scholarly journals Distribution and habitat use of the Madagascar Peregrine Falcon: first estimates for area of habitat and population size

2021 ◽  
Author(s):  
Luke J. Sutton ◽  
Lily-Arison Réné de Roland ◽  
Russell Thorstrom ◽  
Christopher J.W. McClure
Keyword(s):  
Habitat Use ◽  
Population Size ◽  
Habitat Preferences ◽  
High Elevation ◽  
Range Limits ◽  
Tropical Species ◽  
Peregrine Falcon ◽  
Distribution Models ◽  
The Core ◽  
Vegetation Heterogeneity

AbstractAccurately demarcating species distributions has long been at the core of ecology. Yet our understanding of the factors limiting species range limits is incomplete, especially for tropical species in the Global South. Human-driven threats to the survival of many taxa are increasing, particularly habitat loss and climate change. Identifying distributional range limits of at-risk and data-limited species using Species Distribution Models (SDMs) can thus inform spatial conservation planning to mitigate these threats. The Madagascar Peregrine Falcon (Falco peregrinus radama) is the resident sub-species of the Peregrine Falcon complex distributed across Madagascar, Mayotte, and the Comoros Islands. Currently, there are significant knowledge gaps regarding its distribution, habitat preferences and population size. Here, we use point process regression models and ordination to identify Madagascar Peregrine Falcon environmental range limits and propose a population size estimate based on inferred habitat. From our models, the core range of the Madagascar Peregrine Falcon extends across the central upland plateau of Madagascar with a patchier range across coastal and low-elevation areas. Range-wide habitat use indicated that the Madagascar Peregrine Falcon prefers areas of high elevation and aridity, coupled with high vegetation heterogeneity and > 95 % herbaceous landcover, but generally avoids areas of > 30 % cultivated land and > 10 % mosaic forest. Based on inferred high-class habitat, we estimate this habitat area could potentially support a population size ranging between 150-300 pairs. Following International Union for Conservation of Nature Red List guidelines, we recommend this sub-species be classed as Vulnerable, due to its small population size. Despite its potentially large range, the Madagascar Peregrine has specialized habitat requirements and would benefit from targeted conservation measures based on spatial models in order to maintain viable populations.

scholarly journals Influence of environmental parameters on habitat use by sympatric freshwater eels, Anguilla marmorata and A. japonica on Yakushima Island, Japan

2021 ◽  
Author(s):  
Yusuke Kumai ◽  
Mari Kuroki ◽  
Kentaro Morita
Keyword(s):  
Habitat Use ◽  
Current Velocity ◽  
Life Stage ◽  
Habitat Preferences ◽  
Environmental Parameters ◽  
Tropical Species ◽  
River Systems ◽  
Yakushima Island ◽  
Anguilla Marmorata ◽  
Freshwater Eels

It is known that environmental parameters, such as water depth, size of substrate material, and current velocity influence the organization of stream fish communities. However, few studies have investigated the effects of these parameters on sympatric freshwater eels. Here, the habitat use of two anguillid eels, Anguilla marmorata Quoy and Gaimard, 1824 and A. japonica Temminck and Schlegel, 1846, coexisting in the same river systems in Japan was investigated. It was found that the tropical species A. marmorata exclusively utilized habitats with larger substrate materials, fewer fallen leaves and less leaf detritus, higher current velocity, and lower turbidity than the temperate species A. japonica, and the distributions of the two anguillid eels were clearly segregated. Thus, when both species co-occur in the same river systems, clear flowing mainstems and tributaries are preferred habitats for A. marmorata, while stagnant muddy estuaries, backwater areas, irrigation channels, and reservoirs are preferred habitats for A. japonica. These habitat segregations were consistent through body-size increases and life-stage developments from elver to yellow eel and did not show ontogenetic shifts. The findings indicated that both species had strong habitat preferences, and these environmental parameters must be considered in the conservation of anguillid eels in sympatric zones.

Use of Rock-wallaby Faecal Pellets for Detecting and Monitoring Populations and Examining Habitat Use.

