scholarly journals A phantom road experiment reveals traffic noise is an invisible source of habitat degradation

2015 ◽  
Vol 112 (39) ◽  
pp. 12105-12109 ◽  
Author(s):  
Heidi E. Ware ◽  
Christopher J. W. McClure ◽  
Jay D. Carlisle ◽  
Jesse R. Barber
Keyword(s):  
Body Condition ◽  
Laboratory Experiments ◽  
Habitat Degradation ◽  
Traffic Noise ◽  
Bird Community ◽  
Autumn Migration ◽  
Population Declines ◽  
Vigilance Behavior ◽  
Migratory Stopover

Decades of research demonstrate that roads impact wildlife and suggest traffic noise as a primary cause of population declines near roads. We created a “phantom road” using an array of speakers to apply traffic noise to a roadless landscape, directly testing the effect of noise alone on an entire songbird community during autumn migration. Thirty-one percent of the bird community avoided the phantom road. For individuals that stayed despite the noise, overall body condition decreased by a full SD and some species showed a change in ability to gain body condition when exposed to traffic noise during migratory stopover. We conducted complementary laboratory experiments that implicate foraging-vigilance behavior as one mechanism driving this pattern. Our results suggest that noise degrades habitat that is otherwise suitable, and that the presence of a species does not indicate the absence of an impact.

scholarly journals Increased Stopover Duration and Low Body Condition of the Pied Flycatcher (Ficedula hypoleuca) at an Autumn Stopover Site

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2208
Author(s):  
Bernice Goffin ◽  
Marcial Felgueiras ◽  
Anouschka R. Hof
Keyword(s):  
Environmental Change ◽  
Body Condition ◽  
Environmental Conditions ◽  
Ficedula Hypoleuca ◽  
Autumn Migration ◽  
Long Distance ◽  
Stopover Site ◽  
Stopover Duration ◽  
Stopover Sites ◽  
Over Time

Many long-distance migratory bird species are in decline, of which environmental changes, such as climate change and land-use changes, are thought to be important drivers. The effects of environmental change on the migration of these birds have often been studied during spring migration. Fewer studies have explored the impacts of environmental change on autumn migration, especially at stopover sites. However, stopover sites are important, as the quality of these sites is expected to change over time. We investigated impacts of local environmental conditions on the migration strategy and body condition of the Pied Flycatcher (Ficedula hypoleuca) at an autumn migration stopover site using long-term ringing data (1996–2018) and local environmental conditions. We found that although the arrival and departure dates of birds at the stopover site remained unchanged, the body condition (fat score) of the individuals caught decreased, and the stopover duration increased. This suggests that conditions at the stopover site during the autumn migration period have deteriorated over time. This study emphasizes the importance of suitable stopover sites for migratory birds and stresses that changes in environmental conditions during the autumn migration period may be contributing to the current decline in long-distance migratory passerines.

Phenotypic indicators of developmental instability in an endemic amphibian from an altered landscape (Monegros, NE Spain)

2013 ◽  
Vol 34 (4) ◽  
pp. 505-516 ◽  
Author(s):  
Carmen Burghelea ◽  
Dragos Zaharescu ◽  
Antonio Palanca
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Habitat Degradation ◽  
Great Sensitivity ◽  
Rice Fields ◽  
Land Disturbance ◽  
Agricultural Conversion ◽  
Highly Sensitive ◽  
Pelophylax Perezi ◽  
Ne Spain

The great sensitivity of amphibians to land disturbance is one of the main causes that contributed to their worldwide decline. One fundamental approach in assessing amphibian ability to reflect habitat degradation is to measure their phenotypic changes in contrasting environments. We examined the extent to which several morphological traits of the endemic anuran Pelophylax perezi responded to agricultural conversion in Monegros, an arid region in NE Spain. Specifically, we determined how body size, body mass, body condition (BC) and fluctuating asymmetry (FA) of different frog classes varied among habitats with different degree of management, i.e. rice fields vs. control ponds (i.e. small reservoirs). Pelophylax perezi juveniles showed a decrease in size and mass in rice fields, revealing that early life stages are generally more susceptible to habitat alteration. Adult body condition, on the other hand, increased significantly in cultivated habitats, which apparently indicates a good fitness in this size class. Nonetheless, skeletal asymmetry of both, juveniles and adults was significantly higher in rice fields. Moreover, during postmetamorphic development FA increased significantly towards adult stage indicating that the development controlling mechanisms were not able to buffer the stress induced by land use change. Among traits, humerus, radio-ulna and metatarsal were highly sensitive in terms of expressing significant FA differences between habitats, contrary to tibio-fibula, whose precise symmetry is essential for animal locomotion. The former bones have therefore the potential to be used as sensitive indicators of stress in amphibians. FA showed no relationship with body condition. This, together with the previous results demonstrates that FA is able to capture habitat stress more reliably than the morphological estimates such as body size, mass and BC. Therefore, FA is a useful morphological tool, highly recommended to monitor stress levels in amphibian populations.

