Waterfowl 2008

Abundance and reproductive success

The breeding populations of the main waterfowl species – mallard, teal, wigeon and goldeneye – have declined slightly from the previous year. The decline was sharpest for the goldeneye, particularly in northern Finland, where the mallard breeding population was also smaller than in the previous year. The coot showed a considerable decline, and the index describing the size of its breeding population fell to its lowest level ever in its monitoring history. Mallards had better breeding success than last year, and the index for breeding success was the second-highest recorded during monitoring history. The wigeon and goldeneye improved somewhat from last year, but the index for the wigeon in particular fell well below the long-term average. The teal produced fewer chicks than last year, both in the south and in the north.

The breeding success of the mallard was very good in the summer of 2008. Nesting was very early, broods were larger than last year, and the bad weather of early summer did not harm the chicks. Photo: Marcus Wikman

The breeding population and brood counts of waterfowl on inland waters were conducted by the Finnish Game and Fisheries Research Institute and the Finnish Museum of Natural History at various locations around Finland. Most of the fieldwork was done by volunteer hunters and ornithologists. Breeding populations were assessed twice in May with counts of nesting pairs, and broods were assessed with one brood count in July. The waterfowl counts are a part of the long-term monitoring of game populations by the Finnish Game and Fisheries Research Institute. The main targets of the counts are the most important game species: mallard, teal, wigeon and goldeneye, but counts also include other species for annual monitoring.

Only locations where counts were done in both 2007 and 2008 are included in the comparison. Comparable nesting pair counts and brood counts were done at 592 and 376 locations, respectively. Annual abundance indexes are based on counts made on the same site in consecutive years; indexes are converted into comparable form for the entire monitoring period.

The breeding populations declined

The total populations of the mallard, teal, wigeon and goldeneye declined somewhat compared with 2007, but the change was statistically significant only in the goldeneye (Table 1). Mallard and goldeneye populations decreased, especially in northern Finland, whereas the wigeon population increased in the north, but decreased in southern Finland. The teal population declined nationwide. The abundance index describing the size of the breeding population was below average for all the species.

Table 1. Numbers of waterfowl pairs in comparable counting spots for 2007 and 2008. Total numbers also include the less numerous species. The index for 2008 indicates the percentage of birds observed when compared with 2007. Southern Finland (S-F) is the area south of the province of Oulu, and Northern Finland (N-F) includes the provinces of Lapland and Oulu.

		Waterfowl pairs
		S-F		N-F		Total		Index 2008
		2007	2008	2007	2008	2007	2008	S-F	N-F	Total
	Mallard	623	597	172	128	795	725	96	74	91
	Teal	474	455	140	128	614	583	96	91	95
	Wigeon	233	202	41	47	274	249	87	115	91
	Goldeneye	884	857	422	341	1 306	1 198	97	81	92
	Coot	222	170	2	3	224	173	77	–	77
	Pintail	36	57	15	11	51	68	158	73	133
	Shoveller	96	71	6	5	102	76	74	–	75
	Pochard	40	49	0	0	40	49	123	–	123
	Tufted duck	75	60	32	31	107	91	80	97	85
	All species	3 414	3 241	977	827	4 391	4 068	95	85	93

Figure 1. Abundance indexes for mallard, teal, wigeon and goldeneye in 1986–2008. Index 100 is the average for the period 1986–2008.

Of the other species that were monitored, coots decreased most strongly from last year. The abundance index fell to its lowest level ever during the monitoring period of 1986–2008. Pintail and pochard numbers increased, while the shoveller population decreased. However, the data on these species was not extensive, and these changes should be regarded with caution.

Successful breeding once again for mallards

For species other than teal, the breeding index of the important game species was slightly better than last year (Table 2). Mallard reproduction was very good, and the index for breeding success reached its second-highest level in monitoring history. The breeding indexes for teal, wigeon and goldeneye were noticeably below average. The breeding index for wigeon was alarmingly low for the second year in a row.

Table 2. The number and average brood size of the most numerous waterfowl species in 2007 and 2008, and the chick breeding index of 2008. The index takes into account both the number and average size of broods, and describes the reproductive success compared with 2007.

	Broods		Average size			Index
		2007	2008	2007	2008	2008
	Mallard	185	182	5,1	5,6	108
	Teal	105	96	4,5	4,4	89
	Wigeon	48	48	4,5	4,8	107
	Goldeneye	181	192	4,0	4,3	114

Figure 2. The fluctuation of breeding index for mallard, teal, wigeon and goldeneye in 1989–2008. Index 100 = average for the period 1989–2008.

Breeding by the mallard was very successful, especially in southern Finland (breeding index 110% ), but it was on the same level as last year in northern Finland (breeding index 99%). Goldeneye followed the same trend: the breeding index in the south was 123% and 103% in the north. The breeding index for the wigeon was slightly higher than last year (south 106%, north 113%), whereas the index for teal was below average both in the south (94%) and in the north (86%).

Breeding was early in the south, but somewhat later than average in northern Finland. The difference in timing could also be seen in the developmental stage of chicks. Based on these observations, the chicks of the most important species had had enough time to fledge before the hunting season, whereas the goldeneye chicks of northern Finland in particular were not yet able to fly when the season opened.

Scientist in charge of project

Hannu Pöysä
Joensuu Game and Fisheries Research
Yliopistokatu 6
FI-80100 Joensuu, Finland
Phone +35820 575 1401
E-mail: firstname.lastname@rktl.fi

Cooperation: The Finnish Museum of Natural History

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