Reproductive success

The impact of chemical pollution on the reproductive success and population sizes of wildlife species is often difficult to assess. In many cases, environmental factors such as habitat restriction, stress due to human intrusion and changes in natural food supplies owing to hunting, fishing and restocking policies may have a significant, even predominant, effect on population size. This makes it difficult to determine to what extent, if any, environmental endocrine disrupters may be contributing to observed effects on reproduction or population size in wildlife species. 

The detrimental effect of organochlorine pesticides on reproductive success in birds of prey is well established following the crash of some populations during the 1950s and 1960s. Links have been established with the DDT metabolite, DDE, the cyclodiene pesticides and Although many raptor species... 

Mutation is a stable, heritable change of a gene from one allele to another, which both creates and maintains genetic variability in populations. Most mutations adversely affect the survival and reproductive success of their bearers, but if the physical or biological environment changes, previously neutral or harmful alleles may become beneficial. Mutation rates typically are very low, but they are sufficient to create considerable genetic variation over many generations. 

Thus, as with studies on the double-crested cormorant in the Great Lakes (see Chapter 16 in Walker et al. 2006), there is evidence of a continuing (although reduced) effect of p,p -DDE on reproductive success even after environmental levels had fallen and eggshell thinning was much less. This raises the possibility that p,p -DDE may have had toxic effects other than eggshell thinning on these species (Nisbet 1989). There is the further complication that other OCs such as PCBs, dieldrin, and hep-tachlor epoxide were present in the same samples and may have had toxic effects. 

Toschik, P.C., Rattner, B.A., McGowan, P.C. et al. (2005). Effects of contaminant exposure on reproductive success of Ospreys nesting in Delaware river and bay. Environmental Toxicology and Chemistry 24, 17-628. 

PCB fraction accounted for 75%+ of TEQ by either assay reduced productivity of birds in this area TEQs mainly due to PCBs, especially 3,3, 4,4 -TCB Reduced reproductive success, but less effect than expected from high TEQs PCDDs, PCDFs, and PCBs made variable, but on the whole similar contributions to TEQ values probably not high enough to adversely affect fish populations TCDD mainly 2,3,7,8-TCDD Reduced hatching... 

PCDDs and PCDEs, together with coplanar PCBs, can express Ah-receptor-mediated toxicity. TCDD (dioxin) is used as a reference compound in the determination of TEFs, which can be used to estimate TEQs (toxic equivalents) for residues of PHAHs found in wildlife samples. Biomarker assays for Ah-receptor-mediated toxicity have been based on the induction of P450 lAl. TEQs measured in field samples have sometimes been related to toxic effects upon individuals and associated ecological effects (e.g., reproductive success). 

Fernie, K.J., Smits, J.E., and Bortolotti, G.R. et al. (2001). Reproduction success of American kestrels exposed to dietary PCBs. Environmental Toxicology and Chemistry 20, 776-781. 

Elliott JE, Butler RW, Norstrom RJ, Whitehead PE. 1989. Environmental contaminants and reproductive success of great blue herons, Ardea herodias, in British Columbia, Canada 1986-1987. Environ Pollut 59 91-114. 

Finley MX, Stendall RC. 1978. Survival and reproductive success of black ducks fed methyl-mercury. Environ Pollut 16 51-64. 

King KA, Custer TW, Weaver DA. 1994. Reproductive success of bam swallows nesting near a selenium-contaminated lake in east Texas, USA. Environ Pollut 84 53-58. 

Louis VL, Barlow JC. 1993. The reproductive success of tree swallows nesting near experimentally acidified lakes in northwestern Ontario. Can J Zool 71 1090-1097. 

Rattner BA, McGowan PC, Golden NH, Hatfield JS, Toschik PC, Lukei Jr RF, Hale RC, Schmitz-Afonso 1, Rice CP. 2004. Contaminant exposure and reproductive success of ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern. Arch Environ Contam Toxicol 47 126-140. 

Steidl RJ, Griffin CR, Niles LJ. 1991. Contaminant levels of osprey eggs and prey reflect regional differences in reproductive success. J Wildl Manage 55 601-608. 

Izard M.K. (1990). Social influences on the reproductive success and reproductive endocrinology of prosimian primates. In Socioendocrinology of Primate Reproduction (Bercovitch F. and Ziegler T., eds.). Wiley-Liss, New York, pp. 159-186. 

Newman B, Ladd P, Brundrett M, Dixon K. Effects of habitat fragmentation on plant reproductive success and population viability at the landscape and habitat scale. Biological Conservation, 2013.159 pp. 16-23. doi 10.1016/j.biocon.2012.10.009... 

Gypsy moth, Lymantria dispar Larvae were fed diets containing 10, 50, 250, or 1250 mg Cu/kg ration from first instar to pupation effects measured on development rate, growth, survival, and reproductive success Oribatid mite, Platynothrus peltifer Fed diets with 13 (control), 28, 64, 168, 598, or 1498 mg Cu/kg DW diet for 3 months... 

Grue, C.E., D.J. Hoffman, W.N. Beyer, and L.P. Franson. 1986. Lead concentrations and reproductive success in European starlings Sturnus vulgaris nesting within highway roadside verges. Environ. Pollut. 42A 157-182. 

Custer, T.W., J.C. Franson, J.F. Moore, and J.E. Myers. 1986. Reproductive success and heavy metal contamination in Rhode Island common terns. Environ, Pollut. 41A 23-52. 

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