1996 ◽  
Vol 19 (2) ◽  
pp. 257
Author(s):  
P.J. Jarman ◽  
S.M. Capararo
Keyword(s):  
Habitat Use ◽  
Population Size ◽  
Colony Size ◽  
Survey Design ◽  
Habitat Preferences ◽  
Faecal Pellets ◽  
Herbivorous Mammals ◽  
Measured Distribution ◽  
Absolute Population ◽  
Over Time

Counts of faecal pellets are commonly used to measure dispersion of medium to large, herbivorous mammals, including macropods. Rock-wallabies, Genus Petrogale, are relatively difficult to observe in the daytime, so indirect techniques for survey and measurement of dispersion and population size are attractive. Faecal pellets of rock-wallabies are easy to identify and to detect, often being rapidly dried and well preserved on rock substrates. Pellets have been used in surveys to detect past and recent presence of rock-wallabies in refuge habitat. Their measured distribution can also indicate limits to foraging range away from refuge habitat, information that is important for their management. By making careful correction for the expected form of distribution of rock-wallaby foraging away from refuge habitat, pellet sampling can be used to measure their habitat preferences. Pellet sampling can be used, with careful survey design, to monitor change in colony size over time; but it could be used only with difficulty to indicate absolute population size accurately. In some circumstances it will be more efficient to attempt to observe and count the wallabies directly.

A Specter of Coexistence: Is Centrifugal Community Organization Haunted by the Ghost of Competition?

2006 ◽  
Vol 52 (2) ◽  
pp. 123-140 ◽  
Author(s):  
Gideon Wasserberg ◽  
Burt P. Kotler ◽  
Douglas W. Morris ◽  
Zvika Abramsky
Keyword(s):  
Habitat Use ◽  
Dominant Species ◽  
Competitive Equilibrium ◽  
Community Organization ◽  
Habitat Preferences ◽  
Asymmetric Competition ◽  
Competitive Systems ◽  
The Core ◽  
Core Habitat ◽  
And Behavior

In a centrifugally organized community species prefer the same habitat (called “core”) but differ in their secondary habitat preferences. The first model of centrifugal community organization (CCO) predicted that optimally foraging, symmetrically competing species would share use of the core habitat at all density combinations. But one might also assume that the competition in the core habitat is asymmetrical, that is, that one of the species (the dominant) has a behavioral advantage therein. In this study, we asked how should habitat use evolve in a centrifugally organized community if its species compete asymmetrically in the core habitat? To address this question we developed an “isoleg model”. The model predicts that in a centrifugally organized community, asymmetric competition promotes the use of the core habitat exclusively by the dominant species at most points in the state space. The separation of the core habitat use by the species (“the ghost of competition past”) may be either complete or partial (“partial ghost”), and behavior at the stable competitive equilibrium between the species could determine whether coexistence should occur at the “complete-” or the “partial ghost” regions. This version of CCO should be a common feature of competitive systems.

Summer stream habitat preferences of Nunavik anadromous Arctic char (Salvelinus alpinus) fry and parr

2022 ◽  
Author(s):  
Véronique Dubos ◽  
André St-Hilaire ◽  
Normand E Bergeron
Keyword(s):  
Habitat Use ◽  
Salvelinus Alpinus ◽  
Habitat Preferences ◽  
Arctic Region ◽  
Arctic Char ◽  
The Arctic ◽  
Stream Habitat ◽  
Physical Habitat ◽  
High Plasticity ◽  
Slow Velocity

Arctic char is a fish species known to occupy diverse habitats within the Arctic region. However, summer habitat use during the juvenile stage of the anadromous form is largely unknown. The present study aims to characterize fry and parr summer habitat preferences. Surveys were conducted by electrofishing, associated with physical habitat characterization on several rivers of the Ungava Bay, Nunavik, Canada. At the microhabitat and station scales, fry showed significant habitat preferences for shallow water and slow velocity. At the mesohabitat scale, fry showed a significant habitat selectivity for riffles. This habitat selectivity implies that habitat models can be built to evaluate the potential of habitat suitability for Arctic char fry. However, no significant habitat selectivity was found for parr. Parr size was nonetheless positively correlated with velocity, which was found to be a limitative factor for juvenile habitat use. This first attempt at modeling juvenile anadromous Arctic char habitat in rivers emphasizes the importance of selecting an appropriate spatial scale and reiterates the fact that parr showed relatively high plasticity in stream habitat selection.

