Seasonal changes in acoustic detection of forest birds

Autonomous recording is commonly used to examine the structure of avian communities in a variety of landscapes. Many birds return to the breeding grounds in May yet acoustic surveys typically begin in June. In many species, singing activity declines through the breeding season and so detections may be lower later in the season. The aim of our study was to compare the species richness and the community composition measured early (mid-late May) and later (mid-late June) in the breeding season. We recorded the community of singing birds at 13 locations in York Region, Ontario, Canada woodlots over two days using autonomous recorders. We used spectrographic analysis to scan recordings and identify all vocalizing species. We found that species richness was significantly higher in early recordings compared to later recordings with detections of both migrants and residents displaying this trend. Most food and foraging guilds were also detected significantly less often later in the season. Despite changes in species richness, the proportion of the community represented by each foraging guild did not vary between early and late recordings. Our results suggest that acoustic recordings could be collected earlier in the breeding season, extending the survey period into May. If the primary goal of monitoring is to document species presence/absence then earlier recordings may be advantageous.

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Orientation-cage experiments with the European Quail during the breeding season and autumn migration

Canadian Journal of Zoology ◽

10.1139/z06-070 ◽

2006 ◽

Vol 84 (6) ◽

pp. 887-894 ◽

Cited By ~ 5

Author(s):

J.D. Rodríguez-Teijeiro ◽

A. Barroso ◽

S. Gallego ◽

M. Puigcerver ◽

D. Vinyoles

Keyword(s):

Breeding Season ◽

Sexual Behaviour ◽

Autumn Migration ◽

Controlled Experiments ◽

Coturnix Coturnix ◽

Preferred Direction ◽

Breeding Grounds ◽

Suitable Habitats ◽

Migratory Period

The directional movements of the male European Quail, Coturnix coturnix (L., 1758), during the breeding season and autumn migration were studied using Emlen orientation cages. The characteristics and evolution of the habitat in which males were captured and the sexual behaviour shown at capture indicate that these birds move in search of mating partners rather than of suitable habitats. These displacements are known as “gypsy movements” but are better described, as argued in this paper, as “movements in search of females”. A majority of caged birds (59%) showed a preferred direction (α = 238.5°), which coincided almost exactly with that observed in recoveries of ringed birds during autumn migration (α = 251.3°) but not with results from cage experiments during the same migratory period (α = 187.8°). Therefore, we conclude that displacements of the male European Quail, as shown in ringing recoveries, are much more influenced by “movements in search of females” than by migration. These movements are clearly towards the southwest, the males taking short flights towards suitable breeding grounds and driven by river-course habitats. In addition, we confirm that Emlen funnels are suitable for controlled experiments on the orientation of males in demes of European Quail.

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Elevational Correlates of Speciation and Intraspecific Geographic Variation in Plumage in Andean Forest Birds

The Auk ◽

10.1093/auk/102.3.556 ◽

1985 ◽

Vol 102 (3) ◽

pp. 556-579 ◽

Cited By ~ 65

Author(s):

Gary R. Graves

Keyword(s):

Species Richness ◽

Geographic Variation ◽

Intraspecific Variation ◽

Geographic Distribution ◽

Ecological Factors ◽

Geographic Range ◽

Forest Birds ◽

Elevational Distribution ◽

The Mean ◽

High Elevations

Abstract Intraspecific variation in plumage was used to test the null hypotheses that geographic variation in 280 species of elevationally restricted Andean forest birds is independent of elevation and is not a function of patchy geographic distribution. Both null hypotheses were rejected. At most taxonomic levels, geographic variation in plumage was correlated positively with both the mean of its elevational distribution and the size of its geographic range. Vertical amplitude of elevational distribution was not a significant predictor of geographic variation in plumage in most taxa. Independent of these elevational correlates, patchily distributed species showed significantly more geographic variation than continuously distributed species. These results show that geographic variation and presumably ongoing speciation phenomena are greater at higher elevations. The decreased species richness at high elevations may be attributable to a higher rate of extinction from catastrophic disturbance as well as to ecological factors that limit sympatry in newly formed species.

