The spatial dynamics of White-browed Babbler groups in a fragmented agricultural landscape

2002 ◽  
Vol 8 (4) ◽  
pp. 271 ◽  
Author(s):  
Peter G. Cale
Keyword(s):  
Home Range ◽  
Breeding Season ◽  
Group Dynamics ◽  
Agricultural Landscape ◽  
Local Population ◽  
Breeding Site ◽  
Home Ranges ◽  
Effective Population ◽  
Study Sites ◽  
Group Movements

White-browed Babbler Pomatostomus superciliosus groups occupying linear strips of vegetation had breeding territories that were smaller in area and had longer linear dimensions than those occupying patches. A group's non-breeding home range was larger than its breeding territory. Groups occupying linear/patch home ranges expanded the linear extent and area of their home ranges more than those within other home range configurations. Some groups moved during the non-breeding season and this was more likely to occur if the group occupied a remnant with a low abundance of invertebrates during summer. Some groups that moved returned prior to the next breeding season, but the majority were never seen again. New groups moved into the study sites and established in vacant home ranges. This suggests that those groups that left the study sites may have established new home ranges elsewhere. Breeding site fidelity was lower in groups that had failed in previous breeding attempts. Therefore, group movements were influenced by the feeding and breeding quality of the habitat. However, the configuration of the local population also influenced group movements with those groups on the edge of a local population being more likely to move than those in the interior. New groups were formed by two processes; group dispersal, where groups generally filled a vacant home range, and group budding, which involved the splitting of a large group. Group dispersal maintained group densities while group budding increased the density of groups in a local population. These two processes were common, producing localized fluctuations in the density of groups. Since babbler groups contain only one breeding pair, changes in group density represent changes in effective population size. Therefore, group dynamics may be important to the persistence of local populations of White-browed Babblers, especially in landscapes that have suffered from habitat loss and fragmentation.

scholarly journals Great Gray Owl home range and habitat selection during the breeding-season

2019 ◽  
Vol 42 ◽  
pp. 90-96
Author(s):  
Katherine Gura ◽  
Bryan Bedrosian ◽  
Anna D. Chalfoun ◽  
Susan Patla
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Breeding Season ◽  
Resource Selection ◽  
Home Range Size ◽  
Breeding Habitat ◽  
Home Ranges ◽  
Effective Management ◽  
Density Estimates ◽  
Resource Requirements

Identifying resource requirements of under-studied species during key stages such as breeding is critical for effective management. We quantified breeding-season home-range attributes and habitat selection of adult Great Gray Owls across multiple spatial (home-range and within-home-range level) and temporal (nesting and post-fledging; day versus night) scales in western Wyoming, USA. In 2018 and 2019 we outfitted adult male owls (n = 18) with GPS remote-download transmitters and collected hourly location data throughout the breeding season (1 May – 15 September). Using 50% and 95% kernel density estimates (KDE), mean core area was 1.2 km2 and mean home-range size was 6.2 km2 (n = 16). Resource selection analyses incorporated both remotely-sensed and microsite data. We conducted microsite surveys at used and available points within 95% KDE home ranges using a stratified random sample design (n = 661). Determining home-range and breeding habitat requirements will improve density estimates and facilitate the effective management of Great Gray Owls and their habitat. We found differing patterns between habitat selection at the home-range and within-home-range scales.   Featured photo by YNP on Flickr. https://flic.kr/p/SA17KT

scholarly journals Factors Associated With Variation in Home-Range Size of Appalachian Ruffed Grouse (Bonasa Umbellus)

The Auk ◽  
2007 ◽  
Vol 124 (4) ◽  
pp. 1407-1424 ◽  
Author(s):  
Darroch M. Whitaker ◽  
Dean F. Stauffer ◽  
Gary W. Norman ◽  
Patrick K. Devers ◽  
John Edwards ◽  
...  
Keyword(s):  
Home Range ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Ruffed Grouse ◽  
Bonasa Umbellus ◽  
High Quality ◽  
Game Birds ◽  
Study Sites ◽  
Juvenile Males