scholarly journals NOTES ON THE ECOLOGY OF THE COLOMBIAN LEAFTOED GECKO (PHYLLODACTYLUS TRANSVERSALIS), ENDEMIC TO MALPELO ISLAND

2016 ◽  
Vol 42 (2) ◽  
Author(s):  
Mateo López Victoria ◽  
Matthias Jurczyk ◽  
Volkmar Wolters
Keyword(s):  
Population Size ◽  
Breeding Season ◽  
Habitat Preference ◽  
Habitat Preferences ◽  
Original Description ◽  
Tropical Pacific ◽  
Reference Points ◽  
Eastern Tropical Pacific ◽  
Reptile Species ◽  
Malpelo Island

The Colombian leaf-toed gecko (Phyllodactylus transversalis) is the least known reptile species of Malpelo Island (Eastern Tropical Pacific). In the 37 years since its original description, no single study strictly dedicated to this species has been conducted. With the goal of providing information on the ecology and population size of this gecko, data collected during two visits to the island are presented. Behavior and reproduction were studied by following individuals during the night and by searching for hidden individuals and eggs during the day. Population’s density and habitat preferences were estimated by classifying the island’s surfaces into four types and counting geckos inside those habitats within band transects. General morphological measurements of geckos were performed as reference points for future comparisons. Phyllodactylus transversalis lays its eggs in narrow crevices of rocks, apparently communally. Reproduction seems to take place during most of the year, probably associated with the peak breeding season of seabirds. Although conspecifics shared shelters during the day, densities during the night suggest no apparent habitat preference for foraging. Population size of this species was estimated at approximately 114000 individuals.

Habitat Use by Arboreal Mammals along an Environment Gradient in North-eastern Victoria

1991 ◽  
Vol 18 (2) ◽  
pp. 125 ◽  
Author(s):  
AF Bennett ◽  
LF Lumsden ◽  
JSA Alexander ◽  
PE Duncan ◽  
PG Johnson ◽  
...  
Keyword(s):  
Habitat Use ◽  
Environmental Gradient ◽  
Forest Type ◽  
High Elevation ◽  
Annual Rainfall ◽  
Distributional Pattern ◽  
Forest Types ◽  
Phascolarctos Cinereus ◽  
North Eastern ◽  
Arboreal Mammal

A total of 1487 observations of nine species of arboreal mammal, Acrobates pygmaeus, Phascolarctos cinereus, Petauroides volans, Petaurus australis, P. breviceps, P. norfolcensis, Pseudocheirusperegrinus, Trichosurus caninus and T. vulpecula, were made during surveys of the vertebrate fauna of northeastern Victoria. Habitat use by each species was examined in relation to eight forest types that occur along an environmental gradient ranging from sites at high elevation with a high annual rainfall, to sites on the dry inland and riverine plains. Arboreal mammals were not evenly distributed between forest types. Three species (P. australis, P. volans and T. caninus) were mainly associated with moist tall forests; two species (P. norfolcensis and T. vulpecula) were primarily associated with drier forests and woodlands of the foothills; the remaining three species (A. pygmaeus, P. breviceps and P. peregrinus) occurred widely throughout the forests. The composition of the arboreal mammal assemblage changed along the environmental gradient, but species displayed gradual changes in abundance with forest type rather than marked discontinuities in distributional pattern. The highest overall frequencies of occurrence of arboreal mammals were in forests typically dominated by a mixture of eucalypt species. The position at first sighting of an animal, and the relative height in the forest stratum, were used to describe the micro-habitats utilised. In general, the microhabitats occupied by each species are consistent with the distribution of their known food resources.

scholarly journals Home range and habitat use of the Vulnerable Virginia northern flying squirrel Glaucomys sabrinus fuscus in the Central Appalachian Mountains, USA

