scholarly journals Do Ovenbirds (Seiurus Aurocapillus) Avoid Boreal Forest Edges? A Spatiotemporal Analysis in an Agricultural Landscape

The Auk ◽  
2003 ◽  
Vol 120 (1) ◽  
pp. 152-162
Author(s):  
Daniel F. Mazerolle ◽  
Keith A. Hobson

Abstract Previous studies suggest that Ovenbirds (Seiurus aurocapillus) are area sensitive and apparently avoid forest edges. In 1999 and 2000, we used radiotelemetry to investigate how breeding male Ovenbirds respond to forest edges. Twenty-one males with home ranges abutting edges of seven forest fragments surrounded by agriculture were tracked for an average of two weeks. We found that sightings of males were situated 8 ± 10 m closer to edges than random locations within each home range. However, the mean time of day for edge sightings (1139 hours, 95% CI = 1052–1227 hours) occurred significantly later than the mean for sightings in the interior of forest fragments (0936 hours, 95% CI = 0856–1016 hours). That indicates that previous studies focusing on morning singing locations to delineate home-range use have likely underestimated use of edges by birds. Habitat characteristics also varied in relation to edges. Forest canopy was lower, shrubs were denser, leaf-litter thicker, and soils dryer near edges than in the portion of home ranges facing the interior of forest fragments. Arthropod biomass varied little in relation to edges, except biomass of larvae, which was greatest at edges. Boreal forest edges abutting agricultural fields do not appear to reduce habitat use or quality for breeding male Ovenbirds, and so we suggest that the generalized association between area sensitivity and edge avoidance for Ovenbirds in forest fragments be reassessed.

Abstract.—Adult burbot <em>Lota lota </em>from Koocanusa Reservoir, Montana, USA were surgically implanted with acoustic (<em>n </em>= 28) and combined radio/acoustic tags (<em>n </em>= 12) to quantify movements and home range. Fish were tagged from November 2003 to April 2004, and tracking efforts were conducted approximately weekly during daylight hours on Koocanusa Reservoir using a motor boat during the period of mid-December 2003 to July 2005, which spanned two burbot spawning seasons. Six (15%) tagged burbot were never relocated after release, and an additional seven (17.5%) of the tagged burbot either died or shed their tag within 60 d after release. We relocated 34 marked burbot (85%) on at least three occasions (mean = 10.0). Burbot frequently used the deepest portions of the reservoir, especially during the summer months. We estimated that the mean 50%, 75%, and 90% kernel home ranges were 14.6, 22.6 and 32.3 km<sup>2</sup>, respectively. We found no evidence that burbot home range differed within the 2 years of this study. Although we did observe burbot moving a maximum distance of up to 64.3 km, we were unable to discern any general movement patterns by month or capture location. Individual burbot tagged in this study had relatively high fidelity to the original capture side of the reservoir, and almost half of our marked burbot were never relocated on the opposite side of the remnant Kootenai River thalweg, and those that did cross the thalweg do so infrequently. One burbot was entrained through Libby Dam approximately 134–276 d after capture and tagging.


Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 100 ◽  
Author(s):  
Priscila da Silva Lucas ◽  
Milene Alves-Eigenheer ◽  
Talitha Mayumi Francisco ◽  
James M. Dietz ◽  
Carlos Ramón Ruiz-Miranda

Linear infrastructures are a primary driver of economic development. However, they also can negatively affect wildlife by mortality and the barrier effect. In this paper, we address how paved and unpaved roads, high-tension power lines, and gas/oil pipelines affect home range size, core areas, and movement in an endangered primate, the golden lion tamarin (GLT). Location data were recorded using radio telemetry on 16 groups in two protected areas and in privately owned forest fragments. The GLT’s home range, not core area, increased in size for the groups that occupied locations far from linear infrastructures; home range was also significantly influenced by available forest size. None of the home ranges contained a road, but home ranges did contain power lines. GLTs used the surrounding landscape near all types of infrastructure. Movement analysis showed that most of the step lengths (distances between subsequent locations) were less than 100 m between two consecutive locations, but step length was longer for roads and longer for groups in fully forested habitats. Tamarins avoided paved roads when in close proximity to this type of infrastructure; this behavior increased in areas without adequate adjacent forest habitat. Our results show that linear infrastructures differ in their level of impact: roads can act as a barrier, whereas other types of infrastructure have minimal effect on movement and home range. We discuss these differences in impact in terms of structure, maintenance schedules, and edge effects of infrastructure.