Abstract From 1996 to 2001, researchers at 10 Appalachian study sites collected radiotracking data sufficient to delineate 1,054 seasonal home ranges of Ruffed Grouse (Bonasa umbellus; hereafter “grouse”). Using information-theoretic model selection and paired comparison of home ranges from individual grouse, we evaluated individual, local, and landscape factors hypothesized to affect grouse home-range size. Females and juvenile males occupied home ranges that averaged >2× larger than those of adult males, and home ranges of females averaged 2.6× larger during successful breeding seasons than during years of reproductive failure. Clearcuts and forest roads are considered high-quality covers, and both were more prevalent in smaller home ranges. Several factors operating at a regional and landscape scale were also important. Previous studies have reported that southern grouse use relatively large home ranges, and we observed a continuous decline in home-range size with increasing latitude across the 710-km range spanned by our study sites. Home-range size of males, particularly juvenile males, was positively related to an index of population density. Given the species' “dispersed lekking” mating system, we interpret this as evidence of competition for preferred display sites. As has been reported for other game birds, all sex and age classes of grouse used smaller home ranges following closure of sites to hunting. Grouse inhabiting oak-hickory forests used larger home ranges than conspecifics in mixed mesophytic forests, and other factors interacted with forest type. In oak-hickory forests, female home-range size was inversely related to use of mesic bottomlands, which support important forage plants, and home ranges of adult grouse increased 2.5× following poor hard-mast crops. By contrast, home ranges of grouse inhabiting mixed mesophytic forests were unrelated to use of bottomlands, and the influence of hard mast was reduced. This is in line with the view that in Appalachian oak-hickory forests, grouse are under strong nutritional constraint. However, this constraint is reduced in mixed mesophytic forests, likely because of the presence of high-quality alternative foods (e.g., cherry [Prunus spp.] and birch [Betula spp.]). Facteurs associés à une variation de la taille du domaine vital de Bonasa umbellus dans les Appalaches

scholarly journals Home Range Attributes and Habitat Selection of Barred Owls and Spotted Owls in an Area of Sympatry

The Condor ◽  
2007 ◽  
Vol 109 (4) ◽  
pp. 750-768 ◽  
Author(s):  
Thomas E. Hamer ◽  
Eric D. Forsman ◽  
Elizabeth M. Glenn
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Breeding Season ◽  
Home Range Size ◽  
Negative Slope ◽  
Home Ranges ◽  
Strix Varia ◽  
Spotted Owls ◽  
Barred Owls ◽  
Selection Of

Abstract We compared home range areas and habitat selection of radio-marked Spotted Owls (Strix occidentalis) and Barred Owls (Strix varia) in an area of sympatry in the northern Cascade Range of Washington in 1986–1989. On average, home ranges of Spotted Owls were 3–4 times larger than ranges of Barred Owls, and there was little overlap of home ranges during the breeding season. Ranges of both species tended to expand during winter. Home range size of both species was negatively correlated with the amount of old forest, but the negative slope of the regression was much steeper for Spotted Owls than for Barred Owls. For both species, home ranges of individual owls typically had high overlap among seasons and years, indicating high site fidelity. Barred Owls generally occupied home ranges at lower elevations than Spotted Owls (mean  =  386 ± 27 m vs. 750 ± 68 m). Both species tended to use old forests more than expected, but Spotted Owls tended to use other cover types less than expected, whereas Barred Owls used most other cover types in proportion to their availability. We suggest that Spotted Owls may use larger ranges than Barred Owls because they prey selectively on a few species of nocturnal mammals, whereas Barred Owls forage more evenly across a broad range of prey types, including diurnal and aquatic species. The low overlap of Barred Owl and Spotted Owl home ranges suggests that territorial Barred Owls exclude Spotted Owls from their territories, at least during the breeding season, thus reducing the amount of habitat available to Spotted Owls.

scholarly journals Movement and Home Range of Nile Crocodiles in Ndumo Game Reserve, South Africa

Koedoe ◽  
2015 ◽  
Vol 57 (1) ◽  
Author(s):  
Peter M. Calverley ◽  
Colleen T. Downs
Keyword(s):  
South Africa ◽  
Home Range ◽  
Satellite Telemetry ◽  
Movement Patterns ◽  
Breeding Site ◽  
Water Levels ◽  
Home Ranges ◽  
Total Length ◽  
Game Reserve ◽  
Nile Crocodile