scholarly journals Age, size and body condition do not equally reflect population response to habitat change in the common spadefoot toad Pelobates fuscus

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11678
Author(s):  
Dan Cogălniceanu ◽  
Florina Stănescu ◽  
Diana Székely ◽  
Theodor-Sebastian Topliceanu ◽  
Ruben Iosif ◽  
...  
Keyword(s):  
Body Condition ◽  
Urban Areas ◽  
Habitat Degradation ◽  
Spadefoot Toad ◽  
Pelobates Fuscus ◽  
Median Lifespan ◽  
Terrestrial Habitats ◽  
The Common ◽  
The Impact ◽  
Physical Expansion

Urbanization impacts biodiversity both directly through physical expansion over land, and indirectly due to land use conversion and human behaviors associated with urban areas. We assessed the response of a common spadefoot toad population (Pelobates fuscus) to habitat loss and fragmentation resulting from urban development by studying changes in size, body condition and age parameters. We compared samples collected in the early 2000s (sample A) and later on during 2012–2014 (sample B). The terrestrial habitats in the study area were severely reduced and fragmented due to the expansion of the human settlement. We found no significant differences in the age parameters between the two sampling periods; the median lifespan shortened from 3.5 (sample A) to 3.0 years (sample B), while the other age parameters were similar in both samples. In contrast, snout-vent length, body mass and body condition experienced a significant decrease over time. Our results suggest that changes in body size and body condition, rather than age parameters, better reflect the response of the common spadefoot toad population to declining habitat quality. Therefore, body measurements can provide reliable estimates of the impact of habitat degradation in amphibian populations.

Population genetics in a fragmented population of the European tree frog (Hyla arborea)

2013 ◽  
Vol 34 (1) ◽  
pp. 95-107 ◽  
Author(s):  
Astrid Krug ◽  
Heike Pröhl
Keyword(s):  
Gene Flow ◽  
Habitat Fragmentation ◽  
Habitat Degradation ◽  
Isolation By Distance ◽  
Sampling Site ◽  
Source Population ◽  
Tree Frog ◽  
Population Declines ◽  
Hyla Arborea ◽  
Genetic Clusters

Habitat degradation and fragmentation are known to be major threats for population persistence in European amphibians. The European tree frog Hyla arborea has suffered from dramatic population declines in the last decades and has therefore been categorised as threatened in many Red Data lists. In the region of Hannover (Germany), the European tree frog has a fragmented distribution. The aim of our study was to infer the genetic consequences of habitat fragmentation in this area by examining genetic variation and population structure. DNA samples from 193 individuals from 11 sampling sites (10 sampling sites located 2 to 32 km apart from each other near Hannover and for comparison one sampling site 140 km northeast) were analysed with eight highly polymorphic microsatellite loci. Bayesian analyses indicated that the tree frog occurrences near Hannover were fragmented into four genetically distinct clusters according to their geographical distribution. Pairwise genetic distances between sampling sites varied between 0 and 0.23 (FST) and 0 and 0.48 (Dest) and indicated high to moderate gene flow within genetic clusters and nearly absent gene flow among genetic clusters. Moreover, we identified a potential source population within the region for an introduced population in the southwest of Hannover. Our data suggest that the genetic structure is influenced in part by isolation by distance and in part by lack of habitat or migration barriers. Habitat fragmentation should by counteracted by targeted conservation measures in areas where gaps in distribution and genetic fragmentation have been revealed.

