scholarly journals Population trend status of Ontario’s forest birds

2009 ◽  
Vol 85 (2) ◽  
pp. 184-201 ◽  
Author(s):  
Peter J Blancher ◽  
R. Dean Phoenix ◽  
Debra S Badzinski ◽  
Michael D Cadman ◽  
Tara L Crewe ◽  
...  
Keyword(s):  
Agricultural Landscapes ◽  
Forest Birds ◽  
Population Trend ◽  
Individual Species ◽  
Population Declines ◽  
Breeding Bird ◽  
The North ◽  
Aerial Insectivore ◽  
Monitoring Reliability ◽  
Wide Scale

Recent population trends of Ontario’s forest birds were assessed by integrating results across 8 bird surveys to provide an estimate of trend status for all of Ontario, and for 2 forested regions of Ontario separately. Surveys with mid- and longterm trends were relied on most extensively in this assessment. Comparison of the first and second Breeding Bird Atlases was especially important for estimating trends in northern forests, but overall reliability of status assessments in the north was considered poor due to limited coverage and significant potential for bias. Trends of most forest birds were stable or positive at the Ontario-wide scale, with trends at least as positive as forest birds elsewhere in North America, and showing more positive trends overall than birds of agricultural landscapes. Nevertheless, individual species trends ranged from large declines to large increases, and several forest birds have been added to Species at Risk lists largely because of population declines. There were few differences in trend status among forest birds grouped by habitat association or migratory guild, although all 5 aerial insectivore species have declined. Better monitoring coverage of the boreal will be needed if improved reliability of trends is desired in the near future. Key words: Ontario, forest birds, boreal forest, population trend, bird surveys, monitoring reliability

scholarly journals Using a large-scale biodiversity monitoring dataset to test the effectiveness of protected areas at conserving North-American breeding birds

2018 ◽  
Author(s):  
Victor Cazalis ◽  
Soumaya Belghali ◽  
Ana S.L. Rodrigues
Keyword(s):  
Species Richness ◽  
Protected Areas ◽  
North American ◽  
Large Scale ◽  
Individual Species ◽  
Biodiversity Monitoring ◽  
Breeding Bird ◽  
The North ◽  
Forest Sites ◽  
Declining Species

AbstractProtected areas currently cover about 15% of the global land area, and constitute one of the main tools in biodiversity conservation. Quantifying their effectiveness at protecting species from local decline or extinction involves comparing protected with counterfactual unprotected sites representing “what would have happened to protected sites had they not been protected”. Most studies are based on pairwise comparisons, using neighbour sites to protected areas as counterfactuals, but this choice is often subjective and may be prone to biases. An alternative is to use large-scale biodiversity monitoring datasets, whereby the effect of protected areas is analysed statistically by controlling for landscape differences between protected and unprotected sites, allowing a more targeted and clearly defined measure of the protected areas effect. Here we use the North American Breeding Bird Survey dataset as a case study to investigate the effectiveness of protected areas at conserving bird assemblages. We analysed the effect of protected areas on species richness, on assemblage-level abundance, and on the abundance of individual species by modelling how these metrics relate to the proportion of each site that is protected, while controlling for local habitat, altitude, productivity and for spatial autocorrelation. At the assemblage level, we found almost no relationship between protection and species richness or overall abundance. At the species level, we found that forest species are present in significantly higher abundances within protected forest sites, compared with unprotected forests, with the opposite effect for species that favour open habitats. Hence, even though protected forest assemblages are not richer than those of unprotected forests, they are more typical of this habitat. We also found some evidence that species that avoid human activities tend to be favoured by protection, but found no such effect for regionally declining species. Our results highlight the complexity of assessing protected areas effectiveness, and the necessity of clearly defining the metrics of effectiveness and the controls used in such assessments.

Die Brutvogelfauna eines Nadelwaldes der nördlichen Voralpen nach dem Sturm Lothar

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer
Keyword(s):  
Forest Succession ◽  
Coniferous Forest ◽  
Bird Species ◽  
Individual Species ◽  
Mountain Forest ◽  
Breeding Bird ◽  
Point Counts ◽  
Federal Institute ◽  
Central Switzerland ◽  
Bird Fauna

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

scholarly journals Is Hay for the Birds? Investigating Landowner Willingness to Time Hay Harvests for Grassland Bird Conservation

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1030
Author(s):  
Matthew Gruntorad ◽  
Katherine Graham ◽  
Nico Arcilla ◽  
Christopher Chizinski
Keyword(s):  
Great Plains ◽  
Critical Factor ◽  
Information Support ◽  
Conservation Strategies ◽  
Bird Conservation ◽  
Willingness To Participate ◽  
Population Declines ◽  
Grassland Bird ◽  
The North ◽  
Hunting Activity