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Novel methods reveal shifts in migration phenology of barn swallows in South Africa

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2011.1897 ◽

2011 ◽

Vol 279 (1733) ◽

pp. 1485-1490 ◽

Cited By ~ 27

Author(s):

Res Altwegg ◽

Kristin Broms ◽

Birgit Erni ◽

Phoebe Barnard ◽

Guy F. Midgley ◽

...

Keyword(s):

South Africa ◽

Breeding Season ◽

Environmental Variability ◽

Southern Oscillation ◽

Bird Species ◽

Breeding Population ◽

Migratory Bird ◽

Recent Climate ◽

Breeding Grounds ◽

Barn Swallows

Many migratory bird species, including the barn swallow ( Hirundo rustica ), have advanced their arrival date at Northern Hemisphere breeding grounds, showing a clear biotic response to recent climate change. Earlier arrival helps maintain their synchrony with earlier springs, but little is known about the associated changes in phenology at their non-breeding grounds. Here, we examine the phenology of barn swallows in South Africa, where a large proportion of the northern European breeding population spends its non-breeding season. Using novel analytical methods based on bird atlas data, we show that swallows first arrive in the northern parts of the country and gradually appear further south. On their north-bound journey, they leave South Africa rapidly, resulting in mean stopover durations of 140 days in the south and 180 days in the north. We found that swallows are now leaving northern parts of South Africa 8 days earlier than they did 20 years ago, and so shortened their stay in areas where they previously stayed the longest. By contrast, they did not shorten their stopover in other parts of South Africa, leading to a more synchronized departure across the country. Departure was related to environmental variability, measured through the Southern Oscillation Index. Our results suggest that these birds gain their extended breeding season in Europe partly by leaving South Africa earlier, and thus add to scarce evidence for phenology shifts in the Southern Hemisphere.

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Effects of oil palm plantations on anuran diversity in the eastern Amazon

Animal Biology ◽

10.1163/15707563-00002481 ◽

2015 ◽

Vol 65 (3-4) ◽

pp. 321-335 ◽

Cited By ~ 14

Author(s):

Fabricio S. Correa ◽

Leandro Juen ◽

Lenise C. Rodrigues ◽

Heriberto F. Silva-Filho ◽

Maria C. Santos-Costa

Keyword(s):

Land Use ◽

Species Richness ◽

Oil Palm ◽

Soil Conditions ◽

Total Abundance ◽

Anuran Species ◽

Forested Areas ◽

Acoustic Surveys ◽

Negative Impacts ◽

The Tropics

The extent of land use for oil palm plantations has grown considerably in the tropics due to climate, appropriate soil conditions for cultivation and its profitability. However, oil palm plantations may endanger biodiversity through reduction and fragmentation of forest areas. Herein we analyzed the effects on anuran species richness, composition and total abundance in oil palm plantations and surrounding forests in eastern Amazon. We installed seven plots in oil palm plantations and seven plots in surrounding forests, which we surveyed for the presence of anurans through active visual and acoustic surveys during periods of high and low rainfall levels. Anuran assemblages found in forests and oil palm plantations differed in species richness and composition, with a loss of 54% of species in oil palm plantations. No difference was observed in total abundance of anurans between both environments. While conversion of forests to oil palm plantations may result in less negative impacts on anuran diversity than other types of monocultures, such loss is nevertheless high, making the maintenance of relatively greater forested areas around oil palm plantations necessary in order to conserve anuran diversity.

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Different definitions of species presence to refine estimates of local species richness

10.7287/peerj.preprints.3077v1 ◽

2017 ◽

Author(s):

Alejandro Ruete ◽

Tomas Pärt ◽

Åke Berg ◽

Jonas Knape ◽

Debora Arlt

Keyword(s):

