COMPARISON OF WOOD DUCK NEST BOX SUCCESS

Transcription

1 COMPARISON OF WOOD DUCK NEST BOX SUCCESS YEAR HOUSES NEST BOX USE (% USE) /59 for 34% /39 for 59% /47 for 77% /48 for 81% /47 for 89% /52 for 81% /55 for 80% /54 for 69% /52 for 79% /52 for 71% EGGS THAT HATCHED (% HATCH) 135/172 for 78% hatch 112/218 for 51% hatch 181/311 for 58% hatch 254/475 for 53% hatch 252/570 for 44% hatch 316/682 for 46% hatch 397/746 for 53% hatch 340/579 for 59% hatch 468/620 for 75% hatch 310/517 for 60% hatch **NOTE: County Line Forest Preserve wood duck data was not included. This ** preserve was closed for public access until January 18, GOALS 1. A minimum of 50% hatch or better per nest box, area and including all sites. 2. To provide a safe and suitable artificial nest box for wood ducks. 3. Provide an adequate number of nest boxes whenever natural cavities are limited. 4. Work with the public whenever possible to increase their environmental awareness or educate them to the importance of this important natural resource.

2 21-YEAR COMPARISON OF SUCCESS Year Total Hos Percent Hatched Percent Eggs Hatches Total Eggs Hos Used Ho Use Eggs Hatched per Box % % % % % % % % % % % % % % % % % % N/A % % % % % % % % % % % % % % % % % % % % % % 6.0 Average Ho Use Total Eggs Total Hatches Average Hatch Success Average Hatches/Box 63% % 3.7 Based on this data, hatch success goals (>50% hatch) are being met. Hatch success has not been below 50% since 2010, and hatches per box have been trending strongly upwards since 2004.

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4 RESULTS In 1994, a few wood duck nest boxes were constructed out of pine. The wood duck nest box program needed improvement. All former nest boxes that were mounted to trees were removed. Mammals instead of wood ducks were occupying nest boxes. The plastic Duck s Unlimited nest boxes that appeared usable were then mounted onto galvanized pipe and placed in areas of open water that were adjacent to brood habitat. Following this, we monitored a large increase in nest box, as well as a successful hatch. In 1994, one hundred and eleven wood duck eggs hatched successfully from 96 nest boxes. In 1995, after most plastic wood duck nest boxes were removed from trees and placed on water pipe along with wooden nest boxes, we monitored a hatch of three hundred and seventy-two ducklings from 89 nest boxes. The single largest increase of 261 additional ducklings due to successfully relocating nest boxes into suitable habitat, over water, on galvanized pipe where predators and other mammals were less able to negatively impact the nesting wood ducks. From 1996 to 2004, we studied and monitored nest box designs. We came to the conclusion that the Duck s Unlimited plastic wood duck nest boxes were just not as suitable or preferred by wood ducks. Instead, the wooden nest boxes made of cedar were more productive. From 2005 through 2009, four major improvements occurred in the wood duck nest program: 1. Increased nest box from 34% in 2005; to 59% in 2006; to 77% in 2007; to 81% in 2008; to 89% in 2009; 2. Increase in the number of eggs that have been laid in nest boxes from 172 in 2005; to 218 in 2006; to 311 in 2007; to 465 in 2008; to 570 in Despite the long period of flooding in 2008 and 2009, seven of the total ten sites (or 70 %) had 100% of wood duck nest boxes

5 2010 Results During the production year 2010, Hooded Mergansers (another cavity nesting duck) impacted nine wood duck nest boxes (5 at Pecatonica Wetlands; 2 at Crooked River; 1 at Sugar River; 1 at Yale Bridge Forest Preserve). This is not the first time we have seen impact. In 2010 nest box dropped 8% due to other wildlife (hooded merganser, screech owl, flicker, etc.) Even though nest box decreased in 2010, their was an increase in the number of eggs that have been laid in nest boxes from 172 in 2005; to 218 in 2006; to 311 in 2007; to 465 in 2008; to 570 in 2009; to 682 in As a result of the success of the nest box program, the increases shown above (high nest box ; greater number of laid eggs each year; greater number of hatched eggs each year) show clear results of success. Flooding in production year 2010 was significant like in past years but newly implemented management techniques reduced the overall impact. It is believed that the spike in hooded merganser is just a result of higher than normal floodwaters during the wood duck nesting season. Even though a total of 30 hooded merganser eggs were laid in wood duck nest boxes, we did not see any development inside these eggs. Indicating egg laying behavior but not incubating behavior by hooded mergansers Results 1. Six out of twelve forest preserves with wood duck nest boxes had 100%. 2. Over all sites there was 80% of wood duck nest boxes out of 746 eggs hatched for 53%

6 2012 Results 1. The worst drought conditions in 50 years in the USA. 2. Hooded mergansers have now occupied 7 of 12 preserves where the district monitors wood duck nest boxes. 3. Despite drought conditions there was only a slight decrease in number of Ducklings that hatched per nest box (2011, 7.1 per nest box to 6.1 per nest box in 2012) 4. Overall percent hatch (57%) was up in 2012 by 4% compared to 2011 at 53% hatch Results 1. Even though Riverine System Water Levels remained higher than normal in spring 2013, by fall and the beginning of winter 2013 water levels have not returned to prior level before the 2012 drought. 2. Hooded Mergansers impacted two preserves and only 3 nest boxes (Pecatonica Wetlands and Sugar River) 3. It appears the extensions that have been attached to pipes are having a large positive impact on wood duck nest box production. 4. A record high number of wood ducks hatched from 52 nest boxes, 468 out 620 for 75% hatch.

7 2014 Results 1. Spring Riverine System Water Levels appeared to be back to normal in 2014, but by late summer through December 16, 2014 water levels were lower than the normal. This pattern of Riverine System Water Levels may be effects of the 2012 drought. The fragmentation of sediments cad by the drought, emergent vegetation (rooting into these zones), and natural scouring effect of the river channel are natural occurrences impacting riverine basins. 2. Hooded Mergansers impacted eight nest boxes: two nest boxes at Crooked River (3 eggs); four nest boxes at Pecatonica Wetlands (8 eggs); one nest box at District Headquarters (2 eggs); one nest box at Oak Ridge (1egg). This impact was comparable to the hood merganser impact in 2010.