جستجوی مقالات مرتبط با کلیدواژه « habitat selection » در نشریات گروه « محیط زیست »

In order to perform studies on the selection of the Syrian woodpecker nesting (Dendrocopus syriacus) in the natural region of Naeen township, the job of finding the nests of this bird was done by a multi-personnel team in the Spring of 2015 by establishing random transects with a length of 2000 meters on a map in the area during field operations. Sixtyfive nests of this bird were indentified on trees and the coordinates of the nests were registered by GPS. Initially, the height and diameter of the opening of the nests were measured and then the habitat variables including type, height, and diameter of plant species for each species, the distance of the nest to the nearest water source and road around the nests were calculated. By randomly distancing the nests from different directions, the job of finding the control points or their absence was done. In these areas, no trace of the Syrian woodpecker nests was found. Sixty- five absence points were also identified for the number of the nests and after registering the coordinates, the above variables were also measured. According to our observations, 75.38 percent of the nests had been established on mulberry trees (Morus alba). Due to its having more nectar, the mulberry tree is a more suitable food source for the Syrian woodpecker chicks. Furthermore, the soft bark of this tree is more economical and easier than that of walnut (Juglan nigra) and almond (Amygdalus sp) trees with hard barks. The results of the t-test showed that there was a meaningful difference between the presence and absence regions in terms of some habitat variables for the Syrian woodpecker’s nests. The average distance of the nests to the nearest water source in the presence regions was meaningfully less than that in the absence regions (p<0.05). Our study region was part of the desert areas of Iran and consequently the need for water was a vital parameter; furthermore, water sources absorb more insects to their surfaces which are a food source for the chicks of this bird bringing about their existence. No meaningful difference was obtained in terms of the height and diameter of mulberry trees as well as the average distance to the road between the presence and absence regions. It can be due to the aged mulberry trees (no obvious external difference) along with low traffic which do not have much effect on the nesting of Syrian woodpecker. To protect the Syrian woodpecker population by paying attention to the important ecological role of this bird in Naeen region for the control of insects and pests, it seems necessary to protect the mulberry trees and prevent the destruction of this bird’s habitat along with the protection and provision of new water sources.

Nesting areas by Crested Lark (Galerida cristata) were studied in 10000 hectares of Marvar hunting stop area in Yazd Province in 1394. 

Habitat variables such as plant species, height, and plant cover percentage, as well as distance to the closest plant patches, water resources, fields, roads and the number of terrestrial insect dens in the presence areas were measured and compared with those of the absence areas.

The results showed that the mean of total vegetation percentage around the nests; the percentage of Artemisia sp vegetation, and its height; the percentage and height of Astragalus sp,peganum sp vegetation; the percentage and height of Alhagi sp vegetation; and the mean number of terrestrial insect dens were meaningfully higher in the presence points than those of the control areas (P<0.05). Furthermore, the distance to the nearest water source in the nesting areas was meaningfully lower than that in the control areas (P<0.001). This bird selects the points with high vegetation and higher number of insect dens near water for nesting. Logistic Regression test showed that the vegetation was the most important influencing parameter in nest-site selection by crested lark in the study area.

Higher vegetation in the camouflage of the bird and a high number of insect cavities and proximity to water sources help the bird to survive longer.

Characteristics of Wood Pigeon (Columba palumbus) nesting in Baghshadi e Khatam protected area were evaluated in the spring of 2015. Twenty nests of this bird were detected in the study area by establishing 10 random transects in the spring of 2014 and 20 control points were also obtained within 500 meters from each nest in different directions. Habitat variables such as the area of canopy, height of plant species, distance to the nearest water source and road were measured in presence points and compared with those of control points. The results of independent t-test compared with the mean of variables between the presence and absence points showed that Wood Pigeon prefered Pistachia atlantica trees with more canopy areas and higher heights far from roads for nesting. In most cases, nests of Syrian Woodpeckers were seen beside the nests of Wood Pigeons on a stand tree indicating no feeding competition between the two species. Logistic regression analysis showed that the canopy area of P. atlantica trees was an important variable in nest site selection for this species (P= 0.002, r2 =0.54). Conservation of Woodland Climax will play an important role for species survival in the region.

