Animal Populations in Relation to Their Food Resources

1972 ◽  
Vol 36 (2) ◽  
pp. 676
Author(s):  
Richard G. Wiegert ◽  
A. Watson
Keyword(s):  
Food Resources ◽  
Animal Populations

scholarly journals The effect of habitat degradation, season and gender on morphological parameters of lesser jerboas (Jaculus jaculus L.) in Kuwait

2012 ◽  
Vol 35 (1) ◽  
pp. 119-124
Author(s):  
M. Al–Mutairi ◽  
◽  
F. Mata ◽  
R. Bhuller ◽  
◽  
...  
Keyword(s):  
Habitat Degradation ◽  
Tail Length ◽  
Food Resources ◽  
Arid Environments ◽  
Morphological Parameters ◽  
Escape Behaviour ◽  
Animal Populations ◽  
And Gender

Arid environments suffer anthropogenic interference causing habitat degradation. This degradation can influence animal populations. We randomly captured a total of 198 lesser jerboas Jaculus jaculus in three seasons (autumn, spring and summer) in two relatively close areas (intact and degraded). All animals were sexed, and weight, body and tail length, and thigh thickness were taken. We found significant differences in weight (p < 0.001), which was lower in summer (p < 0.05) when fewer food resources were available. Thigh thickness was greater in the intact habitat (p < 0.01), explained by the greater amount of food resources and also by the higher numbers of predators in this area, prompting escape behaviour. Females in the intact area were heavier and had longer bodies and tails. This was related to greater availability of time for mothers to search for food in this area.

Animal Populations in Relation to Their Food Resources.

1971 ◽  
Vol 8 (3) ◽  
pp. 978
Author(s):  
B. Shorrocks ◽  
A. Watson
Keyword(s):  
Food Resources ◽  
Animal Populations

scholarly journals Inflated population density of island antechinus: a case of allochthonous marine inputs leading to increased food availability?

2012 ◽  
Vol 60 (5) ◽  
pp. 343 ◽  
Author(s):  
M. G. Sale ◽  
J. P. Y. Arnould
Keyword(s):  
Food Availability ◽  
Soil Nutrient ◽  
Growth Period ◽  
Food Resources ◽  
Animal Populations ◽  
Colonial Seabirds ◽  
Increase Productivity ◽  
Food Subsidies ◽  
Marine Food ◽  
Island Habitats

Resource availability and other processes that affect maintenance, growth and decline of animal populations are central to ecology and conservation. This study quantified features indicative of population fitness and the availability of food resources for island and mainland populations of an insectivorous marsupial, the swamp antechinus (Antechinus minimus). The aim of the study was to test the hypothesis that colonial seabirds increase productivity of island habitats, ultimately providing greater food resources. The study found that antechinus biomass density was 4–13 times greater on the island site compared with the mainland site and was associated with higher recapture rates, suggesting that more individuals were surviving on the island during spring and summer months. An index of antechinus food availability (abundance and biomass of invertebrates) was also higher on the island site. Island antechinus also accessed marine food subsidies, in the form of seabird carrion, during the energetically demanding post-weaning growth period in spring and summer. Furthermore, based on soil nutrient and stable isotope analyses, there was strong evidence of nutrient enrichment from marine sources in the island ecosystem, commonly linked to increased productivity. Therefore, greater antechinus biomass and abundance on offshore islands are likely to be, in part, due to greater survival caused by higher availability of food resources.

scholarly journals A tale of two islands: evidence for impaired stress response and altered immune functions in an insular pit viper following ecological disturbance

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Mark R Sandfoss ◽  
Natalie M Claunch ◽  
Nicole I Stacy ◽  
Christina M Romagosa ◽  
Harvey B Lillywhite
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Food Resources ◽  
Small Sample ◽  
Innate Immune ◽  
Immune Functions ◽  
Ecological Disturbance ◽  
Cell Counts ◽  
Animal Populations

Abstract The frequency and intensity of ecological perturbations affecting wild animal populations is expected to increase in the future with animals facing numerous global threats. Seahorse Key is a continental island off mainland Florida that has historically been a major rookery for several species of waterbirds. As a result of an unknown disturbance, the entire rookery abandoned Seahorse Key in April 2015 and shifted nesting activities to nearby Snake Key, resulting in an influx of food resources in the form of fish carrion to resident Florida cottonmouth snakes (Agkistrodon conanti), while snakes on Seahorse Key experienced a drastic reduction in food resources. Our objective was to assess plasma corticosterone concentrations, corticosterone negative feedback using dexamethasone, blood glucose, body condition, packed cell volume, natural antibody agglutination, white blood cell counts and ratios and erythrocyte sedimentation rate to characterize the long-term effects of differential resource availability in these two snake populations 3 years after this major ecological disturbance. We collected blood samples at three time points from cottonmouths on Seahorse Key (n = 6 individuals) and Snake Key (n = 13 individuals) in fall 2018. In due consideration of the small sample size, our study shows evidence that 3 years after the shift in waterbird nesting Seahorse Key cottonmouths exhibit a dampened acute stress response and presumptive impaired innate immune functions relative to cottonmouths on Snake Key. These results highlight the context-dependent nature of biomarkers and implicate the significant decrease in food resources on Seahorse Key in altering hormonal stress responses and innate immune functions, possibly leading to unknown long-term downstream effects. This study assessed the response of a wild population of pit viper to ecological disturbance in situ with the aim to improve our understanding of how animals cope with such perturbations and improve our capacity to make informed decisions for conservation.

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