta-analysis to test whether there is, on average, a detrimental effect of urbanization based on baseline and stress-induced glucocorticoid levels of wild vertebrates. We found no effect of urbanization on glucocorticoid levels, and neither sex, season, life stage, taxon, size of the city nor methodology accounted for variation in the observed effect sizes. At face value, our results suggest that urban areas are no more stressful for wildlife than rural or non-urban areas, but we offer a few reasons why this conclusion could be premature. We propose that refining methods of data collection will improve our understanding of how urbanization affects the health and survival of wildlife.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
Paternal age and past mating effort by males are often confounded, which can affect our understan... more Paternal age and past mating effort by males are often confounded, which can affect our understanding of a father's age effects. To our knowledge, only a few studies have standardized mating history when testing for effects of paternal age, and none has simultaneously disentangled how paternal age and mating history might jointly influence offspring traits. Here, we experimentally manipulated male mating history to tease apart its effects from those of paternal age on female fertility and offspring traits in the eastern mosquitofish (Gambusia holbrooki). Male age did not affect female fertility. However, males with greater past mating effort produced significantly larger broods. Paternal age and mating history interacted to affect sons' body size: sons sired by old-virgin males were larger than those sired by old-mated males, but this was not the case for younger fathers. Intriguingly, however, sons sired by old-virgin males tended to produce fewer sperms than those sired by old-mated males, indicating a potential trade-off in beneficial paternal effects. Finally, neither paternal age nor mating history affected daughter's fitness. Our results highlight that variation in offspring traits attributed to paternal age effect could partly arise due to a father's mating history, and not simply to his chronological age.
As cities continue to grow it is increasingly important to understand the long-term responses of ... more As cities continue to grow it is increasingly important to understand the long-term responses of wildlife to urban environments. There have been increased efforts to determine whether urbanization imposes chronic stress on wild animals, but empirical evidence is mixed. Here, we conduct a meta-analysis to test whether there is, on average, a detrimental effect of urbanization based on baseline and stress-induced glucocorticoid levels of wild vertebrates. We found no effect of urbanization on glucocorticoid levels, and neither sex, season, life stage, taxon, size of the city nor methodology accounted for variation in the observed effect sizes. At face value, our results suggest that urban areas are no more stressful for wildlife than rural or non-urban areas, but we offer a few reasons why this conclusion could be premature. We propose that refining methods of data collection will improve our understanding of how urbanization affects the health and survival of wildlife.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
A systematic review and meta-analysis testing the effect of paternal age on offspring survival, l... more A systematic review and meta-analysis testing the effect of paternal age on offspring survival, lifespan and development in non-domesticated animals.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
Citizen science programs are becoming increasingly popular among naturalists but remain heavily b... more Citizen science programs are becoming increasingly popular among naturalists but remain heavily biased taxonomically and geographically. However, with the explosive popularity of social media and the near-ubiquitous availability of smartphones, many post wildlife photographs on social media. Here, we illustrate the potential of harvesting these data to enhance our biodiversity understanding using Bangladesh, a tropical biodiverse country, as a case study. We compared biodiversity records extracted from Facebook with those from the Global Biodiversity Information Facility (GBIF), collating geospatial records for 1013 unique species, including 970 species from Facebook and 712 species from GBIF. Although most observation records were biased toward major cities, the Facebook records were more evenly spatially distributed. About 86% of the Threatened species records were from Facebook, whereas the GBIF records were almost entirely Of Least Concern species. To reduce the global biodivers...
The global rise of pharmaceutical contaminants in the aquatic environment poses a serious threat ... more The global rise of pharmaceutical contaminants in the aquatic environment poses a serious threat to ecological and evolutionary processes. Studies have traditionally focused on the collateral (average) effects of psychoactive pollutants on ecologically relevant behaviors of wildlife, often neglecting effects among and within individuals, and whether they differ between males and females. We tested whether psychoactive pollutants have sex-specific effects on behavioral individuality and plasticity in guppies (Poecilia reticulata), a freshwater species that inhabits contaminated waterways in the wild. Fish were exposed to fluoxetine (Prozac) for 2 years across multiple generations before their activity and stress-related behavior were repeatedly assayed. Using a Bayesian statistical approach that partitions the effects among and within individuals, we found that males—but not females—in fluoxetine-exposed populations differed less from each other in their behavior (lower behavioral in...
Scientific awards can shape scientific careers, helping secure jobs and grants. Awards also have ... more Scientific awards can shape scientific careers, helping secure jobs and grants. Awards also have a potential to reinforce the “Matthew Effect” and the quest for “novelty” in science when eligibility and assessment criteria give preference to nominees with traditional careers and to “excellent” research. As such, recognition awards for early and mid-career researchers can contribute to the lack of intersectional diversity at the senior levels and in elite networks of scientists. To assess the status quo and historical trends, we evaluated “best researcher” awards and “best paper” early and mid-career awards from broad-scope international journals and societies in ecology and evolution. Specifically, we collated information on eligibility rules and assessment criteria and quantified historical gender biases in the lists of past winners. Our results reveal that, overall, few awards foster equitable access and assessment. Although many awards now explicitly allow extensions of the eligi...
