Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, Western Australia – Avifauna and Flora
Revegetation 7 (planted 2010 and re-planted 2014)
Yüklə 7,54 Mb. Pdf görüntüsü
|
Revegetation 7 (planted 2010 and re-planted 2014) Plate 80: Quadrat in Revegetation 7 – photograph taken April 2015 by Tanith McCaw. GPS Quadrat (NW corner): 0405686 E, 6788452 N Elevation: 301 m asl Location: West of main remnant (Remnant 4A, 4B); in newly planted areas (2014); some small shrubs/trees from previous planting. Landform: Hillside; lower slope; gentle; granite/ gneiss near surface; westerly aspect Land surface: Red (2.5YR 4/6) sandy loam to sandy clay loam; surface rock (weathered granite, quartz, dolerite) 10–20% ^20cm; litter <10% <1cm deep; fallen timber 0%; cryptogams <1% (lichen); bare ground 25–30% Condition: Degraded Disturbance: Historic clearing, cropping/pasture; weeds; recent cultivation for revegetation; few survivors from prior planting in area. Table 21: Quadrat data for Revegetation 7 (obtained in 2014) Stratum & Height (m) Crown cover % Habit Dominant species & no individuals (trees & shrubs) No. stems <0.5 (0.2) <1 Tree Eucalyptus loxophleba subsp. supralaevis (6), Melaleuca ?hamata (1) 7 <0.5 (0.3) <1 Shrub Acacia ramulosa (1), A. acuminata (2), A. ?stereophylla (1), Maireana tomentosa (3), Melaleuca eleuterostachya (2), Ptilotus obovatus (1) 10 Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 84 15–0 Grass Hordeum leporinum*, Lamarckia aurea*, Avena barbata*, Pentameris airoides* 35–40 Forb Atriplex/ Chenopodium (?murale), Limonium sinuatum*, Echium plantagineum*, Emex australis*, Mesembryanthemum crystallinum*, Medicago polymorpha*, Maireana carnosa, Ptilotus gaudichaudii subsp. eremita, Sclerolaena eurotioides, Enchylaena seedlings, Brassica tournefortii*, Salsola australis Table 22: Quadrat data for Revegetation 7 (obtained in 2015) Stratum & Height (m) Crown cover % Habit Dominant species No. stems <0.5 (0.2) <1 Tree Eucalyptus loxophleba subsp. supralaevis (2), Melaleuca ?hamata (1) 3 <0.5 (0.3) <1 Shrub Maireana planifolia (9), Acacia ramulosa (1), A. acuminata (2), Maireana tomentosa (1), Ptilotus obovatus (2), Acacia seedling (1) 16 <1 Grass Tragus australiensis, grass sp. 30–40 Forb Salsola australis, Enchylaena lanata, Atriplex gaudichaudianum, Chenopodium sp. *, Echium plantagineum*, Emex australis *, Arctotheca calendula* 2014 No. stems/400 m 2 = 17 2015 No. stems/400 m 2 = 19 Stem counts in 2015 showed a slight increase. However, there were deaths of Eucalyptus, Melaleuca and Acacia species and germination of Maireana, Ptilotus and an Acacia seedling. The surviving trees/shrubs from 2014 appeared healthy and will hopefully continue to grow well throughout 2015. There is also the possibility that there will be some further germination of seed from the 2014 planting program. 5. Discussion 5.1 Landscape patterns of habitat loss, fragmentation and land use The human ecological footprint on the native vegetation of the Western Australian wheatbelt has been particularly heavy and extensive (Figure 13). In many districts, less than 7% of the original native vegetation cover remains. The central wheatbelt has only 2% to 5% of its woodland/shrubland left which is typically confined to highly isolated nature reserves and narrow roadside strips (Frost et al. 1999). Not surprisingly, the ecosystems of these landscapes and their indigenous biodiversity are ranked among some of the most fragmented and threatened in the world (Saunders and Ingram 1995; Department of Environment and Conservation 2008; InSight Ecology 2009; Laurance et al. 2011). Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 85 Figure 13: The spatial distribution of remnant native vegetation across the south-west of Western Australia. The extent of historical land clearing is clearly evident, spanning the area from north of Geraldton east to the pastoral zone - delineated on this zone’s western border by the clearing line - and south to the Southern Ocean coast from Albany to east of Esperance. Image: Google™ earth 2013. In the northern agricultural region, retention rates of native vegetation in some areas reach approximately 12% (Huggett et al. 2004; InSight Ecology 2009). Remnant shrubland and woodland communities tend to occur in larger blocks than their generally more fragmented central and southern counterparts. These occur in nature reserves and on crown land, rail and road reserves. The degree of habitat connectivity in some parts of the northern zone is slightly to moderately higher than in the central and southern wheatbelt zones. The Morawa district retains approximately 10% of its remnant native vegetation including samphire communities along ancient salt lakes and saline drainage channels (Figure 14). These provide important natural linkages for fauna that move across landscapes in search of food and breeding sites. For instance, the summer breeding migrant White-winged Triller has been observed moving en masse along saline drainage channels in the Yarra Yarra Lakes system south-west of the