Koedoe ◽  
1975 ◽  
Vol 18 (1) ◽  
Author(s):  
G.L. Smuts

Annual home range sizes were determined for 49 marked zebra family groups in the Kruger National Park. Sizes varied from 49 to 566 sq. km, the mean for the Park being 164 square kilometre. Mean home range sizes for different zebra sub-populations and biotic areas were found to differ considerably. Present herbivore densities have not influenced intra- and inter-specific tolerance levels to the extent that home range sizes have increased. Local habitat conditions, and particularly seasonal vegetational changes, were found to have the most profound influence on the shape and mean size of home ranges. The large home range sizes obtained in the Kruger Park, when compared to an area such as the Ngorongoro Crater, can be ascribed to a lower carrying capacity with respect to zebra, large portions of the habitat being sub-optimal, either seasonally or annually.


1999 ◽  
Vol 26 (6) ◽  
pp. 847 ◽  
Author(s):  
Paul D. Meek

In this study 10 free-roaming domestic dogs from an Aboriginal community were radio-collared to determine the sizes of their home ranges and to observe their wandering behaviour. Half of the radio-tagged dogs went on wandering forays, while the other five roamed only within the vicinity of the community. Home-range size was highly variable within the study group: the mean for the wandering dogs was 927 ha whereas that of the sedentary dogs was 2.6 ha. Dogs travelled 8–30 km on forays. All forays were initiated at night and those that were recorded had an average duration of 26 h. Foray destinations were usually riparian habitats where macropod quarry were abundant.


2004 ◽  
Vol 31 (3) ◽  
pp. 327 ◽  
Author(s):  
Helen Puckey ◽  
Milton Lewis ◽  
David Hooper ◽  
Carrie Michell

Radio-telemetry was used to examine the home range, movement and habitat utilisation of the critically endangered Carpentarian rock-rat (Zyzomys palatalis) in an isolated habitat patch in the Gulf of Carpentaria hinterland over a 13-month period. Two home-range estimators were used in the study, (i) minimum convex polygon (MCP) and (ii) fixed Kernel (KL), the latter also being used to estimate core areas of activity. Based on a total sample size of 21 individuals, the mean MCP home range was 11 165 m2, similar to the mean KL home range of 10 687 m2. Core areas were, on average, 11.9% of the KL home-range estimate. There was no significant difference in the size of home range or core area of males and females. Juveniles had a significantly smaller home range than adults. Home ranges and, to a lesser degree, core areas were non-exclusive, with multiple areas of overlap (averaging 41% and 38% respectively) within and between all age and gender categories, but especially between males and between juveniles. Movement frequencies showed that animals made many short forays in a central area close to the arithmetic home-range mean and far fewer long forays of distances greater than 100 m from the central area. The spatial and temporal activity of Z. palatalis was concentrated in, but not confined to, the 'valley' and 'slope' habitats, with fewer movements of rats onto the surrounding 'plateau'. Resource selection analyses showed that Z. palatalis tended to prefer valley and slope habitats over the plateau and that the proportion of point locations was significantly higher for adults in the slope habitat and for juveniles in the valley habitat. Most home ranges were centred on the ecotone between these two habitat types. Although isolated and spatially limited, these habitat patches provide high-quality resources for dense populations of Z. palatalis. This study exemplifies a species' attempt to make efficient use of a limited resource in an otherwise hostile environment. Even small declines in habitat area or quality due to their vulnerability to fire would impact upon many animals.


Koedoe ◽  
1982 ◽  
Vol 25 (1) ◽  
Author(s):  
B. L Penzhorn

The mean home range size of Cape mountain zebra breeding herds was 9,4 km2 (range 3,1 @ 16,0 km2). In two herds which split up, the home ranges of the resultant herds included the original home ranges, but were larger.