Birds in agricultural environments have exhibited steep global population declines in recent decades, and effective conservation strategies targeting their populations are urgently needed. In grasslands used for hay production, breeding birds’ nest success improves substantially if hay harvests are delayed until after mid-July. However, few studies have investigated private hay producers’ willingness to alter their harvesting practices, which is a critical factor for bird conservation where most land is privately owned, such as in the North American Great Plains. We surveyed Nebraska hay producers to examine whether livestock production, wildlife knowledge, and hunting activity affects their willingness to alter haying practices for bird conservation. The majority (60%) of respondents expressed willingness to delay harvesting hay to allow birds time to nest successfully. Livestock producers and those more knowledgeable about wildlife were more willing to delay hay harvests, whereas active hunters were less willing to do so. Our findings suggest that a majority of private producers show a high potential for engaging in grassland bird conservation activities. Landowners’ willingness to participate in bird conservation programs and actions could be further encouraged through extension and education efforts connecting hay producers with information, support, and funding for bird conservation.

A multi-proxy reconstruction of climate during the late-Pleistocene to early Holocene transition in the northeastern, USA

2021 ◽  
pp. 1-17
Author(s):  
Laurie D. Grigg ◽  
Kevin J. Engle ◽  
Alison J. Smith ◽  
Bryan N. Shuman ◽  
Maximilian B. Mandl
Keyword(s):  
Late Pleistocene ◽  
Climatic Variability ◽  
Warming Trend ◽  
Early Holocene ◽  
Individual Species ◽  
Environmental Preferences ◽  
The North ◽  
Show Evidence ◽  
Dry Conditions ◽  
Components Analysis

Abstract A multiproxy record from Twin Ponds, VT, is used to reconstruct climatic variability during the late Pleistocene to early Holocene transition. Pollen, ostracodes, δ18O, and lithologic records from 13.5 to 9.0 cal ka BP are presented. Pollen- and ostracode-inferred climatic reconstructions are based on individual species’ environmental preferences and the modern analog technique. Principal components analysis of all proxies highlights the overall warming trend and centennial-scale climatic variability. During the Younger Dryas cooling event (YD), multiple proxies show evidence for cold winter conditions and increasing seasonality after 12.5 cal ka BP. The early Holocene shows an initial phase of rapid warming with a brief cold interval at 11.5 cal ka BP, followed by a more gradual warming; a cool, wet period from 11.2 to 10.8 cal ka BP; and cool, dry conditions from 10.8 to 10.2 cal ka BP. The record ends with steady warming and increasing moisture. Post-YD climatic variability has been observed at other sites in the northeastern United States and points to continued instability in the North Atlantic during the final phases of deglaciation.

scholarly journals Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1909-1921 ◽  
Author(s):  
CAMILA I. MEDEIROS ◽  
CAMILA BOTH ◽  
IGOR L. KAEFER ◽  
SONIA Z. CECHIN
Keyword(s):  
Life Histories ◽  
Management Strategies ◽  
Reproductive Activity ◽  
Ex Situ ◽  
Reproductive Phenology ◽  
High Fertility ◽  
Seasonal Activity ◽  
Population Declines ◽  
American Bullfrog ◽  
The North

ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.

scholarly journals Interacting effects of cold snaps, rain, and agriculture on the fledging success of a declining aerial insectivore

2021 ◽  
Author(s):  
Daniel Roy Garrett ◽  
Fanie Pelletier ◽  
Dany Garant ◽  
Marc Bélisle
Keyword(s):  
Climate Change ◽  
Agricultural Intensification ◽  
Prey Availability ◽  
Tree Swallow ◽  
Landscape Changes ◽  
Population Declines ◽  
Negative Effects ◽  
Fledging Success ◽  
Inclement Weather ◽  
Aerial Insectivore