study area (A.H. pers. obs.). The northern agricultural region was cleared of its native vegetation later than the central wheatbelt and parts of the southern wheatbelt. The last phase of clearing for farming in the region was in the late 1970s and early 1980s (Neil Kupsch - long-time Nabawa farmer, pers. comm.) compared with the 1950s in the southern zone (Gibson et al. 2004). This may confer a time lag advantage to attempts to restore and re-connect native plant communities in the northern wheatbelt relative to the central and much of the southern wheatbelt zones. It may also mean that the northern wheatbelt has yet to fully pay the extinction debt described in Section 1.1. Thus, some species that were recorded at “Hill View” during the study may be in the process of becoming functionally extinct despite their persistence in the remnants. More work is needed to confirm this but the low numbers of birds such as Crested Bellbird and Inland Thornbill recorded in the study are of concern (see Sections 5.2.2, 5.2.3 and 6.2.2, 6.2.3, 6.2.9). wheatbelt Perth Geraldton clearing line N Albany Esperance “Hill View” 0 447 km Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 86 Figure 14: Large blocks of remnant shrubland and woodland characterise the Morawa district landscape near its boundary with the clearing line and pastoral lands further east. They provide important habitat ‘stepping stones’ and refugia for birds and other species dispersing from drier inland habitats in the east to moister ones in the west. Some of the district’s saline drainage channels are prominent in this image and form part of Lake Moore catchment. Image: Google™ earth 2015. The study area occurs in the northern sector of the south-west WA landscape which is characterised by decreasing intensification of land use along a gradient from west - coastal and inland towns - to east - grain cropping and livestock grazing. The highly urbanised Swan Coastal Plain lies to the south and contrasts strongly, in terms of the amount, extent and configuration of remnant native vegetation, with central wheatbelt districts to the south-east. Some bird species such as Western Gerygone, White-winged Triller and Grey Fantail migrate or nomadically move between these disparate sections of landscape and so only utilise habitat at “Hill View” for parts of each year. “Hill View” is also located in a key regional biodiversity transitional zone between arid inland shrub-dominated ecosystems of the pastoral zone to the east and woodland/shrubland communities of higher rainfall areas to the west. This creates a unique mixing of plant and animal species associated with both contrasting zones and conveys additional conservation significance to the study area. Some bird species present at “Hill View” are at or near the edge of their normal distributional range such as Southern Whiteface, Redthroat and Torresian Crow. 5.2 The bird communities of “Hill View” 5.2.1 Key determinants of species abundance, composition and habitat use A set of key landscape, habitat, threat-based and species and individual-specific factors influenced the occurrence, relative abundance, composition and structure of bird communities recorded at “Hill View”. Together these variables were responsible for shaping the type of extant bird assemblages present on the property and indeed elsewhere in the northern agricultural zone (see also Huggett et al. 2004; InSight Ecology 2009, 2012, 2013). 0 13.1 km N Nullewa Lake “Hill View” Moonagin Range Milhun Range Morawa clearing line Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 87 Characteristics of the landscape in which birds occurred influenced their abundance, species composition, community structure and patterns of habitat use (Section 5.1). Relatively small- scale variation in the type, amount, condition, spatial arrangement and structural complexity of habitat helped determine the abundance, diversity and composition of bird assemblages present on “Hill View”. This was particularly evident in the largest remnant - Remnant 4. In this remnant the amount and range of different microhabitats varied substantially over small distances – from Jam woodland and acacia/melaleuca shrubland on the lower slopes, Acacia umbraculiformis tall open shrubland with rocky outcrops on upper slopes to York Gum patches with low shrubland at Remnant 4A. This level of habitat heterogeneity and complexity supported a healthy and relatively diverse shrubland/woodland endemic bird community. In contrast, smaller more degraded remnants such as the northern section of Remnant 5 and the western portion of Remnant 1 were smaller in size and offered a narrower range of microhabitats for bird use. A consequently smaller suite of shrubland/woodland bird species occurred at these sites. The floristic composition of habitats in the remnants also influenced bird community composition and structure but possibly to a lesser degree than habitat heterogeneity and complexity. This may have been attributable, in part, to the unseasonably dry conditions