The study of movement patterns and home range is fundamental in understanding the spatial requirements of animals and is important in generating information for the conservation and management of threatened species. Ndumo Game Reserve, in north-eastern KwaZulu-Natal, bordering Mozambique, has the third largest Nile crocodile (Crocodylus niloticus) population in South Africa. Movement patterns of 50 Nile crocodiles with a total length of between 202 cm and 472 cm were followed over a period of 18 months, using mark-resight, radio and satellite telemetry. The duration of radio transmitter attachment (131 ± 11.4 days) was significantly and negatively related to total length and reproductive status. Satellite transmitters failed after an average of 15 ± 12.5 days. Home range was calculated for individuals with 10 or more radio locations, spanning a period of at least 6 months. There was a significant relationship between home range size and total length, with sub-adults (1.5 m – 2.5 m) occupying smaller, more localised home ranges than adults (> 2.5 m). The largest home ranges were for adults (> 2.5 m). Home ranges overlapped extensively, suggesting that territoriality, if present, does not result in spatially discrete home ranges of Nile crocodiles in Ndumo Game Reserve during the dry season. Larger crocodiles moved farther and more frequently than smaller crocodiles. The reserve acts as a winter refuge and spring breeding site for an estimated 846 crocodiles, which also inhabit the Rio Maputo during the summer months. Nile crocodile movement out of the reserve and into the Rio Maputo starts in November and crocodiles return to the reserve as water levels in the floodplain recede in May.Conservation implications: Movement patterns of Nile crocodiles show the important role the reserve plays in the conservation of Nile crocodile populations within the greater Ndumo Game Reserve–Rio Maputo area.

Use of space by the marsupial Micoureus demerarae in small Atlantic Forest fragments in south-eastern Brazil

1999 ◽  
Vol 15 (3) ◽  
pp. 279-290 ◽  
Author(s):  
Alexandra Dos Santos Pires ◽  
Fernando Antonio Dos Santos Fernandez
Keyword(s):  
Home Range ◽  
Breeding Season ◽  
Atlantic Forest ◽  
Reproductive Season ◽  
Home Ranges ◽  
Forest Fragments ◽  
Population Densities ◽  
Metapopulation Structure ◽  
Eastern Brazil ◽  
Short Period

The spatial patterns presented by the marsupial Micoureus demerarae were studied through capture–mark–recapture in two small Atlantic Forest fragments (areas 7.1 and 8.8 ha). The study took place from March 1995 to August 1997. Considering all captures of each individual, males did not have larger home ranges within the fragments than did females. A negative correlation was found between home range sizes and population densities. For males, home ranges overlapped often, and were larger during the breeding season. For females, home ranges did not overlap except for a short period when there were many individuals present, and home range sizes were not significantly larger in the breeding season. Five movements between the two forest fragments were detected, across 300 m of open vegetation. All the movements were performed by males during the reproductive season. M. demerarae in the small fragments therefore displays a metapopulation structure, although possibly an atypical one where only males disperse.

scholarly journals Size of home range of Tengmalm’s owl (Aegolius funereus) males during breeding season assessed by radio-telemetry in the Jizera Mountains, Czechia

2018 ◽  
Vol 12 (1) ◽  
pp. 1-7
Author(s):  
Marek Kouba ◽  
Václav Tomášek
Keyword(s):  
Home Range ◽  
Breeding Season ◽  
Radio Telemetry ◽  
Home Range Size ◽  
Range Size ◽  
Time Interval ◽  
Home Ranges ◽  
Aegolius Funereus ◽  
The Mean ◽  
Tengmalm's Owl

Abstract Animal home ranges are typically characterized by their size, shape and a given time interval and can be affected by many different biotic and abiotic factors. Understanding of animal movements and assessing the size of their home ranges are essential topics in ecology and necessary for effective species protection, especially concerning birds of prey. Using radio-telemetry (VHF; 2.1 g tail-mounted tags) we studied the movements of two Tengmalm’s owl (Aegolius funereus) males during the breeding season 2008 in a mountain area of Central Europe (the Czech Republic, the Jizera Mountains: 50˚ 50’ N, 15˚ 16’ E). We determined their average nocturnal hunting and diurnal roosting home range sizes. The mean hunting home range size calculated according to the 90% fixed kernel density estimator was 251.1 ± 43.2 ha (± SD). The mean roosting home range size calculated according to the 100% minimum convex polygon method was 57.9 ± 15.8 ha (± SD). The sizes of hunting home ranges during breeding in this study coincide with those previously reported by other studies focusing on Tengmalm’s owl males. However, we found the roosting home ranges were smaller in size compared to those previously reported. This result was most probably connected with different habitat structure in our study area, which was severally damaged by air-pollution in the past, thus probably offering fewer suitable hiding-places, for instance from predators. We found the roosting locations were concentrated in the oldest and densest Norway spruce forest patches. We emphasize that these parts of forest stands require the highest possible protection in our study area.