2010 ◽  
Vol 124 (2) ◽  
pp. 139 ◽  
Author(s):  
F. Neil Dawson ◽  
Audrey J. Magoun ◽  
Jeff Bowman ◽  
Justina C. Ray

We conducted the first radio-telemetry study of Wolverines in northwestern Ontario during the winter of 2003-2004 to determine whether home ranges and movements of Wolverines in lowland boreal forest were typical of this species in other ecosystems and to describe reproductive den sites in this habitat type. Seven Wolverines (3 M, 4 F) were radio-tagged and monitored for 31 to 269 (Mean ± SE = 153 ± 35) days using a combination of remotely monitored Argos satellite and conventional aerial telemetry. Male and female 95% minimum convex polygon (MCP) home ranges (±SE) during December to October were 2,563 (796) km2 and 428 (118) km2, respectively, for combined VHF and Argos locations. A lactating female had a 95% MCP home range of 262 km2. The den site for this female included large boulders and downed trees, similar to dens described for this species in montane ecosystems. Boulder complexes and downed trees may be critical features of wolverine dens in lowland boreal forests. Mean road densities (± SE) within 95% MCP and 50% MCP home ranges were 0.43 (0.13) and 0.33 (0.23) km/km2, respectively, and our results suggest that road densities may affect selection of home ranges by Wolverines. The Wolverine population was a resident, reproductive population. Erratum for table included.


The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Maurie J. Beck ◽  
T. Luke George

Abstract We used a hierarchical approach to describe habitat characteristics of song posts and foraging sites used by Varied Thrushes (Ixoreus naevius) in coastal redwood (Sequoia sempervirens) forests of northwestern California. We measured mesohabitat (0.04-ha circular plots) and microhabitat (0.5-m radius) scale attributes centered on occupied and random song posts and foraging locations at four study sites during March–August of 1994 and 1995. Ninety-five percent of song posts were in trees or snags. Male thrushes used song posts with low foliage density near the top of large conifers (microhabitat scale), located on steeper slopes, surrounded by a high density of trees, and centered in drainages closer to water (mesohabitat scale) as compared to random locations. Varied Thrushes foraged predominantly on the ground early in the breeding season, then subsequently included fruit in their diet after the young had fledged. Although many variables were correlated with ground foraging locations, microhabitat foliage density had the greatest explanatory power, indicating thrushes selected foraging locations primarily at the microhabitat scale, and emphasizing the importance of measuring habitat characteristics at the appropriate spatial scale. Abrupt forest edges, such as those produced by clearcuts, may reduce habitat suitability for Varied Thrushes possibly explaining their absence from small forest fragments during the breeding season.


1999 ◽  
Vol 59 (1) ◽  
pp. 125-130 ◽  
Author(s):  
C. F. D. ROCHA

The home range of the Tropidurid lizard Liolaemus lutzae, an endemic species of the costal sand dune habitats of Rio de Janeiro State, was studied in the beach habitat of Barra de Maricá restinga, Maricá County. Home ranges were studied using a mark-recapture technique in a delimited area at the beach habitat. I considered for estimates and analysis the home ranges of those lizards with a minimum of four positions. The size of L. lutzae home ranges varied according to the segment of the population. The mean home range size of adult males (x = 59.8 ± 33.7 m²) was significantly larger than that of adult females (x = 22.3 ± 16.1 m²). Juvenile mean home range size was significantly smaller than that of adult males, but did not differ from that of adult females (t = 1.058; p = 0.149). The overlap between male home ranges was usually low (3.6%), being in general only peripheral. Conversely, there was a considerable overlap between home ranges of adult females with those of adult males, the home range areas of two or three females being enclosed in the home range of one adult male. The small overlap between home ranges of adult males suggested mutual exclusion. The observed between-sex differences in the size of L. lutzae home range may be explained by the sexual dimorphism in body size in this species, and by the need of adult males to establish larger areas so as to include many females in their areas, during the reproductive season. The differences in home range along ontogeny probably result from differences in body size of the different segments of the population, due to trophic differences (carnivory and herbivory levels), and the dispersal of young after birth. Because L. lutzae is omnivorous, but primarily herbivorous when adult, and due to its sit-and-wait foraging behavior (mainly on arthropods), it does not need to move around over large areas to find food, which in turn reduces the area necessary for it to live.


Sign in / Sign up

Export Citation Format

Share Document