Understanding the implications of climate change for birds of the Phasianidae family: incorporating fleshy structures into models for heat. This figure illustrates the evidence for global warming as presented by the Intergovernmental Panel on Climate Change (IPCC 2014). In general, species are expected to shift their ranges poleward and to higher elevations due to climate change (Chen, et al. 2011, p. 1024).
Studies have evaluated the realized and potential effects of climate change on a wide variety of species. In fact, different populations of Adélie penguins have very different responses to climate change (Croxall et al. 2002). 2012) contrasted responses of three populations of the spotted owl (Strix occidentalis) in the southwestern United States and predicted that each population would respond differently to climate change.
Studies of changes in species' ranges predict much more severe declines than palaeoecological studies have shown to have occurred in response to past climate change. It is important that studies predicting species' responses to climate change consider the possibility of both relocation and thermoregulatory adaptation.
HDL Theory
What is HDL theory?
Metabolic rate can be defined as the overall rate of the processes of energy uptake from the. Both MTE and more traditional ways of thinking about energy supply and demand place the constraint on the supply side of the energy equation (Speakman and Król 2010). Efforts to understand this fundamental limit have shed light on the nature of the metabolic constraints animals face.
An early proposed theory was the central limitation hypothesis, which claimed that the ability of the digestive tract to absorb nutrients limited maximal energy intake and thus maximal lactation (Speakman and Król 2010, p. 728). The heat loss through the shell (Hs) can be calculated from the thermal conductivity of the insulation layer, the surface area of the body, the depth of the insulation layer and the surface temperature of the shell, which is mainly determined by the ambient temperature. . Thermal conductivity of the insulating layer, surface area and depth of the insulating layer can be estimated based on body mass.
Climate change is projected to result in surface warming over most of the globe, although the effects will be proportionally greater at high latitudes. In particular, if the HDL theory is correct, then extreme temperatures, such as the maximum temperature of the warmest month (WM), may be a limiting factor in organism survival.
Study Group
Of course, behaviors such as daily torpor or panting may allow organisms to continue to function under such conditions. Understanding such physiological constraints will benefit from studies that incorporate physiological characteristics into models of heat dissipation. Of the galliform species listed on the IUCN Red List, 15 percent are considered at risk at least in part due to climate change (McGowan et al., p. 321).
Despite this, few studies exist that evaluate the responses of Galliformes to climate change, but see R et al. 2010), focusing only on Galliformes in China. My project focuses on the family Phasianidae, which consists of pheasants, partridges, junglefowl, chicken, quail and peacock. According to Johnsgard, "of all major bird groups, pheasants are among the most severely affected by human exploitation and habitat destruction" (1986, p. xviii).
FS have been considered sexual adornments, but few studies have considered the costs of FS (Buchholz 1996). Instead, it presents a simplified model that assumes that heat dissipation depends only on geometric biophysical parameters (that is, volume: surface area) that are calculated based on the body as a sphere or cylinder.
Objectives, Hypotheses and Predictions
Materials and Methods A. Compiling data
Species distribution maps for all currently known phasianid species were obtained from BirdLife International and NatureServe (2012). ArcInfo networks of bioclimatic variables under current and projected future scenarios were downloaded from the worldclim database (Hijmans et al. 2005). Data on body masses and height ranges of the species were collected through a literature review conducted by Dr.
For species for which elevation values were not available in the literature, occurrence points were downloaded from gbif (The Global Biodiversity Information Facility 2013). If more than 10 points were available, the minimum and maximum altitudes represented by these points were obtained using a script in R. Additional species were omitted from some analyzes when body mass or FS size data were not available at willing.
Using ArcGIS to determine which bioclimatic variables characterize species current and future ranges
When new rasters were created, it was noted which rasters were converted from unsigned 16-bit rasters to 8-bit rasters, as this changed the values. The copy raster tool was then used to convert these rasters back to the original depth (unsigned 16-bit), which restored the original values. I converted the resulting raster layer to polygons and intersected these polygons with the current distribution polygons to create polygons containing the areas in the current distribution that will continue to be.
The field geometry tool in ArcGIS was used to calculate the area of the current distribution and of the overlap between the current distribution and the potential future distribution. Finally, the extract by mask tool using current distributions as the mask was used to determine the TM.
Measuring FS Size
The percentage of birds covered by FS was calculated and FS areas were calculated (Table 1).
Modifying the HDL Equation
Ts is the surface temperature of SF in DK, which was considered to be 2 °C less than Tb (Richards 1971).
Statistical Methods in R
Results
Climate Change and Species Ranges
The red-legged partridge is native to Europe and is categorized as Least Concern by the IUCN Red List, but populations appear to be declining (BirdLife International 2012). The buff partridge is believed to occur in India and China, but is rare and poorly known (BirdLife International 2012). The IUCN Red List categorizes this species as Least Concern, but the population is believed to be declining fast enough to approach the Vulnerable criterion (BirdLife International 2012).
The variables considered were the highest temperature of the warmest month, the lowest temperature of the coldest month, the mean diurnal range and the mean annual temperature. For a map showing an example of which parts of a species' range will be characterized by acceptable bioclimatic variables in 2070, see Figure 9. For some species, such as the Common Pheasant (Phasianus colchicus), little or no range change is projected.
However, for species such as the yellow-throated partridge (Tetraophasis szechenyii) and the mountain peacock pheasant (Polyplectron inopinatum), range changes of more than 99 percent are expected. The mountain peacock pheasant is categorized as Vulnerable on the IUCN Red List (BirdLife International 2012). The shaded areas indicate the predicted portion of the native range that will be characterized by the same bioclimatic variables in 2070.
Modeling HDC
There is no difference in which species exceed or will exceed their HDC in males and females; There are two fewer species where females will exceed their HDC by 2070 than the number of species where males will exceed their HDC, because no information was available on the weight of females of these species. The species that exceed the HDC are the same species that exceeded the HDC before head and neck were included. Again, the species that exceed the HDC are the same species that exceeded the HDC before head and neck were included.
The Role of FS in Heat Dissipation
The green grouse (Gallus varius) has the largest proportion of FS with its FS covering more than 11 percent of the body in males and more than four percent of the body in females. Contrary to my expectations, significantly more species are not predicted to exceed their heat dissipation capacity in 2070 than currently (χ p = 0.3120). Species not currently exceeding their HDC but expected to be in 2070 include the red-necked partridge (Arborophila rufogularis) and Heuglin's francolin (Pternistis icterorhynchus), both of which are listed as Least Concern by the IUCN Red List (BirdLife International 2012). .
Correlates of FS variation
Discussion