scholarly journals Home Ranges of Sympatric Black and Turkey Vultures in South Carolina

The Condor ◽  
2004 ◽  
Vol 106 (3) ◽  
pp. 706-711 ◽  
Author(s):  
Travis L. DeVault ◽  
Bradley D. Reinhart ◽  
I. Lehr Brisbin ◽  
Olin E. Rhodes
Keyword(s):  
South Carolina ◽  
Home Range ◽  
Agricultural Landscape ◽  
Savannah River Site ◽  
Agricultural Landscapes ◽  
Home Ranges ◽  
Savannah River ◽  
Cathartes Aura ◽  
Turkey Vultures ◽  
River Site

Abstract We examined home-range characteristics of seven Black Vultures (Coragyps atratus) and four Turkey Vultures (Cathartes aura) at the Savannah River Site, South Carolina. Birds were captured at their primary roost and tracked via aerial telemetry from 11 February 2002 through 29 January 2003. Mean annual home-range sizes (95% fixed kernel) for Black and Turkey Vultures were 12 399 ± 5199 ha [SE] and 34 053 ± 8567 ha, respectively. Black Vultures concentrated their movements around the primary roost, whereas Turkey Vultures demonstrated less site fidelity. Home-range sizes and time spent soaring for both species were much greater than reported for vultures residing in an agricultural landscape. We suggest that food resources at the heavily forested Savannah River Site were fewer and less predictable than in agricultural landscapes, requiring larger home ranges and increased time spent foraging. Rangos de Hogar de los Buitres Simpátricos Coragyps atratus y Cathartes aura en Carolina del Sur Resumen. Examinamos las características de los rangos de hogar de siete Coragyps atratus y cuatro Cathartes aura en Savannah River, Carolina del Sur. Las aves fueron capturadas en sus sitios de descanso principales y fueron rastreadas mediante telemetría aé rea desde el 11 de febrero de 2002 hasta el 29 de enero de 2003. Los tamaños medios de rango de hogar (kernel fijo del 95%) fueron de 12 399 ± 5199 ha [EE] para C. atratus y de 34 053 ± 8567 ha para C. aura. Cathartes atratus concentró sus movimientos alrededor de sus sitios de descanso principales, mientras que C. aura demostró menor fidelidad al sitio. Para las dos especies, los tamaños del rango de hogar y el tiempo que permanecieron planeando fueron mucho mayores que los reportados para buitres que habitan paisajes agrícolas. Sugerimos que en Savannah River, un sitio con alta cobertura forestal, los recursos alimenticios eran más escasos y menos predecibles que en paisajes agrícolas, requiriendo rangos de hogar mayores y un incremento en el tiempo de forrajeo.

Habitat selection, philopatry and spatial segregation in rural Irish hedgehogs (Erinaceus europaeus)

Mammalia ◽  
2013 ◽  
Vol 77 (2) ◽  
Author(s):  
Amy Haigh ◽  
Ruth M. O’Riordan ◽  
Fidelma Butler
Keyword(s):  
Habitat Selection ◽  
Home Range ◽  
Breeding Season ◽  
Carrying Capacity ◽  
Arable Land ◽  
Compositional Analysis ◽  
Spatial Separation ◽  
Home Ranges ◽  
Radio Tracking ◽  
Dispersal Period

AbstractAs a non-territorial species with no known dispersal period, there are no obvious factors that regulate hedgehog numbers in an area. This study aimed to examine these factors and involved the radio-tracking of rural hedgehogs over a 3-year period. Males had a significantly larger mean annual home range (56 ha) than females (16.5 ha), which was at its maximum during the breeding season. Outside of the breeding season, the home range was relatively small (4–5 ha) in both sexes. The home ranges of males completely overlapped both each other and all of the females. In contrast, females occupied more exclusive areas with little overlap between one another. On a nightly basis, both sexes occupied spatially independent areas with little overlap. Compositional analysis of the data showed that habitats were not used in proportion to their availability but were selected, and this changed seasonally, with the highest preference being for garden and arable land. Hedgehogs tagged for consecutive years exhibited site philopatry and followed the same pattern of habitat selection annually. It is suggested that the spatial separation observed amongst individual hedgehogs could restrict numbers in an area and that female numbers reach a carrying capacity before that of males.