preceding the spring survey which reduced flowering and insect abundance levels in the remnants and revegetation alike. Inland Thornbill and Splendid Fairy-wren favoured Dodonaea inaequifolia, Acacia tetragonophylla and other acacia species. The only two honeyeater species recorded in remnants – Singing Honeyeater and Spiny-cheeked Honeyeater – foraged mostly on insects but also on nectar from flowering shrubs such as Eremophila oldfieldii subsp. oldfieldii and Melaleuca radula and some of the eucalypts, principally York Gum. Reduced nectar flows among proteaceous and myrtaceous flora particularly in the remnants seems likely to have triggered this pattern of resource switching which is typical for these honeyeater species. The abundance, species composition, reproductive success and, ultimately, survival of bird populations in these communities were influenced by several key threat-based stressors. These included pressure exerted by predation - particularly by fox and cat, interspecific and intraspecific competition, loss of habitat condition through grazing by feral herbivores such as goat and rabbit, historical grazing by sheep and cattle, fire, disturbance by mining exploration activities and the effects of a changing climate including increased severity of drought events. Weed incursion did not significantly influence bird abundance or species composition in the remnants. However, weeds provided supplementary food supplies for ground-foraging bird species, particularly after good late summer rainfall in revegetation sites in autumn. Species-specific factors also helped influence the composition, structure and habitat utilisation patterns of bird communities in the study area. Different bird species were able to exploit available resources in different ways and at different times of the year and respond to seasonal changes in the abundance and availability of food supplies (see also Section 5.2.4). For example, several core woodland/shrubland resident species such as Chestnut-rumped Thornbill, Inland Thornbill, Yellow-rumped Thornbill, Splendid Fairy-wren, Redthroat, Western Gerygone, Rufous Whistler, Grey Fantail and Red-capped Robin formed ground-foraging flocks in remnants in autumn. This ‘teamwork’ strategy maximises the bird’s potential for encountering invertebrate prey when food supplies become less abundant or less available, typically with the onset of the cool season or sometimes during drought conditions. Each member species is able to expend less energy foraging as a group than they would individually. This is thought to be an adaptive Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 88 response that helps improve species’ survival prospects during times of environmental stress imposed by cooler (or very dry) temperatures and reduced food supplies. Migratory species also varied in their patterns of resource utilisation across the study area (see also Section 5.2.4). Banded Lapwing foraged for grasshoppers and other invertebrates and nested in naturally regenerating open paddocks and planted sites in spring but by autumn had departed. Flocks of insectivorous Crimson Chat and White-winged Triller used remnants as migratory ‘stopover’ points to rest and ‘re-fuel’ before continuing their spring/early summer journeys south. Some individuals of both of these species also nested in the remnants but by autumn had also departed. Western Gerygone and Grey Fantail, in contrast, arrived in remnants in autumn, often foraging in all layers of shrubland and woodland habitat in search of insect prey. Intraspecific variation also contributed to shaping the composition and structure of bird communities in the study area. Behavioural, foraging efficiency, recognition and avoidance of predators, and disturbance tolerance differences between individual birds of the same species can affect their ability to persist and reproduce in fragmented habitats and landscapes. These reflect age, stochastic and possibly genetic factors – for example, young birds require experience gained over time to know their habitat, interpret environmental cues, where to find food, shelter, mates, build nests and successfully raise young, and how to recognise, avoid or repel potential predators, competitors and nest parasites (cuckoos). Two species of cuckoo - Black-eared Cuckoo and Horsfield’s Bronze-Cuckoo - were present in some remnants in spring and most likely parasitised the nests of some breeding pairs of Red-capped Robin, Splendid Fairy-wren, Chestnut-rumped Thornbill, Inland Thornbill, Crimson Chat or Redthroat. 