Citizen science programmes are becoming increasingly sophisticated and popular among those with a... more Citizen science programmes are becoming increasingly sophisticated and popular among those with an interest in natural history, but remain the domain of a relatively small portion of the public and heavily biased toward certain areas. Although systematic recording of biodiversity data has been practiced for centuries in the Global North, many tropical nations are still vastly under-surveyed. Yet with the explosive popularity of social media, and the near-ubiquitous availability of smartphone cameras, millions of people are posting photographs on social media daily. Here, we illustrate the potential of harvesting these data to enhance our biodiversity understanding using Bangladesh, a megadiverse South Asian nation, as a case study. We compared biodiversity records extracted from Facebook with those from the Global Biodiversity Information Facility (GBIF) collating geospatial records for 1,013 unique species, including 970 species from Facebook (representing 25% of observation record...
Old age in males is commonly associated with negative effects on reproduction and offspring trait... more Old age in males is commonly associated with negative effects on reproduction and offspring traits. Even so, how a male's age affects reproductive traits under sexual selection is poorly understood. In Chapter 1 I note that a problem in quantifying male age effect is that age and mating history are highly confounded: older males usually have more mating experience. This begs the question: to what extent does mating history rather than male age explain variation in traits under sexual selection? The answer requires an experimental approach. In this thesis, I disentangle the effects of male age and mating history to test for their independent and interactive effects on reproduction in eastern mosquitofish (Gambusia holbrooki). Chapter 2 investigates the effect of paternal lifetime mating history on offspring traits. I found that the daughters, but not the sons, of 'no-mating' treatment males matured significantly sooner, and at a significantly smaller size, than those of &...
As cities continue to grow it is increasingly important to understand the long-term responses of ... more As cities continue to grow it is increasingly important to understand the long-term responses of wildlife to urban environments. There have been increased efforts to determine whether urbanization imposes chronic stress on wild animals, but empirical evidence is mixed. Here, we conduct a meta-analysis to test whether there is, on average, a detrimental effect of urbanization based on baseline and stress-induced glucocorticoid levels of wild vertebrates. We found no effect of urbanization on glucocorticoid levels, and neither sex, season, life stage, taxon, size of the city nor methodology accounted for variation in the observed effect sizes. At face value, our results suggest that urban areas are no more stressful for wildlife than rural or non-urban areas, but we offer a few reasons why this conclusion could be premature. We propose that refining methods of data collection will improve our understanding of how urbanization affects the health and survival of wildlife.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
Paternal age and past mating effort by males are often confounded, which can affect our understan... more Paternal age and past mating effort by males are often confounded, which can affect our understanding of a father's age effects. To our knowledge, only a few studies have standardized mating history when testing for effects of paternal age, and none has simultaneously disentangled how paternal age and mating history might jointly influence offspring traits. Here, we experimentally manipulated male mating history to tease apart its effects from those of paternal age on female fertility and offspring traits in the eastern mosquitofish (Gambusia holbrooki). Male age did not affect female fertility. However, males with greater past mating effort produced significantly larger broods. Paternal age and mating history interacted to affect sons' body size: sons sired by old-virgin males were larger than those sired by old-mated males, but this was not the case for younger fathers. Intriguingly, however, sons sired by old-virgin males tended to produce fewer sperms than those sired by old-mated males, indicating a potential trade-off in beneficial paternal effects. Finally, neither paternal age nor mating history affected daughter's fitness. Our results highlight that variation in offspring traits attributed to paternal age effect could partly arise due to a father's mating history, and not simply to his chronological age.
As cities continue to grow it is increasingly important to understand the long-term responses of ... more As cities continue to grow it is increasingly important to understand the long-term responses of wildlife to urban environments. There have been increased efforts to determine whether urbanization imposes chronic stress on wild animals, but empirical evidence is mixed. Here, we conduct a meta-analysis to test whether there is, on average, a detrimental effect of urbanization based on baseline and stress-induced glucocorticoid levels of wild vertebrates. We found no effect of urbanization on glucocorticoid levels, and neither sex, season, life stage, taxon, size of the city nor methodology accounted for variation in the observed effect sizes. At face value, our results suggest that urban areas are no more stressful for wildlife than rural or non-urban areas, but we offer a few reasons why this conclusion could be premature. We propose that refining methods of data collection will improve our understanding of how urbanization affects the health and survival of wildlife.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
A systematic review and meta-analysis testing the effect of paternal age on offspring survival, l... more A systematic review and meta-analysis testing the effect of paternal age on offspring survival, lifespan and development in non-domesticated animals.
Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, ... more Older males often perform poorly under post-copulatory sexual selection. It is unclear, however, whether reproductive senescence is due to male age itself or the accumulated costs of the higher lifetime mating effort that is usually associated with male age. To date, very few studies have accounted for mating history and sperm storage when testing the effect of male age on sperm traits, and none test how age and past mating history influence paternity success under sperm competition. Here, we experimentally manipulate male mating history to tease apart its effects from that of age on ejaculate traits and paternity in the mosquitofish, <i>Gambusia holbrooki</i>. We found that old, naive males had more sperm than old, experienced males, while the reverse was true for young males. By contrast, neither male age nor mating history affected sperm velocity. Finally, using artificial insemination to experimentally control the number of sperm per male, we found that old males sir...
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