Species Richness ◽

Breeding Season ◽

Temporal Resolution ◽

Explanatory Power ◽

Bird Species ◽

High Temporal Resolution ◽

Occupancy Models ◽

Local Species Richness ◽

Site Use ◽

Local Species

Abstract Aim To improve predictions of spatial and temporal patterns of species richness it is important to consider how species presence at a site is defined. This is because this definition affects our estimate of species richness, which should be aligned with the aims of the study, e.g. estimating richness of the breeding community. Here we explore the sensitivity of species richness estimates to criteria for defining presence of species (e.g. in relation to number of days present during the breeding season) at 107 wetlands. Innovation We use opportunistic citizen science data of high density (a total of 151,817 observations of 77 wetland bird species; i.e. about 16 observations per day) to build site-occupancy models calculating occupancy probabilities at a high temporal resolution (e.g. daily occupancies) to derive probabilistic estimates of seasonal site use of each species. We introduce a new way for defining species presence by using different criteria related to the number of days the species are required to be present at local sites. We compared patterns of species richness when using these different criteria of species inclusions. Main conclusion While estimates of local species richness derived from high temporal resolution occupancy models are robust to observational bias, these estimates are sensitive to restrictions concerning the number of days of presence required during the breeding season. Unlike complete local species lists, summaries of seasonal site use and different presence criteria allow identifying differences between sites and amplifying the variability in species richness among sites. Thus, this approach allows filtering out species according to their phenology and migration behaviour (e.g. passer-by species) and could improve the explanatory power of environmental variables on predictive models.

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LATE BREEDING-SEASON DEFINITIVE PRE-BASIC MOLT BY MALES, AND LATE BREEDING SEASON BROOD CARE BY FEMALES, IN CENTRAL CALIFORNIA WILSON'S WARBLERS

10.22541/au.163656586.68846226/v1 ◽

2021 ◽

Author(s):

William M. Gilbert

Keyword(s):

Breeding Season ◽

Brood Care ◽

Central California ◽

Breeding Grounds ◽

Breeding Seasons ◽

Unique Study ◽

California Population

Abstract. I made late breeding season (after 1 July) observations of a central California population of Wilson’s Warbler, Cardellina pusilla, over nine breeding seasons. I sighted males in definitive prebasic molt from 4 July in 2007 through 1 September in 1999. Possibly all territorial males molted on their breeding territories, and molt lasted a maximum of 46 days. Following prebasic molt, territorial males engaged in subdued “post molt singing,” which lasted 14 days in one male, but usually no more than seven days, and was last heard on 6 September in 1999. I sighted no female in definitive prebasic molt, nor in bright basic plumage, during the study. Of 12 color-banded females sighted after 22 July, I confirmed 11 had been in late breeding season uniparental brood care. Possibly all resident females not engaged in late uniparental brood care vacated their breeding territories earlier, and before resident males. They presumably underwent prebasic molt at later times and locations not known. Remaining late nesting females must have molted much later than resident males, and likely later than early departing resident females, and at unknown locations. I last sighted uniparental brood tending females still in dull alternate plumage on 26 and 29 August respectively, whereas some males had completed prebasic molt by 13 August. Three unique study findings are the occurrence of male post molt singing, a male/female difference in location of prebasic molt, and a likely dichotomy of prebasic molt timing between females leaving their breeding grounds early, and those remaining in uniparental brood care.

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Species Richness and Nesting Success of Migrant Forest Birds in Natural River Corridors and Anthropogenic Woodlands in Southeastern South Dakota

The Condor ◽

10.1093/condor/108.1.140 ◽

2006 ◽

Vol 108 (1) ◽

pp. 140-153

Author(s):

Dale J. Gentry ◽

David L. Swanson ◽

Jay D. Carlisle

Keyword(s):