Landuse and Water Quality Threats to Current and Historical Cryptobranchus Alleganiensis Streams Across Multiple Ecoregions

2021 ◽  
Author(s):  
J.G. Da Silva Neto ◽  
Lori A. Williams ◽  
Charles R. Lawson ◽  
John D. Groves ◽  
T. D. BYL ◽  
...  
Keyword(s):  
Water Quality ◽  
Habitat Degradation ◽  
Specific Conductivity ◽  
Sampling Technique ◽  
Eastern United States ◽  
Population Declines ◽  
Watershed Development ◽  
Cryptobranchus Alleganiensis ◽  
Salamander Species ◽  
Aquatic Contaminants

Abstract The hellbender (Cryptobranchus alleganiensis) is a large, long-lived, and fully aquatic salamander species endemic to streams and rivers across 15 states in the Midwest and Eastern United States. Hellbender populations have experienced drastic declines due to habitat degradation, accelerated sedimentation, aquatic contaminants, and infectious diseases. Although declining water quality is often suggested as a major contributing factor to hellbender population declines, few studies have evaluated the presence of aquatic contaminants at sites with current and historical C. alleganiensis populations. We used a novel passive sampling technique to assess the presence and concentration of two herbicides (glyphosate and atrazine) in the water and analyzed heavy metal (cadmium (Cd), mercury (Hg), and lead (Pb)) concentrations in stream sediment samples at 30 sites across a watershed development gradient throughout the C. alleganiensis range in Tennessee (TN) and North Carolina (NC). Our results indicated the presence of atrazine in 23% of our sites. All 30 sites contained Cd and Pb, and 26 sites contained Hg. Levels of glyphosate were too low to detect using our methods. Although percent watershed development was not significantly different among ecoregions, Blue Ridge watersheds were overall less developed than watersheds in the Ridge and Valley and Interior Plateau ecoregions. The model with greatest support suggested that percent watershed development and specific conductivity were negatively correlated with hellbender population status. Because this research focused on assessing the prevalence of commonly encountered aquatic contaminants, our results and study design are broadly applicable to C. alleganiensis populations across the species range.

scholarly journals Arabian ungulates—their status and future protection

Oryx ◽  
1986 ◽  
Vol 20 (2) ◽  
pp. 100-103 ◽  
Author(s):  
Khushal Habibi
Keyword(s):  
Saudi Arabia ◽  
United Nations ◽  
Endemic Species ◽  
Habitat Degradation ◽  
Northern Province ◽  
Population Declines ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The Status ◽  
Main Factors

Ungulate populations are at a low ebb in Saudi Arabia. Indiscriminate hunting and habitat degradation are the main factors causing population declines in three of the five endemic species. The author collected information on the status of these animals while working as a wildlife ecologist for the Food and Agriculture Organization of the United Nations in the northern province of Al-Jouf.

Woodland bird declines in the Murray–Darling Basin: are there links with floodplain change?

2010 ◽  
Vol 32 (3) ◽  
pp. 315 ◽  
Author(s):  
Heather M. McGinness ◽  
Anthony D. Arthur ◽  
Julian R. W. Reid
Keyword(s):  
Water Availability ◽  
Habitat Degradation ◽  
Migratory Bird ◽  
Source Population ◽  
Population Declines ◽  
Woodland Birds ◽  
Bird Populations ◽  
Irrigation Water Use ◽  
Secondary Productivity ◽  
A Site

Woodland bird population declines in Australia have been attributed to various factors including habitat loss, fragmentation, and degradation. However, the influence of altered water availability in the landscape upon woodland bird populations has not been examined, particularly in terms of changes in flood regimes and subsequent loss of floodplain productivity. In this review, we examine the importance to woodland birds of floodplains, floods, and associated vegetation communities, highlighting potential links between declining water availability, habitat degradation, and bird populations. Floodplain woodlands and forests may be important refuges for woodland bird populations because (1) floodplain woodlands and forests comprise some of the largest and most continuous vegetation remnants in south-east Australia; and (2) floods intermittently supply water, sediment and nutrients that drive greater primary and secondary productivity than found in woodlands not subject to flooding. However, floodplains in south-east Australia have been subject to substantial flow regime change, driven predominantly by dams and irrigation water use. Consequently, habitat quality for woodland birds has been degraded, potentially exacerbating population declines. We suggest that despite such change, floodplain communities and their requisite floods remain of great importance for the persistence, productivity and diversity of woodland birds in Australian drylands. We hypothesise that (1) the influence of flooding upon primary and secondary productivity in floodplain and riparian zones is a key driver of resident bird populations, and a key determinant of nomadic/migratory bird use of a site; (2) alterations in flooding and consequent changes in productivity and condition of floodplain vegetation have contributed to observed declines in resident woodland birds in Australian drylands; and (3) the influence of flooding upon productivity extends beyond local populations of floodplain residents to non-floodplain populations via dispersal, and that floodplain woodlands often act as a source population for surrounding non-floodplain woodlands. We make several testable predictions regarding these hypotheses.