Oryx ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 204-210 ◽  
Author(s):  
Jennifer M. Menzel ◽  
W. Mark Ford ◽  
John W. Edwards ◽  
Tamara M. Terry
Keyword(s):  
West Virginia ◽  
Home Range ◽  
Habitat Use ◽  
Kernel Method ◽  
High Elevation ◽  
Glaucomys Sabrinus ◽  
Ecosystem Research ◽  
Flying Squirrel ◽  
Northern Hardwood ◽  
Northern Flying Squirrel

The Virginia northern flying squirrel Glaucomys sabrinus fuscus is a Vulnerable sciurid that has experienced a 90% reduction of suitable high elevation boreal montane forest habitat over the last century in the central Appalachians of West Virginia and Virginia, USA. Using radiotelemetry and GIS analyses we examined the species' home range size and habitat use in the Monongahela National Forest, Kumbrabow State Forest and the MeadWestvaco Ecosystem Research Forest in West Virginia during the summers of 2000–2003. The mean home range sizes of male and female squirrels were 54.2 and 15.3 ha, respectively, based on the adaptive kernel method. Euclidean distance analysis indicated the squirrels used spruce, mixed spruce-northern hardwood, and open habitats more than was available across the landscape. Selection of spruce and mixed spruce-northern hardwood habitats indicates that forest management activities designed to restore and increase these types in the central Appalachian landscape are required to conserve and increase this Vulnerable species.

scholarly journals Long-term inference of population size and habitat use in a socially dynamic population of wild western lowland gorillas

2019 ◽  
Vol 20 (6) ◽  
pp. 1303-1314 ◽  
Author(s):  
Laura Hagemann ◽  
Mimi Arandjelovic ◽  
Martha M. Robbins ◽  
Tobias Deschner ◽  
Matthew Lewis ◽  
...  
Keyword(s):  
Habitat Use ◽  
Population Size ◽  
Western Lowland Gorillas ◽  
Dynamic Population ◽  
Lowland Gorillas

scholarly journals Seasonal Habitat Use and Movements of Mountain Goats, Oreamnos americanus, in East-central British Columbia

2003 ◽  
Vol 117 (4) ◽  
pp. 565 ◽  
Author(s):  
Kim G. Poole ◽  
Douglas C. Heard
Keyword(s):  
British Columbia ◽  
Adverse Effects ◽  
Home Range ◽  
Habitat Use ◽  
High Elevation ◽  
East Central ◽  
Oreamnos Americanus ◽  
Mountain Goats ◽  
Mineral Licks ◽  
Forest Use

To identify the potential for adverse effects of forest development on Mountain Goats (Oreamnos americanus), we documented the patterns of forest use by goats and the factors influencing goat habitat use. We used a combination of 15 very high frequency (VHF) and six global positioning system (GPS) radiocollars to document the distribution and movements of 21 (15 female, 6 male) goats from 1997 to 1999 in the mountains surrounding the Robson Valley in east-central British Columbia. Because canopy closure reduces the likelihood that a GPS receiver will obtain a location fix, we estimated that GPS collars underrepresented forest use by about 23%. Three goats used separate winter and summer ranges separated by 8–13 km, while most simply exhibited seasonal shifts in elevation. In winter, goats were more often at lower elevations, in commercial forest stands, on southerly aspects, and moved less each hour and over the course of the winter. Goat use declined in areas >500 m from escape terrain and goats were found lower in elevation from evening to dawn compared to daylight hours. Collared goats used high elevation licks, which were either within their home range, or in two cases, 6 and 14 km from their typical home range. We documented use of known mid-elevation mineral licks by three collared goats, but no use of known low elevation (valley bottom and lower slopes) mineral licks. Robson Valley goats appeared to be at relatively low risk from disturbances related to logging, because although forest use was documented during winter, it occurred primarily on high elevation, steep slopes where trees are currently of low commercial value, and goats made little use of low elevation mineral licks. We recommend that in this area a forested buffer of 500 m around cliffs be left to reduce the possibility of adverse effects on goats especially, on southerly aspects above 1300 m.

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