scholarly journals The Spatial Response of Male Hooded Warblers to Edges in Isolated Fragments

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 595-600 ◽  
Author(s):  
D. Ryan Norris ◽  
Bridget J. M. Stutchbury ◽  
Trevor E. Pitcher
Keyword(s):  
Space Use ◽  
Forest Edge ◽  
Time Of Day ◽  
Forest Edges ◽  
Forest Patches ◽  
Wilsonia Citrina ◽  
Use Patterns ◽  
Continuous Forest ◽  
Hooded Warblers ◽  
Occupancy Rates

Abstract We tested whether Hooded Warblers (Wilsonia citrina) avoided abrupt forest edges by radiotracking males breeding in small, isolated forest patches (0.5–2.0 ha) in northwest Pennsylvania. Because territory edges were synonymous with abrupt forest edges in all cases, we compared space use patterns with males radiotracked in a nearby continuous forest (150 ha), where we defined edge from territorial boundaries. Based on the proportion of edge to core area, males in both habitats avoided the area within 20 m of the edge, implying that males responded to the presence of territory edge rather than forest edge. Surprisingly, however, males in isolated fragments used the edge area significantly more than males in continuous forest, even when measured against the relative amount of edge area within each territory. Elevated levels of edge use were not related to distance of nests to edges, nest stage, or time of day. We conclude that the presence of physical edges is not the sole determinant of territorial space use in this species and there are likely additional social factors influencing occupancy rates in small, isolated woodlots. Therefore, definitions of forest-interior species based on edge use need to be reconsidered.

scholarly journals Sexual Differences in Gap-Crossing Ability of a Forest Songbird in a Fragmented Landscape Revealed Through Radiotracking

The Auk ◽  
2002 ◽  
Vol 119 (2) ◽  
pp. 528-532 ◽  
Author(s):  
D. Ryan Norris ◽  
Bridget J. M. Stutchbury
Keyword(s):  
Breeding Season ◽  
Radio Telemetry ◽  
Sexual Differences ◽  
Fragmented Landscape ◽  
Fragmented Habitat ◽  
Wilsonia Citrina ◽  
Continuous Forest ◽  
Gap Crossing ◽  
Hooded Warblers ◽  
Extrapair Copulation

Abstract We used radio telemetry to examine extraterritorial movements of female Hooded Warblers (Wilsonia citrina) breeding in small, isolated woodlots. Only 44% of the nine females tracked left their woodlots (n = 6 forays in total). Compared to males followed in the same fragments (Norris and Stutchbury 2001), females spent significantly less time off territory and traveled shorter distances across nonforested gaps. Unlike males in fragmented habitat and females in continuous forest, we found no evidence that females were actively seeking extrapair copulations. We conclude females are relatively more restricted to isolated fragments during the breeding season and suggest that the lack of extrapair copulation opportunity could contribute to female avoidance of fragmented habitat, resulting in a high number of unmated males. This study emphasizes the importance of examining the potential effects of fragmentation in both sexes.

scholarly journals Evaluation of Forest Edge Structure and Stability in Peri-Urban Forests

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 338
Author(s):  
David Hladnik ◽  
Andrej Kobler ◽  
Janez Pirnat
Keyword(s):  
Urban Forest ◽  
Residential Buildings ◽  
Canopy Structure ◽  
Urban Forests ◽  
Forest Edge ◽  
Canopy Height ◽  
Forest Edges ◽  
Forest Patches ◽  
Forest Patch ◽  
Edge Structure

In the presented research, we studied the forest edge structure of urban and peri-urban forests on the outskirts of Ljubljana (Slovenia) consisting of a number of patches covering the collective surface of 1884 ha. They differ from each other according to the degree of fragmentation and by the share of the interior forest area. On the basis of LiDAR data, we conducted an analysis of the edges of the persistent forest patches and estimated them with regard to the land use they bordered on. The horizontal estimation of forest edges and the changes of forest edges, in the last decades, were estimated using digital orthophoto images of cyclic aerial surveys of Slovenia, from 1975 to 2018. The data, provided by LiDAR, were used to obtain an accurate estimate of forest edges and the metrics of their vertical canopy structure. On the basis of the canopy height model (CHM), we determined the height classes, the heights of the tallest trees, and indices of canopy height diversity (CHD) as variables subjected to a k-means cluster analysis. To determine the forest edge and trees stability, their heights and diameters at breast height (DBH) were measured and their canopy length and h/d (height/diameter) dimension ratios were estimated. In the study area of the Golovec forest patch, more than half of the forest edge segments (56%) border on residential buildings. After the construction of buildings, 54% of the newly formed forest edges developed a high and steep structure. Unfavorable h/d dimension ratio was estimated for 16% of trees, more among the coniferous than among the deciduous trees. Similar characteristics of newly formed forest edges bordering on built-up areas were determined in other sub-urban forest patches, despite the smaller share of such forest edges (19% and 10%, respectively). Tools and methods presented in the research enable the implementation of concrete silvicultural practices in a realistic time period and extend to ensure that adequate forestry measures are taken to minimize possible disturbances.