scholarly journals Loss of cultural song diversity and the convergence of songs in a declining Hawaiian forest bird community

2019 ◽  
Vol 6 (8) ◽  
pp. 190719
Author(s):  
Kristina L. Paxton ◽  
Esther Sebastián-González ◽  
Justin M. Hite ◽  
Lisa H. Crampton ◽  
David Kuhn ◽  
...  
Keyword(s):  
Population Decline ◽  
Bird Community ◽  
Time Frame ◽  
Population Declines ◽  
Honest Signal ◽  
Acoustic Characteristics ◽  
Song Complexity ◽  
Hawaiian Honeycreepers ◽  
Vocal Signals ◽  
Declining Species

The effects of population decline on culturally transmitted behaviours in animals have rarely been described, but may have major implications to population viability. Learned vocal signals in birds are of critical importance to behaviours associated with reproduction, intrasexual interactions and group cohesion, and the complexity of vocal signals such as song can serve as an honest signal of an individual's quality as well as the viability of a population. In this study, we examined how rapid population declines recently experienced by Hawaiian honeycreepers on the island of Kaua‘i (USA) may have influenced the diversity, complexity and similarity of learned honeycreeper songs. We analysed the acoustic characteristics of songs recorded during three time periods over a 40-year time frame for three species of declining Kaua‘i honeycreepers. We detected a loss of song complexity and diversity over the 40-year time period that paralleled dramatic population declines. Concurrent with the loss of complexity, we also found that the acoustic characteristics of the three honeycreepers' songs became more similar to one another. To our knowledge, this is the first documentation of convergence of acoustic characteristics among rapidly declining species. The reduction in song complexity and diversity and convergence of songs not only signals a loss of culturally transmitted behaviours in these endemic Hawaiian honeycreepers, but also potential challenges to the recovery of these rapidly declining species. Moreover, the present study highlights that there is a ‘hidden’ cost to declining populations beyond just the loss of individuals that is not often considered, the loss of culturally transmitted social behaviours.

Effects of habitat degradation on mixed-species bird flocks in Indian rain forests

2008 ◽  
Vol 24 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Hari Sridhar ◽  
K. Sankar
Keyword(s):  
Rain Forest ◽  
Habitat Degradation ◽  
Bird Community ◽  
Encounter Rate ◽  
Forest Fragments ◽  
Forest Species ◽  
Mixed Species ◽  
Number Of Species ◽  
Open Forest ◽  
Induced Changes

Abstract:Habitat degradation affects mixed-species bird flocks (flock hereafter) through two mechanisms – changes in the bird community from which flocks are drawn and changes in the propensities of species to flock. We determined the relative influence of these two mechanisms by examining variation in flocks across nine rain-forest fragments (range 11–2600 ha) in a plantation landscape in the Western Ghats, India. We found differences between fragments in average number of species (range 10.8–15.2) and individuals (range 19.0–37.6) per flock, number of species that participated in flocks (range 34–59), encounter rates (range 0.5–2.4 flocks h−1) and flock composition. Multiple regression and randomization tests revealed that different mechanisms contributed to this variation. Three flock variables (open-forest individuals per flock, total open-forest species that participated in flocks in a fragment, flock composition) mainly reflected changes in the bird communities of fragments. Habitat structure strongly influenced three flock variables (open-forest species per flock, total and rain-forest individuals per flock) and flock composition to a lesser extent. Finally, flock encounter rate was strongly related to fragment area, but not to abundance of flock participants indicating habitat degradation-induced changes in propensities of species to flock.

Sign in / Sign up

Export Citation Format

Share Document