5.2.2 Trajectories of bird responses The monitoring of diurnal bird communities in the study area has identified three postulated trajectories of response in species occurrence, abundance and persistence over time - stability, increase and decrease. Understanding how and why these responses have occurred including the ecological processes that have driven them is integral to the protection of remnant woodland/shrubland and strategic revegetation of “Hill View” over the longer term (see Section 6). A caveat is necessary in the interpretation of these responses given the short-term nature of the recent avifaunal monitoring program at “Hill View” and poor winter-spring 2014 rainfall. Continuation of monitoring will, however, help determine if these outcomes hold true for the birds of “Hill View” over time. An additional trajectory could also emerge - species recovery. This response is a core goal of all ecological restoration initiatives worldwide. It is also the hardest to achieve since it requires the commitment of adequate resources to enable long-term scientific monitoring of sites, populations and communities. The current bird and flora study has laid the foundation for this work to continue at “Hill View” (see Section 6.2.9). Populations of a core group of primarily remnant-dependent woodland and shrubland birds appeared to be persisting in relatively stable numbers, at least over the short-term, in the study area. These were a mix of core woodland/shrubland birds – Crested Bellbird, Inland Thornbill, Spiny-cheeked Honeyeater and Splendid Fairy-wren, Weebill - a canopy insectivore that foraged and nested in 4 year-old+ planted eucalypts, and a ground granivore - Zebra Finch which responds to increasing aridity in the interior by moving coastwards, in search of seed and water supplies. Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 89 Three of the woodland/shrubland species - Crested Bellbird, Inland Thornbill and Spiny-cheeked Honeyeater - maintained small populations of 7, 9 and 7 individuals, respectively, over both seasons. Further monitoring is needed to determine whether this really is a pattern of population stability or one of gradual loss and decline (see below and Section 6.2.9). Spiny- cheeked Honeyeater is a part-nomadic, part-sedentary species that tracks seasonally available nectar flows in remnants sometimes separated by significant distances. Thus, it is of less concern than Crested Bellbird and Inland Thornbill, both species that live all their lives in better quality remnants of above 30-40 ha in size and separated by gaps of not more than 300-350 m (Huggett et al. 2004; InSight Ecology 2009). Significantly, neither Crested Bellbird or Inland Thornbill were recorded in Remnant 1, the most isolated and smallest remnant on “Hill View”, but were detected in Remnants 2, 3, 4A and 4B. Inland Thornbill was also detected in Remnant 5 and likely crossed from the main remnant (c. 130 ha in size) - a gap of c. 200 m. A cohort of birds recorded in the study increased in number after completion of the spring- summer breeding season. In a moderate departure from a trend evident in previous surveys undertaken in the northern wheatbelt (see, e.g., InSight Ecology 2009, 2013) in landscapes located further from major remnants such as those 17 km east of “Hill View” with stepping stones of smaller remnants spaced c. 2-2.5 km apart, these were mostly remnant-dependent birds of woodland and shrubland habitats. The population increases of White-browed Babbler (30%), Rufous Whistler (15.4%) and Chestnut-rumped Thornbill (14.3%) were testament to the quality of habitat in the larger remnants and, in the case of the babbler, its cooperative breeding system. There may have also been individuals that immigrated from other remnants outside of “Hill View”. However, further monitoring of these populations over several seasons is needed to confirm that this trend can be sustained over time. This would help eliminate (or confirm) the possibility that these increases simply reflect the annual breeding increment, that is, the addition of young birds to the populations of these species after a breeding season. The third response trajectory identifies several remnant-dependent bird species that had decreased in number after the end of the 2014-15 breeding season. Plausible reasons for this outcome include losses from predation, reduced food availability following poor spring/summer rainfall, post-natal dispersal of young within and between remnants, emigration of birds out of “Hill View” remnants to bush on adjoining properties, and lack of detection during surveys conducted for this study. The Galah’s decrease of 89.7% reflected a poor breeding season in which few suitable tree hollows were occupied by nesting pairs – a response to poor rainfall and seed production in spring and summer. Reduction of numbers of Yellow-rumped Thornbill (51%) and Red-capped Robin (36%) may have been due to predation of eggs and nestlings by Australian Raven, Grey Butcherbird and reptiles, reduced food availability during the dry spring and summer, predation of adult birds by cat and fox, nest parasitism by small cuckoos, natural death of old birds and dispersal/emigration out of remnants to remnants on adjoining properties. Similar factors may have been implicated in losses suffered by Grey Shrike-thrush (21.7%), Redthroat (18.5%), Singing Honeyeater (15.1%) and Southern Whiteface (13.1%). Whether these population sizes are larger enough to survive major events such as wildfire, prolonged drought or elevated predation levels (or a combination of all three) is unknown. Further monitoring would help confirm population sizes and detect within and between-year fluctuations in the numbers of these core species in the remnants over time (Section 6.2.9). Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 90 5.2.3 Extinction debt and time-lag effects There is an urgent need to determine the demographic structure and reproductive success of remnant-dependent core woodland/shrubland bird populations. We particularly need to know the number and age (if possible) of males relative to females and the number of young birds successfully raised to independence each year (see Section 6.2.9). This information will help determine if these species are successfully reproducing and thus surviving over time in the remnants or are declining and edging closer to local extinction. In effect, we need to know if the “Hill View” remnants are still paying an extinction debt and can restoration action be effective under this scenario. There is also a key question of whether the time-lag effect will be felt at “Hill View”. That is, will the revegetation areas start providing supplementary or preferably alternative foraging and breeding habitat to core woodland/shrubland bird species soon enough to help offset any population declines that may occur in especially the smaller remnants? This is an important question that needs addressing through the continuation of monitoring of bird populations at the established sites on “Hill View” (see Section 6.2.9). 5.2.4 Bird utilisation of habitat More individuals and species of birds were recorded in remnants than in revegetation at “Hill View”. This reflected the larger size, higher habitat complexity and generally better ecological condition of remnants relative to revegetation on the property. The key remnants – Remnants 4 (sites 4A and 4B), 3, 2 and 5 - provided a wider range of foraging, nesting, roosting and refuge substrates and food supplies than were available in the structurally simpler revegetation. Rocky outcrops, small escarpments, boulders and gnamma holes provided watering and bathing points generally not available in the revegetation. Standing dead trees and hollow-bearing York Gums in remnants offered perch and nest sites for raptors, migratory insectivores and aerial insectivores. Fine-scale variation that occurred within habitats in individual remnants influenced the range and type of microhabitat available for use by birds. This may also have helped shape the composition and structure of resident and migratory bird communities recorded in the study. Differences in the amount and distribution of foliage cover, height of cover, floristic composition, and spatial arrangement of ground substrates such as logs, leaf litter, grasses and rocky outcrops are factors implicated in influencing bird community composition and structure (see, e.g., Wiens 1989; Huggett 2000). Some evidence for this was found in the apparent preference of the core woodland/shrubland insectivores for sites containing a range of microhabitats, sampled in Remnant 4A, 4B, 3 and 2. Selection of dense low shrubs for nesting and creching of recently fledged birds by Splendid Fairy-wren, Chestnut-rumped Thornbill, Inland Thornbill and Red-capped Robin highlighted the importance of remnants in facilitating the reproductive success and thus contributing to the survival of these species on “Hill View”. Variation in the condition, structural complexity and floristic diversity of habitats in remnants also reflected the impact of historical land use practices and current stressors including past land clearing, grazing, mining exploration and feral herbivore incursion. Sites such as the western part of Remnant 1, upper southern and western slopes of Remnant 2 and northern Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 91 extension of Remnant 5 varied substantially in habitat condition, with patches degraded by past grazing, hervibory by goats and mining exploration activities. Bird utilisation of revegetated habitats was essentially in its infancy, in terms of the number and diversity of bird species recorded foraging, sheltering and in, some cases, nesting in planted eucalypt and shrub rows. Older planted sites - Revegetation 1, 2 and 6 - had begun to provide these resources to some species more associated with habitats available in the remnants. The recorded breeding of Weebill and the presence of Singing Honeyeater, White-winged Fairy- wren, Brown Falcon and Nankeen Kestrel provided encouraging evidence of the supplementary habitat role of these sites in the study area. With time, these plantings will develop to provide a wider suite of resources for other woodland/shrubland birds on the property. Species such as Red-capped Robin, Yellow-rumped Thornbill, Inland Thornbill, Rufous Whistler, Grey Shrike-thrush and even Crested Bellbird and White-browed Babbler could be expected to forage through revegetation from the c. 6+ year age class for robins and thornbills and c. 10+ year for