Species Richness ◽

Nesting Success ◽

Forest Birds ◽

Individual Species ◽

Natural Habitats ◽

Riparian Corridors ◽

Neotropical Migrant ◽

Riparian Woodlands ◽

Migrant Birds ◽

River Corridors

AbstractForest fragmentation is thought to be partially responsible for declines in many Neotropical migrant birds due to the combined effects of higher rates of brood parasitism and increased predation near forest edges. A majority of the forested habitat in the northern prairie region is found in riparian corridors, but this native habitat has been much reduced from its historical extent. However, additional woodland nesting habitat has been established within the last century in the form of isolated woodlots on farms. We compared abundance, species richness, and nesting success of migrant forest birds breeding in native riparian corridors and anthropogenic woodlots. The two habitats had similar bird abundances but native riparian woodlands were more species-rich than woodlots. We located a total of 650 nests, with 320 nests of 15 species in woodlots and 331 nests of 25 species in riparian corridors. Nesting success was not significantly different between the two habitats for all species combined or for individual species with ≥15 nests in each habitat. Nests above 5 m were more successful than lower nests, but distance to woodland edge did not influence nesting success. Nests initiated in the middle and late portions of the nesting season were more successful than early season nests, significantly so in woodlots. Thus, anthropogenic woodlots were as suitable as natural habitats for successful nesting. However, many of the Neotropical migrants occurring in riparian habitats were absent from woodlots, which suggests that riparian corridors are especially important habitats for breeding birds in the northern prairie region.

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Grasslands and migratory birds of the Himalayan region

Indian Journal of Forestry ◽

10.54207/bsmps1000-2016-cv9806 ◽

2016 ◽

Vol 39 (2) ◽

pp. 97-100

Author(s):

Chandra Kala

Keyword(s):

Breeding Season ◽

Migratory Birds ◽

Himalayan Region ◽

Wild Animals ◽

Horizontal Migration ◽

Breeding Grounds ◽

Multiple Uses ◽

Grazing Lands

The Himalayan grasslands from sub-tropical to temperate, alpine and steppe have been exploited historically by humans for multiple uses including grazing lands for livestock. Besides domestic and wild animals, a large number of migratory birds use these grasslands and wetland areas dotted in these grasslands during their vertical and horizontal migration in the Himalayan region during breeding season. Despite quite unique and sensitive ecosystems these grasslands are least studied. The present study, therefore, aims to study the structure and composition of Himalayan grasslands with respect to their multiple utilities, including breeding grounds for migratory birds.

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Sonar Surveys for Bat Species Richness and Activity in the Southern Kalahari Desert, Kgalagadi Transfrontier Park, South Africa

Diversity ◽

10.3390/d10030103 ◽

2018 ◽

Vol 10 (3) ◽

pp. 103 ◽

Cited By ~ 2

Author(s):

Rick Adams ◽

Gary Kwiecinski

Keyword(s):

South Africa ◽

Species Richness ◽

Low Frequency ◽

Abundant Species ◽

Desert Ecosystem ◽

Survey Period ◽

Sparse Vegetation ◽

Call Structure ◽

Kalahari Desert ◽

Site Design

Kgalagadi Transfrontier Park is located in northwestern South Africa and extends northeastward into Botswana. The park lies largely within the southern Kalahari Desert ecosystem where the Auob and Nassob rivers reach their confluence. Although these rivers run only about once every 100 years, or shortly after large thunderstorms, underground flows and seeps provide consistent surface water for the parks sparse vegetation and diverse wildlife. No formal studies on bats have previously occurred at Kgalagadi. We used SM2 + BAT ultrasonic detectors to survey 10 sites along the Auob and Nassob rivers from 5–16 April 2016. The units recorded 3960 call sequences that were analyzed using Kaleidoscope software for South African bats as well as visual determinations based on call structure attributes (low frequency, characteristic frequency, call duration, and bandwidth). We identified 12 species from four families: Rhinolophidae: Rhinolophus fumigatus. Molossidae: Chaerephon pumilus, and Sauromys petrophilus, Tadarida aegyptiaca; Miniopteridae: Miniopteris schreibersi (natalensis), Vespertilionidae: Laephotis botswanae, Myotis tricolor, Neoromicia capensis, N. nana, Pipistrellus hesperidus, Scotophilus dinganii, and S. viridus. The most abundant species during the survey period was N. capensis. We also used paired-site design to test for greater bat activity at water sources compared to dry sites, with dry sites being significantly more active. We conclude that species richness is much higher than previously known from this region and that more species may be present during the warmer months of the year. In addition, activity of bats during the dry season in Kgalagadi would likely be more concentrated around drinking opportunities, thus allowing for better detection of species richness in the area.

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