The effect of habitat on the breeding season survival of Mallards (Anas platyrhynchos) in the Great Lakes region

2018 ◽  
Vol 96 (7) ◽  
pp. 700-706
Author(s):  
Ryan A. Boyer ◽  
John M. Coluccy ◽  
Robert A. Montgomery ◽  
Kyle M. Redilla ◽  
Scott R. Winterstein
Keyword(s):  
Home Range ◽  
Great Lakes ◽  
Breeding Season ◽  
Anas Platyrhynchos ◽  
Habitat Associations ◽  
Home Ranges ◽  
Great Lakes Region ◽  
Habitat Types ◽  
Risk Of Predation ◽  
Core Areas

Modeling the effect of habitat on animal survival is critical for understanding population dynamics and developing effective habitat management strategies. Despite the importance of this information, knowledge of survival–habitat associations are often lacking, particularly for waterfowl species. Here we evaluated female Mallard (Anas platyrhynchos Linnaeus, 1758) survival during the breeding season in relation to habitat conditions within each individual’s home range. We implanted telemetry transmitters and tracked 283 female Mallards across nine study sites in the Great Lakes region. For each Mallard, we quantified core breeding season home ranges via the creation of utilization distributions (UDs). We then fit known-fate models in the program MARK to predict breeding season survival as a function of the proximity of core home ranges to various habitat types, the proportion of habitat types within the core areas, number of core areas, and home range size. We found that breeding season survival decreased as the proportion of forestland habitat within core home ranges increased (β = −1.740, SE = 0.787). No additional upland or wetland habitat types significantly affected breeding season survival. Managers striving to increase breeding season survival for Mallards should focus their efforts on restoring habitats in areas with low proportions of forestland habitat to mitigate the risk of predation.

scholarly journals Temporal and spatial resource use by female three-toed sloths and their young in an agricultural landscape in Costa Rica

2018 ◽  
pp. 1743-1755
Author(s):  
Oscar Ramirez ◽  
Christopher Vaughan ◽  
Geovanny Herrera ◽  
Raymond Guries
Keyword(s):  
Costa Rica ◽  
Home Range ◽  
Tree Species ◽  
Agricultural Landscape ◽  
Riparian Forest ◽  
Habitat Type ◽  
Riparian Forests ◽  
Home Ranges ◽  
Secondary Forests ◽  
Use Of Resources

The information on ecological behavior of wild sloths is very scarce. In this study we determined the home ranges and resources used by three adult female three-toed sloths (Bradypus variegatus) and their four young in an agricultural matrix of cacao (Theobroma cacao), pasture, riparian forests and living fencerows in Costa Rica. Births occurred during November-December and the young became independent at five to seven months of age. Initially, mothers remained fixed in one or a few trees, but expanded their use of resources as young sloths became independent from them. Mothers initially guided the young to preferred food and cover resources, but they gradually left their young in small nucleus areas and colonized new areas for themselves. Home range sizes for young sloths (up to seven months of age) varied between 0.04-0.6 hectares, while home range sizes for mothers varied from 0.04-25.0 hectares. During the maternal care period, 22 tree species were used, with the most common being Cecropia obtusifolia (30.9%), Coussapoa villosa (25.6%), Nectandra salicifolia (12.1%), Pterocarpus officinalis (5.8%) and Samanea saman (5.4%). However, young sloths used only 20 tree species, with the most common being C. villosa (18.4%), S. saman (18.5 %) and N. salicifolia (16.7%). The cacao agroforest was used only by mother sloths and never by their young following separation. However, in the riparian forest, both mother sloths and young used the tree species. A total of 28 tree species were used by the mother sloth; including the food species: C. obtusifolia, C. villosa, N. salicifolia and P. officinalis. However, the young used 18 trees species in this habitat with N. salicifolia and S. saman most commonly used, although they rested and fed during the day in C. obtusifolia, C. villosa and O. sinnuata. The cacao agroforest with adjacent riparian forests and fencerows provides an important habitat type that links the smaller secondary forests and other patches.

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