Predator avoidance, feeding and habitat use in the red-necked pademelon, Thylogale thetis, at rainforest edges

2001 ◽  
Vol 49 (1) ◽  
pp. 45 ◽  
Author(s):  
Geoffrey M. Wahungu ◽  
Carla P. Catterall ◽  
Mike F. Olsen
Keyword(s):  
Group Size ◽  
Predator Avoidance ◽  
Foraging Behaviour ◽  
Forest Cover ◽  
Forest Edge ◽  
Time Of Day ◽  
Survival Strategies ◽  
Forest Edges ◽  
Eastern Australia ◽  
Reproductive Females

Food acquisition and predator avoidance are principal, but often conflicting, components of the survival strategies of most animals. We investigated the behaviour of red-necked pademelons, Thylogale thetis, (Marsupialia: Macropodidae) in pasture adjacent to rainforest edges in eastern Australia, by testing the relationships among age and sex of individuals, time of day, season, site, distance from cover (forest edge), feeding, vigilance and group size. Foraging behaviour was responsive to changes in predation risk. Feeding and vigilance activities accounted for most of the activity budget of foraging pademelons, and were negatively correlated. Reproductive females and individuals in smaller groups foraged closer to forest edges, were more vigilant and spent less time feeding. Vigilance decreased with increasing group size even after controlling for other confounding factors. Increased predation risks of feeding further from forest cover were offset by the pademelons doing so only if their group size was large, so that the time allocated to vigilance did not increase.

scholarly journals The home-range concept: are traditional estimators still relevant with modern telemetry technology?

2010 ◽  
Vol 365 (1550) ◽  
pp. 2221-2231 ◽  
Author(s):  
John G. Kie ◽  
Jason Matthiopoulos ◽  
John Fieberg ◽  
Roger A. Powell ◽  
Francesca Cagnacci ◽  
...  
Keyword(s):  
Home Range ◽  
New Technologies ◽  
Animal Movement ◽  
Space Use ◽  
Ease Of Use ◽  
Home Ranges ◽  
Data Intensive ◽  
Use Patterns ◽  
Location Data ◽  
Utilization Distributions

Recent advances in animal tracking and telemetry technology have allowed the collection of location data at an ever-increasing rate and accuracy, and these advances have been accompanied by the development of new methods of data analysis for portraying space use, home ranges and utilization distributions. New statistical approaches include data-intensive techniques such as kriging and nonlinear generalized regression models for habitat use. In addition, mechanistic home-range models, derived from models of animal movement behaviour, promise to offer new insights into how home ranges emerge as the result of specific patterns of movements by individuals in response to their environment. Traditional methods such as kernel density estimators are likely to remain popular because of their ease of use. Large datasets make it possible to apply these methods over relatively short periods of time such as weeks or months, and these estimates may be analysed using mixed effects models, offering another approach to studying temporal variation in space-use patterns. Although new technologies open new avenues in ecological research, our knowledge of why animals use space in the ways we observe will only advance by researchers using these new technologies and asking new and innovative questions about the empirical patterns they observe.

Space use patterns of sharks in relation to boat activity in an urbanized coastal waterway

2021 ◽  
pp. 105489
Author(s):  
Mitchell J. Rider ◽  
Oliver S. Kirsebom ◽  
Austin J. Gallagher ◽  
Erica Staaterman ◽  
Jerald S. Ault ◽  
...  
Keyword(s):  
Space Use ◽  
Use Patterns

scholarly journals Studies of Ant-Following Birds North of the Eastern Amazon

1972 ◽  
Vol 2 (2) ◽  
pp. 127-151 ◽  
Author(s):  
Yoshika Oniki ◽  
Edwin O. Willis
Keyword(s):  
Forest Edge ◽  
Forest Edges ◽  
Army Ants ◽  
Forest Interior ◽  
Second Growth