whistlers, shrike-thrush and, potentially babblers and bellbirds. Red-capped Robin, Inland Thornbill and Rufous Whistler have been previously recorded foraging in 11 year-old melaleuca and eucalypt revegetation in the southern part of the northern agricultural region (see InSight Ecology 2012) and in 10+ age-class plantings in Waddy Forest catchment near Coorow, c. 56 km to the south/south-west of “Hill View” (InSight Ecology 2013). Inland Thornbill nested in the 11 year-old plantings which had moderate nearby connectivity with a riparian remnant of York Gum (InSight Ecology 2012). Proximity to source habitats in remnants, the nature of the surrounding landscape which typically features a mosaic of cleared, naturally regenerating, planted and remnant vegetation (see Section 5.3), and the type and degree of threats to bird movement within this system are key factors that will influence the future bird species composition and habitat use patterns in this new future bush on “Hill View”. 5.2.5 Conservation-reliant species and their management Ten bird species recorded in the study require management intervention to ensure they are able to successfully reproduce and survive in the highly fragmented northern wheatbelt. They are termed ‘decliners’ or ‘conservation-reliant’ species (InSight Ecology 2007, 2013; Scott et al. 2010). These are species whose local populations may become extinct if intervention does not occur as the condition, size, connectivity, and intactness of their habitat continues to be eroded by grazing livestock, local land clearing events such as grading and burning of road verges, mining activities, predation by cat and fox, browsing of native vegetation, erosion and compaction of soil by rabbit and goat, and weed incursion. In the study area, conservation-reliant species included Crested Bellbird, White-browed Babbler, Chestnut-rumped Thornbill, Inland Thornbill, Redthroat, Southern Whiteface, Variegated Fairy-wren, Splendid Fairy-wren, Grey Shrike-thrush and Wedge-tailed Eagle. It seems likely that these species have fine-scale differences or thresholds (see Huggett 2005) in sensitivity to habitat type and size, threats, and characteristics of the landscape in which they occur. These differences require flexibility in the type or mix of conservation management strategy used. For instance, some - Chestnut-rumped Thornbill, Southern Whiteface, Splendid Fairy-wren and Variegated Fairy-wren - are ground/near-ground foragers with small home ranges in high quality woodland/shrubland remnants. They are particularly vulnerable to Final Report: Systematic Biodiversity Monitoring of “Hill View”, Morawa, WA – Avifauna and Flora InSight Ecology, Jennifer Borger and Tanith McCaw – July 2015 92 predation by cat and fox. Thus, the reduction of cat and fox numbers and the maintenance of habitat structural complexity may be all that these birds need to survive in the remnants. Others, however, will require more intensive management including the creation of new habitat linking remnants, reduction of key threats and improvement of the condition of existing core habitat. They include Crested Bellbird, White-browed Babbler, Inland Thornbill, Redthroat and Grey Shrike-thrush. Figure 15 illustrates these species-specific characteristics and responses and the different broad types of conservation management intervention required, using data from another study in the northern wheatbelt (InSight Ecology 2009). While numbers of Wedge-tailed Eagle have increased in recent years, the impact of their persecution by some farmers over the past few decades mean that this species is still recovering and requires ongoing habitat protection, particularly of standing dead and living trees for use as nest sites. The conservation of these species and the protection and expansion of their habitat on “Hill View” needs to be a key management priority (Section 6.2.1, 6.2.3). Figure 15: The influence of differences in the sensitivity of key woodland/shrubland bird species to habitat and landscape attributes on their conservation management requirements in Buntine- Marchagee Natural Diversity Recovery Catchment, 2006-2009 (InSight Ecology 2009, 2010 and courtesy DPaW). Photographs by Graeme Chapman (Redthroat, Crested Bellbird) and Babs & Bert Wells and DPaW (Western Yellow Robin, Southern Scrub-robin). Kataloq: wp-content -> uploads -> 2015 2015 -> Oitsning ma’nosi – Orttirilgan Immunitet Tanqisligi Sindromi. Bu dahshatli va bedavo kasallik hozirgi zamonning “vabosi” deb yuritiladi 2015 -> Klinik protokol Az ərbaycan Respublikas 2015 -> Приложение №3 Информированное согласие пациента на пародонтологическое лечение 2015 -> Vision, missions et structuration 2015 -> Ümumi məlumat 2015 -> Azərbaycanda siyasi məhbusların 2015 -> Yaxşı biznes planı qurmağın 9 yolu 2015 -> Kənd Təsərrüfatı İlin də Azərbaycan Respublikasında aqroparkların formalaşdırılması mexanizmləri və fermərlərin prosesdə iştirakçılığının gücləndirilməsi 2015 -> Premedikasyon • Xylazine Hydrochlorure Rompun Yüklə 7,54 Mb. Dostları ilə paylaş:
|