Climate change predicts the increased frequency, duration, and intensity of inclement weather periods, such as unseasonably low temperatures and prolonged precipitation. Many migratory species have advanced the phenology of important life history stages, and as a result are likely exposed to these periods of inclement spring weather more often, thus risking reduced fitness and population growth. For declining avian species, including aerial insectivores, anthropogenic landscape changes such as agricultural intensification are another driver of population declines. These landscape changes may affect the foraging ability of food provisioning parents, as well as reduce the probability a nestling will survive periods of inclement weather, through for example pesticide exposure impairing thermoregulation and punctual anorexia. Breeding in agro-intensive landscapes may thus exacerbate the negative effects of inclement weather under climate change. We used daily temperatures related to significant reductions of insect prey availability (cold snaps), combined with measures of precipitation, and assessed their impact on Tree Swallow (Tachycineta bicolor) fledging success, a declining aerial insectivore breeding across a gradient of agricultural intensification. Fledging success decreased with the number of cold snap days experienced by a brood, and this relationship was worsened during periods of prolonged precipitation. We further found the overall negative effects of experiencing periods of inclement weather are exacerbated in more agro-intensive landscapes. Our results indicate that two of the primary hypothesized drivers of many avian population declines may interact to further increase the rate of declines in certain landscape contexts.

scholarly journals Insectivorous bats are less active near freeways

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247400
Author(s):  
Manisha Bhardwaj ◽  
Kylie Soanes ◽  
José J. Lahoz-Monfort ◽  
Linda F. Lumsden ◽  
Rodney van der Ree
Keyword(s):  
Agricultural Landscapes ◽  
Individual Species ◽  
Insectivorous Bats ◽  
Predator Prey ◽  
The Road ◽  
Environmental Impact Assessments ◽  
Wildlife Populations ◽  
Roadside Verges ◽  
The Impact ◽  
Plant Pollinator

Traffic disturbances (i.e. pollution, light, noise, and vibrations) often extend into the area surrounding a road creating a ‘road-effect zone’. Habitat within the road-effect zone is degraded or, in severe cases, completely unsuitable for wildlife, resulting in indirect habitat loss. This can have a disproportionate impact on wildlife in highly modified landscapes, where remaining habitat is scarce or occurs predominantly along roadside reserves. In this study, we investigated the road-effect zone for insectivorous bats in highly cleared agricultural landscapes by quantifying the change in call activity with proximity to three major freeways. The activity of seven out of 10 species of bat significantly decreased with proximity to the freeway. We defined the road-effect zone to be the proximity at which call activity declined by at least 20% relative to the maximum detected activity. The overall road-effect zone for bats in this region was 307 m, varying between 123 and 890 m for individual species. Given that this road-effect zone exceeds the typical width of the roadside verges (<50 m), it is possible that much of the vegetation adjacent to freeways in this and similar landscapes provides low-quality habitat for bats. Without accounting for the road-effect zone, the amount of habitat lost or degraded due to roads is underestimated, potentially resulting in the loss of wildlife, ecosystem services and key ecosystem processes (e.g. predator-prey or plant-pollinator interactions) from the landscape. We suggest all future environmental impact assessments include quantifying the road-effect zone for sensitive wildlife, in order to best plan and mitigate the impact of roads on the environment. Mitigating the effects of new and existing roads on wildlife is essential to ensure enough high-quality habitat persists to maintain wildlife populations.

scholarly journals Can Topographic Variation in Climate Buffer against Climate Change-Induced Population Declines in Northern Forest Birds?

Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 56 ◽  
Author(s):  
Raimo Virkkala ◽  
Juha Aalto ◽  
Risto K. Heikkinen ◽  
Ari Rajasärkkä ◽  
Saija Kuusela ◽  
...  
Keyword(s):  
Climate Change ◽  
Temperature Variation ◽  
Survey Data ◽  
Bird Species ◽  
Forest Birds ◽  
Local Temperature ◽  
Population Declines ◽  
Northern Forest ◽  
Bird Density ◽  
Topographic Variation

Increased attention is being paid to the ecological drivers and conservation measures which could mitigate climate change-induced pressures for species survival, potentially helping populations to remain in their present-day locations longer. One important buffering mechanism against climate change may be provided by the heterogeneity in topography and consequent local climate conditions. However, the buffering capacity of this topoclimate has so far been insufficiently studied based on empirical survey data across multiple sites and species. Here, we studied whether the fine-grained air temperature variation of protected areas (PAs) affects the population changes of declining northern forest bird species. Importantly to our study, in PAs harmful land use, such as logging, is not allowed, enabling the detection of the effects of temperature buffering, even at relatively moderate levels of topographic variation. Our survey data from 129 PAs located in the boreal zone in Finland show that the density of northern forest species was higher in topographically heterogeneous PAs than in topographically more homogeneous PAs. Moreover, local temperature variation had a significant effect on the density change of northern forest birds from 1981–1999 to 2000–2017, indicating that change in bird density was generally smaller in PAs with higher topographic variation. Thus, we found a clear buffering effect stemming from the local temperature variation of PAs in the population trends of northern forest birds.

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