The selection of nesting habitat of Galerida cristata was studied in an area of 8000 hectares of the hunting ban area of Ghareh Tabpeh and wildlife shelter of Borooeyeh in Herat region of Yazd Province in the spring of 2014. Habitat variables such as the number of plant species; soil texture; distance of the nests to the nearest water source, farm, and road were measured at the presence points of this species and compared with its absence (randomly).The results showed that the average number of Zygophyllum atriplicoides plant species, Artemisia sp , and soil percentage with a rather soft soil texture were meaningfully higher than that of the control areas (P<0.05) in the presence areas. The most important factors influencing the selection of the nesting points by this bird is the number of Z. atriplicoides plant species and type of the soil texture. With regard to the fact that this species builds its nest on the ground, the Z. atriplicoides and Artemisia sp species prepare the required camouflage for its nest and chicks; these plants also protect the nest against the sun radiation or possible storms in the region. The establishment of nests in an area with soft soil texture causes the collapse of the nest. Therefore, this bird meaningfully selects locations with harder soil texture for its nesting (P<0.05). Some of these nets are observed in Alfa alfa farms. It seems that this location has been chosen for more nesting camouflage; furthermore, the insects present in the farm are a good source of food for the chicks of this bird.

Touran Biosphere Reserve is located in the North east of Semnan Province and Iran which is the most important core area for critically endangered (Cr) Asiatic cheetah in the country. Identifying suitable habitats and mapping of species distribution area have an important role for appropriate conserving of the endangered species and designing management planning. In this study we applied Maxent software to model the distribution of suitable habitats, identification of the most important environmental, climate and geographical factors for the species in Touran BR which is the second largest habitat of the species in Iran. Cheetah presence data are from 2001 to 2015. Our results showed that 20 percent of Touran is suitable for cheetah and water resources and the perpendicular vegetation index have provided unique information. Moreover, cheetah suitable habitats are plains and hilly areas which have highly overlap with the distribution of the Jebeer Gazelle, Wild sheep and Goitered Gazelle. Moreover, according to the results, cheetah avoid mountainous habitats where is larger competitor, Persian leopard, territory.

Habitat is one of the significant factors for species protection and determining the pattern of wildlife species distribution and their habitat selection is an important part of managing wildlife and its habitat. So, the purpose of this study is to investigate the habitat selection of Gazella subgutrrosa in Kalmand Conservation Area. Sampling was carried out using random steady transects 200 meters long by 2 meters wide and with two replications during five field investigations. When dung groups were observed, a 10*10 plot was placed in the center of the dung masses and the environmental variables were measured. Then, dung was removed for further monitoring and the transects were investigated every 45 days. The results showed that there is a significant difference among three plant communities in terms of dung group density. The most and the least utilization by deer was related to Artemisia-lactuca and other Artemisia communities, respectively, but there is no significant difference between Artemisia and Artemisia-Salsola communities in terms of habitat use. The Artemisia-lactuca community had the least distance to the nearest post and the Artemisia-Salsola community had the least distance to the nearest water sources and the road. The Artemisia community also had the least distance to the nearest farm. There was no significant difference between the two seasons in terms of dung group density in plant communities. It seems that Artemisia-lactuca community provided better refuge (because the Astragalus species is part of this community), greater safety (because of being near to the post), and more food and water resources (because of the presence of Artemisia and Astragalus species) for Gazella subgutrrosa compared to the other communities.

The understanding of the species habitat requirements and parameters affecting the habitat selection would be essential for sustainable coservation. The black-beilled sandgrous (Pterocles orientalis) occurs in some southern plains of Sabzevar including Shir-Ahmad Wildlife Refuge. Although it suffers intensive habitat destruction and hunting, still there is no enough information about its population ecology in this distribution area. The study area was surveyed for recording presence and absence sites of bird. Using logistic regression analysis the association between species presence/absence and habitat parameters was examined. It was found that vegetation height, height of tallest shrub, canopy cover percentage, stony coverage, distance to roads, distance to water resource, altitude and slope, negatively and ant nest occurring, gravel percentage and stone number ,positively, in assessment plots are significantly associated with the black-beilled sandgrous presence (p<0.05).