Abstract Birds that prey on arthropods flushed by army ants north of the eastern Amazon were studied at Serra do Navio and Reserva Ducke (Brazil) and at Nappi Creek and Bartica (Guyana). Regular ant-followers are two medium-sized antbirds (Percnostola rufifrons and Gymnopithys rufigula) and two smaller ones (Pithys albifrons and Hylophylax poecilonota), plus five woodcreepers of differing sizes (from very large Hylexetastes perrotti through Dendrocolaptes picumnus, D. certhia, and Dendrocincla merula to medium-sized Dendrocincla fuliginosa). Four other regular ant-followers occur in the region but were not found at the study areas. Forty-five species of casual or nonprofessional ant-followers, including 16 antbirds, 5 woodcreepers, and 5 manakins, also were recorded. Percnostola rufifrons tends to be at the forest edge or in second growth. Pithys albifrons works around Gymnopithys rufigula, Hylophylax poecilonota peripheral to both, in the forest interior. The large Dendrocolaptes picumnus and medium-large Dendrocincla merula often capture prey near the ground, like antbirds. Unlike antbirds, which use vertical or horizontal slender perches, the woodcreepers use thick vertical perches. Dendrocolaptes certhia and Dendrocincla fuliginosa also tend to capture prey high over the ground-foraging antbirds. The woodcreepers tend to forage lower at midday. Hylexetastes perrotti is rare, and overlaps strongly with D. picumnus. There is fairly large overlap among the 9 professional ant-followers, and large ones chase away smaller ones. Nonprofessional birds tend to forage briefly or peripherally when or slightly after the professional species are active. They also forage above the antbirds and below or above the woodcreepers, and concentrate at forest edges or in second growth. The guild of ant-following birds in this region differs fairly widely from guilds in Panamá and at Belém, Brazil; the absence of large antbirds and the predominance of large woodcreepers north of the Amazon are the major differences.

Preadaptation and spatial effects on retention-tree survival in cut areas in Estonia

2008 ◽  
Vol 38 (10) ◽  
pp. 2616-2625 ◽  
Author(s):  
Raul Rosenvald ◽  
Asko Lõhmus ◽  
Andres Kiviste
Keyword(s):  
Natural Disturbance ◽  
Forest Edge ◽  
Forest Site ◽  
Spatial Effects ◽  
Forest Edges ◽  
Dead Trees ◽  
Tree Survival ◽  
Tree Retention ◽  
Standing Dead ◽  
Retention Trees

Survival of live retention trees is a key issue for stand-scale applications of natural-disturbance-based silviculture. We explored the survival of 3255 trees in 102 cut areas (mean size 2.3 ha) in Estonia for 6 years, focusing on spatial variation and preadaptation of the trees. Altogether, 35% of the trees died during the study period, contributing 4.4 m3 of downed dead trunks and 1 m3 of standing dead trees per hectare. The annual mortality rates declined over time. The main survival determinants were tree species (higher for hardwood deciduous trees), diameter (species dependent), position relative to forest edge (higher for trees near current or former forest edges), retention density (positive), and exposure (negative). The results suggest that (1) green-tree retention can effectively increase the abundance of large shade-tolerant trees, but it is equally important for producing deadwood; (2) larger individuals, former interior-forest trees near current forest edges, and preadapted trees in open conditions should be preferably retained; (3) there is no obvious necessity to modify tree-retention techniques for tree survival according to geographical region or forest site type.

Capture–recapture estimates of space used in streams (CRESUS) at the population scale: case study on Zingel asper (percid), a threatened species of the Rhône catchment

2004 ◽  
Vol 61 (3) ◽  
pp. 476-486 ◽  
Author(s):  
Delphine Danancher ◽  
Jacques Labonne ◽  
Roger Pradel ◽  
Philippe Gaudin
Keyword(s):  
Spatial Data ◽  
Abiotic Factors ◽  
Estimation Method ◽  
Space Use ◽  
Longitudinal Axis ◽  
Spawning Period ◽  
Data Movement ◽  
Use Patterns ◽  
Capture Recapture ◽  
Population Scale

In this study, capture–mark–recapture statistics were applied to spatial recapture histories to assess the intensity of fish restricted movements along the longitudinal axis of a river using a previously described model for survival and recruitment analysis. Adapting the stopover estimation method to spatial data, movement probabilities were then used to estimate space used at the population scale. This capture–recapture estimates of space used in streams (CRESUS) method may thus be seen as a complementary tool of classic home range methods and should be used to explore the consequence of behavioural strategies on population mechanisms. We propose a methodological example where movements and space use strategies of a Zingel asper (percid) population in the Beaume River (Ardèche, France) were directly estimated at the population scale taking account of the effects of different biotic or abiotic factors. Results showed differences in Z. asper space use patterns among sexes, periods of biological cycle (growing and spawning period), and types of mesohabitat. Downstream movements were more important during the spawning period and by the way the riffle was more intensively used.

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